# Anti-Lag, ever heard of it?



## MKIII_96 (Nov 25, 2006)

so my friend whos all into subarus told me that all the crazy subarus have some kind of setup that has something to do with backfiring and almost completly eliminates turbo lag. thought this was pretty sweet. not totally sure how it works.
couple vids
http://www.youtube.com/watch?v=kKvqvi3KsdI
http://www.youtube.com/watch?v=FvqTImWfz0w
http://www.youtube.com/watch?v=D53yHBT8-LM


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## lucas13dourado (Oct 1, 2007)

*FV-QR*

it says on your profile you have a GTI with a gt30/40r and you dont know what anti-lag is...?


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## the_q_jet (Mar 19, 2005)

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some people just throw money for things but dont know much about it.







(not pointing fingers)


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## dub101 (Jul 19, 2002)

*Re: FV-QR (the_q_jet)*

Isnt this a forum where people can just ask questions??








Anti-lag is nothing new. However what is new about it, is that with the advances in tuning o.e.m. management systems it has become more available to the average customer. Basically the ecm retards the timing which causes the exhaust temp to go up and results in boost pressure without engine load. A relatively simple function of processor controled electronic ignition. 
Stan


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## filthyeuropean (Sep 23, 2006)

*Re: FV-QR (the_q_jet)*

^^ what he said.


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## lucas13dourado (Oct 1, 2007)

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_Quote, originally posted by *dub101* »_Isnt this a forum where people can just ask questions??










this _is_ the vortex


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## the_q_jet (Mar 19, 2005)

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tru...and i just felt like givin grief today


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## -RalleyTuned- (Nov 17, 2008)

*Re: FV-QR (dub101)*


_Quote, originally posted by *dub101* »_
Anti-lag is nothing new. However what is new about it, is that with the advances in tuning o.e.m. management systems it has become more available to the average customer. Basically the ecm retards the timing which causes the exhaust temp to go up and results in boost pressure without engine load. A relatively simple function of processor controled electronic ignition. 
Stan

im not quite sure that is how it works...how does higher exhaust temps creat boost?
the way the WRC subaru's do it is they have a valve the bypasses air back into the turbo which spins it up iirc, havn't heard of retarding timing to create boost though, i really cant imagine how that would work








here is is, direct from ProDrive (if that doesn't sound familiar they prepare incredibly badass race cars)
"Basically allows air to pass from the intercooler straight to the exhaust ie bypass the heads, direct to the turbo, to allow air to tumble through the turbo fins, even though the throttle flap is closed. Stops turbo stalling its fan. The anti lag unit that meters the air apparently steps the flow of air, rather than allowing it to run smoothly. Common misconception that fuel is also injected, creating flames pop/bang etc, but seems this is more a bi-product of the mapping which surrounds a throttle lift off state. "
looks like this










_Modified by -RalleyTuned- at 8:56 PM 10-6-2009_


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## speeding-g60 (Aug 1, 2004)

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welcome to the VWKotex.... where anyone can Man-Struate at will.


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## lucas13dourado (Oct 1, 2007)

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hahahahahahaha


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## dub101 (Jul 19, 2002)

*Re: FV-QR (-RalleyTuned-)*


_Quote, originally posted by *-RalleyTuned-* »_
im not quite sure that is how it works...how does higher exhaust temps creat boost?
the way the WRC subaru's do it is they have a valve the bypasses air back into the turbo which spins it up iirc, havn't heard of retarding timing to create boost though, i really cant imagine how that would work








here is is, direct from ProDrive (if that doesn't sound familiar they prepare incredibly badass race cars)
"Basically allows air to pass from the intercooler straight to the exhaust ie bypass the heads, direct to the turbo, to allow air to tumble through the turbo fins, even though the throttle flap is closed. Stops turbo stalling its fan. The anti lag unit that meters the air apparently steps the flow of air, rather than allowing it to run smoothly. Common misconception that fuel is also injected, creating flames pop/bang etc, but seems this is more a bi-product of the mapping which surrounds a throttle lift off state. "
looks like this









_Modified by -RalleyTuned- at 8:56 PM 10-6-2009_

That's pretty wild!! 
I guess I am wrong. Maybe I am confusing "launch control" for "anti-lag". However randomly retarding the timing past 0 degress while still injecting fuel in the combustion chamber will cause a increase in exhaust temperature. Ignitine the mixture with the exhaust valve still open will reult in boost at lower rpm, or lower engine loads.
Wait my man-pon is leaking and I have to go change it now. 
Still don't understand why people "flame" others for asking questions. I guess that makes you feel good about yourself. http://****************.com/smile/emthup.gif 
Stan


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## -RalleyTuned- (Nov 17, 2008)

*Re: FV-QR (dub101)*

so basically you are forcing air through the exhaust valves by retarding the timing really far is what you are trying to say? that sounds a bit harsh on the motor and very complex to do!


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## vdubbugman53 (Nov 7, 2006)

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some units force a misfire creating boost pressure aswell

http://www.npcompleteperformance.com/wotbox


_Modified by vdubbugman53 at 9:44 PM 10-6-2009_


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## MarcoVR6SC (May 3, 2003)

*Re: FV-QR (vdubbugman53)*

Anti-lag is used to keep the turbo spooling when entering/exiting a slow corner in rally’s, and has nothing to do with launch control or flat shift. It uses an air bypass valve over the throttle plate, just like an idle vale, which opens when the anti-lag kicks in, additional fuel is injected and the ignition is retarded so that most of the mixture is expanding when the exhaust valves are already open(thus not much torque is produced by the engine), which in turn spooled up the turbo. The biggest problem with this technique is that it’s very harsh on the turbo an therefore needed to be replaced regularly, and even though the engine does not produce much torque, it still does, so it’s also harder on the breaks. 
Although almost any aftermarket ECU has an anti-lag feature, it’s rarely used in non rally cars because of the big downside.
The above shown setup is a new technique, which bypasses the boosted air right into the exhaust(turbine) side of the turbo, instead of blowing the air out.


