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Anti Lag system

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Taken directly from www.dsmlink.com....

"Generically speaking, the term anti-lag refers to a technique commonly used by WRC style cars to quickly spool a turbo while the car is under hard deceleration in anticipation of the hard acceleration that's likely to follow. The technique involves retarding ignition timing so far as to cause the exhaust valve to open well into the power cycle, resulting in extremely hot and explosive gases rushing past the turbine, spinning the turbo up like crazy."

Basically what it does is retards your ignition timing so much that the explosion occurs when your exhaust valves are open. As a result, you can build boost of the line. If you have a 2G, use the 2G DSM link; if you have a 1G, wait a month or so and get the 1G DSM link. Both have the capability to do antilag if you think you need it. Oh, and by the way, if used all the time, it will ruin your turbo.

Hey 14.5 drift, it sounds as if you are talking about stutterbox, not antilag.
~Mark
 
ever watch initial d? the evo that you see has an antilag system and you can tell because of the explosion that comes out of the muffler. it does rape your turbo big time though... i definately wouldnt use an antilag system on an expensive turbo, ever. maybe occasionally on your stock turbo if you have plans for an upgrade...
 
No lift to shift and anti-lag are two different things. I believe flyingfin (by virtue of his screenname sounding an awful lot like WRC driver and former world champ Marcus Gronholm's nickname) is talking about the types of systems used in World Rally cars, which is all about keeping the turbo spooled while you're hard on the brakes coming into a corner so that you can blast out of them without waiting for the turbo to spool back up when you get on back on the gas. Drift is thinking of the DSMlink setup and described their shift limiter which is basically a stutterbox-type that cuts the ignition quickly when the clutch is pressed in so that you don't have to lift off the throttle on upshifts (the really basic explanation). DSMlink does have an anti-lag function which is completely different, and is probably about the closest thing us DSMers can get to true anti-lag for the money. Because of what anti-lag does, it's something that must be programmed into an engine management system, not just a box you can add on to your stock ECU like and AFC or something. So what does it do? Well, DSMlink's site has a really simple explanation that goes like this:

"Generically speaking, the term anti-lag refers to a technique commonly used by WRC style cars to quickly spool a turbo while the car is under hard deceleration in anticipation of the hard acceleration that's likely to follow. The technique involves retarding ignition timing so far as to cause the exhaust valve to open well into the power cycle, resulting in extremely hot and explosive gases rushing past the turbine, spinning the turbo up like crazy."

Then they go on to say what their "anti-lag" actually does:

"While we don't provide a full-on WRC style antilag system, we do provide a very effective drag style system that operates at the line and during those hard power shifts you make down the track. This helps to quickly spool the turbo for those pesky pro-trees and keep the turbo spooled in between shifts. Combined with the no-lift-to-shift feature, this can have a dramatic impact on 1/4 mile times."

TTE (Toyota Team Europe) first developed anti lag for their WRC program on the Celica world rally car back in the 90's. Similar systems are employed on every top WRC car today. A detailed description of how their and similar systems work can be found here.

So, DSMlink has a simplified version of anti-lag which seems more geared to drag racing than rally or road racing, which is about as close as you're gonna get unless you have a huge budget for a custom engine management solution for a DSM. What's missing from their setup is an anti-lag valve, which is basically a valve that bypasses a metered amount of air past the throttle body (I imagine the ISC could do this, but probably doesn't bypass enough air to be effective) while the ECU is severely retarding timing and adding fuel. This is why you always see WRC cars spitting out flames from the exhaust when downshifting for turns. Which brings up another point...anti-lag is literally hell on exhaust components. We're talking around 1100°C! WRC teams are running exotic alloys (like Inconel) in their turbine housings and manifolds to put up with the heat, some going as far to use these alloys throughout the exhaust system. Considering that DSM EGT's should be around 900°C, it's something to consider if you're seriously thinking about impementing such a system.

Having not tried DSMlink's anti-lag personally, I can't speak for it's effectiveness. There's a lot of info out there on engine management systems that include this feature, but they're mostly for cars that are widely used in rallying worldwide, including the WRX, Evo and the Escort Cosworth.

John
 
a local guy here has dsmlink with the antilag system and says its awesome. Antilag, stutterbox, and no lift to shift is the perfect combo to drop some NICE times.
 
I run anti-lag on my car. Basically when I flip the switch on the line, I floor it, it holds the rpm's at 6500 (two-step), pulls 20deg of timing, and throws in x% more fuel. Makes for some insane boost sitting there :D
 
14.5 drift said:
, LOL, my bad. Just get dsmlink like the man said, you wont need a stutterbox. :) :dsm:

Seriously, stop answering questions.

