Hi guys, I was just referred to you when I came up with a question. I have an 85 Iroc/z28 with the TPI305/700R4 and am ready to change it up over the winter. I just built a 327(will also be a manual swap in teh future) that was formerly in a corvette and wondered what all would be necessary to keep my TPI setup. I originally planned on a carb setup but wanted to know if it was feasible, monetarily, to keep my tpi. I know I will need upgraded injectors and such but what about the computer. Would the L98 type computer work or what type of custom work would I need done. IF it is too much of a hassle my tried a true holley is always there. Any help would be great, thanks.

 

Why the desire to keep the TPI? For performance purposes you are way better off with the carb. Of course, up there in MI its probably nice to have the FI in the winter time. However, if this engine was rebuilt for performance, TPI will hinder probably. What are the specs on the engine?

 

Well my main reason to keep the TPI was the tuning properties, the ease in which it adapts to our quick change climate and the extra mpg it offers. I don't drive it in the winter, for that I have my trusty Geo Tracker, so its not toooo important. My original plan was the Edelbrock Performer RPM AirGap to keep up with the revs of the engine but just wondered if the TPI was possible.

The Engine was built to a fairly stout specs.
-10:1 CR
-Crane Xtreme Energy XR270HR cam
-Lunati Street Race Rods (got brand new from a trade)
-Stock 2.02/1.60 Heads w/ porting (Looking for possible AFR's)
-Crane Pro Magnum Roller Rockers
-Crane Valve Springs
-Edelbrock RPM AirGap
-Holley 600cfm
-MSD Ignition System

I was looking to build a 400hp NA motor which it surpasses on pump gas that would spin to near 7,000 no problem and that I have done. Now a small 100shot from the Sniper kit through the (hopefully) upcoming T56 and it will be all set

 

you want this motor to spin high rpms ~7000. you will never do this with TPI. if you want to keep fuel injection, go with a stealth ram, mini ram, or super ram depending on your exact powerband and the money you want to spend

 

That was what I figured, I heard the TPI kind of kills anything above 5500 but didn't know if there were a way to cure it. Like I said I am mainly a carb kind of guy but though I would give this a shot. The Mini/stealth/superram are all way to expensive for my blood I am building this car on a budget. All in all I am still just over the $2000 mark INCLUDING the price of the car. My goal is mid 12's without breaking $3000 just because I think it is possible. And this will stay a "sleeper" just because I'm very particular about not having a gawdy car and I want to drive it without the extra attention. But also it will have the go to put the pimp hand down when someone gets dumb. And if its not enough I'll bring out my 406 RX7 for them to play with (10.30 ALL day in street trim)

 

since budget is a concern, you could get some SLP runners for like 250 (thats from them, maybe cheaper on ebay or classifieds) and port the stock base. that would increase the RPM potential somewhat

 

It would be a horrible shame to put TPI on top of that engine, even with mods. An aftermarket setup, like the HSR maybe, but not TPI.

 

yeah thats basically waht i was saying. i mean the porting and new runners would help a little, but its still just a waste and would restrict it terribly

 

Get an LT4 intake... much better design and pretty cheap too.

 

LT1 intake. Works nicer in terms of port compatability.

 

the good: sure you can keep the TPI

the bad: you will have to have a new computer chip burned

the ugly: your gonna have to get a cam thats computer friendly

~Nick~