Old tpi

[Pozest1]

I've got a 86 Z28 with a tpi on top. I heard that in 87 that they changed it a bit and made the tpi unit a bit faster. Is my info wrong?
If not what should i do to the old unit. Should i just replace chip or should i buy a new unit.

p.s. engine was original 305 but now has crate 350 in it.
just bought it couple months ago and getting bugs out before i use it often. thanks for the help

[89IROC&RS]

ok so its a TPI from an 87 305, being used on a crate 350 with pre 87 style heads??? or 87 and up heads??? first things first, youll want 350 injectors and rails, and probly the PROM chip from the ECM. now the only changes to TPI that were major that i know of, are in 89 the deleted the cold start injector, and in 90 they switched to speed density over MAF systems. but they are all pretty much the same thing. i think the Speed density systems are worth like 5hp or so from the removal of the MAF sensor in the intake track.

[Dober89]

Ya i think 85-88 tpi systems are the same.

[DaMoNe6969]

89iroc was right, there were no changes made to the TPI from 86 to 87..

What they did change in the 305's was the cam.. The 86tpi had a weaker cam at 190hp.. In 87' they added a stronger cam that was worth 25hp

[Pozest1]

I new that id have to changes the injectors, just have to crowbar open my wallet far enough for me to do that. I'll ask about the heads tomorow at a reasonable hour to the guy, (got him on speed dial). Thanks again for the very prompt help

[89IROC&RS]

no prob man, what were all here for, well, that and hounding the mods lol

[Dober89]

damone is right about the stronger cam in 87. You could still get the peanut cam with 190hp in 87, but if you ordered a manual transmission you got the better camshaft and 25 more hp.

[4onFloor]

i thought 305 and 350 both used 19lb injectors

[Pozest1]

While we are on the subject of injectors. Do you have any preference what brand. Me (not knowing squat about it, and new to the whole camaro thing entirely), I dont have any idea.

Should i just go with stock or ......

[4onFloor]

i've used ACCEL injectors, i hear holley injectors are pretty good. go with the stock rating unless you've modified the induction or displacement of your engine. i strongly urge you not to buy injectors from a parts store. i did some work for my uncle bout a month ago changing injectors in a tuned port. the mechanic that he had his problem diagnosed with was going to charge him $90 per injector!!

[Dober89]

Stock injectors work good, if you want them all fixed up send them do a place that will flow match them or whatever its called. They just test fire them and tune them so they all work at the same rate.