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Replacement carb

Which replacement carb should I use?

  • Edelbrock Q-Jet

    Votes: 2 5.9%
  • Edelbrock Q-Jet (replacement)

    Votes: 5 14.7%
  • Jet Peformance Stage I Q-Jet rebuild

    Votes: 5 14.7%
  • Local auto parts store rebuilt carb

    Votes: 2 5.9%
  • Rebuild it yourself -- you can do it!

    Votes: 7 20.6%
  • Go with a performance carb!

    Votes: 13 38.2%

  • Total voters
    34
J

jsimpson

Guest
you're on target! For $2600 to $3800, I'd be getting a used complete LT-4 or LS-1 instead of a TPI unit!
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Don't get discouraged. I have 150K miles on the injectors in the 90 Vette and as far as I know they are still kicking butt. Enough so that I can suck the headlights out of Nikki's C5! In fact, the injectors and chip are the only thing stock left on that engine.

There is no need to replace them unless you know they have a problem. Remember I am also running just a tad more hsp than stock on the same units.

The reason why I suggested you call Street and Performance was to see if you could get any ideas, suggestions, etc. One time when I called them for something else, they offered me a complete used TPI system, harness, and computer through one of their customers that was upgrading to a different system for $300. Mark had even given me the fellows number to follow up.

When I called the guy, it was already sold.

If the IROC system has it all, and came from a 350, I would make the fellow a strong offer of $250 and let it go at that. He would be crazy not to sell it for that. This gets you well on your way to pulling this off for low dollars.

We have a local car trader paper that has a section for engines. There is almost always a complete TPI engine in there for $150 to $500.

Of course, if you just whip out the old Visa card, you could have a complete aftermarket injection system headed your way in no time:D

You might also put some feelers out in the C4 area for fellows that have replaced the stock manifolds with aftermarket ones. They may have a unit collecting dust that they might want to sell cheap. Check with Ken here at CAC. He is yanking his entire 1987 system out in favor of a wild small big block.
 
J

jsimpson

Guest
I'm with 69myway on everything he said except the injectors. He's been blessed. Old injectors need cleaning. They almost never flow at the same rate as each other. The odds of having a bad injector in a take-off unit are very high. For the cost of a new injector, you can probably get them all cleaned, flowed and balanced. (They don't actually change the flow rate of the individual injectors, but rather send you back eight that are well matched instead of the eight you sent in!
 
H

Hijinx

Guest
Well, a funny thing happened on the way home last night. You see, there was this TPI setup that I put a bid in on, on Ebay. And, well, when I get home last night, wouldnt you guess that its the first thing I've won the bid on through Ebay that I really thought someone else would have out bid me on. :eek

Anyhow, I now have an '88 IROC TPI setup in the mail. I paid about what you guys were saying it would cost (maybe a bit more, as it had been cleaned and powdercoated). So, now I need to start figuring out how what all I need to do to get it hooked up.

Fuel pump, I know and plumbing a return line. The TPI I have coming has the wiring harness, but I still think I will order a Painless harness (unless you guys say this one would be better), get the injectors cleaned and balanced.....what else?

Now might be a good time to think about doing the work to install that Griffin radiator Chris got me as well.
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Excellent. I will do all I can to walk you through the process. Get a list of everything you are getting for me, and I will give you an idea of what else you need to plan on getting/doing.

Of all the EFI systems out there, the TPI may not be the highest performance model, but it is the best looking and will make gobbbbs of low end torque which equates to red light to red light tire blistering fun.


I will get some photos of the brackets I made and post them up here on the C3 Forum.


See if you can snap of pics of your new stuff for us too.
 
J

jsimpson

Guest
Not to mention fantastic fuel mileage and driveability!
 
B

Bullitt

Guest
Hey Hijinx, there's a guy up there in North Texas parting out a '91 Z28, if you need any other TPI related parts. He's in the local Auto Trader with a phone # 972-293-9851.

--Bullitt
 
H

Hijinx

Guest
Chris, I will definately pick you brain. Here are some initial questions;

1. Will I need to make exhaust changes, beyond putting the O2 sensor in? Will this work with the Ram's horns or will I need to go to headers?
2. Will I need to make a cam change or other valve train changes? Seems that I saw a post on this at some point and that these systems look for some specific cam lobe designs?
3. With the Ignitor II installed in my original distributor, can I retain this and not switch to HEI?
4. Will it work OK with my existing A/C, alternator and valve cover setup?
5. Will I need to run the evap canister any longer and how does this change the vacuum line setup? Especially with the brake booster.

