tpi to old stuff
Thread Starter
Burning Brakes
Joined: Sep 2014
Posts: 776
Likes: 98
From: carroll ohio
tpi to old stuff
have a chance to get a tpi from 92 firebird 350 less dizzy and harness. i noticed that the center bolt holes are of the vortec type,so without the dizzy and harness and what looks like work needs to be done on the intake will this be a pita to convert to my 388 sbc. will an older tpi intake with the conventional bolt pattern for older heads work? don't want to sink a ton of money into this swap as i have some nice old school intakes and holley and q-jet carbs. thanks
Le Mans Master
Joined: Oct 2010
Posts: 6,937
Likes: 848
From: melbourne florida
2023 C3 of the Year Finalist - Modified
They start running out of power about 4500 to 5000 r.p.m and with a 383 it may be lower than that.it's so out of date guys that converted to it 20 yrs ago are going other directions. I wouldn't sink alot of money into one.
What I think you have is the later version that has the l98 heads they have those bolts arranged that way.they don't have vortec ports.
Alot of people have converted to them so it can be done, but I think there are better options.
What I think you have is the later version that has the l98 heads they have those bolts arranged that way.they don't have vortec ports.
Alot of people have converted to them so it can be done, but I think there are better options.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
The Tuned Port Injection systems were designed for the smaller 305's and were never meant to be used on the larger 350's and that's why they run out of breath around 4000 rpm. If you bought the larger diameter aftermarket runners it would work okay for a 383" up to about 6000 rpm if you had enough camshaft to support 6000 rpm.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
IOW TPIs are perfect for cars that don't run headers(which make power from 4000 to five million RPM).
Honestly though, the TPI is a good match for a relatively stock L-48 build. The computers are pretty archaic - but there's kits out there to control TPI, or you can roll your own.
If you want it to support big RPM, you're going to be spending enough bucks that you're better off just going a different path.
Honestly though, the TPI is a good match for a relatively stock L-48 build. The computers are pretty archaic - but there's kits out there to control TPI, or you can roll your own.
If you want it to support big RPM, you're going to be spending enough bucks that you're better off just going a different path.
Last edited by Shark Racer; Jan 12, 2016 at 06:46 PM.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Did my TPI on L48 stock engine '72 vette in '95 the changes here in Florida have been done many years ago....L98 engine, LT1 with HEI thanks to a TIG welder buddy.....the computer is still speed density, as fail to see the need for any 'upgrade'.....
NOW having some $$$ and being younger, yeh, a LS conversion would be in line.....but car runs fine, so leave well enough alone....
age 71 and arthritic as hell.....
NOW having some $$$ and being younger, yeh, a LS conversion would be in line.....but car runs fine, so leave well enough alone....
age 71 and arthritic as hell.....
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
The Tuned Port Injection systems were designed for the smaller 305's and were never meant to be used on the larger 350's and that's why they run out of breath around 4000 rpm. If you bought the larger diameter aftermarket runners it would work okay for a 383" up to about 6000 rpm if you had enough camshaft to support 6000 rpm.
-- Joe
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
have a chance to get a tpi from 92 firebird 350 less dizzy and harness. i noticed that the center bolt holes are of the vortec type,so without the dizzy and harness and what looks like work needs to be done on the intake will this be a pita to convert to my 388 sbc. will an older tpi intake with the conventional bolt pattern for older heads work? don't want to sink a ton of money into this swap as i have some nice old school intakes and holley and q-jet carbs. thanks
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Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
Thread Starter
Burning Brakes
Joined: Sep 2014
Posts: 776
Likes: 98
From: carroll ohio
tpi
thanks for all the replies
- . cam is crower solid lift .458 in.468 ex 230,236 dur at .050. crower s
The Tuned Port Injection systems were designed for the smaller 305's and were never meant to be used on the larger 350's and that's why they run out of breath around 4000 rpm. If you bought the larger diameter aftermarket runners it would work okay for a 383" up to about 6000 rpm if you had enough camshaft to support 6000 rpm.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
SLP sold for years Siamese Runners to dramatically improve top end flow....but this requires plenum mods on the Throttle Body end and the entrance of the runners to be effective...as well as opening up the base or using the Edelbrock base.....
