Lt12s - Antilag Through Aux Instead Of Aircon Adjustments

[PM-R33]

Wondering if some of the guys that know a bit about tuning ECU's in general could help me out here. I can't find any info on this.

I've nearly finished setting up the launch control and antilag setup in the car through the AUX input on the LT12S. Now the problem is, currently this AUX input is being used for the aircon adjustment. When the aircon switches on, the AUX input is triggered and adjusts the tune with the following:

Adds air through the cold bypass valve by 0.86

Adds fuel by 0.05

Adds timing by +02 degrees

Now if i get rid of this in favour of the launch control/antilag, what effect will that have on the car with the aircon on and giving it some stick?

I don't care to much if the car has a bit of trouble idling with the aircon on as i can simply turn the aircon off when coming to a stop. The main thing im worried about is whether the engine will start pinging with the aircon on if i give it some. It's only giving it a tiny bit of fuel and 2 degrees of timing, surely if that wasn't there it wouldn't effect it too much......

Do you guys that tune cars notice much of a difference in the tune with the aircon on, will it start pinging noticably if you havent tuned the AUX map for it?

Some extra info would be good, that way i dont have to worry about the car running the aircon without it having any adjustments to the map.

I might just turn all those values to zero and take it for a drive tomorrow during the day with the aircon on and see how it goes. Would rather get some insight into it first though.

Cheers guys

Edited April 15, 2009 by PM-R33

[Guilt-Toy]

those settings would only effect the idle and low rpm cruising. if you cut the aux and use it for anti-lag it sould be ok. if anything -2 deg of timing will make you lose power on boost not cause pinging.

try it and see how you go.

[Haines]

My aircon switches off if you give it some anyway

it think they all do over a certain TP %

and why do you want antilag?????

doesnt yours make full boost at 2500rpm

hardly lag if you ask me

Edited April 15, 2009 by Haines

[Weapon]

Its for when he is sitting next to a grandma at the lights he can RH9 launches with popping and flames spitting out the exhaust yo

[PM-R33]

Couldn't have said it better myself

Nah i really don't care about the anti lag, mainly want it for the launch control having it holding at a certain rpm with the foot flat. 1.5 bar is by 3500rpm, so yeah, obviously no lag.

Thanks Guilt-Toy, ill play around with it this weekend.

Edited April 16, 2009 by PM-R33

[Haines]

ill sell you my decat pipe

[Lukas 33]

ill sell you my decat pipe

hahaha there will be no need for that Phil's cat is f**ked so he took to it with a hammer

[bozodos]

Haha now thats one thing I'd never do again - bash out a cat myself (well not without a wide drillbit anyway lol)

[Lukas 33]

Yeh I dont think Im ever going to have that issue. I think a nice piece of straight through pipe should help emisions

[Fastrotor]

With your MT it just senses the Aircon clutch line to trigger the aux input, then add's some extra air via the idle solenoid, adds some fuel and adds 2 deg of timing. Purely for keeping the idle nice really. There is no full throttle cutout, unless its built into the factory wiring, which it is not from memory...... So unlike more capable computers, the aircon will stay on.. (unless you have piggybacked it to the std ecu ????)

Anyway, its pretty limited, but you would just drop the rpmlimit "inpRPMlim" to suit what you need , and id play with the timing "inpTiming" , retarding it some to aide boost to build on the limiter. I would set the "inpAIRadd" to 0 (as its not enough for proper antilag, and for launch control , your flat out on the throttle already.) Probably leave fuel "inpEnrich" alone too... or add abit . Be prepared to change a few plugs as you foul them trying to get it all right.

Guilttoy could share some figures of timing retard and fuel add as he has it running on his car and is more authoritative than i on the subject ..... guilt ??...

Gary

[Haines]

Bit scary if its leaving the aircon on at high revs

that cant be good for the poor old aircon compressor

[PM-R33]

hahaha there will be no need for that Phil's cat is f**ked so he took to it with a hammer

lol I don't know what you are talking about....

