408 going in, base tune for initial fire-up

Guys, I don't post much but I read a lot! I think here on this board are some of the smartest people with experience from whom I have learned enough to have tuned my H/C car by myself.

I have a 408 GM LQ9 iron short-block going in and need some ballpark adjustments to a stock 2002 LS1 tune for initial fire-up. From everything I've read and heard, the first couple heat cycles are critical to seating the rings and all that. So I don't want to spend time dicking around with a stock LS1 tune to ballpark A/F and timing so the car will run right for break-in.

I already have done the calculations for IFR table and displacement/cyl. But need to know what adjustments to VE might help aside from the 60%-70%-80% in the low-RPM (400/800/1200 RPM columns). Or maybe other tables that that need adjusting.

Anyone out there can share some of their experience doing this right the first time?

I use LS1Edit for programming and EFILive v7 for scanning, but even if the info is in HP Tuners values, I'm sure it can be converted to LS1Edit values...Thanks guys.

Engine configuration is:

- Compression 11.4
- Forged rotating assembly w/Diamond -10cc pistons
- FAST 90mm intake/90mm TB
- SLP 85mm MAF
- Stage II LS6-style CNC ported heads 59cc chambers
- 42# injectors.
- 25% UD pulley
- Texas Speed "MS3" cam (237/242, .603"/.609" 112LSA)

can you post a copy of your tune?

Quote:

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Originally Posted by RUTAN TA

can you post a copy of your tune?

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I'm starting from a stock 2002 LS1 tune (346ci). The 408ci is a new motor entirely.

Attached the stock tune that GM put in the PCM. Didn't upload because the extension is .LS1, so here's a link you can download from...

LS1Edit v1.5 file:

http://www.elizabethford.net/2002ceta/misc/stock.ls1

heres a copy of my start up tune i used for the first drive out till i started actully tunning it. worked out great and actully drove pretty damn well for just a guess. I didnt do to much, and you are basicly already there, just changed the displacment for my 370 inch motor, scaled the injectors, reduced the ve table below 1200, changed the timeing a bit, and did some idle stuff.

Take a look at the history and you'll be able to see everything that was changed. My set up was a 370 inch, ported darts, 240/250 cam to give you an idea about what i had.

Also i've never done tunning for a Fast 90 so there might be somthing you need to do i think for the increased area of the 90 mm opening.

Justin

Thanks.