Im thinking about converting from a carb to TPI is the process hard and what would i need?

 

computer, wiring, manifold ASSEMBLY.
not too hard, not too easy either.
get a repair manual and you should be able to figure it out.

 

what do you have so far so we can tell you what you are missing

 

well all i have so far is money but this weekend i am planing on going up to carlyle which is like a huge car swap where u can get all sorts of used items and some new so i was just seeing what i needed to hunt for

 

Look for a 90 to 92 TPI setup with ECU and Harness. I have seen them at Carlisle before for $300ish. You can get all of the sensors and injectors at the local auto parts store, so don't worry too much about them. The more complete you can get the setup the better.

Look on line at Amazon.com for the "TPI swappers guide". This book is an outstanding and will give you all the information you need to help install and debug the system. Here is the link:
http://www.amazon.com/Chevy-Injectio.../dp/1884089127

Good luck, happy hunting this weekend and let us know what you find.

 

u might want to find a car bieng parted out and take what you need under the hood and the dash

 

k thanks for the advice im pretty excited about this weekend and to finaly get started on my first f-body. ill keep u informed about what i find and im sure ill have more questions.

 

Go to www.chevythunder.com and read some.
A good article on changeovers.

 

well i was able to fine one TPI system and it was out of a corvette but the guy was asking to much money for it and wouldnt budge on the price. So i just said screw it. I did, however, grab and exhaust system because i wasnt about to go home empty handed. Im guessing my next best bet in finding a tpi is ebay?

 

I read that book a couple years ago. Read it with a grain of salt and ALWAYS double check what it says. Its filled with quite a few errors, typos, and flat-out wrong information. Its a decent book, but its not to be considered a bible on TPI engines.

 

How much do u think a wiring harness is for the tpi system and where can i get one?

 

I used one from painless and it worked well

I dont remember how much I paid, somewhere in the 300 range

 

Recommend you identify the real goal of what you want. Why do you want TPI over your carb? I’m not trying to be flippant, just don’t jump to a solution without knowing what capability you’re really trying to get.

I wanted good cold start, proper A/F ratio (my carb always seemed too rich) and better fuel economy. I could have gotten that with a good TBI (less expensive than TPI) setup.

If you keep the 305, the stock TPI system will be okay, but if you go larger cubes, you might want aftermarket parts to increase the airflow. I had to go with a lot of aftermarket parts to support my 406 $$.

I’ve seen stock TPI wiring harnesses “reconditioned” along with a computer for about $190. I bought my new harness with 3 wire heated O2 sensor for $220 at
http://www.eficonnection.com/eficonn...i_harness.aspx but I see the price now starts at $250. The service was very good.

 

I've used one TPI harness and one OBDII harness from www.eficonnection.com also. S10Wildside makes a great harness at a reasonable price.

 

I want better gas mileage and from what i know a tpi seems more reliable and makes more power then a stock carb...am i going about this all wrong?

 

it makes sweet torque but it sure aint made to rev or make hp

 

In the carb vs EFI comparison, you are not going to see a huge increase in power in one over the other. The unrestricted nature of the carb/manifold usually provides a little more power toward the upper RPMs. – (If both carb and EFI are properly sized and set up for the application)

The long tube runner length of the TPI will enhance torque in the lower to middle RPMs, but will restrict air flow at the upper RPMs so you won’t have the same horsepower as a carb. TPI (and the long runner tubes) was specifically built for the 305 to enhance the low and middle RPM torque where most street daily driving is done.

(Chevy was not originally going to use the 350, at the last minute they kept it, but had no induction system for it except the TPI. Note the later LT1 had a higher hp rating, but lower torque down low due to the short runners of that manifold.)

The carb is less expensive, but not as accurate/efficient across the RPM spectrum. (Hope I don’t get flamed by good carb tuners here.)

I think I’ve gone overboard retrofitting a TPI EFI to my 406 and should have considered TBI more seriously. I think it would have been cheaper and provided me the good cold start and better efficiency I was looking for.

If you keep the 305 displacement, the TPI runners will provide a torque increase down low. If you later move to a 350 (potential for an easy 50hp/50ftlbs), the (stock) TPI will choke off performance. TPI will give you what you're looking for, but don't discount TBI for cost vs benefit ratio.

 

DZcode, thanks for the information i think im gunna just stick with my carb for a while longer untill i get some bolt ons and then c where im at with the car. After that ill decide if i want to go TPI of stay carb.

 

i agree with the tbi comments, despite its underdog status, it is a reliable modable system and the tgo tbi crew is very helpfull and knowledgable

 

DID U GET THE TPI SETUP? I HAVE AN LT1 TPI WITH FUELS RAILS OFF A 91 VETTE AND MY OLD COMPUTER BUT NO HARNESS! IF UR INTERESTED I MAY SELL THEM FOR A COUPLE HUNDRED COMP AND INTAKE W/FUEL RAIL! INTAKE JUST NEEDS A LIL CLEANING AND THE FUEL RAILS HAVE INJECTORS BUT I DUNNO IF THEY R NE GOOD!

 

i converted to TPI from a ccc q-jet, i dont regret it one bit, of course it does cost some money, i have an aftermarket base/runners/throttle body and all ported.

 

I did the conversion 6 years ago on my 86 Trans Am since I wanted a more modern looking engine bay and got tired of fiddling with the Edelbrock carb everytime the air temperature changed.

 

was the conversion process hard and around how much money did it cost?

 

You can probably do it much cheaper than I did, but I needed aftermarket parts to ensure enough air flow for a 406.

Accell intake $300
SLP runners $300
BBK 52mm throttle body used $150
Wiring Harness $220
30# fuel injectors used $150
Autoprom $350
High pressure fuel pump $70
High pressure fuel line $50
Additional fuse box $75
Throttle cable aftermarket $12
plus misc stuff $$

Stock TPI setup with wiring harness and computer $450
Intake was thrashed – threw it away
Throttle body was thrashed
Sold wiring harness $80
Sold 19# injectors $60
Kept upper plenum
Bead blasted stock runners - look good sitting on the shelf

 

wow thats a parts list and a half. not to be an a** but you can buy a whole tbi car for that much and get almost all the parts you need, get a tbi caprice and you're golden.