Well, I'm back with proof. Running OEM Atmosphere BOV.

[forcefed86]

Well I was bashed and instantly had 100 people telling me I couldn't do it. Well I did, and it works just fine. Nothing crazy rich on the shifts and no poor idle or driveabilty issues.

Installed LC2 WB02. Went for a test run...

First run with the BOV setup OEM style. At 18lbs WOT I'm seeing around 9.5:1 AFR's. Lifting to shift (BOV active) AFR's jump to mid to high 12's. Then jump back up to 9.5:1.

Swapped in my brass check valve vented to atmosphere. PLugged open hole on intake tube. Same WOT AFR's same boost. At the shift AFR jumps up a bit less at 10.2-10.6, then drops back to mid 9's.

So there it is... do what U will with it. It's sure not washing down any cylinders running at 10:1. That is leaner than the factory map!

The factory AFR targets are as follows.

Also for what it's worth I've done the "dodge garage" MOD to the BOV. If anything this probably slows down the BOV, but thought I'd mention it.

Simple brass check valve installed. I've since painted everything black. But this pic shows the valve assy better.

 

[dsm-onster]

Amen! the "noise" sounds so sweet when you have a metal pipe (you need for performance sake anyway) and a metal recirculation tube (easier to do than this).

What is the difference between shifts of the vented bypass and the vented bypass with a check valve? You know how the check valve works right? The direction of airflow through the bypass still doesn't change between shifts when using a check valve. You still have a valve venting metered air into the atmosphere. You're logs proved it. Though you lifted and probably activated the fuel cutting throttle switch, your motor still ran 2 points richer.

I can give you my own example on 2 of my cars where the motors stalled between shifts venting the bypass. Justin said it happened to him. Spyderturbo said it happened to him in severity. What is this? You now don't believe us unless we show you the same conditions you already showed in your first post? Venting has nothing to do with controlling the idle issues and light throttle issues. I had an safc on one and a maft on another. I just tuned out the open vent the bypass proved to be when no connected to the intake.

A check valve only rememdies having to re-tune your safc, maft, or other mass sensor compensation. But you're still dumping air the mass sensor has already metered. You ran rich between shifts. even after the fuel was probably cut off completely. The difference in time it took for the throttle plate arm to bounce on to the throttle switch sent a/f rations plumetting two points. . . You're saying that yourself.

Here:

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Now, let it die. You're own motor ran much richer. Mine and justin's stall, and Spyderturbo's car runs like a$$ with it not recirculated.

 

[forcefed86]

Just for peace of mind, the "Pros" which you are reffering Usually....
A. Dont even use a air filter or intake tube....

B. Even if they had an intake tube, the BOV could be 2-feet away from the tube, according to the pro's set-ups.

C. I cant really see too much performance loss VTA on a "pro's" car that has a monster turbo pushing 35+ lbs of boost anyway, The BOV pressure recirc'd wouldn't really even help spin the turbo.

D. Points B and C, make reason for Point A.....Which resolves the reason why pro's don't Recirc.

As stated before, most "pro's" no-lift shift, have a dogbox, or have auto's.

Your with this post.
that it worked for you supposedly, but Count how many people told you it messed up their cars...Personally, metal recirc. with Type-S bov = lovely

I'd say it would all be relevant. If your pushing 35 lbs through 3"+ piping the "blow-off" would have alot more pressure and volume. Enough to keep a turbine wheel spinning. It's not done IMO because there isn't that much to gain in that scenario. Possibly there is more of a gain in a road racing scenario.


Couldn't agree with you more about beating a dead horse. I just get a kick out of people posting reply's on how something they haven't tried won't work. I think I've done a pretty good job shooting down each legitimate claim of why this wont' work. So unless you've tried it for yourself and have an issue, don't comment.

Amen! the "noise" sounds so sweet when you have a metal pipe (you need for performance sake anyway) and a metal recirculation tube (easier to do than this).

What is the difference between shifts of the vented bypass and the vented bypass with a check valve? You know how the check valve works right? The direction of airflow through the bypass still doesn't change between shifts when using a check valve. You still have a valve venting metered air into the atmosphere. You're logs proved it. Though you lifted and probably activated the fuel cutting throttle switch, your motor still ran 2 points richer.

I can give you my own example on 2 of my cars where the motors stalled between shifts venting the bypass. Justin said it happened to him. Spyderturbo said it happened to him in severity. What is this? You now don't believe us unless we show you the same conditions you already showed in your first post? Venting has nothing to do with controlling the idle issues and light throttle issues. I had an safc on one and a maft on another. I just tuned out the open vent the bypass proved to be when no connected to the intake.

A check valve only rememdies having to re-tune your safc, maft, or other mass sensor compensation. But you're still dumping air the mass sensor has already metered. You ran rich between shifts. even after the fuel was probably cut off completely. The difference in time it took for the throttle plate arm to bounce on to the throttle switch sent a/f rations plumetting two points. . . You're saying that yourself.

Now, let it die. You're own motor ran much richer. Mine and justin's stall, and Spyderturbo's car runs like a$$ with it not recirculated.

Who's to say the said cars didn't have other issues? I'm not saying I don't believe anyone. I'm just saying if you know the basic principal behind it, there is no reason it shouldn't work for all cars.