Maximum effective power with this unit is about 425......
They ARE very simple and reliable though......and look cool.....
Jebby
Thread Starter
Burning Brakes
Joined: Sep 2014
Posts: 776
Likes: 98
From: carroll ohio
tpi
thanks for the reply. cool and simple and reliable is what i'm after.if and when i start to mess with the tpi i'm not going to drop a bunch of money into it. i planned on using the setup just the way it came off the bird with maybe some injector upgrades if needed.
This is exactly right......team that with smallish diameter individual runners and it is what it is.......
SLP sold for years Siamese Runners to dramatically improve top end flow....but this requires plenum mods on the Throttle Body end and the entrance of the runners to be effective...as well as opening up the base or using the Edelbrock base.....
Maximum effective power with this unit is about 425......
They ARE very simple and reliable though......and look cool.....
Jebby
SLP sold for years Siamese Runners to dramatically improve top end flow....but this requires plenum mods on the Throttle Body end and the entrance of the runners to be effective...as well as opening up the base or using the Edelbrock base.....
Maximum effective power with this unit is about 425......
They ARE very simple and reliable though......and look cool.....
Jebby
Drifting
Joined: Jun 2012
Posts: 1,990
Likes: 183
From: Port St. Lucie Fl
the problem with trying to learn EFI with a TPI car is that the ECM is PROM
(Program read only Memory) meaning you have to use pre programed chips.
At a minimum I would do a kit like this and pm a guy on chevytalk.com for the auto tune program he wrote or you will have a difficult time learning to tune your car from scratch.
http://www.ebay.com/itm/Holley-Marin...5WlIVM&vxp=mtr
(Program read only Memory) meaning you have to use pre programed chips.
At a minimum I would do a kit like this and pm a guy on chevytalk.com for the auto tune program he wrote or you will have a difficult time learning to tune your car from scratch.
http://www.ebay.com/itm/Holley-Marin...5WlIVM&vxp=mtr
Last edited by Kacyc3; Jan 13, 2016 at 10:15 PM.
Race Director
Joined: Jan 2000
Posts: 12,399
Likes: 247
From: San Jose CA
Still an archaic ECU, though.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Here is some excellent info.....
They sell everything you need as well:
http://www.hotrodlane.cc/NewTPI%20links%20page/TPI%20links%20page.html#tpitech
These were the first stand alone harnesses that I know of....and were a staple in the high dollar street rod community for many years.....
Jebby
They sell everything you need as well:
http://www.hotrodlane.cc/NewTPI%20links%20page/TPI%20links%20page.html#tpitech
These were the first stand alone harnesses that I know of....and were a staple in the high dollar street rod community for many years.....
Jebby
Burning Brakes
Joined: Sep 2006
Posts: 1,071
Likes: 86
From: Rotonda FL
The Tuned Port Injection systems were designed for the smaller 305's and were never meant to be used on the larger 350's and that's why they run out of breath around 4000 rpm. If you bought the larger diameter aftermarket runners it would work okay for a 383" up to about 6000 rpm if you had enough camshaft to support 6000 rpm.
While TPI will never be a high RPM system - it was designed to produce torque - the entire system can be tremendously improved by adding vortec style heads and a TPI manifold designed for these heads (Scroggins-Dickey). These changes combined with larger tubes. cam and bigger throttle body will produce a smooth running easy starting torque monster for the street - happy at lower RPMs, quiet and much more responsive than a carb engine.
Safety Car
Joined: May 2006
Posts: 4,290
Likes: 140
From: Salem NH
I've been using a Megasquirt ECM for the past couple of years, and it's quite fantastic. Will run a TPI, LT1, LS1, just about any trigger method.
-- Joe