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Old 04-15-2002   #1
89GTA
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Question what carb to buy?

hey, whats the best carb to buy for a 350 GTA?? ive been looking at the edelbrock carbs at their web page www.edelbrock.com and i couldnt really figure out what carb to buy. does anyone know what would be the "best" carb/intake manifold to buy for a GTA? best in terms of reliability, and cost(cheap)
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Old 04-16-2002   #2
OkadaKimC
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First poo poo on the carb, go with a TPI specialities mini ram, new injectors, throttle body, etc, etc, etc. CHEAP, port the plenum go with TPIS big tube runners. If monies allow change intake to the TPIS to match the runners. Then save for the 52MM throttle body, 26LB injectors, and at least the LT4 hot cam or TPIS's and of course the chip.

Second, intake combos depend on a few things. Number one on the list is what do you want to have the car do? Big torque, high RPM racing, mid range, daily driver. You also need to match the cam to what you want the car to do. Next you have to change the fuel pump. EFI's are 14 (TBI) to 50 (TPI, SFI) PSI. Carbs are usually 6 (OEM) to 12 (racing) PSI. All Quadrajets like 6-7.

For a basic daily driver with the stock cam, Edelbrock Dual Plane, Edelbrock Quadrajet. This should put you just "hair" better than stock TPI at mid and top end but a little loss at the bottom and about 2-3 MPG less.
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Old 04-16-2002   #3
nblanchard
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GTA89, aren't you the one that always gets the "Keep TPI" argument? The thing with a Carb, is you have to select the proper CFM to get optimal performance.... I am guessing a 700cfm would be OK, but I am not sure. If you can find out what your heads flow, then find out how many cylinders are pulling in air at the same time (even if it is just half a stroke), then multiply your intake port flow by the number of cylinders pulling in air, then you should have a ballpark cfm flowing. This is my own theory.. so I could be talking out of my a$$.
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Old 04-16-2002   #4
89GTA
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Talking carbs

yeah im the guy who always gets the keep TPI arguement im not gona keep it though, this time its a final descision. only problem now is, i dont know anything about carbs. edelbrock has too many different carbs and its confuseing, whats the difference between square bore and spread bore? wtf are q-jet carbs? whats the difference between a q-jet and a regular carb? im really not into this whole sentemental "keep the tpi" arguement i keep getting. i want to customize this car to fit MY needs, and i think buying a carb will be a step in the right direction for once. i dont want the car to be all stock, i dont care about its re-sale value either. TPI may be working well for most of you, but for me its been my worst nightmare. anyways, with that said, what about this "all-new" performer EPS intake manifold on edelbrocks web page? most people ive been talking to say go for the performer rpm manifold. is there a huge price difference or something?
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Old 04-16-2002   #5
nblanchard
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the performer RPM is a good intake.. as for all the carb questions... I have no clue...
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325.8ft-lbs @ 3250rpm (at the wheels)
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Old 04-24-2002   #6
5finger
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For all of your TPI -> Carb needs head over to:

5finger.8m.com/tpi2carb/tpi2carb.html

As the web page says (but w/ more detail and pics):

The problem with most intake manifolds is the 86 and down center bolts, the 87+ ones are slightly different. Different enough to require a fair bit of time with the dremel to modify some holes that'll probably never look all that great. However, I hear that Weiand has some spacers that straighten out the bolts on modified 86/previous maniolds. Most companies offer 87+ manifolds. RPM's are highly regarded, but no manifold is going to make or break an engine. Just get whatever fits that you can get the cheapest. (FYI, you cannot get an 87+ RPM manifold)

Yes, tpi has many advangates. High performance advantages can only really by harnessed if you just have waaay to much cash lying around that you are just looking for a way to burn through as quickly as possible. One 58 throttle body will run you as much as or more than a brand new carb. Now consider that Holleys can be had at swap meets for like 30 bucks. TPI is rediculously expensive! Its just not economical for anyone on a budget with little/no electronic know how.

Switching to a carb really flattens out you're power band. When you get on the throttle at around 25 mph, you wont get shoved back into you're seat. On the other hand, when you are doing 60 on a highway and you stomp on it, instead of hearing a screaming engine while a honda zips past you, you will be able to feel the push as the power goes to the pavement as you zip merrily past everyone.

As far as carb choice goes, Holley is the way to go for high performance, but be prepared to do some tuning to get your gas mileage where it should be and have everything running right (holleys are rich out of the box). Edelbrock's are more likely to work pretty close to dead on out of the box, and will probably get you better gas mileage. But, they are more expensive, rebuilds are not nearly as easy, and you will not be able to exceed the holley performance. Demons are supposedly better than Holleys, but they're not worth all the extra cash. Holley recommendations: DO NOT get the street avenger. No Trouble this, No Trouble that. Its really No Trouble ripping you off an extra couple 20s for a standard Holley with some 5 buck bolt ons. For an engine with headers, heads, and camshaft, you'll want a 750 cfm carb. For a stock 350, a 600 with be much more satisfying (mpg, throttle, etc). You'll probably want a vaccum secondary carb, but get the quick change spring kit.

