TPI system

[53burb]

I have a chance to get a TPI from an '86 IROC with a 305.. Is the TPI compatible with a Comp Cams 268 in a 350?? Should the chip be replaced?? Any other input??

[neonlarry]

Which 268 cam they make at least 6? At the very least you would need a new chip at worst the vacuum will be too low for the MAF sensor to be able to set the idle.

[incoma]

You'll also need to upgrade the injectors to like a ...22lbs injector I believe.

[53burb]

I know I would need to replace the injectors. I would have to look up the specs on the cam, but I know it has a .454 lift.

[53burb]

Didn't get it.

[Russell]

Yeah, if it wasn't an EFI cam, you'd have had a lot of trouble getting it running.

I've got an XE262-H in my truck, and the TPI won't run with it. I'm pulling it out, and getting a smaller EFI version that makes power down low, instead of up higher like the 262

[53burb]

I'm still looking for a TPI. I think you mentioned before not to use an '85 TPI. Is it possible to use a TPI, and still have a large cam?? I guess not. This would be on a '69 Burb. I was planning on using headers, 3.08 gears, 26" tires, and 400 tranny. Which cam do you recommend for this??

[mocwon]

Go buy the TPI Fuel Swappers Guide. Cheap investment for anyone doing or thinking about swapping over to a TPI setup. It helped me a bunch doing my swap.

http://www.amazon.com/gp/product/188...Fencoding=UTF8

[Russell]

Actually, you can easily run a larger cam with the setup. Biggest thing is to make sure that it is designed for a fuel injection system, and has a higher numerical LSA to match. The problem you'd have with the 268 is valve overlap. The overlap allows 02 straight into the exhaust, which causes the 02 sensor to detect an extreme lean condition, and pour fuel into the engine to compensate. However, that just makes things really rich, and will make the engine run terrible. Once you get it into the higher RPMs, she'll be better, but will definitely still require a custom chip for your engine.

But, you have to keep in mind that a stock 350 with a stock TPI intake runs outta breath by 5000 rpm, at the very latest.

You can get other TPI intakes such as a super ram, or have an LT1 intake converted to fit your 350, and then run a larger cam, but you just have to remember to keep the cam matched to what the heads / intake are capable of

[neonlarry]

^ What Russell said. The best of both worlds is a TPI setup with a modified LT1 intake manifold (Look here: http://www.lt1intake.com/services.htm). It shouldn't be that hard to come by I am seeing more and more of them in the salvage yards. I would get your EFI setup first and then call around to the cam manufactures and see what they reccomend.

[Bowtie67]

Originally Posted by 53burb

I'm still looking for a TPI. I think you mentioned before not to use an '85 TPI. Is it possible to use a TPI, and still have a large cam?? I guess not. This would be on a '69 Burb. I was planning on using headers, 3.08 gears, 26" tires, and 400 tranny. Which cam do you recommend for this??

large cams and TPI's dont go together, niether does 3.08 gears. Reason, on TPI is the fact that after 5200rpm performance is nill, because the runners are to long and restricted. Now saying this is and considering what you have, the TPI is not a bad choice for your application.

Pros- with your setup, heavy vehicle, higway gears. The TPI is an excellant choice for this type of application because it has great lowend tourque capabilities.

The biggest problem you will have with factory type setups is more to be with the ECM, the ecm in some cases are not reprogramable or you have to get chips for and sometime this can run up some dollar usage because you are relying on someones tuning ability and hope he gets it done on the first try, some will offer a reprograming resonable or free. With the factory ECM the biggest issue in selection of the cam is because of vacuum, if it sees a low vacuum signal it will keep trying to compensate and will set codes, casue real eradic running, dumps fuel to compensate, also tries to adjust timing as well to compensate.
Even with aftermarket ECM's to control the fuel injection big lumpy cams are still a big chore to deal with, but you can still do it.

[aitch]

I've been looking for a TPI unit for my 383 for a while. It's low compression with a Crane 266 duration .440/.440 cam.
I plan on installing a 87 Corvette 700R4 and a F++d 9" posi/disc 3.0 rear.
I think when I ordered the cam it was listed as "not computer compatable".
Anyway, I'm totally inexperienced at this stuff and think for performance and economy, a TPI would be a good way to go.
Any comments or suggestions welcome. Leads on TPI's?
I just ordered the TPI Swappers Guide.

[53burb]

You can look on ebay, craigslist.com, or thirdgen.org. Those are the places I have been looking at.

[Russell]

One more thing to add here:

Do yourselves a favour, and don't buy a setup off ebay, or thirdgen. No matter how complete they state it is, you'll always be missing something, and it will always cost you a lot to replace those missing somethings.

Your absolute best bet is to put some money down on a good running TPI 3rd gen with a 350, swap all the EFI parts over, then put a carb onto the third gen's engine, and re-sell it.

The initial cost may be moderately high, but in the end, you'd pay far more for all the little bits and peices.

Say you spend 3000 on a good running car, then re-sell it for 2500, you're only out 500, and you have absolutely everything you need for your truck.

While I on the other hand, bought all the bits and peices, and I am nearly 1200 US into my swap

[Bowtie67]

Originally Posted by aitch

I've been looking for a TPI unit for my 383 for a while. It's low compression with a Crane 266 duration .440/.440 cam.
I plan on installing a 87 Corvette 700R4 and a F++d 9" posi/disc 3.0 rear.
I think when I ordered the cam it was listed as "not computer compatable".
Anyway, I'm totally inexperienced at this stuff and think for performance and economy, a TPI would be a good way to go.
Any comments or suggestions welcome. Leads on TPI's?
I just ordered the TPI Swappers Guide.

I have 2 different and complete EFI setups, the only peice they lack is a later model Distributor. I also have one used and one new of these Distributors. One of the EFI setups is a Holley Multiport, it has the earlier computor than what they are currently using. I actually liked it better than the Comander950 that came with the other system I have, a Holley Stealthram setup. The MPI setup has 24lb injectors and the stealth has 30lb injectors. $1000 for the MPI and $1300 for the Stealthram setup. I also have a couple of good EFI retro roller cams and one later model roller cam. The two retro cams are 1. Crower special grind for EFI has if AI remeber correctly 452/477 lift and around 269 duration LC 112, I will have to dig up the card for it, I got 22mpg with my 67 350, 700r4, & 3.73 gears. The other retro cam is a CompCams extreme 276/282 503/510lift LC 112, this ran good with my 413 and stealthram setup, cam is also good with a 383 with at least 9.5cr $200ea on the Cams. No Retro Roller Lifters they are in my 427SBC.

[Andy4639]

I have had this setup now for over 16 years and couldn't ask for a better running truck. Man it's nice jump in it in the morning crank it up and go.
When I did my swap it was far and few on here and hardly any advice was know of. Street & Performance helped me in everything I needed.
86 camero 305 HO motor completely rebuilt to stock
V-6 ferrio computer with S&P chip
700-R4 trans
4-10 rear gears
42 gallon fuel tank in back