Help with 92/92 fast intake tune

[MathiasBlum]

Hi Guys,

Okay, so, I just finished my LS1 upgrades.

Im having troubles though.

I cant get the idle to return correct, i will under- and overspeed, hunt for idle, sometimes it dies too. Restarts immediately, no problem

Spec list is:

Stock bottom end LS1

PRC 225 heads milled to 62cc
42lb bosch injector
233/239 tsp cam
Fast 92/92 intake
Hooker 1 7/8 LT headers

Im running SD tune and with my old tune i was able to get it running perfect with the old Howards mild cam. But the new setup im having troubles with.

Have anyone tuned the 92/92 fast intake setup and are there anything i should change in the tune for the bigger throttle body? And what about trans, I think the trans need to be changed too, because of the bigger TB?

[kevin87turbot]

A datalog and a look at your cal file will help us pinpoint the problem.
If your fuel trims are good, then I'd check the IAC position. Should be between 40-60 at a hot idle.
If it's not, then adjust the throttle body screw accordingly.
Also make sure that the min airflow tables are set properly. If they aren't set properly, then you'll never get a consistent idle.

[MathiasBlum]

Hej Kevin,

Thanks for your reply I found out the problem today, problem was in IAC steps vs effective area

[farmer44]

Hej Kevin,

Thanks for your reply I found out the problem today, problem was in IAC steps vs effective area

do you mind if I see a copy of your tune? im having similar trouble and im pretty new to tuning. would like to see a compare and contrast difference to learn what im doing wrong please

[curiousg7]

I changed my shift points to stay away from low rpm high load scenarios. The bigger TB feels so good! I can race a camry at 5% throttle lol