what do you thank of tpi

[motorz350]

i want to put a tpi set up on my 72 gmc and wanted to know what everyone has to say

[kgt]

I dont own one, but have been a gm tech for years, I recall them as a decent set up, limited in rpm and horsepower(240 hp) in oem form. A MUCH better set up is a lt-1 or a ls motor in my opinion...

[Ticker]

Don't

If you want FI, you're far better off with one of the aftermarket systems than trying to retrofit a factory setup.

FAST EZ-EFI

Edelbrock Pro Tuner EFI

Holley Avenger EFI

...and others. It seems like retrofitting factory EFI will be cheaper...but by the time you get the wiring harness and tuning squared away you'll be in for some coin. It CAN be done, for sure - but you gotta work for it.

[71meangreenc10]

I would also do it if it wasnt so expensive.....

Smitty

[Fitz]

Got $3500.00? That's about what it will take for a closed loop system. An open loop is cheaper but not much better than running a carb. If I still had the 350 in my 67 this is how I would go for the same money. The cool factor is way up there! Four DCOE 48 Webers!

[Andy4639]

I love mine had it now since 1989 and haven't had any major problems with it.

[68C15]

I'm not sure the performance is much better than a Throttle Body setup. TBI is cheaper and sooooo simple/reliable.

[Ticker]

Originally Posted by Fitz

The cool factor is way up there! Four DCOE 48 Webers!

Yeah...that is...amazing.

<drool>

[motorz350]

ok cool the tpi is off a 89 305 h.o.p. and its all free all i have to do is pull it out and put it in and deal with the computer and stuff but it works. and i have a tbi set up i got off a 90 chevy i need the intake for it im just can figer out what to do

[Ticker]

Originally Posted by motorz350

deal with the computer and stuff but it works.

It works with a stock, emissions 305. You're going to learn pretty quickly that the factory TPI computer has limited ability to be reprogrammed and burning EPROMS gets expen$ive. $575 right out of the gate just for programming...and programming that won't be quite right. Figure 2-3 tries to get it right with instrumented dyno runs at $250/hour. Trust me; I've been there.

Tuned Port Induction Specialties

This is why an aftermarket system, although initially more expensive, will virtually always end up being cheaper in the end.

If you feel like you gotta go this way, at least look at an aftermarket harness and computer. Painless Performance TPI harness. Still looking at more than $1500 by the time it's all hooked up. And you know you need to plumb an EFI-capable electric fuel pump with return, right?

[Ticker]

Here's a good link if you're moving forward with this:

http://tpisuburban.edgesz28.com/suburban-home.htm

[danman987123]

DO IT.....ESPECIALLY IF YOU HAVE EVERYTHING....they are right....its not a huge monster for power but its a million times more reliable than a carb or tbi.....do it i support you...i use to drive one everyday and was completely satisfied now i put one in my 68 and its sweet

[truckster]

Originally Posted by danman987123

DO IT.....ESPECIALLY IF YOU HAVE EVERYTHING....they are right....its not a huge monster for power but its a million times more reliable than a carb or tbi.....do it i support you...i use to drive one everyday and was completely satisfied now i put one in my 68 and its sweet

I can see how it might be a little more reliable than a carb, but I'm not clear on how it would be significantly more reliable than a TBI. I'm not saying it's not cool or that he shouldn't do it, but TBI is simpler and extremely reliable.

[jayman68]

Originally Posted by motorz350

ok cool the tpi is off a 89 305 h.o.p. and its all free all i have to do is pull it out and put it in and deal with the computer and stuff but it works. and i have a tbi set up i got off a 90 chevy i need the intake for it im just can figer out what to do

Be sure to verify it has the correct injectors for a 350 (that's what you are putting it on right?) The 305 ones are less flow, but I see it says h.o.p. so they might be the same as the 350. better safe than sorry.
Jay

[motorz350]

Originally Posted by truckster

I can see how it might be a little more reliable than a carb, but I'm not clear on how it would be significantly more reliable than a TBI. I'm not saying it's not cool or that he shouldn't do it, but TBI is simpler and extremely reliable.

