Guest Locutus Posted September 23, 2000 Share Posted September 23, 2000 What do you guys think of the quadrajet carbs. I have a neighbor that has 4 or 5 in his garage and he thinks they are better than your Holleys, and Edlebrock carbs. It might be a route to follow if these are indeed good carbs. Mike Quote Link to comment Share on other sites More sharing options...
pparaska Posted September 23, 2000 Share Posted September 23, 2000 Quads are good street carbs since they have lots of tunable metering for part throttle, etc. They aren't easy to get rebuilt correctly, in my experience. But when they are right, they are fine. Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted September 23, 2000 Share Posted September 23, 2000 Streetable is good, because I am shooting for a 400-450HP street/strip but mostly street. my neighbor seems to be pretty informed about them so maybe I can get him to volunteer some of his exoerience. I have also heard that QuadraJets don't need alot of tuning once you are set up right, has this been your experience as well? Mike Quote Link to comment Share on other sites More sharing options...
John Scott Posted September 23, 2000 Share Posted September 23, 2000 I love the ol' Q-Jets. Yes they are a pain to tune, change jets, etc. When they are set up right, on the right engine, have amazing throttle response. Very sophisticated idle to power circuts. My experience with these were most had the secondary spring set to loose causing the tell tale baaa...WHAAAAH! Came in many sizes from the one on my 4.3 300+ cfm to 800. Don't ask 'cause I don't remember what #s are what any more. Also give great milage on the primaries. I'm hooked on Holleys for their ease of tuning and perf. potential. Most performance manifolds cater to the Holley as well. Try a Qjet! Maybe you'll be sold. (When Rochester plant burned down, Carter took over for a few years, or so I was told. Had an old Carter Qjet on my olds 425!) JS Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted September 24, 2000 Share Posted September 24, 2000 If I had a qjet tuner next door at a decent price or free I'd be back to one in a flash. V. good tuners often use them on street and strip cars up to 500hp and above. I just got tired of trying to get all tuning aspects nailed down. Doug Roe offers the best book IMO on them offered by HP books FWIW. Nothing hard about rebuilding them etc, they just offer many more variances you can tune in. For the less patient DIY'r that needs some economy too I like the 600cfm carters on a non-wild motor. good luck PS let him know I have a matching #'s '68 camaro/vette qjet if he needs one:-) Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted September 24, 2000 Share Posted September 24, 2000 from what I understand, in thier peak, Rochester couldn't keep up the demand so they contracted out to carter to assemble the qjets for a few years. That being the case if carter did take over they would like be exactly the same as the rochester since the old qjets made by carter were. Mike PS, I will find out how good my neighbor is at tuning these babies, and if he is worth his salt then I will definately go with the Qjet Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted September 24, 2000 Share Posted September 24, 2000 FWIW - I believe the Edelbrock carbs are pretty much just liek th eQjets so I'm puzzled that he thinks they're better. Tuning rods and all - sort of liek Demons and Holly's I think. BTW - Edelbrock has a nice looking dual quad intake. A pair of 500CFM carbs on that would be interesting. Progressive linkage and 1000CFM of carb when it's all done! Pricey but if you're hooked on carbs.... P.S. Spoke to a guy tonight who's running a Procharger blower through a Demon carb. He's having a HELL of a time tuning it but it's running a nice 10lb of boost. Very clean early fastback Mustang with big brakes, Torque Thrust wheels, fresh paint etc etc - it was sweet. Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted September 24, 2000 Share Posted September 24, 2000 quote: Originally posted by BLKMGK: FWIW - I believe the Edelbrock carbs are pretty much just liek th eQjets so I'm puzzled that he thinks they're better. Tuning rods and all - sort of liek Demons and Holly's I think. Well edelbrock does make CARB/OEM replacement qjets which are v. similar and some parts swap back and forth. But the squarebore/performer series is quite different in design (vast improvement for us less patient DIY tuners) with no real parts crossing over. Needles do look similar but that's about as far as it goes. Otherwise I wouldnt' of bought their performer tuning kit as I have lots of qjet tuning bits (anyone need any...). Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted September 25, 2000 Share Posted September 25, 2000 Well first off I hope to learn to tune the carb myself, rather than call on him all the time, second I have thought about fuel injection but its the intial cost that is driving me from FI. As far as weather changes in Texas, there really isn't much more than 50 degrees between winter and summer on the coldest and hottest days. We average 75-80 even thru most of winter and highs in the 100's I think I could strike a good balance that would work most days, and since there is no heat in my Z right now, its not coming out of the garage on any cold days anyway. If anyone has suggestions on a FI system that can handle 450Hp and still have room to grow that won't cost me an arm and a leg(under a grand is about all I could afford in the long run maybe a little more) I am open to suggestions always, this