tuned port injection on Ad - The 1947 - Present Chevrolet & GMC Truck Message Board Network

fredscarryall · 02-29-2012, 02:59 AM

is anyone running a tpi on there non emission chevy 350s. i was wonder how well they run and is anyone having any problems. it seems like alot of people on ebay and craiglist are selling there complete systems with the painless wiring conversion after they install them.i would like to install one on my 1950 suburban 383 stroker motor with 375 horse,a 512 lift cam and a turbo 350,but i dont know about runability and reliablity.

OKGMC4 · 02-29-2012, 07:50 AM

TPI runs as well as any injection system when it's set up right. It seems like all the street rodders are caught up in the LS swap frenzy right now. You can find complete TPI for cheap because everyone is putting in LS1, LS2, LS3, LS7 , 5.3, 6.0 etc. Out of the box an LS1 will kill a small block chevy. TPI will run like that but the engine and the injection system will have to be modified alot. Edelbrock and others have the stuff to do it but it will likely cost you more. TPI Speciatilties may be the best source for the higher level parts and tuning you are looking for. Don't expect that kind of power from stock parts, though. If you go the ebay route try to find one with aftermarket runners, throttle body, etc. And if you go for a nearly stock system to get started, get all the parts from one car. There are at least three different TPI setups I know of and cobbling one together from scratch will cause you headaches if the parts don't match.

solidaxel · 02-29-2012, 08:27 AM

I am putting one together for my 55 GMC.
Of all the aftermarket parts you listed, which has more benifit, the throttle body or the runners?
Do you have one on a vehicle now?

Amorget · 02-29-2012, 11:34 AM

Runners will give a bigger gain then the TB. TB is about one of the last modifications TPI needs.

If you want power from a TPI setup you are better off just going straight to the Holley Stealth Ram and skip the stock TPI stuff.

The main issue behind TPI is the runner length is long, it is "tuned" (hence Tuned port) to work really well at the lower RPM, however they run out of breath rather quickly. This means they make great torque, but a weak on the HP. My 1991 305 TPI car made nearly as much torque as my 2000 Trans Am but 130 less HP.

TPI was a best truck motor GM never put in a truck

*edit* To note, I own 4 TPI cars, one is a 350 swap from 305, one is turboed, one is heavily modified and one has basic bolt on upgrades.

02-29-2012, 02:59 AM	#1
fredscarryall Registered User Join Date: Feb 2010 Location: gresham oregon Posts: 806	tuned port injection on Ad is anyone running a tpi on there non emission chevy 350s. i was wonder how well they run and is anyone having any problems. it seems like alot of people on ebay and craiglist are selling there complete systems with the painless wiring conversion after they install them.i would like to install one on my 1950 suburban 383 stroker motor with 375 horse,a 512 lift cam and a turbo 350,but i dont know about runability and reliablity. Attached Images

02-29-2012, 07:50 AM	#2
OKGMC4 Registered User Join Date: Oct 2009 Location: Broken Arrow, OK Posts: 1,245	Re: tuned port injection on Ad TPI runs as well as any injection system when it's set up right. It seems like all the street rodders are caught up in the LS swap frenzy right now. You can find complete TPI for cheap because everyone is putting in LS1, LS2, LS3, LS7 , 5.3, 6.0 etc. Out of the box an LS1 will kill a small block chevy. TPI will run like that but the engine and the injection system will have to be modified alot. Edelbrock and others have the stuff to do it but it will likely cost you more. TPI Speciatilties may be the best source for the higher level parts and tuning you are looking for. Don't expect that kind of power from stock parts, though. If you go the ebay route try to find one with aftermarket runners, throttle body, etc. And if you go for a nearly stock system to get started, get all the parts from one car. There are at least three different TPI setups I know of and cobbling one together from scratch will cause you headaches if the parts don't match. __________________ 56 GMC BUILD THREAD: http://67-72chevytrucks.com/vboard/s...d.php?t=368649 69 long bed Chevy turned 67 gmc jimmy roadster: https://67-72chevytrucks.com/vboard/...d.php?t=851167

02-29-2012, 08:27 AM	#3
solidaxel Registered User Join Date: Dec 2002 Location: Cactus Patch So. Az Posts: 4,749	Re: tuned port injection on Ad I am putting one together for my 55 GMC. Of all the aftermarket parts you listed, which has more benifit, the throttle body or the runners? Do you have one on a vehicle now? __________________ 53 TuTone Extended Cab 350 4-Spd 3:08 (SOLD) 53 Chevy Moldy pearl green ZZ-4 4L60E 9" 3:25 55 GMC 1st Black Mll (ZZ4) ZZ6 TKO 600 5 sp 3:73 62 Solidaxle Corvette Roman Red (327 340hp 4spd 3:36) C4 & C5 suspension tube chassis LS 3 4L70E 65 Corvette Coupe 327 350hp 4spd 4:11 78 Black Silverado SWB (350/350) 5.3 & 4L60E 3:42 2000 S-Type 3.0 (wife cruiser) 2003 GMC SCSB 5.3 4L60E 3:42 Last edited by solidaxel; 02-29-2012 at 08:27 AM. Reason: sp

02-29-2012, 11:34 AM	#4
Amorget Registered User Join Date: Feb 2012 Location: Camano Island, WA Posts: 166	Re: tuned port injection on Ad Runners will give a bigger gain then the TB. TB is about one of the last modifications TPI needs. If you want power from a TPI setup you are better off just going straight to the Holley Stealth Ram and skip the stock TPI stuff. The main issue behind TPI is the runner length is long, it is "tuned" (hence Tuned port) to work really well at the lower RPM, however they run out of breath rather quickly. This means they make great torque, but a weak on the HP. My 1991 305 TPI car made nearly as much torque as my 2000 Trans Am but 130 less HP. TPI was a best truck motor GM never put in a truck edit To note, I own 4 TPI cars, one is a 350 swap from 305, one is turboed, one is heavily modified and one has basic bolt on upgrades.



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