i have a s-10 blazer 4x4 with a 350 thats tbi and i have problems with it my bigst problem is that it just dosnt have power i cant get it to slip a tire so the tpi is looking realy good i dont have much money. i have a 3 month old baby so im just trying to get it figerd out and then done and i dont get it i dont know i had to mess with the computer i thout if i pulled it and just droped it in. it would work im not much of a computer guy if it got a carb on it i can work on it so it a big new step for me

[Blackbird66]

From what I've picked up on the F Body forums, the TPI itself does not make a big power difference over TBI, and is more limited as the runners are tuned for a set RPM use. All 305 TPIs are HO. Otherwise you have a tbi. In addition to smaller fuel injectors ( witch can be fixed by upping fuel pressure) the knock sensor is not the same as 350.
TPI is a great set up for a stock motor although TBI will give better torque. This is why trucks always got TBI.

You really need to read up on everything involved before you make a decision. The third generation f-body forum is a good place to start, because that is where the motor in question was orginally installed.........

[motorz350]

Originally Posted by Blackbird66

From what I've picked up on the F Body forums, the TPI itself does not make a big power difference over TBI, and is more limited as the runners are tuned for a set RPM use. All 305 TPIs are HO. Otherwise you have a tbi. In addition to smaller fuel injectors ( witch can be fixed by upping fuel pressure) the knock sensor is not the same as 350.
TPI is a great set up for a stock motor although TBI will give better torque. This is why trucks always got TBI.

You really need to read up on everything involved before you make a decision. The third generation f-body forum is a good place to start, because that is where the motor in question was orginally installed.........

oh ok ill have to look in to it all more and figer it out if i go tbi ill just sell the tpi and all the stuff for it or vice versa

[capev86]

tpi is better for high end horsepower, but tbi is the best all around and gives the advantages of fuel injection with nearly the simplicity of a carb. the only way to get truly better power is with direct injection.

the best bang for a small block is to hog out a tbi intake to mate with the larger throttle body off a big block truck. right now i plan to replace the rochester 2 barrel on my 72 burb with a q-jet. i will get better mpg and throttle response AND wake up that little 307. when i get my 406sb in it will really make a difference. but a hybrid tbi setup like i mentioned previously would be marginally better and have automatic adjustability for changes in altitude, etc.

i do like how the factory tbi system looks like an old school carb setup when the air box is on top. there is a kit out there ($$$) that looks just like the tbi setup but with multiple injectors and a fuel rail down each side on the intake.....the looks of the carb, the throttle response of the tbi and the extra precision from having multi port injection.

the 80's corvette style fuel injection does look awesome though, especially when chromed out.

[jayman68]

Originally Posted by motorz350

i have a s-10 blazer 4x4 with a 350 thats tbi and i have problems with it my bigst problem is that it just dosnt have power i cant get it to slip a tire so the tpi is looking realy good i dont have much money. i have a 3 month old baby so im just trying to get it figerd out and then done and i dont get it i dont know i had to mess with the computer i thout if i pulled it and just droped it in. it would work im not much of a computer guy if it got a carb on it i can work on it so it a big new step for me

The computer is matched to the engine, so if you did not replace the computer(chip) with the engine, then it still thinks it is running the V-6 and you will not get much power.

[Andy4639]

1989 TPI more than likely one of the first to do this on here.I did this swap before anybody had all the kits and stuff out for them except S&P.
Computers are no problem as long as you know what you want. I'm running a V-6 computer with a chip from Street & Performance. As long as you plan it and stick with the plan it's a peice of cake. Aftermarket wiring is the best way though. It's a simple plug and ride.
Motor before redoing the paint job.


Motor after new paint job.

[motorz350]

as for my blazer i dont know what they did i bout it with the v8 in it and i have all the reseats for all the work and it dosent say it thang about the comp so ill have to look in to it

the 71 you have looks good under the hood i cant wait to start on mine heres a pic of my 2 wheel drive the first pic is when she sat for six months and the other was after i got her back on the road i whent and showed the 4x4 up

[motorz350]

well iv done it now i snaped the inner axle on my truck and blow the spider gears to hell so i have to put my other rearend in it man no fun