Whats up everyone. New to the board. Usually hang out at MonteCarloss.com and thought I'd get some expert advice on tpi systems. So here we go.

This is what I plan on using:383ci, Holley Stealth ram manifold, Gm SD ecm and harness, and an intercooled ATI Procharger. I'd like to run around 12-14lbs of boost.

Questions:
Will the stock ecm with a custom chip handle the boost? and what mods other than the chip would I need to do if any?

What size injectors would be right for the setup?

What specific ecm should I look for?

Not SC related but I dont want to run emissions so what would I have to do to the stock harness? I'm sure I'll have to have the chip burned for that but not sure about the harness.

I like the board here, lots of useful info.
Thanks

Chris

 

The stock '90-'92 TPI ECM ('730) with the stock code ($8D) will not handle boost. However, the stock ECM with the $58 mask (Turbo Sunbird, Sy/Ty, . . .) along with a 2 bar MAP sensor will handle up to 15 psi of boost.

With the $58 mask you can use either the '727 (underhood), the '730 (underdash) or the '749 (underdash) ECM. They will all run the $58 mask.

RBob.

 

Rob, you lost me when you started talking about masks, LOL. Is the code in the chip and is there an aftermarket chip I can find?

 

it was confusing to me atfirst too.

the mask is like the name of the program.. and inside the program you can have your tables and stuff setup for your motor.

the mask or name of the program thats stock on that harness is $8D... its what my 91TPI setup has on it right now.

the computers that the programs run on are known by their GM part number.. usually the last 3 digits... mine (and yours) is a 730.


now alot of the computers are the same or similar under the case.. the typhoon and cyclone cars had a computer called the 747.. the 747 is soo similar to the 730 that you can run programs from one on the other..


well the typhoon/cyclone (TY/SY) trucks had turbos.. so the code GM put in there can handle boost and boost related functions. this program is called the $58.

the only diff between the $8D and the $58 is 7 pins or so were in diffrent spots.. so if you swapped these pins on the connector to the ECM, the $58 code will work on your 730 ECM!


so what you need to do is swap these pins, and then setup a chip file with the $58 code.. in this file you can change the table values and constants for your engine... then you burn your chip file onto a chip.. stick it in the car, and it should run.


its actually not that complicated, but the problem is learning all the info you need to get started... its like its own lil language with dollar sign this and BIN that..... but once you know what they're saying, you can re-read posts and learn the answer to any question you can think of.

 

mrdude, that helped me out quite a bit. So basically all I need is a 730 computer, chip with the $58 code, and a harness with the pins switched around for the $58 code right?

Can you program the chip yourself or would it be better to get a company to do it?

Thanks for your help :hail:
Chris

 

I suggest learn to burn. I change my whole system over from an ACCELL DFI just so I could do what I wanted with it.
I like to know what is going on and be able to troubleshoot and fix.
I hated wondering why certain areas of my drivability were suffering and some went real rich (couldn't get software to change an obsolete box program, dealing with other guys to fix small things,yada, yada, yada)
Bottom line is YOU would have control!

There is alot of reading involved to get a good working knowledge of the system, but by rewiring and reviewing the schematics you get to learn the hardware.
The basics get you interested, then you get deeper and see what can be done, Then the hook is set!
There is a wealth of info and alot of good people here that are willing to help out us newbies.
Explore your options, This is just my suggestion.



Although, Sometimes I wonder if I should've taken the other pill!

 

the better option in my opinion is to do it yourself. the inital investment is higher, mostly because of the hardware, but once you get the hang of it, you can tweek your car to perfection and then redo it if you change somthing.

the second best option (the ONLY other option to me) is to take the car to someone. this could be expencive, depending on the place. the guy will tune it for you test the car, tune it again, ect... until its right... usually they know what they're doing, and can get it running great, quick.

the other option that i do NOT advise for any boosted app, is a mail order chip. for a mild motor, or one thats been done several times (like a TBI 305 with a LT1 cam) a mail order chip is accepable. the car will run better with it... but the people making the chips are just guessing what they should be. they dont see the cars results and while some will retune for free/small charge if its off, the consequences of it being off in a boosted car is too great. lean in a TBI car, doesnt do much... lean on boost is a melted piston.


to be fair though, i have to note:
being that this is a DIY EFI website where most people here are doing it on their own, the opinions here are probly a lil bias toward the do it yourself side....

 

And the reason some of us got started in this, is, because the Pros that do chips in some cases, have few clues, and their billing practices are just short of thieft.

At one point I bought every chip available for my car. Once I got to burning my own, in a couple dozen attempts, I was doing better then any I'd bought. I guess you could call that bias, or just not liking to see people ripped off.

Having been in this for years and helping I don't know how many people, I've never heard of anyone not being able to do better then an aftermarket chip.

 

i have a 91 730 ecm and am pushing 9 lbs stock ecm and chip, idk how its workin properly but it is.... ... i just got a 383, should i switch to a syclone ecm (749?) I have no tuning or chip buring experience.

 

If you toss enough aftermarket pieces such as boost spark retard boxes and FMU's at it, anything will work, somewhat.

But the fact remains, the $8D code is boost stupid, it knows nothing above barometric pressure. So it can not help when tuning for boost. Which is what I posted. You will also note that the OP was going to run 12 - 14 psi AND wanted to use the ECM to handle the boost requirements. .... ...

RBob.