I am swapping out my TPI 305 for a 383. I am using my TPI intake on the engine to start out.( I can't afford the miniram just yet.) Here is the rundown on what I am doing. I am using World Products 64cc heads. I am using an edelbrock 52mm throttle body and I am having the TPI ported and port matched to the heads. I am running the Walbro 255lph pump into the hypertech AFP regulator and 30# injectors. I am running the exhaust through the SLP 1 3\4 inch headers. I was under the impression that the stock computer would work with the new motor. As far as I know all I had to change out was the ESC and the Knock sensor. I am using the Hypertech thermomaster chip and the Accel digital ignition and supercoil. Am I on the right track? Did I leave anything out? If I have just spent 3weeks planning this out for nothing I'm gonna be real pissed!

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1989 GTA TRANS AM
305 TPI, 5 SPD
SWAPPING TO TPI 350 NEXT MONTH.

 

I.......huh, could use a little help here.

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1989 GTA TRANS AM
305 TPI, 5 SPD
SWAPPING TO TPI 350 NEXT MONTH.

 

My EFI knowledge is limited to this IROC project I'm doing now. However, I can tell you I'm running 24# injectors with the 305 chip and the car runs really rich,, mainly at idle. I would think a Hypertech thermochip,, if for a 305 would be little to no help,, if not worse. Anyway,, I'm sure with the 30# injectors,, unless the chip is calibrated for 30# injectors,, you'll run way rich,, especially at idle. Everything should work - how well will depend on the cam selection and whether or not the chip is calibrated for the 30# injectors. I can only speak on my experiences so far - hopefully someone more knowledgeable than me about EFI / programming will be able to help more!!

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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

 

You HAVE to have a custom chip made to use those injectors. If you dont, its going to drown that poor engine in fuel, and it wont run worth a damn. Forget adjusting the AFPR (its not gonna make it) or that chip, which will just make matters worse (I have one, they run rich). As for the TPI itself, sounds like you are sticking with the stock manifold for now. Sometime in early-mid January I am going to be doing some dyno testing and hopefully I will have some good news for those of us who dont want to shell out the big bucks for aftermarket parts. At this point I am not making any promises, but from my initial testing it looks good. Definitely get or learn how to burn a chip, cant run that setup without one. And just my initial impressions without knowing the cam profile or how much you are going to mess with the heads, the 30# might be too much.

 

Max.......would you suggest 24lbs injectors instead? If I got the AFPR couldn't I turn down the pressure to keep it from funning rich? I have never had any experience with burning chips and this is my daily ride, Who burns a good chip? I have about $170 budgeted for a chip. Also the cam is a custom grind by Lunati. I will call the machinist tomoroww and get the numbers for you. The heads are the World products cast iron heads. they have a 64cc fst burn chamber and am told they will flow around 200cfm(don't hold me to that I will have to talk to the machinist.)right out of the box. They said that with the stock TPI I won't need alot of head work. The only porting is to have the intake portmatched and then port matched to the heads.
Thanks
Robert

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1989 GTA TRANS AM
305 TPI, 5 SPD
SWAPPING TO TPI 350 NEXT MONTH.

[This message has been edited by GTARob (edited November 28, 2000).]

 

The only way to get your combo right is tuning, meaning different chips. Might start reading in the Prom area.

 

So then it will work with the 30# injectors, as long as I burn or have burned a chip custom taylored to my engine? Which would be better, the 24# or the 30#? Thanks for all the help, BTW



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1989 GTA TRANS AM
305 TPI, 5 SPD
SWAPPING TO TPI 350 NEXT MONTH.

 

24lbs are much easier to tune. You only need the 30lbs if you're running boost or nitrous with a DFI computer.

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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=-

 

I agree with Kevin and the 24's. You'll be able to use a higher fuel pressure and get a better spray pattern than turning down the pressure on 30's.

 

Thanks guys! I learned something and saved 20 bones in the process.

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1989 GTA TRANS AM
305 TPI, 5 SPD
SWAPPING TO TPI 350 NEXT MONTH.