Hello, I do not get to post much but need some help.

I have done several MODS to my cars without getting the results I had hoped for.

1989 IROC-Z 350 TPI with AC

Upgrades:



-SLP runner siamesed to the upper plenum, bored out lower intake.

-Bored throttle body

-Accell injectors

-Fuel pressure regulator

-Magnaflow 3 inch exhaust system

-Upgraded 3.70 rear end gears with new series 3 carrier (from stock 2.77)

-Transmission has been upgraded with shift kit and shift point adjustment/Tranny cooler

-ECU flashed by PCM for less for 93 octane

-MSD coil/cap/wires

-Most of the free MODS done.

The cars fastest times are 14.6 at 94mph. I expected more considering that to be a stockish time.

I do plan on installing headers will that get me where I need to be? Is it just being bottle necked.

It also likes to get hot but i have read and am thinking about putting a 3 core radiator in it.

I was hoping for low 14's out of the car with out tearing apart the engine.

HELP any suggestions.

 

You have increased the amount of air coming in, the amount of fuel coming in, after the headers, you'd probably want to get it tuned. A custom/burned chip will make a huge difference.
I know people who have picked up an extra 30-50 horse just by getting their tune down better. Granted this was on an LS1, but the same basic principles apply.

 

what size injectors did you put in?

 

Thats not SO bad. In perfect tune my stock 89 iroc with 2.77s ran 14.8's. I think with your combo you should be able to hit a 14.3. I think you are in need of some headers, an aftermartet intake manifold, 2800 stall, and some sort of aftermarket chip. I think those mods would get you 13.7's if not better. Also those 3.73 gears are a bit much and MAY actually be hurting you. I have found that anything over 3.45's for TPI with the stock cam is overkill.

 

my friend had an iroc and wanted to get in the 13s so i told him a decent set of headers ..373 gears and 125 shot of nos..whch if installed properly will not hurt the stock motor...guess what 13.3 on street tires ..it works..all those other bolt ons ..they are expensive and dont make up for the nos..

 

yep, thats one thing i forgot. TPI motors dont like the low gears.

 

Thanks, anyone in the upstate NY area that tunes third gens? I know I heard about the 3.70's maybe being high but, I could not find the 3.45's anywhere. I think the stock injectors are 19lbs the accells are 21lb

 

Stock 305 injectors are 19 lb/hr.

Stock 350 injectors are 22 lb/hr.

If you got 21 lb/hr Accels, you downgraded.

 

How is your reaction time? May not be the car?

 

RT doesn't affect ET. The ET timer starts when your tires clear the staged beam, and stops when your tires break the finish line beam.

 

If that the case on the injectors, I could not remember they are 24lbs

Yeah Reaction time is nothing. I am around 550-700. The MPH never gets any faster lol which is what I need to get that faster time