FAST Importance of IAC

[KTamez]

How tough would it be to run this sucker w/o IAC?? Fans and all that other crap can be handled seperately, but the ECU is maxed w/ what I consider other more important features.

I'm assuming I could get away with just adjusting the TB blades some to get the desired idle, but what about on the Throttle release, etc....?

Combo:
396 SBC 12:1 CR
Dart Single Plane Intake
Force EFI Dominator Throttle Body

Drag Race car only. Might see 30 miles on the street at the most.

Many Thanx in advance!

-K

 

[Craig Smith]

On a naturally aspirated race engine it would not surprise me if it was easier to tune and get it to idle and drive well without the IAC motor. I have a 388 SBC with a big single plane intake and the same 2000 cfm TB you have. I do not use the IAC provision and it idles nicely. You may have to give it a little throttle blade to fire it, MAYBE, and you may also have to goose it a little while it's stone cold. I think you'll be fine without it.

 

[KTamez]

Awesome! Thanx for the reassurance Craig.

-K

 

[TwinTurboIroc]

i dont plan to run one.....my buddies twin turbo sbf stang doesn't have one either.

Basically you have to hold the throttle open a bit when its stone cold like craig said....then once it warms u just a bit it will idle by itself

Take a bit of tuning to get it there but once its there you're done and dont have to be watching for idle counts and other stuff

 

[Craig Smith]

The fuel control capability you have with EFI vs. a carb will make it a lot easier too. You can richen it while it's cold with warmup enrichment and afterstart enrichment and that really seems to help. The IAC motor is a great thing, but engines like mine simply don't work well with IAC motors. I tune my engine in Alpha-N mode, which can really make the IAC motor a detriment. Since my tuning depends on throttle position and the IAC motor can vary the airflow without a change in throttle position, it's tricky at best to avoid idle surge and dead spots off idle. With speed/density it isn't hard but I don't make enough vacuum for speed/density to work well. The cam I am sticking in will be about 290 degrees of duration at .050 lift.

 

[TwinTurboIroc]

Originally posted by Craig Smith
The cam I am sticking in will be about 290 degrees of duration at .050 lift.

lol, you are going to have cam roll-over like my buddies cam did

what kinda motor is that going on?

 

[Craig Smith]

388 SBC (3.75 stroke, 4.060 bore), 15:1 compression, AFR 220 heads, Team G intake, Force EFI 2000 cfm throttle body. Shooting for 9.50 or better with it and I think I can do it... I hope.

 

[v8zcar]

Hmmm, this is interesting for sure.

Craig, I was waiting for your reply to my other thread on the IAC, you said something about 2 minutes of work or something? I'd still like to know, for my own knowledge.

But right now I can start the engine by just giving it some gas pedal movement and it idles fine. So I may go without it all together. Mine is a 383SBC and MiniRam2 intake with 1000cfm TB.

Thanks,
Owen