late 80 tuned port inj swap in 72 info needed

[dukcaln]

interesting reading and very detailed which helped clear some issues I had understand up. thanks for taking the time to post

[pat386]

Some may say it's a waste and the persormance isn't that great. My view is, it's late 80's GM, what do you expect?
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[MARKDTN]

Originally Posted by pat386

Some may say it's a waste and the persormance isn't that great. My view is, it's late 80's GM, what do you expect?
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I read this and I just don't understand. It may not be an LS, but the TPI is a quantum leap above the 70s carbed and smogged stuff and the mileage increase is hard to argue. In my '83 K20 I swapped the original 350 for an L98 TPI from a Corvette. I went for 14 or so mpg to almost 18. I used to be on the gas to maintain 70 on the interstate, now it is just steady. Would an LS be great, sure, but a TPI is not bad-as long as you don't hot rod it. TPI was designed for a 305 and in stock form do not breathe past say 5500 rpm. For a truck, they make a great engine.

[dukcaln]

so, just how difficult is it to just instal the tpi portion ontop of my current 350, if possible?

[72 K20]

so, just how difficult is it to just instal the tpi portion ontop of my current 350, if possible?

You would probably want to change the cam,, but everything else will work as long as the chip you have burnt for it has the correct parameters.
I did a TPI speed density swap into an "84 cutlass . Fastchips.com is who burnt the chip for mine,,, he wanted the full specs of the engine/trans/rear end ie cam specs, compression ratio, valve size, runner size,injector size,converter stall,trans model,rear end ratio,etc.
Mine was a 355 with flat tops and 64cc Dart iron eagle heads, comp cam,and a "92 vette TPI. I used the painless harness,,worked great.

With 3:73 gears, and a TH350 the car would get 18-20 MPG and was very responsive.
Keep in mind ,, the TPI in stock form is only good to about 5500 RPM. You can make more RPM with a TPI but it will cost you for bigger runners,different plenum,etc.

[dukcaln]

thanks for the info, I just keep tossing this idea around for the tpi... but really I just picked up tonight (as a matter of fact) a brand new edelbrock 750cfm carb and dual plane manifold. Perfect set up for my cam and heads, so it official no tpi. guess I will stick with the 8-10 mpg...LOL

[pat386]

Originally Posted by MARKDTN

I read this and I just don't understand. It may not be an LS, but the TPI is a quantum leap above the 70s carbed and smogged stuff and the mileage increase is hard to argue. In my '83 K20 I swapped the original 350 for an L98 TPI from a Corvette. I went for 14 or so mpg to almost 18. I used to be on the gas to maintain 70 on the interstate, now it is just steady. Would an LS be great, sure, but a TPI is not bad-as long as you don't hot rod it. TPI was designed for a 305 and in stock form do not breathe past say 5500 rpm. For a truck, they make a great engine.

I always hear people knocking the TPI. As for me, I love mine. After replacing all 8 injectors and 20year old sensors, it feels like a whole new engine to me.
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[MARKDTN]

Originally Posted by dukcaln

thanks for the info, I just keep tossing this idea around for the tpi... but really I just picked up tonight (as a matter of fact) a brand new edelbrock 750cfm carb and dual plane manifold. Perfect set up for my cam and heads, so it official no tpi. guess I will stick with the 8-10 mpg...LOL

You really ought to ride in a Camaro or Corvette with TPI before you give up on it. It will make a believer out of you. The low end torque will snap your neck. How often do you really go above 5500 RPM? As far as putting it on your existing engine, it will bolt on with 2 exceptions; 1-you would need to swap to a FI type cam. You have to have good vacuum for fuel injection. and 2-you would need a corvette TPI intake because of the center bolt angle. You can make the F-body straight ones work, but as cheap as TPI stuff is now there is no need to.

I would buy a TPI setup, use a Corvette PCM in the engine compartment, and convert to speed-density. The chip burners can put all your specs in and give you a chip based on your engine setup. The visual appeal is awesome, the torque is awesome, cold weather and/or long term startup is fast, and better mileage to boot.

[Lastson03]

i swapped an 1987 TPI setup in my 68'. The donor car was an abandoned bargain at $200. I considered the LS swap but couldn't beat the bargain i already had. If it is cheaper do it. The experience will help out when you upgrade again. Mine is MAF. Look into Jagsthatrun.com TBI/TPI swappers guide.

[Lastson03]

One more comment. A close friend of mine had his 86 IROC running 8.20s in an 1/8 mile with bolt on stuff and a small cam, It even had the stock intake on it. So with a little help they are not the slow dogs everyone claims them to be.
2011-11-22_11-19-16_992

[Andy4639]

My setup is fine for street use. I drive it mostly to work and to see my parents in NC which is a 3 hr ride. It has all the power I need for that and why people say it's a dog is beyond me.
Why would you put a 305 in a truck and think it's suppose to do like a 454! For what this motor is it's just right for our trucks and for the money can't be beat.
Mine will cruise at 70-80 all day long.

[dukcaln]

I hear all of you, I really guess it boils down to rerally the cost of the entire swap and the time. I got this carb and manifold, 2" drop shackles and blazer tank... think I will stay ols school for now and let my 16 enjoy his high school ride..

[pat386]

they sure do look good

[dukcaln]

wow pat you tease!!!!!!!!!!

[FRENCHBLUE72]

Theres a thread on here somewhere started by??????r.f.????? its a great fuel injection thread and the guy knows what seems like everything there is to know on fuel injection..

[dukcaln]

tried to fund, no luck, can you post it

[FRENCHBLUE72]

http://67-72chevytrucks.com/vboard/s...d.php?t=317519 There is lots of reading in this thread soooo grab a cup of coffee and sit back for a spell.... If you have any questions r.f and pretty quick about answering back and giving it to ya in a way a 2nd grader can understand if ya know what I mean very clear and precise..

