I've got an '85 Z28 TPI 305. I want to know lots of options to make my car go faster. I'm tired of GT Mustangs beating me. Though I don't have a tremendous amount of cash. Complete header to tail pipe renovation is in the makings. Just wanted to know what else I can do! Thanks!
-Paul

 

The biggest gain would be had from porting the plenum, runners, and intake and also heads if you can afford it. Check out the tech articles for several suggestions. Of course it's usually cheaper to go to a 350 then to build up a 305.

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89 Iroc-Z LB9 305 TPI auto 2.73 posi:
3" Dynomax "cat" back,K&N filters, TB bypass, 3" pipe in place of cat, cleaned and flow-matched injectors, 180' thermo, mild ignition mods, synthetic oil, kicker sound system, soon to attempt engine swap...

 

Red,

How old is your '85? I know that sounds like a stupid question (and I know I've asked a few of those), but there was a change in the mid-year production on TPI engines. The early model year '85s had the old 8-bit processor and Delco digital MAF. The very few late TPIs that were produced got the new processor and analog MAF from Bosch. There is a little difference in the two systems, and some of what you can reasonably expect to achieve depends on the ECM and fuel system. Check the plate/decal in the drivers door liner to see what month/year the car was produced, or get the GM part number from the ECM.

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Later,
Vader
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"No matter how hard you try you can't stop us now"
Adobe Acrobat Reader 4.0

 

If you are already doing the exhuast make sure the tubing is mandrel bent crush bends will not yeild nearly as much. Get a tpi airfoil. Gut your airboxes and MAF. Use K&N filters. Get larger tube runners and a custom burned chip for all your mods and an adjustable fuel pressure regulator. You would be screaming then. The 85's cam with a decent cam so you should breathe significantly better than us "peanut cam cars".

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

 

The car could possibly have been repainted. I don't know exactly what you mean by drivers door liner. If you mean the end of the door there is nothing there. I will look for the ECM Part No. tomorrow. I know that right now I have a Bosch MAF sensor. Don't know if it's original. And my ECM is rectangular, is behind the passenger side dash, sivler, and approx 1'X5'' (just an estimate from when I had it out.)

 

ECM Numbers.

There is a large skinny silver rectanular cube, with a smaller thicker box attached.
The small Box Indicates:
Bosch
0 280 215 001
Made in Germany (078)
14080620

The large skinny box:
16052541
BARCODE
862541M522135312

Those are the numbers I've come up with.

How do I gut my maf and air boxes efficiently. I live in Washington, where it rains alot. Will gutting the air boxes let water come up into the air filters?

 

The best bang for the buck thing you can do is install a steeper ring and pinion. I don't know what axle ratio your Z came with but I went from 2.73's to 3.73's and I am very pleased with them. Best "seat of the pants" mod you can do

 

See the tech article about suggested mods for TPI thirdgens, written by Tom Keliher. Its a good place to start.

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1991 Camaro Z28
5.7L 5-Speed (originally 305)
13.25 @ 107.18 MPH
Southern California
Member: SoCal 3rd Gen F-Bodies
Webmaster: SoCal F-Bodies
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