Why do you think you want your AFR's to be close to stoich during a shift? While U say my motor ran richer, I disagree. I'm running 9.5:1 @ wot. So I'm closer to the original fuel maps venting. Where as when I'm recirculating I lean out 4 points briefly and then AFR drops back down to the 9's. Thats alot of bouncing around the injectors, ECU, and MAS try to compensate for. I prefer to stay closer to my fuel maps. Either way it didn't make a shyt of difference performance wise.

Yes, I know how a check valve works, but do you know how this particular unit works? It does play a part in shifting, and part throttle driving as well. The valve is adjustable and spring loaded. So after the majority of the air is "blown-off" It will close alot faster than the bypass valve will close on it's own. It will also take a tiny bit more pressure to open. This will result in a slower air bypass all together. Slowing everything down and allowing the ECU and sensor to compensate is one of the factors that contributes to it working so well.

You are comparing setups that did not incorporate the same parts I used. So it's really no comparison at all.

Next.....

 

[the_mork]

I'd say it would all be relevant. If your pushing 35 lbs through 3"+ piping the "blow-off" would have alot more pressure and volume. Enough to keep a turbine wheel spinning. It's not done IMO because there isn't that much to gain in that scenario. Possibly there is more of a gain in a road racing scenario.

Those guys don't blow off during a race, some of them don't even have a bov. Your point doesn't have anything to do with that type of car so I'm not sure why you (or anyone else) is arguing this point.

Couldn't agree with you more about beating a dead horse. I just get a kick out of people posting reply's on how something they haven't tried won't work. I think I've done a pretty good job shooting down each legitimate claim of why this wont' work. So unless you've tried it for yourself and have an issue, don't comment.

Even if you tell me that sticking your hand in a blender feels good with only the minor issue of excessive bleeding (but your hand still works!) I probably wouldn't do it. Now you could point out a fallacy of false alternatives on this little argument but the truth is that the parallel works and I'm choosing an extreme example to get a point across, I could as easily use a less extreme example and the point would still be valid.

Who's to say the said cars didn't have other issues? I'm not saying I don't believe anyone. I'm just saying if you know the basic principal behind it, there is no reason it shouldn't work for all cars.

Considering we are talking in the strictest sense about people who have been dubbed on this site as "Wise Men" for a reason I would suggest that they probably had cars that run fairly well or at least knew if the cars weren't running well and why. You could try to tell me that all of their cars had the same issue but I think I'd rather believe you about the blender.

Why do you think you want your AFR's to be close to stoich during a shift? While U say my motor ran richer, I disagree. I'm running 9.5:1 @ wot. So I'm closer to the original fuel maps venting. Where as when I'm recirculating I lean out 4 points briefly and then AFR drops back down to the 9's. Thats alot of bouncing around the injectors, ECU, and MAS try to compensate for. I prefer to stay closer to my fuel maps. Either way it didn't make a shyt of difference performance wise.

You want your AFR to be close to stoich because that is what the fuel map calls for and because it saves fuel. Being lean when you aren't under load is a good thing. 12.5:1 creates the most power, 14.7:1 the best emissions 15.3:1 the best economy. The reason that the fuel map richens out so much is to use fuel to cool the combustion chamber so that you don't knock or burn a hole in your piston and/or valve. Also if you knew anything about ecu tuning you would know just how ridiculous your statement about the ecu not keeping up is. Hell the evo8 ecu can literally log individual spark events up to 26,000 events per minute, that is while it is still controlling those spark and fuel events and translating those occurrences as well as several hundred others into a format that can be passed through the MUT interface. Yes the 1g ecu is a different and older ecu but if it needed to be faster then the Mitsubishi engineers would have built it faster. It is something that engineers do. They use their engineering knowledge to make systems that work together. In modern cars if something exists a certain way it was done that way for a reason, and there is no part of the car that wasn't considered and redesigned several times to work more cohesively with the rest of the system. I'll just bet that sentence makes you want to make an argument about changing the system for performance or racing applications, and you'd be right to some degree. There is a reason why aftermarket parts often do not fit the same or last as long as OEM parts. Every aftermarket part is a tradeoff, usually you either spend a whole lot of money for an engineered part or you get a part that does not have the same quality as the original even if it is an "upgrade" in the performance category. It is about balancing and what we are telling you is that what you trade is not worth what you lose here, and we specifically are warning others that it would be a poor decision to follow in your footsteps since you appear to be beyond help which is probably okay. It is your car but I would hate to see someone else do this in the mistaken belief that there are minimal side effects.

It does make a "shyt" of difference. Just because you don't care about the difference doesn't mean that others don't. Some of us give a damn about performance and can track it in terms of timeslips or heaven forbid whether you're seeing tail lights or the other guy is at the end of a highway race.

Yes, I know how a check valve works, but do you know how this particular unit works? It does play a part in shifting, and part throttle driving as well. The valve is adjustable and spring loaded. So after the majority of the air is "blown-off" It will close alot faster than the bypass valve will close on it's own. It will also take a tiny bit more pressure to open. This will result in a slower air bypass all together. Slowing everything down and allowing the ECU and sensor to compensate is one of the factors that contributes to it working so well.

Again, the ecu doesn't need things slowed down. Your bov is also spring loaded and I would hope that it has a lot more tension than your check valve or else you have some very very large problems.

You are comparing setups that did not incorporate the same parts I used. So it's really no comparison at all.

They aren't any different. For all intents and purposes any aftermarket bov that is closed at idle does the same thing.

Next.....

This is DMV-like service, don't expect a tip.

 

[dsm-onster]

^^^ don't expect a tip.

