1992camarors

Ok well I'm changing directions with my car and I want a little more tuneability with my along with some good power gains. And with out doing a full engine swap to an LT1 or LS1. I plan on converting my 1992 TBI to a TPI. My main question is would it be benifical to run speed density or maf. I have heard it would be harder to hook up the maf system in my car since its not from the same year. Honestly if sd TBI is anything like sd TPI I want to stay away from it. I mean honestly is that way 99% of GM cars still use MAF sensors along with the hailed LSX engines. I be running aftermarket heads, intake, runners, TB, injectors, exhaust, cam, etc. So you guys chose for me, you know much more about tpi then I do. Maybe you could give me some insight about which year of tpi I should look for and maybe some tricks that might save me along the way.
Thanks guys,
Cory Mohr

Azrael91966669

hey cory i think i talked to you about this some time earlier in the year
speed density makes for a cleaner install and tuned will provide the most power

maf lets you do minor mods with out needing a tune as measures the exact amount of air comeing in
speed density uses the about of manifold pressure to figure out how much is comeing in from preset values

but with 3.73 gears tpi will run out of steam pretty fast mite want to look into an aftermarket setup like super ram or steath ram for what your going for
or even getting a converted lt-1 intake

1992camarors

Hey Azrael91966669, how are you doing? Well I just noticed you got your swap done, as I was reading thorugh it in the TBI section. Ok first questions how did you do your wiring harness? And did you use MAF or SD. I am going to use SD because it would be some much easier. And I will be able to use a lot of my original stuff. I was reading on how to repin a 730ecm to be compatible with the TPI SD. I'm still not sure what car to find a 730 ecm in though. I also can get a 1985 TPI MAF wiring harness from my friend, I'm not sure this would help or not? Like what all would I have to connect off the tpi wiring harness to the TBI harness, I know how to do the injectors. Also does the 730 ecm use the same connectors to it as the orignal TBI ecm. I believe I understand repining which means changing the order of of wires in the bulk connecters? Also I am able to purchase a 1989 TPI MAf system for about $200.00. Now how would I convert the actually TPI to be compatible with TPI SD. Well if I'm missing anything please share.

shocker89bird

Look into the cost of this including harness and computer and everything and write everything down, sensors including mass airflow burn of and so on. You might want to take a look at the sticky on tpi to obdII and consider going that way. Just a suggestion. this way you can switch to a better breathing intake and have the tuning capabilities to go with it.

Mongoose

iTrader: (2)

I used an '89 TPI with a '91 ECM and harness. There's no real "converting" the actual TPI with the exception of adding an extra vacuum port to the plenum in my case.I also kept the MAP sensor on the firewall bracket just as with the TBI. The 7730 ECMs can be found in any '90-'92 TPI F body. Be sure to get the TPI harness from another Camaro as there are a few differences from the Firebirds such as the secondary fan, main power hookups and the evap canister which swap sides from Firebird to Camaro.

1992camarors

Ok thanks a lol guys it all seems to be comming together in my mind clearly now. I know during this swap I might have questions and I will defiantly look to guys for support and knowledge. Also last thing I am still in doubt about my wiring harness and what to do with it once I get my 1985 Camaro Z28 TPI harness. I pretty much get everything except the repinning thing, please comebody make this easier for me to understand. I feel somewhat dumb but basically I just don't want to make any mistake or shortcuts along the way.
Thanks

Azrael91966669

my biggest issuses was extending the wires for the ecm and fan power
and the evap as i used a firebird harness

also my speedo didnt work untill i did some cutting and patching with my stock dash harness 3 wires that go to the vss buffer as the tpi ecm dosnt use a vss buffer so i had to directly connect those to the engine harness

but an 85 harness mite give you some more trouble
you well end up needing 2 seperat service manuals to figure out what wires do the same things repinning isnt as hard as it sounds
as long has you figure out what wires do what and where they need to go

and mistakes will be made i know made a few even being as carefull as possible

like swaping the fan switch with the knock sensor or my fan wireing a problem that ended up because i thought had used normal wire but used a fusible link that blew 1st time they tried to turn on lol took me a full day to figure that out as it blew where you couldnt see it lol

i made sure to get a speed density harness as i wanted it to be an almost direct swap and it was other then the minor issus i listed

i ended up with a much faster car as a result

Pat Hall

iTrader: (31)

Wheter you decide to run MAF or SD, you don't want to mess with that 85 harness either way. The 85 MAF TPI system is a one year deal. It used the 870 ecm, which makes even the 165 ecm look like a super computer in comparison. It also used a piggyback harness to control the MAF sensor. Even if you're repinning to SD, it'd probably be a major task to repin the 85 harness, if it's even possible. There's a tech article from Anesthes on here somewhere on how to repin the TBI harness to SD TPI. It's cheap and fairly simple to do. If you decide you don't want to attempt repinning yourself, there's two sponsors here on the site that do it for a fair price. EFI Live and TPI parts.net.

Mongoose

iTrader: (2)

I'd just locate the correct 90-92 harness and 7730 ECM and save the hassle.

BMmonteSS

If you're goal is tunability you may want to consider staying with TBI.....just hear me out as I'm well aware that I'm the TPI board.

Ignoring the physical differences between TPI and TBI lets look at the ECM's. The stock 746' ecm that's in your car now is a bit lacking, although it is one of the few ecm's that's completely understood. So in reality it's probably one of the most "tunable" ecm's out there. That doesn't mean it's the easiest and it most deffinately isn't the best ECM GM ever made.

The 730 TPI SD ecm is one of the most popular and has a lot of features the TBI ecm doesn't have. Once of the nicest is a couple of rather comprehensive VE tables where the TBI uses a funky adder table that's hard to understand.

The ultimate DIY tuning ECM available right now is the old 746/747 tbi ecm with Rbob's new EBL system. This system fixes the slow logging rate and uses Rbob's ultimate TBI code, he also recently added MPI features which means it will run any multi port setup you connect it to. This setup has lots of features that no stock ECM has like rpm limiters, extended VE curves, idle tables that are specialized for big cams, and one of neatest features is WB afr sensor support with an autotune feature. What this does is takes your WB signal and actually tunes your fuel curves for you. This is great stuff that you had to go to a $2000 ecm to get in the past.

This is right up your alley no matter what induction setup you get because you can continue to use your ecm, wiring harness and bolt whatever you want on top of the heads. All you would have to do for a MPI setup is splice in 8 injector plugs where you have two now.

Now I'll make my plug for TBI, with a cheap 454 tb off of ebay for 100$ and a better flowing carb intake you can support up over 425 HP pretty easily. You'll be hard pressed to get a complete stock TPI setup for the same cost and will require hundreds of dollars in upgrades to reach 400 hp. If you want to go MPI I would most deffinately look to the stealth ram or converted LT1 intake and save yourself the trouble.

Hope this helps.

Pat Hall

iTrader: (31)

Since he was already talking about repinning, I figured I'd make some suggestions pertaining to that. I totally agree with Mongoose though. It's much easier to just get the right harness and ecm to begin with. I trolled the classifieds enough times that I now have a complete 165/MAF setup, and a 730/SD setup too, so I'm set no matter which one I decide to use. Plug and play is always better for a simpleton such as myself.