2g bov leaking after 10~ psi or so...should I buy this crushed 1g bov?

[91rtstealth]

I just got a dsm (finally) and it's my first turbo car, so this is all pretty new to me.

I did a boost leak test recently and found that my stock 2g bov (96 talon, pretty much stock) leaks after about 10-12 psi. A lot of people recommended getting a 1g bov. I found one for 20 bucks on craigslist near me. It's already crushed the the guy selling it said it worked fine on his car with 22 psi. I plan on running about 16. Should I buy this or is there something else you guys would recommend. I'm not totally sure what factors to consider when buying a bov or bpv. Do you want one that will handle well beyond what you plan on running, or do you buy one that handles CLOSE to what you plan on running? I don't get it.

also, what are my options for installing it. So far I"ve found that I could buy a flange adaptor or buy Dave Brode's UIP. What do you think?

 

[91rtstealth]

for the sake of money, I think I'm just going to order a 1g bov from a gentleman on here.

This is fairly off topic, (maybe not since it's concerning my car?) but i'm going home this weekend to work on the talon again. I got a boost gauge in the mail....that seems easy enough to install, but I'm also going to try to replace the front and rear sway bar bushings. Is this fairly easy? i've never done it before...seems straight forward, but I wanted to make sure there isn't something I need to know before I go for it.

 

[NHerron]

Well for the boost gauge, tap the rubber line that runs to the fuel pressure regulator located on the fuel rail with a plastic tee. I don't know how the last owner did it but he (she?small hands?) ran the electrical right below where the clutch master cylinder is. It's really nice and doesn't look as bad as running them through the steering columm boot. There's also the opening in the passenger firewall side where the main engine harness runs which has TONS of extra room. That's actually where I ran my 10 wire harness for the additional sensors I'm running and for future plans.

Sway bar I haven't done yet but from what I have seen - heard tips of, is to use a little grease/lube on the bushings so they don't start squeaking in a few months. I'm talking about the bushing which holds the bar to the subframe, not the end links. Other is, torque down what you can and check out the knuckle bushings. I don't know the access space available on the front but it looks like you should be fine from pictures.

 

[travs92vr4]

Thanks. I fear I'm going to put more time Nd money into this car than I had planned. It seems addicting

It is addicting. Once you hit your power mark, you always want more after. Good luck with your mods.

 

[91rtstealth]

Well for the boost gauge, tap the rubber line that runs to the fuel pressure regulator located on the fuel rail with a plastic tee. I don't know how the last owner did it but he (she?small hands?) ran the electrical right below where the clutch master cylinder is. It's really nice and doesn't look as bad as running them through the steering columm boot. There's also the opening in the passenger firewall side where the main engine harness runs which has TONS of extra room. That's actually where I ran my 10 wire harness for the additional sensors I'm running and for future plans.

Sway bar I haven't done yet but from what I have seen - heard tips of, is to use a little grease/lube on the bushings so they don't start squeaking in a few months. I'm talking about the bushing which holds the bar to the subframe, not the end links. Other is, torque down what you can and check out the knuckle bushings. I don't know the access space available on the front but it looks like you should be fine from pictures.

I did the boost gauge and it was pretty damn easy. I was going to do the sway bar bushings this week as well but no one stocks them, so I have to order them online. And yeah, I'm also referring to the ones that hold the bar to the subframe.

It is addicting. Once you hit your power mark, you always want more after. Good luck with your mods.

yeah I know what you are saying. As of now, I just want to get the car in good working order in terms of stock performance. It needs a bunch of tiny things. I actually needs to the two front lateral ball joints, and I looked up my VIN and found out that no one ever had this recall performed so a local dealer is replacing them next week. haha. That's awesome for me. One less thing I have to worry about. When I called the dealer they were like "96?????? eagle talon" Oh well. Recalls last forever so I'm taking advantage of that.






ANYWAYS, now that I have the boost gauge installed I have some questions.
It seems like my turbo is working just fine. It pegs right to 11-12 psi when I hammer down on the throttle. So, like I said this is all new to me so I don't know how boost is supposed to "behave." When I hammer down it goes right to 11-12ish psi but the boost slowly starts to drop down as the rpms get higher. It seems to drop off around 5k. Is this normal?

Also, if I had boost leak, would I be able to tell by what the boost gauge reads?

