TPI on my 78

[tscott9330]

Alright cac. If I can get a tuned port injection off an old corvette or firebird or something what should I make sure I get with the deal? And secondly will it be able to give me the 400hp and ft/lbs I want in my 1978 383 stroker? or should i just pay the extra cash for a aftermarket system?


I'm a little lost here so If you all will give me as much info as is possible I would appreciate it.

Also will i need to upgrade the stock computer?

Tom Scott

 

[MaineShark]

When I was looking into this, I think the consensus was that the stock intake wouldn't work with a larger engine, without modification.

And, that modifying it to breathe would cost more than buying an aftermarket system that would work, right out of the box.

Joe

 

[tscott9330]

Well i guess my question to this is, which price of which aftermarket system you are comparing to? I know edelbrock sell a very nice pro flo efi system but it runs almost 2000 dollars.

I've not really seen a whole lot of sources for this kind of application.

Tom Scott

P.s. I dont really want an aftermarket TBI set up.

 

[MaineShark]

I think that was the sort of aftermarket system being discussed.

The TPI install, for a stock system, is going to run around $1000, once you figure the system itself, the fuel pump, the wiring, possible changes to the fan/shroud assembly, etc.

So a $2000 system really isn't that much more. A modified stock TPI is going to run more than that, from what I've seen.

Personally, much as I like EFI, I'm sticking with a carb for now. Eventually I'd like to get EFI in my car, but the stock run-out-of-air-at-5500-on-a-350 system is going to tolerate larger-displacement engines (383, 406) all that well, without major modification.

I'd say get the engine built. Get the Q-Jet tuned well. Then save up for a while, before going with the fuel injection.

Joe

 

[patsnitrovette]

Me personally if you could get the tpis setup wioth harness and computer and sensors,then buy a super ram set up and youll getyour high rpms out of it.

 

[bossvette]

I built a 383 TPI 3 years ago and If I had it to do over I would just plop the cash for a Holley Stealthnram system. I ended up buying three units off ebay to get the combination of parts I wanted and still had to buy bigger injectors and throttle body
@$500 and the programable electronics @$1000. I don't know about hood clearance on the stealth ram I read somewhere they wont clear a c-4. Corvette fuel rails the fittings/lines are on pass side camaro/firebird are on drivers side corvette uses big cap distributer and engine compartment mounted computer while camaro/firebird uses small cap and interior mounted computer
other then that units are basically the same I still have 2+ units sitting around if you are interested, but no corvette fuel rails

 

[KANE]

You can get to 400 HP with a mini-ram and VORTEC heads. Use the right cam, rockers, CPU program, compression ratio, etc.

Maybe using outsized runners, a matched plenum and a matched base plate.... you can get close. Maybe 350.

I am running about 300 with a slightly modified set up. Injectors, programming, airfoil, lower intake temperatures and a few other little odds and ends.

Your most restrictive parts are the size of the runners. They are tiny. Couple that to the small manifold ports and you lose out on power. Great low end but limited top end. You can only make power with what you take into the cylynders and at what speed. A larger throttle body, siamesed runners, and some porting will reduce these obstacles.

Good luck!

 

[KANE]

Oh, modify your fuel rail for AN fittings. You can use ANY TPI (Corvette / Camaro) to do this.

Fuel leaks are disasterous!!!

 

[wichitacorvette]

My tuned port system i bought on ebay for 250$ for everything but wiring and ecm. then i went to affordable efi www.affordable-efi.com to get my ecm and custom made harness. i spent 700$ through them which seems like alot but they will reprogram my chip indefinately if i ever change anything to my motor. the motor dyno'd at 353hp at the wheels which is about 420 at the crank. (or so the computer told). not bad from an efi. I love beating my neighbors 70 TA built 409 the side pipes helped the flow of the system and the extra 170$ spent for a 52mm throttle body was definatley needed to accomodate the cam. with your 383 you should be able to take on quite a bit of cars otu there if its done right. hey its my first motor build ever, and i'm beating new vettes easy. (and a year ago last january i was had a shop change my alternator because i didnt know how!) Do youre homework and youll come out fine.

oh and the stealth ram fits more than fine under my hood, itll be on after i finish making my fuel rails......

 

[KANE]

I prefer the aftermarket harnesses out there. Its like a buffet... you choose what functions you want to use. They are easy to install and come with their own wiring schematics.

I have a lot of info on my website. Email me if you want any specifics.

Plan to spend at least $800 for a ground up install.

 

[wichitacorvette]

I agree with shark, the custom harness is a must. trying to piece together a factory one is impossible.