You need a stutterbox (lowered rev limiter) even if you're using antilag.
 
Mirage2LTurbo said:
I run anti-lag on my car. Basically when I flip the switch on the line, I floor it, it holds the rpm's at 6500 (two-step), pulls 20deg of timing, and throws in x% more fuel. Makes for some insane boost sitting there :D

that's a stutterbox ... antilag keeps the turbo spooled between shifts I thought ... different features although hte stutterbox may be needed to use the antilag feature.
 
kpt4321 said:
Seriously, stop answering questions.
I was confused, no harm no foul. Some one was right behind to set me straight, I learned, so did the other guy, why get all ugly?
 
I use the studderbox and anti-lag on my 2g. I have the anti-lag set to start around 3200rpm's, and my studderbox at 4500. The result is big change in exhaust note from "3200-4000" rpms, and its kinda slow getting through that point. When it hits the studderbox the end result is 18-20psi of boost and lots of loud popping and black puffs of smoke out the tail. The force is pretty strong it would knock a small child down.
Sounds hella badass! Too bad I'm gun shy now, and wont let the clutch out when I do it. I use it more for intimidation than anything :p
I havent seen anything near 1100C.

It also works farily well between shifts when your at a high enough rpm, but I think thats just my studderbox. Although my exhaust will "pop" while shifting at high rpms.
 
BoostinAWD said:
I use the studderbox and anti-lag on my 2g. I have the anti-lag set to start around 3200rpm's, and my studderbox at 4500. The result is big change in exhaust note from "3200-4000" rpms, and its kinda slow getting through that point. When it hits the studderbox the end result is 18-20psi of boost and lots of loud popping and black puffs of smoke out the tail. The force is pretty strong it would knock a small child down.
Sounds hella badass! Too bad I'm gun shy now, and wont let the clutch out when I do it. I use it more for intimidation than anything :p
I havent seen anything near 1100C.

It also works farily well between shifts when your at a high enough rpm, but I think thats just my studderbox. Although my exhaust will "pop" while shifting at high rpms.

i dont get it though.... i thought the anti-lag was for inbetween shifts? how do you set an rpm range on it?
 
We seem to be talking about two different kinds of Anti-Lag.

The first is the WRC style that will give you boost while braking for a turn and other times.

The second is the drag style that DSMLink is using that will give you full boost or close to it at the starting line.

There are other difference in how they work and what effects they will have on your car, but I do not know the systems well enough to try and explain them.

Hope this was some help, Matt :talon:
 
Anti-lag works the same no matter what application it is used in. It pulls timing and throws in fuel, causing the combustion cycle to take place post TDC and on the exhaust stroke mostly, causing the fuel to still be burning as it is exiting the head into the manifold, expanding in the manifold = big spooley. That's why, if you've ever heard a car on anti-lag, it sounds like a huige series of backfires and stutters.
 
Finally someone know where i can find anti lag for my 1990 Awd alon rally application
 
Any decent standalone should have settings to control anti-lag. I run Autronic, love it, it was recently compared to a Motec in a review this past week on a turbo honda. The anti-lag has tons of features for rpm, load, and speed to control it with. You can use 4 individual speed sensors (4 wheels) to input and use traction control. Definitly take a look into it, www.autronic.com.

I'd hate for you to be ripping down a dirt path and some AEM unit you buy decides to shut off your fuel pump(s) or even worse, just lose your map :barf:
 
Mirage2LTurbo said:
Anti-lag works the same no matter what application it is used in. It pulls timing and throws in fuel, causing the combustion cycle to take place post TDC and on the exhaust stroke mostly, causing the fuel to still be burning as it is exiting the head into the manifold, expanding in the manifold = big spooley. That's why, if you've ever heard a car on anti-lag, it sounds like a huige series of backfires and stutters.

Well, yes and no. In WRC cars, the ECU opens a valve to bypass the throttle plate which in turn keeps the revs up while it's pulling timing and adding fuel when you're on the brakes hard entering a corner. This keeps the turbo spooled up and on the ready for when you jump on the gas upon exiting the corner. DSMlink's anti lag doesn't do this at all, it's just retarding timing and adding fuel while "you" open the throttle plate and bounce of the limiter on a launch. The effect is the same, but the application is not.

BoostinAWD said:
I havent seen anything near 1100C.

The 1100°C figure I put out earlier is for WRC cars, the DSM link setup isn't quite as extreme and you're probably not using it for longer than a few seconds on the line and briefly during upshifts (if you're using a no lift setup), so you won't be seeing those kinds of EGT's. Things are a little different when you're blasting through the woods on gravel for miles!

JiveMasterT said:
i dont get it though.... i thought the anti-lag was for inbetween shifts? how do you set an rpm range on it?

