yeah..this is my problem... I doubt my stock ECM will take 400 cubes, so i'm looking at buying a 5.7 litre ECM.. i already have 30lb/hr injectors, got them from Summit... i'll be buying my 400sbc this Christmas (Merry Christmas to ME!) and will put be putting double hump heads on it.. here are my questions:

1-Will my stock ECM take the bigger displacement?
2-Will ANY stock (305 or 350) ECM take those cubes?
3-Will those ECMs be able to handle the larger fuel injectors?
4-Will I have to have a custom PROM burned?
5-Will I have any problems trying to get any PROM to run half decent with a semi-wild camshaft? I'll be going roller, I'm not too hot on flat tappet..

thanks a ton for the help guys

Sincerely,
Colin Opseth
Webmaster: www.IROC-Z.org

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Webmaster: www.IROC-Z.org

 

What year is your car? I think you have an 87 TPI, right? It uses a 7165 MAF computer, and both 305 and 350 TPI use the same computer. However they have different PROMs. You'll definitely need a custom PROM to make the engine work to its greatest potential. And if you need an engine builder/installer, email me. My dad is awesome. We're just south of you in Orange County.

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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
-=ICON Motorsports=-

 

hey Kevin.. it's actually for my '86 IROC whippeee i get to use my old intake without any mods (until i get my new intake)...

do you know of anyone that could burn me a new PROM? I dont have the tools to do it, and i'm kinda broke so whoever could hook me up for a good deal would be my homie

i'll be doing the motor myself... this will be the first project that i tackle with little or no help from my Dad... after doing the motor in my '87 mostly myself i think i can do it... i think i can i think i can...

we should get together sometime and shoot the **** man... cool?

anyways... back to business... my '86 IROC really is toasted... all the way down to the oily plugs will i be able to run my 400 on the 305 ECM until i get a new PROM burned? i'll be running 30lb/hr injectors... will that give me any problems? any problems with other sensors?

thanks manG

 

hey Kevin, you should have your car up on my site! gimme a call though if you want, 661-252-1707

i'll be working until tomorrow evening, but anytime then is cool, or in the evenings during the week..

ttyl

Colin
Webmaster: www.IROC-Z.org !!

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Webmaster: www.IROC-Z.org

 

Based on my experiences running 24# injectors on a pretty hot 355,, and running the 305 chip,,, since I was running way rich at idle (a little rich at WOT),, I'd think you would be major rich at idle with the 30# injectors,, especially if your intake and runners are stock. I fought doing the custom prom route,, but it looks like it's not an option,, but a must for us 86 "305 folks".

Oh,, what ever chip you do break down and buy (when you do) - - Do not buy a Jet. Their custom stuff (based on my experience with them) is a $500 nugget of crap - the stock 305 chip ran better.

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86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 2.5" Dynomax, TH350, 2200 stall, B&M Megashifter, 3.23 peg leg, 245/45ZR17s on 212 Eagles

[This message has been edited by BadSS (edited November 26, 2000).]

 

BadSS, for the first while i'll be running the stock TPI... i'm going to get a plenum and port the crap out of it, and later get some large tube runners and an Accel intake... i'm expecting with my '305' to really be running lean around 4000rpm even with the ported setup, am I out to lunch? should i just get the 24lb injectors and crank up the fuel pressure a few psi?

 

I'm not calling you, you're long distance! Email me. I'm on AIM and ICQ too.

There is no way in hell the stock 305 chip will make a 400 CI engine run worth a damn, especially with 30lb injectors. It'll run too rich. But it might just work well enough to move the car from your garage to the street, if you're damn lucky.

Porting the plenum wont help you a whole lot, you need the port the intake manifold. And your heads, and everything else to match everything up.

 

kevin... 8986743

 

Hey,, Kevin is right that 305 chip will run terrible - like I said,, it'll run rich!! I was not even remotely suggesting running the 305 chip,,, just emphasizing how messed up JET was with the custom chip they did for my car!!!! I sure wouldn't buy another set of injectors if I were you,,, since you have the 30# injectors,, the custom chip can be "burned" for them.

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86 IROC - 9.8:1 - 355, TFS twisted wedge heads, 218/228-110, fully ported GM base and plenum, SLP runners, 52mm BBK, 24# SVO, 1 5/8" Headman headers, 2.5" Dynomax, TH350, 2200 stall, B&M Megashifter, 3.23 peg leg, 245/45ZR17s on 212 Eagles

 

thanks for the help guys, i'll post back later when i get my motor...

i'll junk the PROM right away and get at the very least a L98 PROM.. atleast then it would have a fart's chance in hell of running half decent...

the MAFs would be the same, correct? only difference is the knock sensor?