Going from street to race with the T+ and extender chip

[Bens87tr]

I have an extender chip setup for 93 octane (19/17) timing. I plan on taking my car to the track and running good gas, 108 or higher octane. My question is how should I set the T+? I think I can guess at the timing, but I don't know what to do with the fuel. I plan on running around 25# of boost. I know each car is different, but I was hoping those with experience could give me a good baseline to start with. I worry about not giving it enough fuel since this will be my first time to the track with this chip. In the past I have run race chips that obviously have different fuel curves.

TIA

 

[bruce]

Leave the dials at 0.
Make a pass. Hopefully the engine ran at least well, and you have a decent run.

Then try adding 2% fuel and make a pass.
If you went faster, then try adding another 2% fuel.

If you went slower, try removing 2% fuel.
If you went the same speed go back to the last fuel setting.

You want to first error in the direction of going too rich. Fouling a plug is alot cheaper then leaning a motor out and blowing headgaskets.

Then you want to try first removing some timing. If you slow down, then go 2d more timing, AND 2% more fuel.

Then just work back and forth, looking for best rich performance with the least amount of timing possible.

There is a noticeable difference from running all the timing possible to running the least amount of timing CONSISTANT with best performance.

 

[salvageV6]

I'd add 8% or more fuel first, WOT only, especially if you are cranking in some timing.

You can always take some out if running rich. Beats watching the KR meter light up if you are lean.

I'd start the guesses on the safer side.

 

[TurboDave]

IMHO, and I've only been running an extender now for a couple years. I run 25# of boost at the track also.

You know what your car's settings are for the street, right?

Make sure you put in at least 114 octane gas. Don't add to what's there, pump out what's there and put in the race gas.

Set BASE TIMING for +6, that's postion 3 I believe. That should set your timing up to 25/23, a good place to start with good race gas.

What ever your WOT MAF is set for on the street, turn it up 3 notches for your first run and make sure to capture the run's O2's. This will be a safe starting point and will tell you which direction to go from there. You may be pig rich, you may not.
Keep good records.

That should get you started.

GOOD FUEL!!!! NO COMPRIMISES!!!!


You see any knock retard, especially in third gear, remove some timing.

Here's one more suggestion. Leave your BASE TIMING where it is, and add those 6 degrees I talked about earlier into the WOT TIMING switch, this way it will help spool on the line with the lower base timing, and as soon as you launch, the higher timing kicks in!!!

 

[c&cgn]

Ditto what Dave said.

I usually run MAF base same as street setting and add 6% fuel WOT. I am also usually around 25/23 on the timing to start off with and have worked it up to 29/27 for balls out passes. If you have an EGT it would make tuning that much easier and quite a bit more accurate. As Dave suggested I usually run Timing at base of 23/21 and add it in @ WOT.

 

[tim87tr]

You are getting good advice here. I have asked some questions recently after buying the trans +, and here are the links for my trans + tuning. One thing I did not do was add timing only at WOT. That will help you with the bigger turbo spoolup. My minor experience is that you can increase the timing to a certain point with the octane you are running. You said you had a good idea. Then start rich at WOT like salvage said and lean out from there, watching kr. I think an EGT at this point, when messing with timing, would be a good idea. It's next on my list.

http://www.turbobuick.com/forums/showthread.php?threadid=43262
http://www.turbobuick.com/forums/showthread.php?s=&threadid=41560