90RS383

I'm getting ready to buy a 90 RS 305 TBI car and want to swap it for a 383 stroker TPI car. Has anyone done this and what problems are normal? What should I expect?

89IrocZ350TPI

With a 383 you may not want tpi. You will be better off with a better intake.

b's90cam

Well, i plan on building a 383, trickflow headed, tpi witha edelbrock hi-flo base, slp runners, and a ported plenum. As long as you take the time to port everything out real well it'll be a great street motor. There are plenty of people running 12's with the 350 setup like this. I plan on running high 11's, and having massive torque and good mpg. Now if it's a pure drag motor and you don't have to worry about smog, stealth ram will probably be the best bet.

89IrocZ350TPI

Oh if its for the streets tpi will be fine. Should be in the 12's.

b's90cam

There is a tech article on it also.

jmiller

I just finished a TBI to TPI swap in my 91' Chevy truck. I used a 87-89 TPI ECM with MAF and a painless wire harness. I also changed all sensors and relays to TPI. I prefere MAF TPI systems over speed density, but that's just my preference.
Change out the fuel pump in the tank to a high pressure pump.
What a difference it made!!!! No hesitation or bog!!!!!
Cruises easily on the freeway at 75mph all 6500 LBs!!! I am so happy with the change!!! TPI should have been in this truck from the factory!!!
I now have 3 vehicles with TPI: my 87' IROC, 67' Camaro, and now my truck.

90RS383

Well, Ive been planning on running the 383 tpi with edelbrock e-tec 200 heads and a good size cam, but ive been doing a little research and found the edelbrock # 60859 heads would probably be just as good and a whole lot easier on my wallet. The tpi base plate should bolt right up with out problems or mods needed to the heads or intake. What do you guys think??

jmiller

I've got a 383 in my 87' IROC, got it running 3 years ago. Went with AFR 190 heads, ZZ9 cam, and TPIS big mouth. Fun car to drive. Exceleration at over 80 mph is incredable. Don't really care about drag racing, but with street tires it ran a 13.23 at 106mph. I was happy considering I have 3.27 rear gears and a 700R4 trans. And it passes CALIFORNIA smog! I stayed with MAF in this car too. No chip tuning required.
I don't know how much money Edelbrock gets for their heads, I paid $1295 for the AFRs. At the time I built the motor I had money, now I don't, so I would probably look at other brand heads as well.

90RS383

well before i do anything with the motor im going to put in moser axles, c-clip eliminators, a 3.73 posi, subframe connectors, and traction bars. i dont want to build a good motor, and not be able to put the power to the ground.

b's90cam

I'd run trick flow heads. They are great out of the box, not too harsh on the pocketbook and can flow up to as much as the afr heads.

sgt0704

i know this is beating a dead horse, but i am looking to do a tpi swap from tbi. is the bull **** of putting everything together worth the gains. or would it be better to just take the 305tbi to a 335 stroker? or maybe stroker and tpi.. just wondering if getting the parts from a donor car at the boneyard would be more trouble than it's worth.

90RS383

you should probably find all the pieces from the same car that way you know everything is from the same year model and will all work right

b's90cam

Well, tbi really takes a lot of work to make any performance. The swap over to tpi opens up a lot of options to what you can do with your engine. If you're gonna make a stroker engine or put any kind of money into your tbi, it would be better off to swap over to tpi. It also is a lot more tunable that the tbi system to really dial in to your setup. Tbi can be tuned, but it takes lots of know how. Also, if you're gonna put money into a stroker, it probably better worth it to just get a 350 unless you're out there to prove something with the 305. If you just want a few extra horses from your tbi system, do exhaust and the ultimate tbi mods before going further. If you're lookng for real power, build a 350+ tpi motor and don't look back.

sgt0704

DOES ANY ONE HAVE ANY NUMBERS FROM A DYNO? BEFORE AND AFTER? IT'S NOT THAT I HAVE SOMETHING TO PROVE WITH THE TBI, IT'S JUST BUDGET. AND INSTEAD OF SWAPING THE WHOLE ENGINE, WHAT WOULD I HAVE TO DO TO PUT THE 305 TO A 350 OR SO. IT'S BEEN BORED 30 OVER. AND I'M LOOKING TO GET A 400 CRANK AND 5.7 RODS. NOT SURE ABOUT THE CAM. DON'T REALLY KNOW ANYTHING ABOUT CAMS. WAS GETTING SOME ADVICE FROM FAST355. I KNOW HEADS ARE A DEFINATE CHANGE, BUT WOULD STOCK 350 HEADS WORK? OR MAYBE JUST ORDER SOME FROM SUMMIT? I'M NOT TOO KNOWLEDGEABLE ON THE WHOLE INTERNALS OF THE ENGINE. AND WHAT WOULD BE AFFORDABLE, AND ALSO POWERFUL. IF THERE IS SUCH A THING. JUST SOMETHING THAT CAN BE A SOMETIMES DAILY DRIVER, BUT SMOKE THE NEAREST ****STANG.

