Meyaht

I have a poncho 455, Hyd roller, NA setup to run about 450ish HP. Im looking to go fuel injected with the goal of eventually running a single turbo. i've gotten advise from other boards here on thirdgen and so far ive established that i want to run the 749 ecm. I migh tbe mistaken but i thought it was a multi-port computer, in the other threads they were talking about it like it was TBI. (probobly because i posted it in the TBI board) Im starting to get pretty interested in TPI. I plan on achieving 1000HP+ after the turbo. i have full confidence that ill be able to mount any hardware neccesary. Im interested also in a destributorless setup. anything is possible. my main goal here is to use almost all factory/junkyard/common components. tough goal but youve gotta have goals. if the 749 can be tpi then its pretty much a sealed deal, ill probobly modify it to run low-impedence injectors. Im thinking of running the throttle body from an LT1 caprice, pretty sure its the same one as the stealth ram that we all know and love. Im running a TH-400 with transbrake, ford 9" rear with 4.11's, in an '87 formula (unless we decide it wont work then ill throw it in my first-gen firebird).

in summary, looking for cheapest way to TPI my pontiac 7.5L, and run ignition control modules, eventually turbo charged, and no need to worry about actual hardware setup in-car, i just want to get it to work on paper.

as always, any advice is helpful.

SATURN5

The 749 is capable of both TBI and MPI. Also able to run with 4/6/8 cyl.


I'm currently running a modified 749 (changed FETs, sense resistors and upgraded circuitry by adding fly wires) on a Stealth Ram SBC with SVO brown top injectors.. runs fine.. BW

gta_88_kicks

the 455 is a big block, and the tpi unit only fits sbc. You'll probably have to make ur own intake out of an edelbrock manifold by putting some injector bungs on it, and custom fabbing a plenum.

2 cents

JP84Z430HP

It would be easy to use a TBI adapter with 454 injectors to get you going. Later, with the boost, you could think about doing a port style injection, or fab up something to feed the boost into the TBI unit.... A few different options to go with.

Grumpy

With 60 PPH saturated injectors being available, there's no need to even crack open the ecm.

Read up and get as informed as you can, and the easier the transistion will be to EFI, and also going Turbo'd.

The 749 is a neat lil ecm to work with.

While it's easy to dream, about DIS, and the best available current answer is Coil Near Plug, and F.A.S.T. makes a bolt in for doing just that called eDist.

FWIW, I'm running the 60's, a 749, and have run the eDist on my lil v6, just fine.

Meyaht

Im almost positive im going to mod the 749 to run low-imped injectors, when i say im going turbo eventually, im only talking a matter of months. Im runnign a larry wenzler gutsram (google it comes right up) it already has bosses for TPI. i've already matched the throttle body to the intake on autocad so im semi-confident i can make it work. Im wrapping up the instalation of the rollcage in the 1st gen i have before i tear into this motor again so we have some time to get this all set up. so far it looks like these are the parts im gonna use

749 modded to run P+H injectors
FAST edist(in a perfect world) or something similar
LT1 caprice throttle body
3 bar MAP sensor
manifold air temp sensor
some setup still needed to get signal from trans to ecm for speed
O2 sensors (before turbo)

anybody see any conficts so far?

Dewey316

is the LT1 TB going to support 1000hp? even under boost?

IIRC the big HP turbo boys (monty, guido, ect) were all running BIG single bore TB's.

Meyaht

thats something i just kindof took for granted, i dotn even know how to look into that, i do know the feb issue of hot rod magazine had an impala SS TT running 900 HP with 26PSI. im pretty sure that was an LT1 platform.

Grumpy

Which LT1 throttle body?. The stocker for 450 is on thing, for 1,000, I dunno.
O2s need to go post turbo, if you want somewhat good info..
For the HP your looking at a WB would be advisable, again post turbo.

You Gutsram, gets all sorts of car pics, nothing with a manifold.

JP84Z430HP

Pretty nice looking intake.

Here's a link: Gutsram

Meyaht

sorry about the delay, i'm in the moving process.
you said to put a WB after the turbo, sorry to sound stupid but whats a WB? and i thought the O2 before the turbo would be more accurate, is that incorrect? also, i should heat-wrap the exhaust right? more heat= faster... right? thats the rumor but id still like some confirmation. if i dont use a LT1 throttble body, what should i use, remember, i wanna stay stock/junkyard parts. is it possible to use 2 TB's?

Grumpy

Wide Band Oxygen Sensor.

All O2 sensors are effected by EGT, and backpressure. Some more then others. Post turbo, is where you want to put it.
Pre turbo for EGTs.

No need to thermal wrap the piping, it does more harm then good. The high EGTs with the wrappings, chyrstilzes the metal until it fatiques. Ceramic coatings done right, work well.

Two TBs off a 87ish 3.8 FWD'er should do. Two of them will take you into the high HP regions, and there are resonably priced bored out ones available.
Some of the V6 Dodges have an interesting twin TB setup, but I don't know the bore diamerters.

JP84Z430HP

That would be the 3.5 used in Intrepids, concorde's, and Vision's, from 93-97. I can get a measurement later this week if it is needed.....

Meyaht

a picture would be helpful, just for some ideas, also, the lt1 TB are readily available for $35, but the TBs for the 3.8 off of something like a buick regal is consistantly around $50. would dual LT1 TB's be possible?