My motors run excellent so you have no worries about whether said cars had other problems. Justin is fairly bright. And spyderturbo is who he is because he knows how to tune someone elses car even over the internet.

The check valve closes earlier than the bypass valve? You can't have a weak cracking pressure for the check valve without having it close at about zero boost. The dodge garage modded bypass valve closes at slightly above zero boost. . .

 

[forcefed86]

Those guys don't blow off during a race, some of them don't even have a bov. Your point doesn't have anything to do with that type of car so I'm not sure why you (or anyone else) is arguing this point.



Even if you tell me that sticking your hand in a blender feels good with only the minor issue of excessive bleeding (but your hand still works!) I probably wouldn't do it. Now you could point out a fallacy of false alternatives on this little argument but the truth is that the parallel works and I'm choosing an extreme example to get a point across, I could as easily use a less extreme example and the point would still be valid.


Considering we are talking in the strictest sense about people who have been dubbed on this site as "Wise Men" for a reason I would suggest that they probably had cars that run fairly well or at least knew if the cars weren't running well and why. You could try to tell me that all of their cars had the same issue but I think I'd rather believe you about the blender.


You want your AFR to be close to stoich because that is what the fuel map calls for and because it saves fuel. Being lean when you aren't under load is a good thing. 12.5:1 creates the most power, 14.7:1 the best emissions 15.3:1 the best economy. The reason that the fuel map richens out so much is to use fuel to cool the combustion chamber so that you don't knock or burn a hole in your piston and/or valve. Also if you knew anything about ecu tuning you would know just how ridiculous your statement about the ecu not keeping up is. Hell the evo8 ecu can literally log individual spark events up to 26,000 events per minute, that is while it is still controlling those spark and fuel events and translating those occurrences as well as several hundred others into a format that can be passed through the MUT interface. Yes the 1g ecu is a different and older ecu but if it needed to be faster then the Mitsubishi engineers would have built it faster. It is something that engineers do. They use their engineering knowledge to make systems that work together. In modern cars if something exists a certain way it was done that way for a reason, and there is no part of the car that wasn't considered and redesigned several times to work more cohesively with the rest of the system. I'll just bet that sentence makes you want to make an argument about changing the system for performance or racing applications, and you'd be right to some degree. There is a reason why aftermarket parts often do not fit the same or last as long as OEM parts. Every aftermarket part is a tradeoff, usually you either spend a whole lot of money for an engineered part or you get a part that does not have the same quality as the original even if it is an "upgrade" in the performance category. It is about balancing and what we are telling you is that what you trade is not worth what you lose here, and we specifically are warning others that it would be a poor decision to follow in your footsteps since you appear to be beyond help which is probably okay. It is your car but I would hate to see someone else do this in the mistaken belief that there are minimal side effects.

It does make a "shyt" of difference. Just because you don't care about the difference doesn't mean that others don't. Some of us give a damn about performance and can track it in terms of timeslips or heaven forbid whether you're seeing tail lights or the other guy is at the end of a highway race.


Again, the ecu doesn't need things slowed down. Your bov is also spring loaded and I would hope that it has a lot more tension than your check valve or else you have some very very large problems.

They aren't any different. For all intents and purposes any aftermarket bov that is closed at idle does the same thing.



This is DMV-like service, don't expect a tip.

Most of the big name DSM manual cars (dog box or not) all have BOV's. Including shep, buschur, rau etc. And while it may not apply to them, if it helped even 1/100th of a second the less extreme classes would take the time to run a pipe back to the turbo inlet.


I'm not going to argue about fuel mileage during a shift at WOT.

Last I checked I was only speaking of the AFR's under WOT load and during shifts. Nothing I've done effects cruise/idle AFR's. That being said, venting keeps the AFR's closer to the factory fuel map's.

As far as modern car ECU's are concerned, thats way off topic. We are talking about a early 90's technology, so why waste my time throwing out random specs on a new evo ECU? Do you know how fast the processor is on a 93 ECU? Especially after it's been altered for 2g MAF and 25+psi. It looses a ton of resolution this way. Personally, I don't. So I won't make any claims on something I know nothing about like yourself. I know back in the early 90's home computers were slow as dirt and 5x the size. I'm doubting they had super micro processors in the car ECU's.



Looks like a long winded attempt to sound intelligent. I'll keep it short and simple.

As far as performance goes, you haven't tried this setup. So you can't comment on how well it does or doesn't work VS any other setup. I have. So until you have tried it why bother commenting at all?

 

[TRBOBLU]

I'm adamant because I'm tired of people telling me what won't work and what I can't do. U say this has been done before and works for some and not others. IMO it will work for everyone. Show me another documented thread or instance where someone has installed a check valve and is venting as I have. Did you have the check valve installed when your AFR's dipped down to 9:1 when shifting? Did you modify the BOV for high boost so it won't leak? If you own a factory original car with no other issues I believe this will work for everyone.



Ooo now I get to be a troll too, sweet! Who said anything about being
upset? I could care less, but I'm not going to be civil to close-minded D-bags.

And contrary to what u may believe I don't care what others think about my car or engine bay. I build my cars for me. Personally I think it's pointless to waste money on aftermarket products when I can make the factory product perform just as well for an additional 9 dollars. U can't even see the check valve the way I have it setup now.



Because instead of just saying "some work and some don't" I chose to find out why. I believe this will work on all (1g's at least) with OEM original or mildly modded setups.

U say this is nothing new, yet I've never seen or heard of anyone doing this with the check valve installed as I have.

