SoCal Rally

Proper anti-lag doesn't so much damage the turbo as shorten its lifespan. This is due to:
- much higher duty cycle of turbo being under boost conditions than normal
- higher EGTs than normal (EGTs of 2000 deg F when system is activated are not uncommon)
- shock waves in the turbo, exhaust manifold and exhaust system when unburned fuel ignites

Exactly how much ALS shortens the lifespan of the turbo depends on:
- how often ALS is activated
- boost pressure at idle/off-throttle (depends on airflow allowed by bypass valve)
- EGTs when off-throttle

house_of_senate

iTrader: (1)

Anyone ever PERSONALLY had a turbo fail from using a 2 step to much? Im just curious, like I said, I do believe it shortens the lifespan and all that. Im also talking about the 2 step our evos use, not an anti lag system!

SoCal Rally

The standard launch control system our Evos use isn't really a true 2-step launch control, but rather a 2-step limiter (i.e. stationary rev limiter). I doubt with the standard Evo stationary rev limiter it does any significant extra damage to the turbo, since the turbo isn't actually really properly spooled. A significant amount of launching using the standard stationary rev limiter is more likely to cause premature wear to your clutch and driveline than to do so to your turbo.

And in general the question you ask is impossible to answer. Turbos fail. How many miles does a turbo get when daily driven normally? How many miles does a turbo get when daily driven spiritedly? How many miles does a turbo get when aggressively tuned? When a turbo fails prematurely, was that a manufacturing problem, a maintenance problem, a tuning problem, some other type of problem, or an undiagnosed problem? The kind of question you are asking is impossible to answer without analyzing thousands of turbo failures, their respective operating conditions and their causes and symptoms of failure; and even then you will get failures that fall outside of the average statistics, as you would with any mechanical part.

house_of_senate

iTrader: (1)

Thats not impossible to answer at all, simple question. Yes I agree with everything you have said too, just wanted to hear from people with experience with damage from this. I know they may not know the exact reason it failed, but they might have blamed it on the 2 step. Thanks for the input none the less.

Babs

iTrader: (26)

So why do you race your car? Why do you buy an evo? Obviously you're tuning your car so that you can go faster, correct? Racing your car will shorten the lifespan of anything. I wish people would just stop being so hypocritical about things and respect my wishes.

And if you read my first post, the reason for this is to build more boost at the line. My clutch is 100% holding fine and if I think it can handle it then I'll try to go for it.

Now back on topic...

Hmmm...I'll try bumping it up later today but when does it get to the point where pulling timing in the higher load cells will interfere with normal driving? And when I say normal driving, I mean during auto-x events where I might be in those cells quite often.

Thanks!

Dennis F

iTrader: (22)

Me personally, no. I did see a friend launch the hotside wheel out the tail pipe though.

Dennis F

iTrader: (22)

I could care less what you do with your car.

My point was this, why do you need more boost on the line? If you can't get the desired times others get with just the 2 step limit, you are not going to achieve it with antilag.

I used to cut deep 1.6's with my DSM @ 7 psi. Running anything more would just melt tires or break parts almost always netting worse 60 foot times.

If you are not already in the high 1.6 low 1.7 range, you have other things you can work on with a street evo on street tires.

Babs

iTrader: (26)

Alright so moving on...any other suggestions on what to do with the maps?

ohhgyeahfasho

iTrader: (14)

wait for tephra's v7 patch that has a launch map. ..And as for adding boost during 2 step. I don't know much about how an anti-lag system really works. edit: cuz im a retard lmao :P

TouringBubble

iTrader: (2)

From what I know, the stationary limiter works via fuel cut where you want it to act like an ignition cut. The effect you want will simply not happen with a fuel cut based limiter. Pulling more timing will help with the boost level, but it won't be as aggressive as a real ignition based 2-step.

And, FWIW, there is a variable to adjust in the ECU to pull more timing than the -10º limit. I don't know the location off the top of my head though.

fostytou

iTrader: (15)

This thread is full of win from all angles.

If your friend is doing it already, why don't you ask him?

Obviously you have to test to see if it will get you better times, but I think there are many other areas you can focus on while you wait for a v7 final so that you can do this properly. IMHO you should never run this map unless you are in a staging lane or on the strip and are sure you will not be in those cells. Running this full time or on an auto-x course is near guaranteed to give you undesired results.

You can't retard timing past -10, so change that hard limit and keep reducing if you want to do this.
Unburnt fuel igniting in the exhaust is expanding and spooling the turbo, so dump more until you get desired results or break something and don't listen to ohhgyeahfasho about going leaner.

I hope Kanye is not your idol, and I say that from a 15 year long stint of his stunts... not anything recent.

jrohner

The tephramods already have exactly what you are looking for, using totally separate timing and fuel maps for launch

Evo_Jay

iTrader: (17)

LOL, on this thread being full of win.

Also just to say, Kayne first stuff in the industry was on Jay-Z blueprint, which was '01. Before this he was %100 unknown.

So, we've only had a 8 year long stint of his stunts. lol.

back on topic.

OP if you notice, someone already said why you cant get true anti-lag results. Its because real anti-lag uses a timing cut to do its thing, but our 2-step only uses fuel cut.

Also WRC cars dont use their anit-lag for launching. They use it because they have to run a restrictor, which makes it harder to spool up the turbo, so they use anti-lag to reduce the lag, hence the name. They dont use it to lunch, like we do our 2-step.

Now do you see how their totally different things and you cant just think of 2-step as "ghetto anti-lag"

Babs

iTrader: (26)

Yea that's what I've read that you need to switch something from -255 to 255 or something like that but I don't know where.

My friend has a different two-step etc etc and I'm pretty sure I'm mapped similar to his but I'm not getting similar results. How do you change the limit for retarded timing?

And no I hate Kanye haha...the avy says "Act like a douchebag...expect praise from people"

Babs

iTrader: (26)

Well isn't that what I'm doing? Retarding timing? I know it's nowhere near the -40 to -50 degrees that WRC cars pull but I'm pretty sure anti-lag is basically retarding timing. I completely understand what you're saying though since I'm not really preventing lag therefore it's not anti-lag. I dunno the term just stuck in my head though...

Thanks for the help everybody! Can someone just point me in the direction of how to adjust the timing limit?