Tuned Port Injection Questions.

[WB72]

What is involved in this swap? Is this a difficult swap?

What vehicles are good donors?

Which heads go with the intake? Do they need modification?

What are the parts I need to look for @ a wrecker? And what will I expect to pay?

Can you use an aftermarket Cam (high lift)?

Any tips or comments are appreciated.

[botboy]

www.chevythunder.com will have a lot of the info you need. F-bodies (camaros, trans-ams, firebirds) are good donation vehicles. 85-86 intakes will require no modifications to your heads (if you have an earlier sbc), 87-on TPI vehicles require the center 2 holes to be remachined. Later model TPI is less tolerant of wear to engine and modifications than earlier as I understand it. Expect to pay $400+ for a complete system w/ECM and engine harness, more for sensors. Good luck finding one at a wrecker, your best bet would probably be on ebay.

[ckhd]

Have you looked at the aftermarket port injection systems? There are some really nice ones out there, and they can be tuned to use whatever internal parts you want. Plus, you'll be getting all new parts, instead of all used parts.

Personally, the only reason I would personally go with a used TPI system is for the looks, but I think that you can even get new FI systems that have the same runners, etc...

[72C203503ONTHETREE]

The best TPI and easiest to find that will woprk with 85 and older heads are Z28/Iroc in 85, and Vettes up to 91 or whenever they switched to the LT1. Use a 350 version to, the 305 had smaller intake ports. Any stock TPI will have low flowing intake runners so you will run out of steam at around 4,500. You will need the complete wiring harness and computer from the donor car, probably have to lengthen wires due to longer distances than a Vette or F body, unless you can get a Painless wiring kit made for trucks or with longer wiring to cut to length. You can get used TPI's fairly cheap since they are no longer the best injection set up and there are much better systems out there that will outperform a TPI. Don't know prices since I never wanted to mess with it anyway. Unless you have mass air you can't use a high lift cam, actually cant use a cam much bigger than stock unles you have a computer tuner make a chip for your engines specs, can be expensive to. Check Summit or Jegs for the aftermarket set ups like Accel, Edelbrock, and Holley has. Accel even has a full TPI style set up if you want the look of TPI. The good ones are from $2000 to $3000 though. Check into the Chevy made ramjet systems from Scoggin Dickey or Pace, they are the ones used on the ramjet crate engines. You may have to use newer style heads though(86 up). If you want to go full out racing get a Hilborn system, lol. Oh yeah, you will need to get a distributor from the donor car also. Its computer controlled and has no mechanical or vacumm advance. If you can do an intake swap and are good with wiring, its not that bad. Make sure all the sensors work good and the wiring is in great shape. If you have an automatic you will need an automatic trans version and if you have a stick you will need a manual trans version. You may get a check engine light if you dont use the trans that was in the car you took it out of since it controlled torque convertor clutch lockup. If you use your auto trans you will not be able to plug it in obviously and the light will come on. If you don't plan on high rpms then a stock TPI will be ok. It sounds like you are wanting to get some power though with the high lift cam, so make sure you don't overcam the stock TPI runners and stay close to the stock TPI cam specs. You will like the cold weather use though if you will drive it in the winter. TPI or any other fuel injection system does well at cold start up.

[WB72]

Which cam specs will I use, from the donor vehicle, or the truck?
I would like a little better than stock setup, maybe I am just dreaming that this system will work.

Will I need the complete car harness, or just the Engine harness, or the computer and harness?

[72C203503ONTHETREE]

Use the cam from the donor vehicle(or a new one with close top the same specs is the best), use the engine and computer harness from the donor vehicle(especially the computer harness) or get a Painless wiring kit designed for your truck and TPI and use the donor cars ECU. The TPI will work good but not for performance. Even in the IROC 350's, a Mustang 302 would beat it. If you want to get a lot more power out of your engine, get an aftermarket system or get a good carb set up, you will go as fast or faster with a lot less expense and difficulty.

[Faster_than_you]

87 and 88 vette and the 89 camaro have the same tpi. there also the easist to adjust to meet your demands, and the most reliable. that is what a book I read on tpi stated.

[71swb4x4]

I am working on a TPI swap now. I bought an 86 IROC for $400. That way I have absolutely all of the sensors. 87 and up have a different angle on the center bolts on the intake, so you have to modify the angle slightly so those bolts will go into older heads correctly.
If you are planning to go with more cam I would get it up and running before you swap the cam. That way you can get any bugs worked out before you modify, so if there is a problem you can isolate to the new cam.
I have used the info on the site that Botboy referenced. The wiring differences were a great help.

Shawn