As far as 2 points being a big deal, the factory recirculating method leans out the mixture 4 points. I don't know about you, but I don't want my fuel ratios jumping up into the 14's between shifts. IMO it's to lean. More importantly, if it was enough of a difference to make the car run like "raped ape" then it would have shown up on the quarter mile passes I logged. Yet it didn't make a difference, as I said it wouldn't.




Like I said I ran my old car this way for years with no issues. With the information I've collected, common sense tells me it won't harm anything.

Correct I did find it is a tad richer for a 1/10th of a second or so. So what? Did this effect performance? NO. Will this cause any damage to an engine? NO.

You say you tried venting before and the car ran poorly. Did you have the check valve installed as I said? I doubt it. Without it you won't be able to vent properly.

I did just buy an old m100 palm pilot. I've got MMCD 1.8 at the moment. Although 02 voltages are pretty useless unless your at idle or cruise. I could log any other parameters though.... I'll play with it some this weekend. I've never used one before.

You did not read my post very thoroughly obviously. You claimed 2 points change in a/f is not very much. I was stating that 2 points on WOT is huge and will cause a noticeable difference. I ALSO said that 2 point a/f in between shifts usually causes a stumble(notice the word usually). If your argument is that 2 points is not huge between shifts Ill agree because I did not notice any huge effects on my car. But if you are arguing that 2 points is not a lot on WOT then you are a fool that has never tuned a car on race gas, E85 or any fuel for that matter. I can post 50+ logs showing how 2 points a/f can make a drastic difference in 70-90mph times(which are very good indicators of what a car will trap in the quarter mile). Your still not proving anything with your check valve. If the BOV is venting to the air, that is METERED air that is not in the intake anymore(thats why cars tend to go rich). The effects on some cars are very noticeable and others not. Just drop it! We are all glad that it works for you. It worked for me too!!

 

[dsm-onster]

AMEN again! I sound like a preacher . Venting works for some and it doesn't for others. There's nothing, nothing here that proves that every setup will be like this. But I feel so bad that I can't vent with a drawthrough maf setup that I want to cry. I want the noise. I want it! I'll trade cars with you.

Looks like a long winded attempt to sound intelligent. I'll keep it short and simple.

As far as performance goes, you haven't tried this setup. So you can't comment on how well it does or doesn't work VS any other setup. I have. So until you have tried it why bother commenting at all?

Oh yes we did. We all know how a check valve works and how the bypass valve works. When under full throttle, and shifting this setup of yours functions just like a simple vented BOV setup. Nice try. Props for the effort. Same results. When you let off throttle and you run 10:1 instead of full lean; they yes, you are running very rich. And yes you will have gas mileage issues. I drive on windy country roads. I have to shift every 10 seconds.

 

[forcefed86]

You did not read my post very thoroughly obviously. You claimed 2 points change in a/f is not very much. I was stating that 2 points on WOT is huge and will cause a noticeable difference. I ALSO said that 2 point a/f in between shifts usually causes a stumble(notice the word usually). If your argument is that 2 points is not huge between shifts Ill agree because I did not notice any huge effects on my car. But if you are arguing that 2 points is not a lot on WOT then you are a fool that has never tuned a car on race gas, E85 or any fuel for that matter. I can post 50+ logs showing how 2 points a/f can make a drastic difference in 70-90mph times(which are very good indicators of what a car will trap in the quarter mile). Your still not proving anything with your check valve. If the BOV is venting to the air, that is METERED air that is not in the intake anymore(thats why cars tend to go rich). The effects on some cars are very noticeable and others not. Just drop it! We are all glad that it works for you. It worked for me too!!

I never claimed 2 points wasn't a big deal. I claimed that 2 points for a tenth of a second isn't going to harm anything.

AMEN again! I sound like a preacher . Venting works for some and it doesn't for others. There's nothing, nothing here that proves that every setup will be like this. But I feel so bad that I can't vent with a drawthrough maf setup that I want to cry. I want the noise. I want it! I'll trade cars with you.



Oh yes we did. We all know how a check valve works and how the bypass valve works. When under full throttle, and shifting this setup of yours functions just like a simple vented BOV setup. Nice try. Props for the effort. Same results. When you let off throttle and you run 10:1 instead of full lean; they yes, you are running very rich. And yes you will have gas mileage issues. I drive on windy country roads. I have to shift every 10 seconds.

Well no, that wasn't my point at all. I said that venting will not cause a rich enough condition to damage the motor in anyway. And went on to say it won't make a significant difference in MPG loss.

U got me guys, while in boost the AFR drops for a half a second (or how ever long it takes U to shift) U may pay an extra 75 cents at the pump every fill up if you shift your car under boost 50 times a day. I'd say 95 percent of the time I don't get into boost unless I'm getting on the highway, passing, or racing. The AFR's don't change under normal driving conditions.

 

[the_mork]

Most of the big name DSM manual cars (dog box or not) all have BOV's. Including shep, buschur, rau etc. And while it may not apply to them, if it helped even 1/100th of a second the less extreme classes would take the time to run a pipe back to the turbo inlet.

Almost anyone with more than a few hundred dollars in their car either recirculates or uses NLTS, every decent tuning solution offers it.

I'm not going to argue about fuel mileage during a shift at WOT.

If bovs only ever opened during WOT I would agree with you.

Last I checked I was only speaking of the AFR's under WOT load and during shifts. Nothing I've done effects cruise/idle AFR's. That being said, venting keeps the AFR's closer to the factory fuel map's.

