ITT: Autocross (I know, not racing) anti-lag. Why not?
Thread Starter
Senior Member
iTrader: (1)
Joined: Apr 2011
Posts: 1,332
Total Cats: 87
From: Columbia, SC
For me, autocross is just an excuse to hang out all day with friends and not really something I look towards as "racing" or competitive (aside from beating my roommates. That **** is serious.)
But, I've worked a lot of NASA Stage Rally events, and anti-lag is heavily used to help drivers stay in boost while braking for corners. Pretty much every stage rally driver I have spoken to running an aftermarket EMS runs anti-lag on their car (several running an MS3X).
So, I'm genuinely curious why it would be a bad idea to run at an autocross. Typically when under heavy braking, you still don't drop below 3-4k rpm, and you aren't off the gas for a tremendous amount of time. With a small turbo, I suppose regaining spool isn't really a huge task. Regardless,
I see two obvious issues:
- It's quite loud. Though with the sites my local SCCA branch use, this is not a problem.
- T25, 2554, 2560, etc. turbos aren't as robust as say, a holset HX40, and the turbine blade might not be up to the heat.
Not a topic I've ever really seen discussed here, so I rather look forward to hearing various inputs. Or the hate when this turns out to be some sort of unspoken satanism.
Tl;Dr:
But, I've worked a lot of NASA Stage Rally events, and anti-lag is heavily used to help drivers stay in boost while braking for corners. Pretty much every stage rally driver I have spoken to running an aftermarket EMS runs anti-lag on their car (several running an MS3X).
So, I'm genuinely curious why it would be a bad idea to run at an autocross. Typically when under heavy braking, you still don't drop below 3-4k rpm, and you aren't off the gas for a tremendous amount of time. With a small turbo, I suppose regaining spool isn't really a huge task. Regardless,
I see two obvious issues:
- It's quite loud. Though with the sites my local SCCA branch use, this is not a problem.
- T25, 2554, 2560, etc. turbos aren't as robust as say, a holset HX40, and the turbine blade might not be up to the heat.
Not a topic I've ever really seen discussed here, so I rather look forward to hearing various inputs. Or the hate when this turns out to be some sort of unspoken satanism.
Tl;Dr:
Last edited by Schuyler; Apr 5, 2015 at 06:10 AM.
Thread Starter
Senior Member
iTrader: (1)
Joined: Apr 2011
Posts: 1,332
Total Cats: 87
From: Columbia, SC
Last time I called autocross racing someone stopped me mid-sentence to explain why it wasn't, which is more where the joke came from. Can't win all the battles, 50/50 chance it offends someone either way.
EDIT: Also, as it turns out, the video is of uavjeep's car.
EDIT: Also, as it turns out, the video is of uavjeep's car.
Last edited by Schuyler; Apr 5, 2015 at 06:09 AM.
I know when I had my wrx there was a hack group-n rom that was floating around that allowed anti-lag with a stock ecu. There was prerequisites in order to run it, but the rom used your rear defroster (IIRC) button to active and deactive ALS.
An autox course isn't that long... I don't think it will be THAT bad. I mean what's a damaged turbo and motor worth, when you're having anti-lag fun?
An autox course isn't that long... I don't think it will be THAT bad. I mean what's a damaged turbo and motor worth, when you're having anti-lag fun?
a t25 makes positive pressure almost off idle, and has one of those ceramic blade turbines or something like that which will likely not hold up to that sort of abuse.
so I'm not sure if at all worth it for you.
butttttt, you do have all the provisions to do it with MS3, so give it a shot. I think you'd need to set up ebc/tps boost/traction control cause you're gonna spin coming on the throttle in boost
so I'm not sure if at all worth it for you.
butttttt, you do have all the provisions to do it with MS3, so give it a shot. I think you'd need to set up ebc/tps boost/traction control cause you're gonna spin coming on the throttle in boost
Most of the guys I used to run with didn't want to run ALSs because of the abuse to the turbo. Another factor these days would be clamp down on noise many (all?) major events. I know that back fires from a rotatory have been known to trip the meters and get a warning from the officials. I would assume that the ALS would be a similar level of noise.
Yeah no way am I passing local sound with anti-lag. But with the EFR its not all that necessary only 1 person ever complained about lag in my car and he's hates turbos and the lag is all in his head.
Thread Starter
Senior Member
iTrader: (1)
Joined: Apr 2011
Posts: 1,332
Total Cats: 87
From: Columbia, SC
I know when I had my wrx there was a hack group-n rom that was floating around that allowed anti-lag with a stock ecu. There was prerequisites in order to run it, but the rom used your rear defroster (IIRC) button to active and deactive ALS.
An autox course isn't that long... I don't think it will be THAT bad. I mean what's a damaged turbo and motor worth, when you're having anti-lag fun?
An autox course isn't that long... I don't think it will be THAT bad. I mean what's a damaged turbo and motor worth, when you're having anti-lag fun?

a t25 makes positive pressure almost off idle, and has one of those ceramic blade turbines or something like that which will likely not hold up to that sort of abuse.
so I'm not sure if at all worth it for you.
butttttt, you do have all the provisions to do it with MS3, so give it a shot. I think you'd need to set up ebc/tps boost/traction control cause you're gonna spin coming on the throttle in boost
so I'm not sure if at all worth it for you.
butttttt, you do have all the provisions to do it with MS3, so give it a shot. I think you'd need to set up ebc/tps boost/traction control cause you're gonna spin coming on the throttle in boost
Most of the guys I used to run with didn't want to run ALSs because of the abuse to the turbo. Another factor these days would be clamp down on noise many (all?) major events. I know that back fires from a rotatory have been known to trip the meters and get a warning from the officials. I would assume that the ALS would be a similar level of noise.
All the weight shifts to the front of the car under breaking that heavy. Break boosting would light the back tires up for sure.
I'll test it out some once I have a turbo that is mine / buy the one I'm running from Lars. Until then, just thoughts and ideas. lol.
I PMed the guy with the yellow car to see if he would share tunes to give me a starting point.
Joined: Apr 2014
Posts: 18,643
Total Cats: 1,870
From: Beaverton, USA
In all seriousness though, if you're gonna destroy the turbo and potentially destroy the engine, why not enjoy the torque that comes with that decision vs some poping and crackling and slightly better boost threshold?
Thread Starter
Senior Member
iTrader: (1)
Joined: Apr 2011
Posts: 1,332
Total Cats: 87
From: Columbia, SC
I would assume the risk of banana-ing a nicer quality muffler like the big *** magnaflow is relatively low, otherwise I would find more posts on here of it as the result of a 2-step. (Which this is almost identical to but with a lot more timing.)
I should be clear, I'm not saying: "Hey I decided to do this thing, what are the thoughts?" It's something I'm considering, and haven't really decided definitively I'd try any more than once/twice up and down the road for a proof of concept. An EGT probe in the manifold is quite likely if I move forward to more testing with it.
This system retards A LOT of timing. Any charts I've seen of other cars is targeting -30 to -40deg when TPS is 0%.
Example of a local autocross from two weeks ago (no antilag, sorry). I didn't attend as the clutch still only has 300 city miles or so on it. (and a several hundred more highway though)