I'll think of more questions, but that's it for now. Thanks
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
Hijinx said:
Chris, I will definately pick you brain. Here are some initial questions;

1. Will I need to make exhaust changes, beyond putting the O2 sensor in? Will this work with the Ram's horns or will I need to go to headers?

You can drill and tap your ram horn for the O2, or, have the local muffler shop weld an O2 bung into the upper part of the pipe about 5" down from where it bolts to the manifold. My local welding shop keeps those threaded O2 bungs in stock as they have become a regular part of exhaust work.

2. Will I need to make a cam change or other valve train changes? Seems that I saw a post on this at some point and that these systems look for some specific cam lobe designs?

It depends on your cam. TPI will work with most cams as long as the lobe seperatoin is 112 or greater. Many older style hot cams use a 110 to 108 lobe seperation. That will cause vacuum problems. You can get a complete 2050 flat tappet Crane Compu cam and lifters very reasonable in price. Get your specs first, as you may not need to change anything.

3. With the Ignitor II installed in my original distributor, can I retain this and not switch to HEI?

This may cause a problem if you are still running a cable tach drive. You wil want an HEI. The good news is you can get a rebuilt HEI at most auto parts stores for $99, and one from the junk yard for $30. You can sell your stock unit for well more than that, or save it for a future "return to stock".

4. Will it work OK with my existing A/C, alternator and valve cover setup?

It should. Open your hood, and draw a mental line just above the water neck and straight to the radiator. As long as that does not hit anything (belts, brackets), you are clear. A Serpentine set would look better, but I don't imagine you will have a problem. There should be no problem with a/c, etc. You can run tall or short covers with TPI and not have any issues.

5. Will I need to run the evap canister any longer and how does this change the vacuum line setup? Especially with the brake booster.

The TPI has a port for brake vacuum booster and PCV. You will hook it up just like the Camaro it came from. You will still want to hook up the evap line to reduce gas vapor smells in the garage. You will need to tag into the vacuum port just under and behind the throttle body to run to the stock Evap line. I installed a EVAP in my 69 to keep the stinky smells to a minimum. That allows you to run a non-vented gas cap.

I'll think of more questions, but that's it for now. Thanks
 
H

Hijinx

Guest
Chris,
With the HEI replacement, will I lose my tach? That would suck!
 

69MyWay

Well-known member
Joined
Jul 3, 2001
Messages
4,364
Location
Auburndale, Florida
Corvette
1969 Killer Shark
It depends. I will do some checking into what you have to see if there is a way around it. I have also seen HEI distributors made up with tach drives.

Then again, those cable tachs are not the most reliable. You might be able to get a 75 model electric tach and balance it all out.
 
J

jsimpson

Guest
Go with the electronic tach, or use an electronic conversion for your stock distributor.
 
H

Hijinx

Guest
That what I have now, the electronic version of my stock distributer. The Ignitor replaces everything inside with an electronic setup.

Chris, could I put an MSD unit in and use their tach connector to set this up? That might be a question for MSD and Ignitor.
 
J

jsimpson

Guest
If you're using the stock distributor with an ignitor and an external MSD control module, why not just use your stock tach drive? I've done it both ways, and the electronic tach is even more troublesome than the mechanical tach!
 
H

Hijinx

Guest
That was my thought. I have the Ignitor installed and working. I have been planning on getting an MSD 6L, so that might work just as well and I get to keep my stock setup.
 
J

jsimpson

Guest
I have a similar setup in my 70. I also have an HEI distributor and a 75 tach laying around. I came to the same conclusion: if it ain't broke, why fix it?
 
H

Hijinx

Guest
Page62, by the way, sorry for taking over your carb discussion.
 
Joined
Aug 29, 2001
Messages
3,236
Location
Norcross, Georgia, United Stat
Corvette
2017 Arctic White Grand Sport
Page62,

After reading various discussions in this forum, I decided to rebuild my Q'Jet. There is a shop here in Atlanta that specializes in carbs and is supposed to work wonders with the stock unit.

Bob
 
K

klb76

Guest
Hijinx - How is the TPI install coming? I am looking into doing it myself and was wondering about the pros and cons.

klb
 

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