Any questions or comments on this or the web page gladly answered.

As always, the above is IMHO, and your mileage may vary.

-5
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Old 04-24-2002   #7
silverado92
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A 650 holley or edelbrock with vacuum secondaries will work just fine.
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Old 04-24-2002   #8
Krazzycowgirl
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q-jet is a Four barrel carb

I agree with the guys here.Before I would get rid of the TPI i would check the whole system out. It may not be your TPI system it could be your engine. Have you owned this car since it was made???? If not check the EGR system.
My 83 someone cut the EGR system off which made it run like chit.

But my brother in law is using a demon carb on his 73 I think holley makes it.
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Old 04-25-2002   #9
5finger
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Krazzycowgirl: But my brother in law is using a demon carb on his 73 I think holley makes it.

Barry Grant makes them.


Krazzycowgirl: It may not be your TPI system it could be your engine.

Problems could be from a variety of sources, but the 300 dollars injectors, 400 dollar runners, 400 dollar manifold, 300 dollar throttle body, and speed density conversion are definately due to the tpi system.
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Old 04-25-2002   #10
Krazzycowgirl
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Your Non Mechanical or Electrical parts are not normally the Problem unless they are crecked or broken. I would say check the Fuel injectors. You can find them for Less then $300 . My husband bought his 30lbs for $249 via summit.

I dont think he would need to replace everything. Come on I am not that stupid.

As for the Demon carb I said I think I was not sure who made it.
__________________
95 Z/hawk w/ LT1,
87 Iroc-Z w/350TPI & 700R4 2nd Best Run 14.686 1/4mile New BEST run as of 4/19/03 14.667
82 Camaro Z/28 Indy Pace car For sale
Silver 2000 GP Daytona Pace car
Newest is a 67 C10 Step side short bed pick up.

2003 South area Rep: Pacific Northwest Camaro Club
www.pnwcc.com forums http://hpiv.net/ipw-web/bulletin/bb/index.php
Webpage: www.hpiv.net
Wife to Darioniv

Krazzy :krazy2:
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Old 04-25-2002   #11
GTABADBOY
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Red face CARBS over the TPI. PLEASE HELP!!

I am having so much trouble with my TPI I have decided to rid of it. It's a 1988 GTA 5.0 Notchback with digital dash. I built a 350 bored .030 over, have S/R Torquer World Product heads 76cc chamber 170cc intake runners, flat top hyperutectic pistons, block and heads decked. I bought a 650cfm Holley Double Pumper, Edelbrock Performer intake (87+ heads) and a Mallory fuel regulator so that I can keep my stock fuel pump. Parts are on the way. BIG PROBLEM----- What wires can I rid of in my engine? Do I need the computer to start my car? I have a chip on my key. Also will I need any of the wires going to my distributor? I bought an MSD Billet mechanical Distributor and MSD Digital 6 plus Ignition Box. I have a digital dash and I want to try to keep it working. What wires from the computer control my dash if any??
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Old 04-25-2002   #12
89GTA
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stuff

ok, isnt there something in bettween a 600 and 750 carb? like a 650 or a 700? what exactly does the term, "computer controlled q-jet" mean? is it only the electric choke thats computer controlled? mainly what i need to know is, on edelbrocks web page, there are 3 different types of carbs (i think) spread bore, square bore and q-jet. what on earth does this mean? what do i need to know when picking out a carb? i just need something thats all around good and reliable. is it better to just dig up an old q-jet off some ruined T/A? it would be nice if edelbrock had a more user-friendly web page..... basicaly, to sum it alllll up in one sentence, what is the carb that is most commonly bought and put on these type of cars? i deffinatly want an edelbrock carb though. also, one more quick question.... if i put headers on my car, will my stock exhaust y-pipe still bolt on to them? or do i need an entirely new exhaust system?
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Old 04-25-2002   #13
silverado92
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Holley makes a 700 cfm carb and Carter makes a 625 cfm vacuum secondary. I would recommend a 650 or 750 vacuum secondary. Edelbrock makes a good carb. Minimal tuning and very reliable. A difference of 100 cfm makes little difference in street performance. If you work with the primary jetting, you'll be shocked at the results you can obtain from a well tuned motor. As a rule, don't over carb it. Larger carbs can slow you down because the bores are bigger and air velocity into the motor decreases. Personally, i would stay away from a q-jet. Computer controlled just means it has electronic metering. No big deal. Go with the edelbrock carb's with the vacuum secondary. Can't beat it for your application.
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Old 04-25-2002   #14
89GTA
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edelbrock

how do i know if the carb has vacume secondarys? several people have told me to go with the 600cfm with the electric choke. other than manual and electric choke, the 600cfm carb didnt seem to mention anything about vacume secondarys, do i just asume that they are on there?
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Old 04-26-2002   #15
silverado92
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Q-jets are vacuum secondaries. Edelbrocks, to the best of MY knowledge, are vac secondaries. Holleys you have to specify vacuum secondaries. On the Edelbrocks and Holleys you have to specify that you want an electric choke.
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