[dukcaln]

thank a million

[fasttech]

And for anyone who thinks a TPI induction system can't make serious power check out this test from Super Rod mag in 2005. They ran a 383 motor with a stock TPI base and runners and got 500 lb-ft of torque and 410hp. With an extrude ported base, larger runners and throttle body they were able to get 534 lb-ft of torque and 451 hp on the same motor. This is some great data. The reason the original stock motors didn't make a tone of power wasn't because of the TPI but because the motor was de-tuned to meet emissions requirements.

[samuellg1977]

I found this thread via the search tool. I have a 63 stepside and i also have a 1989 IROCZ that i just got two weeks ago. I paid $300 for the camaro (just for the motor/trans). I am pulling the TPI 305/700R4 out of the IROC and putting it in my truck. The motor i have in the truck now is a stock 1984 suburban 350 with a 700R4. It runs, but smokes like a log wagon. I have been reading, researching, and I have the TPI swapper's guide. I have to admit, it is terrifying to think that I need ALL THOSE wires just to get down the road!! I would like to keep as much as possible. Most of the wiring harness and even the steering column. The A/C and smog will not make the swap though.

My questions:Can i use the tank and lines from the car? If i keep the column, will the VATS still work as before in the IROC? What will i need to do to the ECM? Does the IROC have an elctronic trans controller (if so) where would it be? I know I have a lot of questions, but I have never done anything with EFI and i really like to drive this truck. I'd hate to screw it up and not finish it - or have to pay to rebuild a 27yr old 350 to put BACK in it.

Thanks.

Sam

[fasttech]

I doubt you can reuse the IROC gas tank and fuel lines in your 63. I have a custom tank and fuel lines, but I have read that some guys have used the existing fuel tank with an external fuel injection fuel pump and high pressure rubber or braided stainless hoses. There could be problems with the gas sloshing from side to side in the original tank starving the fuel system. The custom tanks have anti-slosh baffles built in to resolve this.

As for the trans converter controller that is built into the ECU and not a separate system. You will just need to wire it up to the 700R to work.

If you are removing the emissions stuff and AC you will need a custom chip to remove the logic for EGR, Canister Purge, & Air Pump. If not it will throw error codes and run lean if it thinks it has a vapor canister and doesn't. Also it will never go into highway mode for better gas mileage.

If you plan to use the steering column out of the IROC the VATS should work as long as you have the original keys that go with the column. If not it is probably cheaper to have a custom chip with VATS removed. There are also some custom wiring harnesses that have a VATS eliminator that plugs into a weatherpac connector.

Hope this helps.

[MARKDTN]

Originally Posted by samuellg1977

I found this thread via the search tool. I have a 63 stepside and i also have a 1989 IROCZ that i just got two weeks ago. I paid $300 for the camaro (just for the motor/trans). I am pulling the TPI 305/700R4 out of the IROC and putting it in my truck. The motor i have in the truck now is a stock 1984 suburban 350 with a 700R4. It runs, but smokes like a log wagon. I have been reading, researching, and I have the TPI swapper's guide. I have to admit, it is terrifying to think that I need ALL THOSE wires just to get down the road!! I would like to keep as much as possible. Most of the wiring harness and even the steering column. The A/C and smog will not make the swap though.

My questions:Can i use the tank and lines from the car? If i keep the column, will the VATS still work as before in the IROC? What will i need to do to the ECM? Does the IROC have an elctronic trans controller (if so) where would it be? I know I have a lot of questions, but I have never done anything with EFI and i really like to drive this truck. I'd hate to screw it up and not finish it - or have to pay to rebuild a 27yr old 350 to put BACK in it.

Thanks.

Sam

Don't think the IROC tank will work.

You don't have to use the column, either measure the resistance on the key and add an inline resistor where that used to plug up OR get VATS (and EGR?)
removed with a custom chip burn.

The Transmission controller is part of the ECM, just plug it in.

As cheap as aftermarket harnesses are, I would buy one of those over using stock anymore. It will get rid of a lot of wires.

[samuellg1977]

Thanks for the info. Looking under my truck today (in the rain!), i found steel fuel lines front to rear with a return line that is plugged off at the tank. Apparently, I am not the first owner of this truck to consider EFI. The tank is under the bed and is homemade. It has no place for a sender or in-tank pump, so external is the only way to go with that one. I bought a 33gal blazer tank and didn't measure the space i had to work with - guess what - WON'T FIT. i don't want to mount it in the bed. That looks thrown together to me and i use my bed to haul junk and parts - ok, it's all junk, but i still use it like a truck. It isn't gonna be a show or race truck. I drive it to work everyday, so it is difficult to make time to work on it and get it the way i really want it. fasttech, do you have any pics of yours? And is it possible to ONLY get the harness to run the engine and not the extra stuff like lights, blinkers and such? I have heard that you can do it either way. At this point, I just want the engine to run like it should. And yes, they do look cool in the engine bay of an old vehicle that was never intended for EFI!! Thanks again.

Sam

[MARKDTN]

Yes, all the aftermarket harness are just for the fuel injection. You use your stock harness for blinkers, starter, and power to the distributor.

If you want a stock tank that kinda fits, the S10 Blazer tanks are close. Just swap in the IROC pump and you are good to go.

[fasttech]

My tank is a custom rear mounted tank with the EFI option from Performance Online but it's made by No Limit Engineering.

http://www.performanceonline.com/196...NUM-FUEL-TANK/

Not the cheapest option but it's what I wanted. Internal fuel pump, side filler neck, anti-slosh baffling, and fits the body lines of the truck perfectly. This is a stock picture but I can take some pics of mine if you want.