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## MKIII_96 (Nov 25, 2006)

*Re: Anti-Lag, ever heard of it? (MKIII_96)*

yeah i never heard of anti-lag. sorry.


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## Soundwave_vr6 (Oct 1, 2007)

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_Quote, originally posted by *vdubbugman53* »_some units force a misfire creating boost pressure aswell

http://www.npcompleteperformance.com/wotbox




this is nice







also does W0T shifting(holds boost between shifts)


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## Maverik869 (Jan 3, 2003)

*Re:*

have you looked at WOT Box?


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## iluvfastcarz (Mar 15, 2004)

*Re: Re: (Maverik869)*


_Quote, originally posted by *Maverik869* »_have you looked at WOT Box?

What would this have to do with antilag other then just launching? 
As stated above, one way to reduce lag is to take out some timing in order to get higher EGTs which spool a turbo faster, then the air fuel mixture is enriched and timing is advanced to ignite the unburned fuel that is in the exhaust mixture therefore again increasing turbine speed rapidly. This was only really used in rally cars, since teams like that can afford to destroy turbos after a few races.


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## vdubbugman53 (Nov 7, 2006)

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_Quote, originally posted by *iluvfastcarz* »_
What would this have to do with antilag other then just launching? 
As stated above, one way to reduce lag is to take out some timing in order to get higher EGTs which spool a turbo faster, then the air fuel mixture is enriched and timing is advanced to ignite the unburned fuel that is in the exhaust mixture therefore again increasing turbine speed rapidly. This was only really used in rally cars, since teams like that can afford to destroy turbos after a few races. 


that looks like all the OP was looking at anti lag for was launching


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## iluvfastcarz (Mar 15, 2004)

*Re: FV-QR (vdubbugman53)*


_Quote, originally posted by *vdubbugman53* »_
that looks like all the OP was looking at anti lag for was launching

Go read the first post, it doesn't say anything about launching.


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## vdubbugman53 (Nov 7, 2006)

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i was judging by all the videos he posted....they were all from a dig


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## GoingUp (Oct 14, 2006)

*Re: FV-QR (MarcoVR6SC)*


_Quote, originally posted by *MarcoVR6SC* »_Anti-lag is used to keep the turbo spooling when entering/exiting a slow corner in rally’s, and has nothing to do with launch control or flat shift. 

You have the part about how the anti-lag works, but the WOT box that some company around sells works in a similar way. It retards ignition timing based on the position of the clutch and is basically anti-lag with an independent rev limiter. The flat shift feature is the same, it cuts ignition timing when you hammer the clutch so that the engine temporarily just doesn't get any spark creating what is effectively a soft rev limiter.
Also, anti-lag was developed on F1 cars and applied to rally cars later, although it's better known in rally http://****************.com/smile/emthup.gif


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## EL DRIFTO (Jul 11, 2004)

*Re: FV-QR (vdubbugman53)*

what else do they post 
reaction times


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## boosted b5 (Nov 1, 2004)

*Re: FV-QR (EL DRIFTO)*

Anti-lag...great for turbo life








this isnt new by any means, audi used Anti lag in the 80s on the Group B cars.


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## MarcoVR6SC (May 3, 2003)

*Re: FV-QR (GoingUp)*


_Quote, originally posted by *GoingUp* »_
You have the part about how the anti-lag works, but the WOT box that some company around sells works in a similar way. It retards ignition timing based on the position of the clutch and is basically anti-lag with an independent rev limiter. The flat shift feature is the same, it cuts ignition timing when you hammer the clutch so that the engine temporarily just doesn't get any spark creating what is effectively a soft rev limiter.
Also, anti-lag was developed on F1 cars and applied to rally cars later, although it's better known in rally http://****************.com/smile/emthup.gif 

What that WOT box is giving you is launch control and flat shift, this is not the same as anti-lag, although launch control uses the same technique, anti-lag usually uses a separate by-pass valve and has a second rpm/load map for anti-lag only. Also with launch control you will not be able to build-up a lot of boost, because the engine is not loaded, but it should keep the engine in the power band the moment you release the clutch pedal(but then you need traction control…).


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## stofficer2 (Mar 22, 2007)

*Re: FV-QR (MarcoVR6SC)*

does anti lag have anything to do with 2 step?


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## GTijoejoe (Oct 6, 2001)

*Re: FV-QR (stofficer2)*


_Quote, originally posted by *stofficer2* »_does anti lag have anything to do with 2 step? 









Basically what I think the OP is actually referring to judging by those vids...
In my opinion a launch control can do many different things, its really only a term, the ability to "control" a launch, which can be done a variety of ways. I think most well known is the ability to hold a rev level by spark retard. But the 2step is going to do more than that, it gives you the ability to build boost in neutral, giving it an anti-lag characteristic. 
So call it both if you will, no matter which method, it certainly does achieve lauch control and anti-lag attributes.
All USDM evo's have a 2step from factory, no USDM STi to my knowledge does, although can be had with a reflash (atleast on my buddies '04).


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## l88m22vette (Mar 2, 2006)

*Re: FV-QR (GTijoejoe)*

I'd like to see a setup that uses an SAI pump to keep the turbo spooled


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## vdubbugman53 (Nov 7, 2006)

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_Quote, originally posted by *l88m22vette* »_I'd like to see a setup that uses an SAI pump to keep the turbo spooled











lol doubt that moves enough air


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