Help the new guy. . . .Please

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I have been wrestling with my 82 Turbo sport coupe for almost 2 years now. I will now say what it is before I list my Question(s)

Turbo was built in AL extreme mods, no complaints, about a year on it.

3.8 V6 was built about a year ago too by a local shop I trust here in IL. Built to boost, no complaints. not using the computer at all, except for HEI electric advance distributor. . . . .crap that is. . .to be fixed soon.

350 C trans with 2000 stall was built by my trans guy at Oak Lawn transmissions, best I have ever found and aside from needing a neck brace sometimes, no complaints

Problems. . . . . . . .
Well Since I put it together I have had allot of fun, and have beaten some pretty awesome cars, but I am quite certain that my carburetor is too small. I currently have a Holly Street Avenger 670. I have never felt much difference between half and full throttle with it and I lose power and 5000 RPM which I do understand could be due to other factors. I eventually learned that jetting it up to a bit over the Holly 770 stock jets has helped allot, and I find myself wondering why I have limited my air flow to 670. (well actually I know why, it is because it was sort of forced on me by my motor installer) I have also herd from 2 people that used to run carbureted turbo 3.8 motors that the stock Q-Jet was a 800 CFM, but that is was brings me here. Is it true? And Should I now replace my 670 with an 870? A few days ago my bottom 2 bolts on my front bowl have lost the ability to tighten, and I have a substantial pressure leak that makes the car not really drivable, and I don’t want to put the time and money into a carb that is not right for my car. I want to get it put together this week, but don’t know what I should buy. The Q-Jet is long gone to heaven (or hell depending on your opinion) so that is not an option any more.
Thank you to all who have taken the time to read this. Please help.

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P.S. Section 1 is my Unreal Tournament (Video Game) name, I couldn’t think of anything else

 

[Freddie's Buick]

Be careful....Since you have removed the ECM control..... that would mean you have no way of controlling detonation, (unless you have some kind of after-market knock control).

Next, if it is a THM-350C, you have no way of controlling the lock-up feature, (unless you have some kind of after-market TCC control device or you made one or you trashed the TCC system altogether).

One does not need an 800 CFM carb on these engines, (although there were some Q-Jets made with that CFM). In any event that to me would be over-carburation. That's more for a V-8, (bigger or more is not always better). The standard Q-Jet max was 750 cfm's, and even then with all four barrels opened one does not reach 750 unless one tweaks it. So it all might just be a matter of tweaking that Holly a bit.

The HEI system is not crap-but I suppose if you get the older vac/points or Pertronics advance kit and spend the mega bucks to get close to the voltage an HEI puts out you'll learn that one.

Any air leaks on a turbo will kill it eventually. Re-tap and get that fixed pronto!!

An excellant top street range for a turbo/carb Buick would be about 3000-4000 RPM's. Anything more than that might be with-in the range of an extreme modification or maybe go IC/SFI at a drag level if that's what you're aiming at. The better option is to go with Rich George's non SFI receipes.

Another forum member that can help is Fred Carrado, (master at the turbo/carb set-up). Other guys that are gunning for lower 14's with turbo/carbs are, Pat83t and Ttype83-Jim Seaton. Turbofish Eric Fisher 'The OEM Specialist' also has a great wealth of info on any of this stuff. These are the guys you'd wanna hear from......good luck!

 

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Thanks for your help, and your time.
I guess I am still wonering what the CFM of the stock Q-Jet was, and can too much air flow really hurt a turbo car?


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[Freddie's Buick]

....The standard Q-Jet max was 750 cfm's, and even then with all four barrels opened one does not reach 750 unless one tweaks it. So it all might just be a matter of tweaking that Holly a bit....good luck!

Bigger or more is not always better. Depending on the cam and other factors over-carburation will hurt performance.

 

[Section 1]

Thanks again for your help.
my cam is 3 over factory specs so I imagine that a 770 is a good fit based on what you are saying. Should I not look into the 870 at all then? ?
Thanks again for your help.
Sorry I don't know how I overlooked you clearly answering my primary question. I really do apreciate the help, I have gotten myself into a car that may be a little too advanced for me.

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[Freddie's Buick]

....wondering why I have limited my air flow to 670. (well actually I know why, it is because it was sort of forced on me by my motor installer)......

Sounds like your engine rebuilder knows the answer to that question. After all, he would know the specific cam specs and how much vacuum it puts out or uses. Over-carburation will cause poor performance and defeats the engine mods he cooked up for you. It's all in the cam man....it's all in the cam!

