Anti-lag vs recirculating??

[TheFallenTSI97]

Can someone explain the difference between Anti-lag not using an ignition delay and recirculating the BOV and/or wastegate? Or is this essentially the same thing? I don't want my wastegate dumped into the atmosphere and I'm not sure how the previous owner had the BOV. I think it may have been dumped to the atmosphere so I want to fix that anyways. Thanks in advance.

 

[Phantom DSM]

Can you be more specific ? The Anti lag function is usualy used to pre spool the turbo per se in launch situations. For example in Dsmlink timing can be retarded a bit and in combination with fuel to spool turbo.
Wastgate dumped to atmosphere would have a dump tube coming out of external wastegate.
What BOV do you have, is its not hooked back to intake, then it is not recirculating.

 

[TheFallenTSI97]

Well I saw somewhere, that there is two ways of doing an anti-lag setup. One way is to retard the ignition. and another was to basically I don't another way to describe it, but recirculate air from (they said bypass valve which threw me off) so I'm guessing the wastegate? But it could be the BOV that's kinda what's confusing me, I don't know what they meant by the bypass valve. But run the excess from the 'bypass valve" back to the exhaust pre-turbo.

And my BOV is an HKS SSQ. and I don't remember any lines running from it to the intake. It's kinda of jank install. The whole intake plumping needs to be redone. It looks awful they way they made it work.

 

[Dsmkauai]

The only reason you need to recirculate the bov is if your using a maf or mas pre-turbo, like in stock form. This is because the maf measures the air coming in and assumes it is staying in the loop. If you run it vented the maf doesn't know the air has left and as a result the ecu richens things for a sec during shifts and your left with a drivability problem. When running a maf/mas in blow-thru mode venting or recirculating is fine and up to you, most run vented. Anti-lag has nothing to do with any of this. It's only real useful function is at the drag strip to build boost on launch and hold boost up during shifts. But abit-lag is very hard on a tubro especially journal! The extra heat from the fuel and timing change can quickly melt the thrust plate/bearing and kill your turbo in short time. I wouldn't setup anti-lag just to show off and make noise, although it may seem fun and look cool. Your car will suffer a lot more than you think! I suggest you take a step back and sit down and learn alittle more about turbo cars and tuning!

 

[talonalex92]

Usually the only time I hear anyone (ie peple who don't race in any sanctioned way) talk about anti lag is for the 'cool noises and flames'. Unless you're needing it for launch reasons, there's no function to it except high egt's and possible turbine damage.

 

[Phantom DSM]

^^^ This ! Also with the Dsmlink i saw in your profile, do you have v3 ? Speed density or still on maf?

 

[TheFallenTSI97]

I have a large turbo going on, I need to update the upgrade list but it's not installed yet but I did shell out the extra for ball bearing upgrade. And I expect some lag down low, that's the reason I ask. Not for, "hey guys check this out." I would like to autocross/drag race with this thing but with the large turbo I was afraid I would have a lot of lag and loose a lot of low end power. Also I do have v3 but it's running maft. before the BOV. The previous owner did that so I really know nothing about how it's setup other than that.

I was thinking I could just raise the compression while I'm in the process of building the block to compensate for the lag. Give the motor a little more "umph" while out of boost.

 

[talonalex92]

Unless you're talking 70+mm I don't think you'll find it necessary. And a turbo that size wouldn't be ideal for autox anyways. A two step(stationary rev limit) should be more than enough to help you at the line.

 

[boost97gst]

Higher compression will do it but it wont spool a large turbo off the line. Unless you're running an auto tranny, then its easier to do without antilag.EDITED OUT I know very little about the set up or what turbo you have so i cant comment on the exact settings you would need in link. After your build you can get help in the tuning section im sure.

 

[snowborder714]

What is the difference between a BOV and a Bypass Valve? How do they work, and are they necessary | Turbobygarrett

Some other links that might help you understand it better. I have not watched the YouTube videos yet to know if the info is good or not, so I may remove them later if I don't find them useful.
[ame=http://en.wikipedia.org/wiki/Antilag_system]Antilag system - Wikipedia, the free encyclopedia[/ame]
[ame=http://www.youtube.com/watch?v=5g6cHs5vMRE]Anti-Lag System - Bypass Valve - Explained - YouTube[/ame]
[ame=http://www.youtube.com/watch?v=wyJn40ExwZY]Anti-Lag System - Ignition Delay - Explained - YouTube[/ame]
Turbo Anti-lag systems - A technical description
How Anti-Lag Systems Work


Note - wastegate recirculation has nothing to do with antilag. That air has already exited the system.

If you're still on a stock MAS, then that will dictate that you need to recirculate your BOV.

The air that comes from that recirculation can only help keep the turbo spooled if it's a smaller compressor wheel. And even at that, I'm not sure how much it'd actually help, especially if that's your only method. Since you said you're installing a large turbo, recirculating won't be of much use. You also might want to reconsider the turbo choice for autox. Not exactly sure what you're going with but large turbos don't pair well with autox.

Most of the time when people talk about using an ALS it's electronic/tuning based and changes timing and fuel.

 

[Phantom DSM]

Ok well if your running the gm maf setup before turbo and dsmlink v3 is setup for it, then you dont have to worry about recirculating the bov. Since you are concerned with spool up, What turbo is it, if you dont mind me asking?

