TPI in my 51 GMC

[Katrina/10]

Carburetor went bad again.

[Katrina/10]

I had this TPI I bought years ago at a swap meet. My carb kept screwing up, so I decided to install this. I didn't have a wiring harness or computer, so I went to the U pull it and got that from a 1990 Buick 3.1 V6 and reprogrammed it. I think I have less than 200 dollars in the project, and it seems to run well so far.

[Advanced Design]

Nice fix for a carb problem. Looks good!

[Katrina/10]

Thanks!

[maxdog51]

Looks great!

[Katrina/10]

Thanks, it was a fun project, and it runs much better!

[octanejunkie]

Pretty awesome! What heads are you running and what size injectors?

[Katrina/10]

Originally Posted by octanejunkie

Pretty awesome! What heads are you running and what size injectors?

The motor is an old 305 truck engine that has been in there for a very long time, so its nothing special. The heads are stock pre-85 truck, whatever that is. I think the TPI is an early IROC or Z28 (85 or 86?) so I did not have to modify the center bolt holes. The injectors are the original 305 type, so they would be 19 lb. It all works well together.

[oldman3]

Nice looking set-up...Jim

[OneOffStroker]

Nice install. I have a complete TPI in my attic that I'm waiting to install into the right truck. I have the complete harness from the IROC that it came from, and have already stripped all the stuff I won't need, so it should be pretty straight forward. Probably not as easy as the LS swap that I did to my last truck, but easy enough.

Did you have to reprogram your PROM? If so, who did it? I think I will need a slight tune on mine.

[Katrina/10]

Thanks, I tried to make it look as neat as possible. I don't know anything about LS swaps, but the wiring harness for those looks massive! This one fit through a 1/2 inch grommet in the firewall. I did the programming myself, using a prom burner I got from Moates.net, and Tunerpro to edit the program. Any of the TPI computers are programmable with this stuff, but you have to burn chips and swap them out every time you change anything. That takes some time, but once you get it right, you don't have to mess with it.

[OneOffStroker]

Are you interested in burning a chip or two for mine when I get to that point?

[oossuuu754]

Like your engine, here mine!

[Katrina/10]

Originally Posted by oossuuu754

Like your engine, here mine!

Looks familiar! I used a third gen Camaro throttle cable if you have not worked that out yet.

[oossuuu754]

Do you have AC in your truck? If so is your compressor and blower able to compensate for the external heat these TPIs throw out. I truly forgot just how much heat these engines are producing.

My compressor is old but is engaging and holding pressure, cools when you first start up but as the engine runs it just starts blowing hot and cold.

[Katrina/10]

Originally Posted by oossuuu754

Do you have AC in your truck? If so is your compressor and blower able to compensate for the external heat these TPIs throw out. I truly forgot just how much heat these engines are producing.

My compressor is old but is engaging and holding pressure, cools when you first start up but as the engine runs it just starts blowing hot and cold.

No A/C in my truck, right now I wish I had it! But, I have done other TPI conversions with factory air and had no issues if it is charged up right.

[Katrina/10]

Originally Posted by OneOffStroker

Are you interested in burning a chip or two for mine when I get to that point?

That's a possibility, it depends on which ECM you are using.

[Old Crow]

Usually the compressor cycling on and off is a sign of low Freon charge.

My motor home started doing this to me last weekend. Unfortunately, it's an old R-12 system. Gonna have to hit my friend up and see if anybody's still got some stashed.

[1project2many]

TPI is the best truck intake system Chevrolet never put on a truck. Combine it with a low end cam and you've got a real stump puller. Get some 3.08 or 2.73 rear gears with a 700R4 and you'll have a mild little cruiser that can achieve nice economy.

[2tractors]

I've got carb problems with my 283 in 33 plymouth. It's got vortec heads and roller cam with air. Runs rich even with a 650 holley and stumbles. Gonna do the swap one of these days. Good job on yours.

[Katrina/10]

Originally Posted by 1project2many

TPI is the best truck intake system Chevrolet never put on a truck. Combine it with a low end cam and you've got a real stump puller. Get some 3.08 or 2.73 rear gears with a 700R4 and you'll have a mild little cruiser that can achieve nice economy.

I totally agree with that! I've been very happy with it so far, anytime I want to drive my truck, just turn the key and take off.

[Rickysnickers]

So when does that TPI setup start running out of breath? I've been told it's around 4500 rpm, is that true?

[Katrina/10]

Yes, that's true, 4500 to 5000 is about it. If you want to make power higher than that RPM, they are not the best choice. But a great intake system for a street cruiser.

[Rickysnickers]

Ok. Is that due to the intake itself or the head design?

[1project2many]

The intake will limit power. The main factor is the small runner size which limits airflow. A smaller displacement engine will run to higher rpm, 5200 or so with a 302, while a 383 can see a peak as low as 4200. There is an aftermarket version of the TPI based on a system by Airsensors / F.I.R.S.T. which will support more power / higher rpm but they're spendy. They were offered as a standalone system with a fuel only computer and were also sold through B&M as "Superjection."




Leftover NOS from this defunct company was for sale through a website called auto-nomics but I see they've sold their inventory to first performance. There's plenty of reading on the auto-nomics site and you can view some neat installations and current offerings on the first performance site. Personally I'd use a factory GM ecm with this manifold but standalone kits are available.