 

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It was actually the installer that talked me into it, because he said he couldn't see how I would need any bigger for a V6, well GM saw why if they were putting 750's in at the factory, so that's why I came to you guys. The builder had built the motor for somebody else who backed out of the deal (Saving me alot of $$$). I actually never talked to the builder myself (nor had the installer) The motor was found for me by my local speed shop. Sadly this has left me with a few questions about the motor that I have not been able to get answers to

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[b4black]

The stock Q-jet is 750 CFM for the ECM trubo V6 and 800 for the non-ECM. But from what I understand, the turbocharger is 390 CFM. (What that means for a aftermarket carb, I don't know)

IF I where in your shoes, I get the ECM working again and find a Q-jet, but that's me. It hasn't gotten in my way and the car run great on the street and track.

Fred ran a Holley carb. Not sure what the size was.




Where are you now in IL? I grew up in Evergreen Park, but live out in Oswego now. I should be taking my '83 TR to the track this weekend with the Chicagoland GSCA Club.

 

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Thanks for your response man!
Wow I am in Orland Park (grew up in Palos Hills), maybe we will run into each other soon, if you don't mind allot of questions
are you running at 66?
I have not completly disconected the computer, but I have herd some pinging between shifts, so I have turned my timeing down since, and it has fixed that problem. How would I find out if I had ECM in the first place?

Oh and my Turbo builder said he was able to double the flow, so that would now be about 780 for my turbo I guess. Having my turbo rebuilt was one of the only prodjects I made sure to get the best stuff I could, and to my knowlage I got the best, at least I hope so. . . ..

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[b4black]

Route 66 has not been to receptive to small clubs. They want big money to race there for just a few passes. We usually go to Byron, Morroco, Cordova and Great Lakes. Sometimes they are crowded, but many times I have made 10+ runs in a single day.

Sunday we are at Great Lakes. It's a bit of a drive and it will be hot.

Here's the Club's website. Lots of good poeple and the Midwest Challenege is a pretty big deal. It draws some serious racers. http://chicagolandbuick.org/

ECMs started in 1981. It is located behind the side kick panel under the glove box. You are best off either using it completely or not at all. (I think there are more benefits to using it.)

The active knock control runs thru the ECM. It allows full advance of the timing until it hears a knock, then it retards. It's a pretty important function. It would think you would be better off with an electronic Q-jet off a small V8 (using the ECM) than trying to get an aftermarket carb to work. Obviously the correct Q-jet would be best, but a carbs off a 305 or 307 are a dime a dozen until you could find the right one.

I'd watch ebay for an 82/83 carb (they are the same). Also get a '82 Buick Shop manual while you are at it.

Your car can run 14's without a lot of work.

 

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Thanks again, I will look into the club.
I have had to do so many mods (brackets and such) that I feel I am at the point of no return as far as going back to the Q-Jet, SO I guess the only question I have left is between the 770 or the 870 Holley Street Avenger. I realize this goes against your preferences for my car, but between the 2 which would you choose? and also thanks for tips as far as e-bay, ironicly that is where I got the car from .
You guys are a helpful and knowlagable bunch here, and I look forwards to learning about the club.
Thanks again,
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[b4black]

I have no idea on the carb.

Get a vacuum/boost gauge and Casper's Knock Gauge http://www.casperselectronics.com/ . Both will work without a working ECM. They will let you see what's going on.

Bracket's are easy to find. Without the ECM, you are loosing knock retard, timing advance, TCC lock up, fuel mileage and emissions will be a problem.

 

[Ttype83]

Another forum member that can help is Fred Carrado, (master at the turbo/carb set-up). Other guys that are gunning for lower 14's with turbo/carbs are, Pat83t and Ttype83-Jim Seaton. Turbofish Eric Fisher 'The OEM Specialist' also has a great wealth of info on any of this stuff. These are the guys you'd wanna hear from......good luck!

Jim Doesn't Post here any more Read Rich's Web Site it has a ton of good info...and maybe you can find me

 

[b4black]

Hey Jim, maybe one of the new moderators can help you with your posting problems.

 

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Hey all My cable has been broken, but it is back now
I wanted to thank you all for the help, you guys are awesome!
A-Team is my local Speed Shop, in Tinley Park, and the guy there knows a guy in Rockford IL that Runs one of these machines, and he saidI should be quite pleased with the Holley Street Avenger 770. Well he was right. It went in in less than 45 minutes, and I have been driving for a week and I have only spent about 5 minutes tuning it. I really suck at tuning carbs in the first place. I know my secondaries are going to be jetted up, but I am going to wait til I have $$ for someone that knows more than I do.
It is running real well, and there is deffinatly soe great G force at full boost. I still have much work to do, and much to learn, but it is good to have my car back.
Thank you all again!

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