On DSMlink, the RPM range is set in a dialog for when to activate the anti-lag, how much timing to retard and a percentage to enrich fuel. It only works when the clutch is in (like the stutterbox), so it allows you to build boost on the line while bouncing off the stutterbox limiter and keep it while the clutch is in during a shift.
 
Mirage2LTurbo said:
Any decent standalone should have settings to control anti-lag. I run Autronic, love it, it was recently compared to a Motec in a review this past week on a turbo honda. The anti-lag has tons of features for rpm, load, and speed to control it with. You can use 4 individual speed sensors (4 wheels) to input and use traction control. Definitly take a look into it, www.autronic.com.

I'd hate for you to be ripping down a dirt path and some AEM unit you buy decides to shut off your fuel pump(s) or even worse, just lose your map :barf:

I ran across their site yesterday. Their anti-lag setup seems like the shit and supports the use of actuators to keep the throttle open while downshifting.

Which one are you running? They have a 2G ECU board swap on their site, which wouldn't do me much good since I have a 1G. The SM2 seems like the ticket!
 
Quit being so simple minded :)

I'm running the Autronic SMC, which is just the universal model with it's own wiring harness. I had to run wires for windshield wipers, the starter, and to the ignition to control the car after I removed the stock wiring harness/ECU, then lay in the Autronic harness and start soldering on connecters. It comes with its own water temp sensor, and an air temp (speed density ONLY, the RIGHT way to do it :) ).

It took me a weekend to do all this, probably a good 10 hours.. and I had never done it before. If you have a basic knowledge of how electricity and wiring diagrams work, you'll be just fine. You'll need lots of shrink insulation tubing, solder, soldering iron, wire cutters, strippers, and some 4pin connectors so you dont hardwire the wiring harness straight to your engine. The only thing that hung us up was the CAS,we had to play with pinout combo's to find one that worked :)

Expect to pay $1699 for the SMC, or $1899 for the SM2. In hind sight, I would have bought the SM2, had I not gotten my SMC installed for $1000 total (bought from a broke ass friend).
 
Neuro: those prices are high! I would suggest buying from a shop so you have support. Also, MAKE SURE YOU BUY FROM THE PROPER CHANNELS IF YOU GET AUTRONIC. The prices are controlled by the manufacturer in Aust., so if you find one brand new for cheap cheap, chances are it's not carrying a warranty. I would suggest buying straight from the US distributor if you plan on doing it yourself at http://www.fastenough.com/
 
Mirage, thanks for the info on the Autronic. While I still have quite a bit of work to do on my car before I even have the need for stand-alone engine management, I like to think ahead. I'm not a drag racer, I'm more into autocross and canyon runs and intend to give rallycross a shot, and perhaps later build this car up to SCCA Pro Rally specs. A lot of the Autronic's capabilities are really appealing! Especially anti-lag, traction control, not to mention full engine management including boost control. I'm pretty good with electrical stuff, so I'm not really intimidated by wiring one up. How does that Autotune function work out?

John
 
Up until the most recent version, the autotune was somewhat crude and ineffective. It would compare the set fuel at rpm vs load with the a/f at that point, and try to correct it on the fly. This might work for off boost where you hit those sites frequently, but unless you want to do 100 boost pulls, no dice.

The newest version of the software has a new feature, the mixture table. Basically you drive around, do whatever you want, and log. Then you load that data into the mixture table, it computes the a/f at the given site and corrects your a/f that way. It is extremely effective. After 100 miles on the brand new engine, we have tuned out perfectly up to 14.7psi and 6500rpm. When I say perfect, I don't mean "it looks good on the graph." I mean 14.7 off boost, 11.8 in boost above a certain rpm, and all the transient sites inbetween. I don't have my map on this computer, or I'd show you some screenies. You go through and set what a/f you want at what rpm vs. load, and then the mixture table computes the fuel input based on your logging.

Also, to give you an idea, we made one log run for 32 minutes, and I believe it was 230KB. On the P266 we were using, it took 30 seconds to load the mixture table in, a few minutes to sort through and figure out what sites we wanted to change, and another 10 seconds or so to load the map up and into the ECU. You don't want to modify every site because some sites, such as when you let off the gas completly, register like 18:1-20:1 a/f, and are not correct.

-Colin
 
As far as autotune goes, go find a Dyna Pack dyno or a similar dyno that can keep RPM constant. All you need is ~2 hours and it's fully mapped. You won't have to worry while you drive about AFR going too lean.
 
Mirage2LTurbo said:
You can use 4 individual speed sensors (4 wheels) to input and use traction control.

How are you going to use 4 sensors when there's only 2 inputs on the ECU?
 
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