 

[NHerron]

Yeah that's normal for any smallish turbo especially the T-25. I'm not a wizard on volumetric efficientcy (VE) but basically when the engine is pumping more air volume (High RPM's), the pressure (PSI) decreases if the source (turbo / blower) can't keep up. In other words, the engine is outflowing the turbo and the turbo can't keep up. That's why efficient turbos are desired

Take a hair dryer and put the nozzle into a box with a penny sized outlet in the box- Then hook up a gauge to the box to monitor pressure- Readings are high with a small hole, now gradually make the hole bigger and the readings will taper off / decrease. True, the hair dryer has one constant output and the turbo puts out more as turbo RPM increases but, compressor wheel efficiency begins to drop out past a certain point.

Of course, other problems can effect a loss of pressure like additional holes in the box (boost leaks) but on the T-25, that sounds normal. It's always good to test for boost leaks just in case though

 

[romeen]

I did a boost leak test recently and found that my stock 2g bov (96 talon, pretty much stock) leaks after about 10-12 psi.

When I hammer down it goes right to 11-12ish psi but the boost slowly starts to drop down as the rpms get higher. It seems to drop off around 5k. Is this normal?

That's probably not a coincidence.

Also, you may have multiple boost leaks. Some boost leaks you don't detect until other larger ones are fixed. That's why it's best to spray the intake tract down with soapy water when testing and look for the tell tale bubbles. It often takes repeated boost leak tests to track down and fix all of the leaks.

Also, if I had boost leak, would I be able to tell by what the boost gauge reads?

Maybe if it's a big leak. But the only definitive way to know is by pressure testing the intake.

I'm glad to hear that someone new to turbos is pressure testing. So many guys don't take this advice seriously. From my experience, it's amazing how many driveability issues are sorted out by finding and fixing boost leaks.

Also, good work on taking the initiative to look into the ball joint recall (or lack thereof).

 

[NHerron]

Maybe if it's a big leak. But the only definitive way to know is by pressure testing the intake.

How romeen,

You're referring to such a big leak that you notice on the gauge that its not boosting to stock boost, right? Just checking I understand 100%, thanks

 

[91rtstealth]

yeah I was thinking that my BOV issue could be causing the boost to drop as well. I guess we will see once I replace that BOV with a 1g (or evo..still not sure what i'm going to do)

when I did the boost leak check I followed the tutorials that involved building the tool that fits right onto the turbo. When I did that I heard a huge hissing sound from the intercooler..fixed that. it was just a loose hose. After that, I noticed the air leaking from the BOV when I got to about 11-12 psi. ALSO, however, I did see some bubbles leaking from the BISS and all four fuel injectors. It was mild, but would a tiny boost leak from the injector o-rings make a BIG difference in power?

 

[romeen]

How romeen,

You're referring to such a big leak that you notice on the gauge that its not boosting to stock boost, right? Just checking I understand 100%, thanks

Not so much how high it's boosting since the boost control should compensate by making the turbo work harder to maintain the set boost level. But if the leak is big enough then you might see a boost fluctuation near the set boost level. That was my experience when I had a good size crack at a weld on my j-pipe. Although what tipped me off in that instance was that I could actually hear the leak while driving not to mention a very noticeable loss of power. My observation of what the boost gauge was doing was made after I already knew I had a big leak.

But giving it more thought now I should mention that I have an electronic boost controller. Given the nature of how a solenoid operates to control boost (rapidly opening and closing at the set boost level) vs most manual boost controllers (bleeding off air or reducing the pressure signal to the WG) it's possible that what I observed might not happen if using a MBC.

Either way, I was basing it off of my one experience which is why I said, "Maybe if it's a big leak."

 

[romeen]

yeah I was thinking that my BOV issue could be causing the boost to drop as well. I guess we will see once I replace that BOV with a 1g (or evo..still not sure what i'm going to do)

when I did the boost leak check I followed the tutorials that involved building the tool that fits right onto the turbo. When I did that I heard a huge hissing sound from the intercooler..fixed that. it was just a loose hose. After that, I noticed the air leaking from the BOV when I got to about 11-12 psi. ALSO, however, I did see some bubbles leaking from the BISS and all four fuel injectors. It was mild, but would a tiny boost leak from the injector o-rings make a BIG difference in power?

From what you're describing I doubt that there would be a "big difference in power." It might not even be very noticeable during everyday driving unless you're really in tune with your car. But don't take that as an implication to put off replacing the injector o-rings. The leak is only going to get worse as the o-rings degrade and get harder.

Glad to hear that you're doing a proper boost leak test. It definitely pays off.

 

[91rtstealth]

From what you're describing I doubt that there would be a "big difference in power." It might not even be very noticeable during everyday driving unless you're really in tune with your car. But don't take that as an implication to put off replacing the injector o-rings. The leak is only going to get worse as the o-rings degrade and get harder.

