Hey all, hoping to get some input from those who have used launch control and maybe some input on my timing map.

The MAP - It is a combination map taken from two other boosted V8's. One is a roots (m90 I think) and one is a Vortech car. I took all of the highest numbers between the two maps and made one map. I have run with this map at the track w/o knock issues. If anyone has some input please share.

Launch control - Just not really sure what is the best way to go about using it. With my ECU I have the option to cut fuel and/or ignition. I can set the RPM and disable road speed. From what I understand there is some benefit in cutting ignition on a turbo car, the fuel in the exhaust will help spool the turbo(s) up. My car being supercharged I'm not sure that I like the idea of flaming my expensive AFR sensors. In my case I think that cutting fuel is a better (and safer?) option. Any input?

One problem I have with my car is that when I attempt to "brake boost", my rear wheels will start to spin and sometimes the car will even creep forward. I guess the brakes just can't hold it well enough. With the launch control on at too high of an RPM I have a lurching affect. When the power is on the car wants to go forward. I was thinking about setting it up so that when launch control is on the ECU would be using a second ignition map with retarded timing so that the RPMs will be held and the power will be cut untill it is disabled. Any input?

I'm hoping to get back on a track sometime this weekend.... I'm dying to run some better numbers!

Thanks,

KC

 

Going to Rockingham tomorrow, no one here has used launch control?!?

Seems that fuel and ignition cut (or a combination) will both do the same thing but ignition cut is more widely used. I tend to think fuel cut is safer.

Before anyone says it, being in fuel cut is NOT THE SAME as running lean.

KC

 

every time i have used "launch control" it has been an anti-lag setup, with fuel enrichment and timing retard... this sounds more like a 2 step, which is just an auxillary rev limiter. i have no idea how this would work with your automatic trans though. i would think that if you have an automatic trans and a torque converter, that's all the launch control you need...

what EMS are you running?

as far as lurching forward when you're using the "launch control," you're going to just have to lower the RPM it uses to an RPM at which you don't lurch while standing on both the brakes and throttle. this is out of my element though, as i've never had an automatic trans.

i'm kind of confused about what you're asking, but i'd post this on supraforums. there are many more people over there that have rowdy automatic trans setups.

 

I am a newb to the idea of launch control so please keep that in mind.

EMS is Adaptronic.

I suppose, now that you mention it, launch control makes ALLOT more sense on a manual trans car. But, I think it can be a benefit on an auto as well. My hope in using it was to be able to launch at a higher rpm by somehow getting around the fact that the power wants to make the car go forward even before I'm at my stall speed. Should also note that a trans brake for the a340 isn't really an option.

Normally when I'm standing on the brake pedal the car will either spin the rear tires or want to move forward by about 2400-2500 rpm.

I set up launch control like this: Set it to cut fuel. Set the RPM to 3000rpm. Set it to use the second timing map when launch control is on. Set up the second timing map with less timing. As soon as launch control is de-activated at 1mph the ECU will go back to the normal timing map.

I had a quick try with these settings and was able to get it to 3000rpm without issue so it just might work.

KC

 

okay so you're just going to use it to cut the timing (and power as a result) back so you can take off at a higher RPM without lurching forward at the line.

that makes sense.

hammer down!!!

(then do a 5spd swap)

 

KC, I saw you run yesterday at the Rock. Car moves out for sure. I was there on my white 97 big single Supra. Sorry I didn't get to meet you.

Dee E.

 

did you break the 11 seconds KC?

 

Ya, you got it.

Actually worked out pretty good. Tried with fuel then tried with ignition, didn't seem to matter one way or the other. At 3000rpm and about 38% throttle I had about 1 psi of boost at the start line. Doesn't sound like much but I usually leave the line without any boost and I could probably get more with more throttle opening.

I'll admit that a 5-speed swap sounds sexy but its not really for me.

Thanks man. I think I may have spotted you but I didn't see you run at all. Did you and what'd you do if you did?

Disappointingly no, I would have posted much sooner if I did!

I know I ALWAYS say this but I think I will. Rockingham has always been a slow track for me. Gonna, weather permitting, run at Zmax Saturday. I have something I'm going to try with the water meth injection that should help me out quite a bit.

Runs were:

1.876 - 7.835 @ 90.9 - 12.148 @ 114.41

1.875 - 7.915 @ 90.85 - 12.238 @ 113.9

1.839 - 7.838 @ 91.88 - 12.148 @ 113.81

1.887 - 7.874 @ 91.37 - 12.183 @ 114.10

I know I can do low 1.7 60fts, just wasn't there yesterday.

KC

 

I did not run. I'm waiting on my fuel system, wideband, and a tune before I can do any racing. I have an SC also, but it is my daily driver and is NOT fast at all. You on facebook?