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ALS-why does nt everybody go for it?
Posted: 03 May 2007, 10:41
by ds.raikkonen
If the Anti-Lag System reduces turbo-lag, why isnt it applied in turbocharged cars these days? The Prodrive P2 shows how good it is...plus with the active differential it can go round corners at breathtaking speeds(thats another story)
Posted: 03 May 2007, 15:50
by zender05
I might be wrong, but I think the rally-car anti-lag is very stressful on the drivetrain and turbo, as it's constantly being loaded.
In rally, where things have to be big and chunky anyway, it makes sense. In a street car, where you want your car to go at least 70k miles, it makes sense. Not in something like F1.
I could be wrong though.
Posted: 03 May 2007, 18:50
by Ranald
Remember the P2 uses the engine and drive train from an Impreza STi with many components in that drive train directly derived from the world rally car.
Posted: 03 May 2007, 19:41
by ds.raikkonen
Well Prodrive was a major roleplayer in the design of the Impreza WRX STi World Rally Car.also it played a role in the design of the Aston Martin endurance racer-the DBR9..so the P2 is bound to use some elements from the Impreza...well, i read about Prodrive, and it said that it basically runs the turbine at a higher rpm than it does when the car is idling..to reduce the energy req in building the momentum when the throttle is opened nice & wide...also the spark is retarded to 35deg ATDC...so that the exhaust gases are at a higher pressure when the exhaust valve opens, ands hence more energy is transferred tothe turbine than usual.
Posted: 03 May 2007, 19:42
by pyry
when you lift off the gas, the pressure drops and the turbo is slowing down as it relies on exhaust flow to activate. when you step on it again it takes a while to accelerate up to speed again, thus being called turbolag. an antilag system dumps fuel into the damn hot turbo, which burns on contact resulting in the turbo spinning at some speed. you can probably see why production cars dont do this, its not all that fuel efficient
Posted: 03 May 2007, 19:50
by ds.raikkonen
Well, pyry, your explanation is pretty different from mine

..now what? i think i got that bit from Wikipedia
Posted: 03 May 2007, 20:33
by West
pyry wrote:when you lift off the gas, the pressure drops and the turbo is slowing down as it relies on exhaust flow to activate. when you step on it again it takes a while to accelerate up to speed again, thus being called turbolag. an antilag system dumps fuel into the damn hot turbo, which burns on contact resulting in the turbo spinning at some speed. you can probably see why production cars dont do this, its not all that fuel efficient
It's easier to cook the turbo this way too
Posted: 03 May 2007, 22:55
by Ranald
ds.raikkonen wrote:Well Prodrive was a major roleplayer in the design of the Impreza WRX STi World Rally Car.also it played a role in the design of the Aston Martin endurance racer-the DBR9..so the P2 is bound to use some elements from the Imprezathan
Just for your knowledge ds.raikkonen, Prodrive is more than just a 'role player' in the Subaru WRC and Aston programmes. They are entirely responsible for them. From design, build to track.
Posted: 04 May 2007, 18:37
by flynfrog
pyry wrote:when you lift off the gas, the pressure drops and the turbo is slowing down as it relies on exhaust flow to activate. when you step on it again it takes a while to accelerate up to speed again, thus being called turbolag. an antilag system dumps fuel into the damn hot turbo, which burns on contact resulting in the turbo spinning at some speed. you can probably see why production cars dont do this, its not all that fuel efficient
it does make for nice fireballs though
http://www.rallycars.com/Cars/bangbang.html
a better explanation
Posted: 04 May 2007, 19:16
by ds.raikkonen
Ranald wrote:Just for your knowledge ds.raikkonen, Prodrive is more than just a 'role player' in the Subaru WRC and Aston programmes. They are entirely responsible for them. From design, build to track.
I thought so, was nt sure ... thats why i used 'major' roleplayer