Bovs don't open during WOT, they open when you let off and load drops off quickly, you may think your in a WOT area of the fuel map right after liftoff but you aren't.

As far as modern car ECU's are concerned, thats way off topic. We are talking about a early 90's technology, so why waste my time throwing out random specs on a new evo ECU? Do you know how fast the processor is on a 93 ECU? Especially after it's been altered for 2g MAF and 25+psi. It looses a ton of resolution this way. Personally, I don't. So I won't make any claims on something I know nothing about like yourself. I know back in the early 90's home computers were slow as dirt and 5x the size. I'm doubting they had super micro processors in the car ECU's.

The stock 1g ecu is more than capable of handling every operation that the car needs at any speed, in fact there are a number of people revving to the moon using the stock ecu except for changes in the Eprom and they are quite happy, if you don't believe me then ask Steve Twdorris or Hakcenter about what the ecu is capable of. I listed the capabilities of the evo8 ecu which is hardly modern since they are nearly the same as any 4plug Mitsu ecu including the 2gb ecu because they are capabilities that I am familiar with and they provide a reference point, if that isn't good enough then fine I was only trying to offer prospective. I'm really not trying to be an asshole to you it just happens that you are making claims that are untrue from assumptions that are false.

Looks like a long winded attempt to sound intelligent. I'll keep it short and simple.

Ahh getting personal now. That's okay by me since I've thrown a few sideways comments at you but it wont help you make your point.

As far as performance goes, you haven't tried this setup. So you can't comment on how well it does or doesn't work VS any other setup. I have. So until you have tried it why bother commenting at all?

You are under the mistaken assumption that your setup is unique. It isn't and I do have personal experience with a properly vented bov, it sucks, an improperly vented bov wont be any better. Your setup does exactly what every aftermarket bov that isn't designed for recirculation does which is that it stays closed at idle. The check valve does not make your setup unique in practice only in implementation.

 

[Cmele89]

isnt it better to go richer than lean? leaning out is hotter combustion and richer is a colder combustion
Ive heard numerous ghost stories of melting pistons/rings from too lean of a mixture all you should be worried about on goin rich is the carbon build up.. Correct me if im wrong

OH ANDD btw When everyone says "i took the pipe off the BOV and the car fell on its face so i reattached it" i dont get this statement is it that you just took it off and shoved the recirculate pipe somewhere or did you block it off because it is infact past the MAF and if you leave it open it creates a vaccuum leak which would cause the car to "fall on its face" JUSTT need to know

 

[dsm-onster]

Took it off and blocked the hole in the intake pipe with a crown royal 750ml bottle top . Still didn't run well. Because the bypass valve opens during idle and light cruise. With a check valve you would remedy the idle and part cruise. But I still also had WOT shifting problems. In between shifts during a run the car would stumble terrible. At those times air is soley escapping as any check valve would allow, except for one with such high crack pressure that it would render the bypass valve useless.

This time I'm really done. Im not going to mop up the mess left here. Cylinder wash doesn't happen over a few days. It can take weeks or months of fuel slightly degrading the oil in between the rings causing premature wear. I don't know about you, but I'm not into letting xylene and other gasoline octane additives that are known thinners for oil-based paint contact my oil at the most critical point in the motor. And Your wideband reads what happen over a span of time not when you instantly run a cylinder super rich just before the throttle plate cuts the fuel (lifting COMPLETELY). Have fun with the noise though. It sound kewl

 

[the_mork]

I think we all assume that the recirculation port on the intake pipe is being blocked off any time we talk about venting.

As far as richer vs leaner it is a matter of where you are. There is such a thing as rich knock and being too rich can wash down the cylinder walls which contaminates your oil and ruins your bearings. Cars like to run under certain conditions so you can just throw more fuel at everything and richer definitely is not always better, in many cases people go rich to be safe but it is from the standpoint of looking at a fairly narrow range.

For example turbo cars need a lot more fuel per unit of air than naturally aspirated cars because of the increased pressure and temperature so we tend to run anywhere from 9.5:1 to 11.5:1 for our WOT fuel ratios. Our ultimate goal would be to have a situation where we could run 12.5:1 which is the ratio that produces the most power. New GM turbo motors can actually do that. So what you are left with is looking at your range and determining where you want to be. 9.5:1 is definitely too rich so you are leaving a lot of power on the table for not a lot of extra safety (none really compared to say 10:1) and if you went any richer you might run into rich knock, fouled plugs, and excessive carbon. 11.5:1 is fairly lean, you are bordering on being too lean to combat knock and you probably have relatively high cylinder temps. 11.5:1 is really pushing the safety limits of pump gas but would probably be okay on race gas. so we know we should be between those numbers. Every bit leaner we go we pick up more power (unless we knock) but we give up a touch of safety. How much safety you lose compared to power changes depending on how close you get to the limits on either side. Generally I feel very safe with a 10.8:1 tune for a DD so that I can go quite a bit leaner and still be okay if something changes on the car that I don't catch immediately. I like 11.2:1 on my race map because in general I'm very aware of the car at those times and I want all the power I can get.

This all skips closed loop driving which is idling and cruising, at idle or cruise the car is designed to be at 14.7:1 which is perfectly safe because we don't have a lot of heat or pressure in the cylinders so we don't need fuel to cool it down and we aren't trying to produce a massive amount of power. 14.7:1 is chosen because it produces in general the least emissions but if we could go as lean as 15.3:1 in closed loop we would get better gas mileage and some tuning solutions do allow you to do this.