Glad to hear that you're doing a proper boost leak test. It definitely pays off.

yeah I planned on replacing them, but I have so many other things I need to do first. There's an exhaust leak in the flex section of the down pipe and god it smells like gas every time I accelerate hard or go up hills. It's getting really annoying. Anyone have a cheap after market down pipe thy recommend? I just want something affordable (this is a cheap toy for now) that will bolt up to my stock cat. I found a local guy on craigslist with another stock one but I don't know if I want to go through the work of bolting a rusty old pipe onto my car. What's cheap and how do I ensure it will bolt to my stock cat.

other than that I still have to :
replace the bov and UIP
sway bar bushings and potentially a bad strut
valve seals
boost controller
replace headliner
front passenger fender damage
missing side skirt
and almost all of the plastic stuff is faded
and I might eventually do the 2g-b eclipse front and rear bumpers depending how much work it is

 

[Duece McCracken]

yeah I planned on replacing them, but I have so many other things I need to do first. There's an exhaust leak in the flex section of the down pipe and god it smells like gas every time I accelerate hard or go up hills. It's getting really annoying. Anyone have a cheap after market down pipe thy recommend? I just want something affordable (this is a cheap toy for now) that will bolt up to my stock cat. I found a local guy on craigslist with another stock one but I don't know if I want to go through the work of bolting a rusty old pipe onto my car. What's cheap and how do I ensure it will bolt to my stock cat.

other than that I still have to :
replace the bov and UIP
sway bar bushings and potentially a bad strut
valve seals
boost controller
replace headliner
front passenger fender damage
missing side skirt
and almost all of the plastic stuff is faded
and I might eventually do the 2g-b eclipse front and rear bumpers depending how much work it is

Nice to see another local DSM doing things right. I have some parts you may be interested in, including a 1g BOV and 1g UICP for it, side skirts and some other jazz, PM me if you are interested in a local deal.

Boost leak testing is probably my favorite diagnostic test, its really satisfying to eliminate leaks. Or im just really weird... .

 

[romeen]

yeah I planned on replacing them, but I have so many other things I need to do first. There's an exhaust leak in the flex section of the down pipe and god it smells like gas every time I accelerate hard or go up hills. It's getting really annoying. Anyone have a cheap after market down pipe thy recommend? I just want something affordable (this is a cheap toy for now) that will bolt up to my stock cat. I found a local guy on craigslist with another stock one but I don't know if I want to go through the work of bolting a rusty old pipe onto my car. What's cheap and how do I ensure it will bolt to my stock cat.

other than that I still have to :
replace the bov and UIP
sway bar bushings and potentially a bad strut
valve seals
boost controller
replace headliner
front passenger fender damage
missing side skirt
and almost all of the plastic stuff is faded
and I might eventually do the 2g-b eclipse front and rear bumpers depending how much work it is

Although an exhaust leak can stink up the cabin, it shouldn't smell strongly of gas. So fixing the exhaust leak will keep less gas fumes out of the interior but it won't address the underlying problem. You're probably just running rich from the boost leak(s). But if you want you can pull the spark plugs to see if one cylinder in particular is not getting complete combustion.

As far as your "DSM to do list," it's only gonna get longer my brother.

 

[91rtstealth]

Nice to see another local DSM doing things right. I have some parts you may be interested in, including a 1g BOV and 1g UICP for it, side skirts and some other jazz, PM me if you are interested in a local deal.

Boost leak testing is probably my favorite diagnostic test, its really satisfying to eliminate leaks. Or im just really weird... .

I found a guy who has a 1g bov uncrushed and I told him I would probably take it but if that doesn't work out I may be interested. Will a 1g UIP fit on on a 2g? I was just going to buy Dave Brode performance one. What side skirt do you have? I need the passenger side panel that goes on the door. I'm really hoping I find a red one. haha.

Although an exhaust leak can stink up the cabin, it shouldn't smell strongly of gas. So fixing the exhaust leak will keep less gas fumes out of the interior but it won't address the underlying problem. You're probably just running rich from the boost leak(s). But if you want you can pull the spark plugs to see if one cylinder in particular is not getting complete combustion.

As far as your "DSM to do list," it's only gonna get longer my brother.

well the smell is only real noticeable when the windows are down. I was thinking the same thing. It might be running rich because of a boost leak. I think that BOV issue I'm having would cause it run right, wouldn't it? The only boost leaks that my test showed were the orings and the BISS. Everything else should be pretty good unless I didn't do something right.