[PM-R33]

With your MT it just senses the Aircon clutch line to trigger the aux input, then add's some extra air via the idle solenoid, adds some fuel and adds 2 deg of timing. Purely for keeping the idle nice really. There is no full throttle cutout, unless its built into the factory wiring, which it is not from memory...... So unlike more capable computers, the aircon will stay on.. (unless you have piggybacked it to the std ecu ????)

Anyway, its pretty limited, but you would just drop the rpmlimit "inpRPMlim" to suit what you need , and id play with the timing "inpTiming" , retarding it some to aide boost to build on the limiter. I would set the "inpAIRadd" to 0 (as its not enough for proper antilag, and for launch control , your flat out on the throttle already.) Probably leave fuel "inpEnrich" alone too... or add abit . Be prepared to change a few plugs as you foul them trying to get it all right.

Guilttoy could share some figures of timing retard and fuel add as he has it running on his car and is more authoritative than i on the subject ..... guilt ??...

Gary

Cheers Gary, ill have a play with it this weekend. On the microtech forums they have some values to use, so i'll just see how the car behaves to it. The limiter function is the main thing i want, ill try the antilag, but it's just going to be wheel spin city Plugs are cheap at work so that's all good.

[Fastrotor]

Phil you keep mentioning antilag like its a selectable feature on the MT ?? Have i missed something here ?

The aux revlimiter, combined with the + or - fuel and + or - timing is basics needed, but there isnt a special feature that allows setting tps thresholds , timers etc etc ..

I only ask as your talking like its a selectable feature on the MT, just making sure its not something new...

You'd love a new G4 Link plugin for things to tinker with ! Makes the MT look archaic, and im being nice.

Gary

[Fastrotor]

So hows the head going ? reckon it was worth it all ? to me it seems more suited to a larger turbo, but for under 300 not really worth it.

What about off boost responce or fuel eccon , anything change ? Noticable fueling changes in any areas ?

Gary

[PM-R33]

Well with the antilag im setting it up to a push button switch that gives the ECU 12V on the aux input. When the button is held down i can have the RPM limit i want and set the fuel and timing up so antilag can be achieved if desired. Have the car in gear, holding the foot flat, then when the clutch is dropped release the switch. It's not a true antilag i suppose, but still allows boost to built while standing still and shoot flames. Like i said, that's not why im doing it, mainly want the RPM limiter but ill play with the antilag.

That's how the guys on the microtech forums are doing it, or having it set off the clutch switch.

http://www.microtechefi.com/forum/viewtopi...ghlight=antilag There's a quick thread there. There are better ones.

Yeah head is good. Well i took the head off to do the valve springs, while it was off i figured i might aswell have it rebuilt, ported, polished and the valve seats cut . Only ended up costing me $1250 for the labour and new guides, seals etc so it wasn't that bad. If i ever do a RB30 conversion atleast the head will be nicely done.

Boost response is amazing, have 1.5bar (full boost) at around 3500rpm, fuel economy aint too bad but its hard to drive around off boost with it being so responsive. Meh gets me to uni and work, can't complain.

Edited April 16, 2009 by PM-R33

[PM-R33]

Well i hooked it all up and it works sweet. Just a note if any one is going to do it on the LT12S with the RB25 harness. Normally you give +12V to the aux input to turn it on, however with the RB25 harness originally controlling the aircon you have to give it an earth instead.

I hooked up a missile switch in the centre compartment to arm it, then i took out the antenna switch on the dash next to the steering wheel (I don't ever use it and am going to shave the aerial off anyway), hollowed it out and fitted a push button switch to activate the launch control. With it held down it limits the RPM perfectly and makes some extremely loud limiter noises lol.

I'm going to go out somewhere private and play around with the fuel and timing settings to see how the car reacts. At the moment i havnt added any fuel to it, just pulled back 10 degrees timing to be a bit safe.

Edited April 20, 2009 by PM-R33

[Fastrotor]

Let us know how it goes for ya. I just dropped my head into bondy's today to get skimmed. Oh and yes, the sprints are on this weekend Phil.

Gary

[PM-R33]

Will do man.

What time do the sprints start/finish?

[Fastrotor]

Usually get underway about 3pm ish, sometimes earlier depending on numbers. Finish around 9-10pm once again depending on numbers.