[123pugsy]

I have a 350ci that I probably will be getting bored over to 060.Crankshaft is stock. I've got a 92 speed density TPI.I've read that max HP is about 340 with this.
How do I build up the 350 to get it to max potential (or a bit more) for use with the stock TPI?
What heads,camshaft would be the best and still have good vacuum?
The only things I want to change are the injectors and the chip.
I mostly want to achieve low end torque but still want max HP with the TPI I have.

Thanks for any responses,
Pugsy

[RippinRon]

Tpi runs out of breath around 5500 rpm. If you want to make more power build a 383 or 400 to keep the powerband lower in the rpm.

[UR50SLO]

Here is a article that I'd use if I were to build a TPI engine.
http://www.popularhotrodding.com/tec...onversion_ls1/
That solves the TPI intake problem. It's easier to work on with a LT1 intake on and makes more power.
Being speed density (no MAF) you'll need some custom programing that you can buy stuff from www.moates.net for that. Chip burning, stock ECM edit hardware/software that will allow you to tune it like a aftermarket system.
I've got the Tuner Pro and Auto Prom for our Typhoon. I can read chips/burn chips and tune on th fly.
There is lots of experienced guy's on the F-body sites to help with all your questions with tuneing.
Hope that helps with the fuel part of your question.
A good set of heads (aftermarket) and the LT1 intake will take you a long way with the proper tune.
~Scott

[123pugsy]

I'll be sticking with the TPI system.What i really am unsure of is what type of heads and cam I should use.What type of pistons and compression ratio should I try to achieve?

Thanks,Pugsy

[ChevyTruckGuy]

Originally Posted by UR50SLO

Here is a article that I'd use if I were to build a TPI engine.
http://www.popularhotrodding.com/tec...onversion_ls1/
That solves the TPI intake problem. It's easier to work on with a LT1 intake on and makes more power.
Being speed density (no MAF) you'll need some custom programing that you can buy stuff from www.moates.net for that. Chip burning, stock ECM edit hardware/software that will allow you to tune it like a aftermarket system.
I've got the Tuner Pro and Auto Prom for our Typhoon. I can read chips/burn chips and tune on th fly.
There is lots of experienced guy's on the F-body sites to help with all your questions with tuneing.
Hope that helps with the fuel part of your question.
A good set of heads (aftermarket) and the LT1 intake will take you a long way with the proper tune.


~Scott

I have two 89 chevy trucks with tbi and I was interested in what one could do with regards to chip performance?

[53_belair]

Keep your cam under 220dur and 480 lift, you can get a custom chip for $100 if you stick to that. As far as some heads, vortecs would be the best. Keep your compression at or under 10:1 and you should have a good runner under 5000 rpm. Thirdgen.org is your best friend on matters of TPI performance.

[Rhansen]

I would say run some vortec heads (will need new manifold base) with a static CR of ~9.5:1 and an RV/towing type (mild) roller cam. Power band should be from just off idle to about 4500 rpm and lobe seperation should be at least 112 deg. In my experience a TPI will fall off drastically after 5k rpm.

If you really want high hp numbers from a TPI put a supercharger in front of it, that will also fix the airflow problem at higher rpm. Most of the chip perormance gains (1/4 mile) are negligible unless you are trapping 100+ mph and then the gains are mostly from delaying the lockup of the converter, which can be accomplished by wiring in an override switch (700r4 trans.).

[UR50SLO]

I have two 89 chevy trucks with tbi and I was interested in what one could do with regards to chip performance?

www.moates.net has all the stuff you'd need to edit your own ECM and be able to burn chips or read a performance chip and dupicate it.

Part is called the "Auto Prom" and you use "Tuner Pro" to edit the ecm.

It's a learning curve hacking into ecm's and changing them to run the way you want but it's a challange with many benifits.

For your TBI, A good set of coated headers, TBI spacer, Home made cold air intake, (lock up converter is good idea) Stated above* roller rockers with self alligning tips, and if you feel the challange do the ECM editing.
I only tune with a Wide band o2 sensor. They are avalible through many makers such as AEM,Inovative motorsports ect. This will allow you to watch what's going on with real time AFR's and edit the fuel curve to match where you want it to be.
We went through everything but a chip many years ago on a 90 p/u with the TBI.. I think we went low 14's with just the above parts with no ecm edit. The gas mileage went up and it ran lots better not all choked up.
The truck then got a 434SBC... for awhile.. with a 308 gear it went low 12's.
Took it out of the truck and into my Camaro chassis and went 11.0's. Those darn trucks are heavy!!!!!!! 4000lbs.

Whew.. anyhow.. getting into editing stock ECM's is fun and challanging. You'll learn ALOT about injection,AFR's and their effect on drivability.
Hope that give's a little insite on that for ya.
~Scott