 

[forcefed86]

Almost anyone with more than a few hundred dollars in their car either recirculates or uses NLTS, every decent tuning solution offers it.


If bovs only ever opened during WOT I would agree with you.


Bovs don't open during WOT, they open when you let off and load drops off quickly, you may think your in a WOT area of the fuel map right after liftoff but you aren't.


The stock 1g ecu is more than capable of handling every operation that the car needs at any speed, in fact there are a number of people revving to the moon using the stock ecu except for changes in the Eprom and they are quite happy, if you don't believe me then ask Steve Twdorris or Hakcenter about what the ecu is capable of. I listed the capabilities of the evo8 ecu which is hardly modern since they are nearly the same as any 4plug Mitsu ecu including the 2gb ecu because they are capabilities that I am familiar with and they provide a reference point, if that isn't good enough then fine I was only trying to offer prospective. I'm really not trying to be an asshole to you it just happens that you are making claims that are untrue from assumptions that are false.


Ahh getting personal now. That's okay by me since I've thrown a few sideways comments at you but it wont help you make your point.



You are under the mistaken assumption that your setup is unique. It isn't and I do have personal experience with a properly vented bov, it sucks, an improperly vented bov wont be any better. Your setup does exactly what every aftermarket bov that isn't designed for recirculation does which is that it stays closed at idle. The check valve does not make your setup unique in practice only in implementation.

I was mistaken. I meant to say while making boost, not while @ WOT. Although if making boost while shifting I'm usually @ WOT.

Maybe my grandpa style of driving is the reason I don't have issues venting. I'm pretty conservative and try to stay in vac while daily driving to conserve fuel. Although when I'm racing I tend to beat on the car pretty hard.

I don't know how you can claim the ECU can handle anything thrown at it? Seems like a pretty broad statement. You would have to know an awful lot about the processor, memory etc to make that assumption. Whether someone is happy with the computer running there race setup really doesn't prove anything about the computer. Anytime U alter the factory prom for more boost, RPM, timing you lose resolution, speed and driveability. That doesn't mean it won't work. But drag cars don't need all the resolution. They just need to idle and run @ WOT.

I don't think your being an "asshole". Sounds like U know these cars, and I respect that. But one can only be poked for so long before they poke back.

I think I've already made my point. My original post simply stated I found a way to vent the BOV valve with minimal side effects. I was immediately told it couldn't be done. The car would never idle correctly and my MPG would go down the drain. Was also told the cylinders would be washed down with excessive fuel leading to engine failure. Then my thread was immediately thrown in the newbie graveyard.

So I came back once I had my WB02 and some data backing up my original post. No EXCESSIVE engine damaging over rich conditions, No idle, and no cruise issues. I even went on to test both vent and recirc in back to back 1/4 mile runs with little to no change. Everything I have claimed I have proven and has worked on both my DSM's.

U say this is not a unique design. I agree! No argument there.

However, with a quick trip to the hardware store and well under $20 I've accomplished the same thing as installing an expensive BOV. Not to mention for those a little less mechanically inclined. No welding, adapter plates, or paying to have the part installed.

I am unaware of anyone else doing this.

 

[inneed4dsm]

Now, let it die. You're own motor ran much richer. Mine and justin's stall, and Spyderturbo's car runs like a$$ with it not recirculated.

damn that cookie looks good and count me in for my car running like a$$ when i tried it

 

[4g64fiero]

Once again, why post on something you don't understand. You don't have a clue.

.

Are you seriously denying the basic operation of the BOV?!? Why the #### do you think they need to be adjusted when venting?! You cant do that with the stock BOV, and with aftermarket valves you ARE flowing enough to make a difference for it to "blow off".

This is simple. You are merely trying to save face with your "debate".

 

[forcefed86]

Are you seriously denying the basic operation of the BOV?!? Why the #### do you think they need to be adjusted when venting?! You cant do that with the stock BOV, and with aftermarket valves you ARE flowing enough to make a difference for it to "blow off".

This is simple. You are merely trying to save face with your "debate".

Not even sure what your trying to prove. Of course it needs to be "adjusted". Unless you have a means to program in a huge vac leak at idle and cruise.

Not trying to "save face" I've proven all my claims. My "modification" will make the stock BOV perform just as well as an aftermarket unit for a 10th of the price.

 

[habitatguy187]

^^^ Give it up man. You've done your research, told us about it, and started a huge fight . I am glad that you actually tested it though.

 

[Zack Huffman]

I'm not looking to take part in the venting argument here, I just want to point out one thing that I see misinterpreted by a few who've posted here.

Recirculating does not really "help spool the turbo" in exactly the way that some are insinuating. It doesn't spin the compressor faster by the force of the air hitting the compressor blades. The compressor is always speed governed by the speed of the turbine blades.

The effect of recirculating that is beneficial to performance is this: The extreme amount of vacuum that is present directly in front of the spinning compressor is, -at throttle lift-, given a decent supply of air mass at a much higher pressure that it can very easily re-compress. Air mass and velocity is the benefit, the compressor now has more molecules to pressurize, and for that short moment it doesn't have to rely on high vacuum to draw air through the filter and air meter to feed itself. The air keeps its momentum and is sent to its duty more easily when the go pedal is returned to the floormat.