 

[tylersevo]

I'm currently on v3 and 2-step is all I need when launching the car. Anti-lag is for built drag cars or ricers

 

[snowborder714]

Anti-lag is for built drag cars or ricers

It was actually invented for Formula 1 and then later commonly utilized by rally cars.

 

[TheFallenTSI97]

I'm running a PTE PT6262. Not a huge turbo but as I previously stated I would like to be able auto-x the car. The ignition delay setup just seems too hard on the engine and seems like it kills drive-ability. That video is what through me off. I'm not sure what he means by the bypass valve. Is that the BOV? I'm just a bit confused on terminology there.

 

[snowborder714]

You must've missed the first link in my previous post. It states:

BOV - vents air
Bypass - recirculates air

They're the same thing.


Not sure how you're saying a 6262 isn't a "huge" turbo or what you're comparing it to. It's capable of 700hp. You will not have fun doing an autox with that turbo. You would probably never hit full boost unless it's set really, really low or the autox course is really long and wide open. If you were getting into road racing, then I'd probably say you could potentially use it with an ALS to help keep it spooled in the corners.

 

[Phantom DSM]

By pass valve, Diverter valve, BOV...Different terms and car specific,but same function.
If you plan on going ball bearing on that turbo, the spool should not be that bad starting past 4k. If you want to autocross and need faster spool up and responsiveness, maybe other members can chime in.. or another turbo choice?


EDIT : Brian you type faster than i do

 

[untouchablecc]

I'm running a PTE PT6262. Not a huge turbo but as I previously stated I would like to be able auto-x the car. The ignition delay setup just seems too hard on the engine and seems like it kills drive-ability. That video is what through me off. I'm not sure what he means by the bypass valve. Is that the BOV? I'm just a bit confused on terminology there.

Not a huge turbo ?WTF That would be a great turbo for auto x if your using a runway. I do not see that being the ideal turbo for auto x. Supra guys dont see boost on those till 4k or something like that. That turbo would be a good drag snail but unless you run 9;1 or higher it will be terrible for your application. Yes BOV=blow off valve=bypass valve.

 

[TheFallenTSI97]

Ok so auto-x is out of the question.. I guess straight line is where I will have my fun. But that is why I was asking about Anti-Lag. There is going to be a lot of lag even if I run 10:1 CR.

 

[untouchablecc]

Im not an auto x expert but if I had to take a stab in the dark just about any responsive turbo would be sweet. I remember seeing Tom Dorris's 2ga talon and I beleive he was running 9:1 on a small HX series turbp,(small HX40 I believe). I would think most HTA and MHI based turbos would suit your needs depending on your power goals. MOST auto x tracks are smaller in size and have tight bends, I would think you would want fast spool to get out of turns and more focus on supension and wheel combos vs turbo and power.

10:1 is hard to run on pump gas. 9:1 seems to be about the best on the street. 10:1 is good for a race gas pump+meth or e85 or higher. Your power band will be strong down low running 10:1 and you will have more bottom end so the transition to boost wont feel like it takes for ever and a day.

 

[TheFallenTSI97]

Would it be asinine to have say an 18 or 20g turbo to interchange for auto-x? I would think my injectors would be too big for something like that though?

 

[snowborder714]

^You're correct. Even a Holset is big for autox. A 16g variety is your best bet for something balanced between response and power. You can go bigger to a 20g or similar or smaller based on what type of courses you run, compression ratio, and other factors.


Ok, now we're getting somewhere. Yes, for straight line racing, you can either use a two step (stutterbox) or antilag to help build boost off the line. These will both need to be implemented via a tuning solution. Recirculating air will not help you spool a turbo that big off the line or keep it spooled between shifts.

Spool off the line - two step or antilag. Both of these are available in tuning solutions (such as ECMlink). Two step is less harmful but builds less boost and slower. Antilag will be more effective, but can harm engine/turbo components. It can also produce too much power that you can't harness on the launch and just cause you to spin. You'll need to work from the bottom up and see what works best for your car and the track.

Spool between shifts - NLTS (no lift to shift) is an option available via ECMlink. It allows you to keep your gas pedal planted while you shift which helps keep the turbo spooled. Another option would be to go with an auto trans which would help as well.


In regards to interchanging turbos for autox, think through that. Do you really want to be swapping out an exhaust manifold, turbo, oil/coolant lines, intake pipe, and possibly exhaust just to autox? That's a much better turbo size, but seems like a lot of work just to go run an autox. No such thing as injectors being too big with a proper tuning solution which can control the injectors.

 

[TheFallenTSI97]

Those were both options I was going to play around with on v3 when I got the new setup together and running. I'm looking at a wiring nightmare. There is a lot of crap splices and things like the Innovative wide band that I'm not even sure are hooked up right.

Damn, I already sold my 16g But that would require smaller injectors and that seems more trouble than it's worth just to change setups.

 

[snowborder714]

Here's a link to help verify the LC-1 install.
http://www.dsmtuners.com/forums/art...21002-innovate-lc-1-installation-options.html

 

[LandSpeed-DSM]

Higher compression does not improve spool, it does help bridge the gap from off boost to positive pressure.

 

[TheFallenTSI97]

Higher compression does not improve spool, it does help bridge the gap from off boost to positive pressure.

That's what I meant I may not have explained myself correctly but yes that's what I was meaning. Have some extra power from the engine on the low end out of boost.