I hope that list doesn't get too long. This is just a little project car. I have 2 other cars and a motorcycle. I just want to get this in descent working order, boost it up a little and hopefully stop there. haha

 

[91rtstealth]

does anyone recommend a cheap down pipe that will mount up to the stock cat? I'm not sure what sizes I need to consider

 

[NHerron]

Hmm I don't know since I've had turbo back exhaust for a while now but, I would just use google and type "downpipe stock cat dsmtuners" or something along those lines

 

[007jimmy]

Sure you could go bigger on the downpipe but it would have to neck down to the size of the stock cat, which sucks. Do you have plans to delete the cat?

 

[romeen]

Cool info I didn't know they were direct to bolt on^

I think romeen just convinced me to upgrade to an evo9 bov... that's awesome that they are a direct replacement! Will the bov sound any different coming from a stock 2g bov to a evo9 bov?

I doubt it but maybe! I haven't seen what one looks like

These aren't my pics but you can see how the stock 2G and EVO valves both use a coupler to mount onto the UICP.

2G

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EVO

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My EVO X BOV

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NHerron, lots of good info contributed to this thread.

 

[NHerron]

Right on, thanks man. I know I sure appreciate it when I receive helpful info on my threads, it's the golden rule too .

 

[91rtstealth]

Nah I don't have plans to delete the cat since it just makes it a bigger pain in the ass to get it inspected. Emissions inspections are getting more Nd more common

I might just get an evo bov too. Seems nice and easy. It sucks they are like 130 bucks though

 

[007jimmy]

I understand. I removed mine but I have no need to worry about getting it inspected. You could get a 2.5-3" high flow cat and go from there. Hopefully ill see ya around one day as I am local.

 

[romeen]

I might just get an evo bov too. Seems nice and easy. It sucks they are like 130 bucks though

Keep an eye out for used ones on the evo forums.

Mitsubishi Lancer Evolution | Reviews, News, Parts, Owners - EvolutionM.net

Here's one up for auction on ebay that you might want to watch.

OEM JDM Mitsubishi Evolution Blow off valve bov | eBay

BTW, the 1G BOV is still a good option and, as you know, much cheaper (although you have to factor in the cost of an adapter or different UICP).

 

[91rtstealth]

Depending on how much you're willing to spend I would consider a stock EVO 8/9 MR or EVO X BOV (the metal ones). For ever day driving there is more to consider than just the maximum amount of boost that a BOV will hold. How rapidly a BOV responds during part throttle operation affects driveability, BOV chatter and transient boost response.

From researching on the evom forums it appears that these BOV's (not crushed or otherwise modded) typically hold boost into the upper 20's. I have tested my own EVO X BOV to 30psi with no leaks. I love how quickly my BOV responds during part throttle driving.

I've seen used ones for as low as $50 but usually they are closer to $80. Keep in mind that a 1G BOV will require the extra expense of an adapter or an appropriately flanged UICP. An EVO BOV will be a direct fit in place of your 2G BOV.

What the EVO BOV lacks is the bling factor which, admittedly, is important to a lot of guys (I'm saying this sincerely, not sarcastically).

I found a few EVO BOV's fairly locally. Asking price is around 100. It's craigslist so I'm sure they would take 80. My question is "does it have to be an MR evo." What's the difference? The one guy just says he has an evo 8 bov, the other guy actually specified that it was an MR. Are they different BOVs?

 

[romeen]

Yes, they are different. The non-MR EVO's have plastic BOV's (similar in appearance to a stock 2G valve) that have weaker springs and therefore can't hold as much boost (high teens from what I've read). Although better than a stock 2G valve, I don't think they are as good as a 1G valve.

The MR EVO's and all EVO X's have aluminum BOV's with a stronger spring. These have been routinely tested to hold boost into the high 20's.

So to answer your question, no, it doesn't "have to be" an MR BOV. Even the plastic one's should be an improvement over the stock 2G although I can't verify that. Depending on your goals it may be sufficient. But personally, I would choose a 1G BOV over the plastic EVO one. They appear to have better performance and are typically cheaper.

True that the metal EVO BOV's are more expensive and harder to come by. But they hold more boost than the majority of DSM'ers will run so there is less chance of "outgrowing" it. And they do this without any type of modification which is something that would be required on a 1G valve in order to hold those boost levels. This allows you to retain good everyday driveability.

Aluminum EVO MR BOV vs Standard EVO Plastic BOV

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[91rtstealth]

so with that said....I'm basically just looking for a "metal" evo BOV and i'm good to go?

I didn't realize the non MR's had plastic ones. The ones i'm looking at are metal, so any evo 8 and up METAL BOV should good to go?