This concept is why turbo drag cars rotate the compressor to face the front of the car and use engine management that doesn't place a restriction in front of the compressor. To them, that's more beneficial than recirculating, especially since they don't usually lift the throttle much when shifting. More air molecules available to the compressor blades means more efficient supercharging. Turbos operate on a pressure ratio, meaning they multiply air pressure by the same ratio no matter what the air pressure is that they're fed.

 

[buryurfear14]

i'm driving to your house right now to recirculate your BOV, this should have ended on page 3. I'm a man of my word. You brought this on yourself!!!

 

[spyderturbo007]

Who's to say the said cars didn't have other issues?

My car had no issues at all when I attempted to vent.

I don't know how you can claim the ECU can handle anything thrown at it? Seems like a pretty broad statement. You would have to know an awful lot about the processor, memory etc to make that assumption.

DSMLink is running around 1000 samples / second, so I'm sure the 1g ECU is fast enough for what we're doing here.

OH ANDD btw When everyone says "i took the pipe off the BOV and the car fell on its face so i reattached it" i dont get this statement is it that you just took it off and shoved the recirculate pipe somewhere or did you block it off because it is infact past the MAF and if you leave it open it creates a vaccuum leak which would cause the car to "fall on its face" JUSTT need to know

No, I just left the giant vacuum leak there and thought I would also put a couple holes in the compressor housing. You know, to let a little extra air in there.

I'm pretty conservative and try to stay in vac while daily driving to conserve fuel.

U got me guys, while in boost the AFR drops for a half a second (or how ever long it takes U to shift) U may pay an extra 75 cents at the pump every fill up if you shift your car under boost 50 times a day.

I sense a little hypocrisy here.

No EXCESSIVE engine damaging over rich conditions

Well that's good, because MINOR engine damage is never a big deal.

My original post simply stated I found a way to vent the BOV valve with minimal side effects.

Once again, good thing they aren't major side effects. That new medication out might make you throw up, but hell, at least you aren't going to die.

I never claimed 2 points wasn't a big deal. I claimed that 2 points for a tenth of a second isn't going to harm anything.

Without long term testing, there is no way you can make that claim.

The entire point here is that you are dumping previously metered air, which does have it's consequences. That's it, period, end of story. Like I said before, the ECU makes certain assumptions when it performs it's calculations. You are screwing with those assumptions.

If you aren't worried about that, they why not mess with the IAT and coolant temp sensor while you are in there. For IAT's over 84 degrees, which is very common, the ECU is going to jack you 1 degree of timing. So you might as well run a resistor in there to manipulate the IAT so the ECU never sees anything above 84 degrees. I mean, it's not like the engineers did that for a reason.

Or, maybe we should do the same with the coolant temp sensor? That jacks you another degree of timing over 206 degrees, but we don't need that either.

Oh, what's this front O2 sensor for anyway, it's not like it's used at WOT. We'll just yank that out as well.

All this so your BOV is louder?

 

[forcefed86]

Well that's good, because MINOR engine damage is never a big deal.

Why would you single out one sentence and use if out of context? If you read the previous post they were claiming venting leads to excessive fuel and fouling plugs etc. It doesn't. I was merely using there words to make a statement. A quick blip to 10:1 is leaner than upper RPM factory map while in boost. It won't cause excessive or minor over rich conditions and won't hurt a damn thing.

The entire point here is that you are dumping previously metered air, which does have it's consequences. That's it, period, end of story. Like I said before, the ECU makes certain assumptions when it performs it's calculations. You are screwing with those assumptions.

U don't need to explain it to me again. Your not saying anything new. The consequences made little to no difference in the performance of my vehicle. Period.

If you aren't worried about that, they why not mess with the IAT and coolant temp sensor while you are in there. For IAT's over 84 degrees, which is very common, the ECU is going to jack you 1 degree of timing. So you might as well run a resistor in there to manipulate the IAT so the ECU never sees anything above 84 degrees. I mean, it's not like the engineers did that for a reason.

Or, maybe we should do the same with the coolant temp sensor? That jacks you another degree of timing over 206 degrees, but we don't need that either.

Oh, what's this front O2 sensor for anyway, it's not like it's used at WOT. We'll just yank that out as well.

All this so your BOV is louder?

Once again, bringing up irrelevant nonsense isn't necessary. I'm happy U know how a sensor works.....really I am. We aren't speaking of altering sensors etc. So why open up that can of worms?

Yup U got it!

All this for a loud BOV. All "this".... what exactly is "this" again? Oh... thats right, it doesn't make a shyt of difference.

Here's my deal. If the I see no loss of performance in the 1/4 mile, and the car drives/cruises/idles as it did before. Why would I care to recirculate. Why would U care to tell me otherwise?

You go your way, I'll go mine.

THE END​

 

[dsm-onster]

If you read the previous post they were claiming venting leads to excessive fuel and fouling plugs etc. It doesn't. A quick blip to 10:1 is leaner than upper RPM factory map while in boost. It won't cause excessive or minor over rich conditions and won't hurt a damn thing.

It doesn't with you. It did with my cars. If you got away with it then you got away with it. Do you even understand what we are saying?

We will always steer users from modifications that don't yield consistant repeatable results. If the stock fuel pump at 20psi works for some but not others, we would tell you to upgrade your fuel pump when you're pusing it that hard. If you get a wally fuel pump upgrade and some can get away with no FPR overrun but others do, we will recommend getting an AFPR. If with that turbo upgrade to see that level of performance you have a choice between a ChinaG and a 16G, we weill recommend the 16G because of the random results with a ChinaG.