Kevin91Z

iTrader: (1)

Whoa, turn off the caps lock. Do a search for posts by me or my dad Dyno Don on swapping from TBI to TPI. We converted his old 92 RS from TBI to TPI keeping everything stock including the heads and cam. The only mod was a stock 350 TPI cat-back which by the way gained 8 HP and 20 TQ with TBI. With TBI, the engine made 158 HP and 220 TQ to the wheels. With TPI, it made 175 HP and 290 TQ to the wheels. Then we swapped to an LT1 cam with TPI and gained another 12 HP to make 187 but the same TQ.
DO NOT MAKE A 334 STROKER! DO NOT MAKE A 334 STROKER!
Stroking a 305 is like polishing a turd. You've spent a ton of money (more than buying a 350) and you're still slow and the engine is under a lot of friction and stress from the huge stroke and a small bore.

CAMAROJOKESTER

iTrader: (4)

I ALSO HAVE A QUESTON. HOW DO I SEPERATE THE TBI WIRING HARNESS FROM THE REST OF THE HARNESS THAT RUNS THE LIGHTS AND WHAT NOT.. I HAVE A HARNESS FOR MY TPI. BUT I JUST NEED TO SEPERATE THE WIRES THAT I NEED SO I CAN PUT MY HARNESS IN. THANKS

jmiller

I did not remove the original TBI harness, I simply unplugged all TBI related connections including the ECM and left them in my truck. I pulled the wires back and stuffed them under the dash and behind the firewall. I have way more room in my truck to do this than you have in your camaro though. Some day I'll seperate them form the original harness and remove them. This approach worked fine for me.

8Mike9

You don't have to swap the harness if going SD:

https://www.thirdgen.org/forums/tpi/...?highlight=746

BKbandit

I got a 350 crate and im lookin to fuel inject it and was thinkin of runin a tpi system. I was in the shop today and was checkin out this 77 vette with a crate injected with the tpi, how much would a trip like this cost me to hook up the whole nine to my crate.

90RS383

I would shop around and see if anyone you know has a tpi setup. One of the guys that I work with had one complete that I bought for 800. The only thing I needed was a block.

BKbandit

they got all kinds of crazy computer chips, what would be the best thing to go with mass air flow? Whats my dollars and cents bill goin to look like after im all hooked up. I get vortec heads will it fit?

bigmaciroc

im wanting to swap my tpi to a tbi, maybe we could help eachother...?

BKbandit

Isnt tbi the a carb? Y would u switch back? I want to get fuel injected because i live in nyc. U can burn a quarter tank of gas just warmin up that carb up. If it was warm all year here i would leave my carb, maybe even try to run a dual carb setup. I love that sound these carbs make. Plus i hate computers, they can be great or the biggest pain in the *** ever. I just dont noe if the tpi would fit my vortec heads. My crate is supposed to run 330 horse straight out the box so wit a good fuel injection system i could prob get 360 . I wish i could just rip it off my friends 91 vette but that wont make him too happy. A shop by me has a 79 vette with a crate with a tpi hooked up, guy told me if i get a good one from a swapp meet the whole trip would cost like 800 900 hunder to hook up. I dont really like those guys and would rather get info from here. Mac are u in the tri state area?

Any one live in long island, every here of a shop called mean street?(this is not the shop with the vette)

bigmaciroc

no, im in dallas, thats why i want tbi, my rs seems to run really good, so i want it on my iroc.

90RS383

check out edelbrock. they have a tpi lower intake made specifically for vortec or vortec style heads. in fact, if i were you, id get the intake for vortec heads, the high flow runners and at least the e-tec 170 heads. if it were me, id run the e-tec 200 heads. they are all meant to work together.but if thats not what you want, then youll just have to do some lookin.

Kevin91Z

iTrader: (1)

Edelbrock makes the Vortec TPI intake for Scoggin Dickey, but SD sells it cheaper: Scoggin Dickey at Sdpc2000: Performance Parts, Racing Engines, Racing Engine Parts, Race Engines, Race Engine Parts - SDPC Those are the only two places I know of to get the Vortec TPI intake.

Hey, a V6 would run really good too, why dont you put one of those in your IROC? No wait, put a Honda 1.8L VTEC in there, those run really great!

BKbandit

So i cant just take the tpi off a 5.7 and bolt it on? What would i need to get that tpi on, just a different manifold? I have a edelbrock under there already. I hope i dont have to get any crazy mods done. So a different manifold should be all i need to hook up a tpi to my engine.

I couldnt even find it on the site , i must be real tired or just blind.

90RS383

TPI Vortec Lower Intake Baseplate :: 12498060 - SDPC

There you go. now you dont have to search for it.

BKbandit

So one of these under the tpi will work, i dont have to change nothin? I took a peak through ebay, would it by a good idea to get it off there. R these system hard to hook up urself, should i get the book "tpi swappers guide"? So i get this vortec intake with the intake housein and runners, fuel rail and injectors and which computer sensor do i need. Im goin to hav to do it myself cause the funds are low. I could prob get a couple bucks towards my tpi system with my edelbrock manifold and carb. I just want every thing to work and then its party time

P.S. Thanks for findin the manifold for me.

Fast92RS

iTrader: (2)

If you do you TPI swap. I recomend contacting TPIparts.net and letting them take your TBI harness and converting it to a Speed density TPI harness its pretty cheap and worth every penny. They did a great job on mine. I did a swap in my 92 RS. I had only slight problems but not because of the harness but because I forgot to hook a connector up and had a vacuumn leak because of forgetting to torque the throttle body down. Once I figured it out I had a great running engine with out all the hastle of getting a seperate harness and trying to marry it to the original one. All you have to do is remove your entire harness and you do not have to cut anything and send it to TPIparts.net. They clean your harness up and remove the TBI specific items and add the TPI items and send it back to you.