Antilag on GTi-R with Autronic SMC

[McLOVIN]

OK so does anyone know what's required to set this up? I don't want it on all the time so what's required to make it a switchable system with the quad throttles?

[Joe]

To run anti-lag on a GTi-R with an Autronic, it would be switchable on the fly, meaning you'd need a device to hold the throttle open when you activate it....I'm not sure if your car has an idle up solenoid, but if it doesnt, you'll need to use something like a Commodore air-con solenoid to kick it open.

You'd then activate the solenoid and the anti-lag off the one switch, so when you turn it on, it activates the anti-lag function and the solenoid at the same time.

[McLOVIN]

Cheers.

I have spoken to SAS about this and they're very reluctant to set it up on anything that is not a dedicated race car. I am considering having them program a 2nd map for race fuel and including the antilag and launch control.

Is it very difficult to set it up?

[gtrken]

Antilag is easy to set up on a switch for the GTIR but you will have to run the car in rotational idle or otherwise known as cool down mode. Other method is as previously discussed which is a idle stepper solenoid but tricky to do.

The throttle stop is wound open to allow the antilag to work and the rotational idle is then adjusted to bring the revs back down.
You can have a mild idle with a slight lump in it or a wild idle that sounds like a full blown drag car.

[Joe]

Cheers.

I have spoken to SAS about this and they're very reluctant to set it up on anything that is not a dedicated race car. I am considering having them program a 2nd map for race fuel and including the antilag and launch control.

Is it very difficult to set it up?

It can be very difficult to setup, or it can be very easy...I know with a Motec, it can take up to a few hours for a tuner just to setup the anti-lag, where as with a Link ECU, I could probably do it myself at home with the hand controller.

Why dont SAS want to set it up?? I suppose its not utilized anywhere near as much as it is in WA (the rexnet boys dont call WA the anti-lag state for nothin ;)), but it really isnt too much of a big deal...it IS switchable after all ;)

[McLOVIN]

OK I'm starting to get confused. I thought the rotational idle cool down mode was just that, a cool down mode. How does that actually get the antilag to work without the solenoid to open the throttles? Or am I way off track?

SAS are always hesitant to do any modifications that might be illegal for street use, or might have the owner of the car coming back to whinge at them. So I'll need to push them if I really want this done. They're also hesitant to tune any car with standard internals much past 1bar boost. Just easier for them in the long run I guess.

[Joe]

The purpose of rotational idle is to control your idle. When you use anti-lag, you need a big throttle opening, and the rotational idle cuts fuel to each cylinder in a rotational sequence, in order to keep the rpm down at idle...if you didnt have rotational idle, your engine would be idling at 5000rpm because of the large throttle opening. Because during anti-lag, there is a lot more fuel entering the cylinders, it also cools the engine during rotational idle.

With anti-lag, you've got your rotational idle, then once you rev your engine over its rpm target, it goes into anti-lag armed mode, which is a higher, more aggressive idle which stays on for a certain period of time after you've used the anti-lag (and later switches back to stand by mode)...and then the anti-lag itself of course when you rev it during anti-lag armed mode. As soon as it comes off idle in anti-lag armed mode, its using anti-lag...and you get pops, bangs, and instant boost (depending on how aggressive its set, you can even have boost at idle if you wish).

A working example is my setup... my rpm target is set at 4000rpm, so if I rev over 4000rpm at any time, it goes into anti-lag mode. This mode switches off after 15 seconds of being below 4000rpm and goes back to rotational idle, but every time I go over 4000rpm, it stays on for another 15 seconds. When I'm track racing, it stays on the whole time basically.

If you dont use a solenoid with your setup to keep the throttle open, you'll have to use the cars built in throttle screw to keep the throttle open 100% of the time, meaning it'll always have that lumpy idle...as Ken said, its harder to setup using solenoids, etc...

My car has a Commodore air-con solenoid on a custom bracket, with a metal tab mounted on the throttle. When I flick my switch, it keeps the throttle open for me, but once I turn the switch off, the car goes back into its standard idle.

With my previous Link ECU, you have to either have rotational idle/anti-lag on all the time, or off all the time. With my Motec, I flick the switch whenever I want anti-lag, and it kicks the throttle open and activates the anti-lag at the same time, and I can turn it off any time too.

Hope that clears things up :)

[McLOVIN]

OK that clears it up perfectly.

Mods, I would like to nminate this man for some kind of award, and perhaps give birth to his children.

I'm guessing a solenoid is going to be an absolute pain in the ass to setup on mine due to the location of the throttle pulley. I'll have to see if I can find some info on GTi-Rs that are already running antilag setups.

Thanks again fellas.

[Joe]

Haha no probs :D

[gtrken]

Very good Joe, don't know why Mandee says your dumb :)

Correct in that it will work with a solenoid and still be able to retain a normal idle. Trouble with a GTIR is lack of room and the quad throttle setup will make it a pain. Hence why I said to just use the idle stop screw and put up with a lumpy idle.

Small correction in the Antilag is that it cuts the fuel, not the spark though the rest is pretty spoton.
I don't want your babies though.
Mandy on the other hand .... hehehe

[Joe]

Hahaha, I may be stupid, but when it comes to cars, I got some smarts in my head :D

(I'm not bad at maths either)