Why would we all make up a story that you can run too rich between shifts and over time can degrade your rings with instantaneous rich conditions that a Wideband averages in for all the cylinders over a brief blip in time for no reason? Why would the factory do it too? Why would ALL mass sensor cars do it? The 'bypass valve conspiracy'? You should work on exposing something more relavent and controvercial. Hanging onto this suggests that you feel the whole cummunity is duped because some of us respected here are lieing. Apparently you're angy that your other thread got shot down or something and you want to redeem your internet intelligence status. But you're not doing a good job in redemption by clinging to your story suggesting that it's all a farce.

You could have just left it that it works ok with your car. Then you wouldn't look so silly.

I still wager you activated the idle switch by closing throttle completely between shifts. 2.5" intercooler piping via short route is about 6ft long. This .2 cubic feet, not including the intercooler endtanks. A typical shift is .5 sec. The bypass valve brings the pressure down to about atmosphering during that time. At 25psi you have 2.7 times atmospheric. So 1.7 times the .2cubic feet measured by the MAF suddenly leaves in .5 seconds. That is a rate or 24 cubic feet per minute. What would your ecu do if it was expecting 24 cubic feet per minute to continue into the intake manifold? Having a MAF read MUCH more air than is actually entering the motor is altering the maf sensor output. It's like putting all the rpm points on an safc on a high postive percent between shifts.

Hense my lm1 always went full rich when venting on a drawthrough maf dsm. Your check valve doesn't stop that flow? . . . . . . . . . . . . . or does it? How is it shaped: even open, isn't it a large disk directly perpendicular to flow? You either activated the idle switch by completely lifting your foot from the pedal; or your check valve is degrading the flow effectiveness of your bypass valve.

 

[spyderturbo007]

Why would you single out one sentence and use if out of context? If you read the previous post they were claiming venting leads to excessive fuel and fouling plugs etc. It doesn't. I was merely using there words to make a statement. A quick blip to 10:1 is leaner than upper RPM factory map while in boost. It won't cause excessive or minor over rich conditions and won't hurt a damn thing.

OK, I'll use the whole section of that post, either way, you're saying the same thing.

So I came back once I had my WB02 and some data backing up my original post. No EXCESSIVE engine damaging over rich conditions, No idle, and no cruise issues. I even went on to test both vent and recirc in back to back 1/4 mile runs with little to no change. Everything I have claimed I have proven and has worked on both my DSM's.

Either way, you're saying, I've got a couple data points here and some half cocked theories and I'm going to sell it as gospel. I've run it this way for a couple days and the motor hasn't blown up yet, so it must be working. As for minor damage, I have no clue.

U don't need to explain it to me again. Your not saying anything new. The consequences made little to no difference in the performance of my vehicle. Period.

Excellent. That's great. Keep doing what you're doing. While you're at it, you should probably keep the stock FP and run about 25psi with no rewire. Bob said it worked for him.

Once again, bringing up irrelevant nonsense isn't necessary.

It's not irrelevant. You're jacking the expected airflow mass. I just used molesting timing as an example.

I'm happy U know how a sensor works.....really I am.

Thanks. I feel much better.

We aren't speaking of altering sensors etc. So why open up that can of worms?

No, I guess it's just better to jack the actual airflow.

All this for a loud BOV. All "this".... what exactly is "this" again?

Sorry, I'll be more specific next time just so you can keep up. "This" would refer to "This" thread.

Oh... thats right, it doesn't make a shyt of difference.

Nope, and the other 4 of us that chimed in are idiots and liars.

Why would I care to recirculate. Why would U care to tell me otherwise?

Because it's not good for your car. Honestly, I don't give a crap what you do to your car or how long it's on the road. It could blow up tomorrow, or run till 2064, and it won't bother me one bit. I'm concerned about other members reading this thread and deciding they are going to start venting without knowing the entire story.

I think I'm done with this thread. I'm going to go talk to my filing cabinet instead.

 

[dsm-onster]

Well some filing cabinets are locked and the key is lost

 

[forcefed86]

Either way, you're saying, I've got a couple data points here and some half cocked theories and I'm going to sell it as gospel. I've run it this way for a couple days and the motor hasn't blown up yet, so it must be working. As for minor damage, I have no clue.

As I have said, I ran my other car like this for 3 years and almost 30k. No issues. I sure don't see you proving that it does cause any damage, minor or otherwise. So what makes your theories better than mine? At least I went to the trouble of gathering a few data points. What have you done?

Excellent. That's great. Keep doing what you're doing. While you're at it, you should probably keep the stock FP and run about 25psi with no rewire. Bob said it worked for him.

As long as your on the same bandwagon as everyone else... why don't you all just go drive it off the end of the earth? It's flat right? That's what everyone else is saying.

It's not irrelevant. You're jacking the expected airflow mass. I just used molesting timing as an example.

Yup I did "jack" with the air flow mass. If I'm not seeing excessive richness for and it didn't slow my car down more than a few hundredths(if at all.) Who cares?

Because it's not good for your car. Honestly, I don't give a crap what you do to your car or how long it's on the road. It could blow up tomorrow, or run till 2064, and it won't bother me one bit. I'm concerned about other members reading this thread and deciding they are going to start venting without knowing the entire story.

Your concern isn't needed here. It will not harm the car. I've proved this. If you care to do some sort of other testing to prove me wrong then by all means do it. Otherwise stop making claims you can't back up.

I think I'm done with this thread. I'm going to go talk to my filing cabinet instead.

Thats a good idea. Then you'll always be right.