is a work in progress and I am not stuck on any idea until I have outlayed the cash and even then sometimes I will still change my mind. Mike Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted September 25, 2000 Share Posted September 25, 2000 Just my 2 cents on this one. When the weather changes so does the fuel mixture. All carbs go out of tune with weather changes so unless your friend loves your car as much as you do he may not be interested in a long term relationship with your carb. If this happens you will be up a creek without a paddle. I do think nothing runs better on a stock motor but when you reach a certain point I think you may need to switch. I like holleys, avs's, afb's and so on. They all have their own good points but a holley is easy to tune. My last holley was a barry grant and BOOOOM what a carb. Now with the gas prices I have left carbs for the injection infection. A lot to understand but efficient. Up to you what is the best option. ------------------ The only stupid question is one you wanted to ask but never did!!! Drewz Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted September 25, 2000 Share Posted September 25, 2000 My car has a funky lookin system on it right now so take a look at some pic.'s. They were posted but a top notch guy, pparadaska. Check out his page and see the freak I am unleashing this spring. It can more than handle 450+ hp. Highly tuneable but like everything it all takes time and effort. There are a lot of inj. choices so look at them all and ask a lot of questions. This was my method to madness. ------------------ The only stupid question is one you wanted to ask but never did!!! Drewz Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted September 25, 2000 Share Posted September 25, 2000 Just to ease the navigation http://members.home.net/pparaska/DrewZ2.htm Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 26, 2000 Share Posted September 26, 2000 The Edelbrock performer is a clone of the old Carter AFB. They're basically identical and are very decent carbs (one of the best carter ever made IMHO). The Quadra-jet is a great carb, but as you have all pointed out its pretty foreign to most people when it comes to tuning it in. From what a old HotRod article said there was something like 70 models of quadra-jets produced in various CFM ratings. Each GM division used variance so unless you know the numbers, merely snagging one at a wrecking yard is a shot in the dark as to what you may have. Anyone seen the RoadDemon (or RaceDemon) line of carbs? Any input on how they are? They look to be Holley clones, but are of a billet construction and have supposedly less problem with power valves. (if you own a holley and get a backfire, a good portion of the time it screws the powervalve up, least thats been my experience with them.) Lone Quote Link to comment Share on other sites More sharing options...
pparaska Posted September 26, 2000 Share Posted September 26, 2000 Lone, I've heard the same thing about the Edelbrocks - they're Carter AFB copies with some changes. I've also heard that the Holley power valve blow out thing was fixed - Holley supposedly puts a check valve in the power valve signal passage so that it can only get sucked on and not blown . I put in the Spectre version into my old 3310. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted September 27, 2000 Share Posted September 27, 2000 Demons - Mike Kelly has one. I've heard good and bad about them. They're close enough to Holly's that there was a lawsuit Apparently one of the outcomes is that hardware to hook them up is unique to their carbs - so I've been told. So don't expect for a Holly fuel log to hook up and the Demon stuff isn't cheap. If I'm wrong here someone please holler. Billet construction and porous free castings should make a difference but I'm not the best source - carbs are foreign to me and will only be on my car for shakedown stuff. I hope to switch to some sort of injection just as soon as posisble! I'm likely going to use a Holley unless a Demon falls from th esky at my feet or someone who knows carbs backwards and forwards sells me on one and helps me tune it. Hey Mike - that could be you buddy! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 27, 2000 Share Posted September 27, 2000 quote: Originally posted by pparaska: Lone, I've heard the same thing about the Edelbrocks - they're Carter AFB copies with some changes. I've also heard that the Holley power valve blow out thing was fixed - Holley supposedly puts a check valve in the power valve signal passage so that it can only get sucked on and not blown . I put in the Spectre version into my old 3310. Yeah I've seen the Spectre checkvalve deal, and thats cool if Holley fixed it, cause it was a pain. I almost had to buy powervalves by the dozen. (well slight exageration, but I worked on the holley way more than I ever had to with AFB's.) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted September 27, 2000 Share Posted September 27, 2000 There was one other carb that deserves mention. And thats the Predator. I've yet to see the internals of one, but I'm told they have a variable venturi design and will flow up to 930 CFM or much less depending on the engines requirement. They have a new street version with an additional idle circuit that make it idle much better. (before the preditors were full race carbs without a decent idle circuit). Anyway I know they really well liked by many racers, and produce good power. I know all this carburator talk is slowly dying out with everyone trying to get familiar with the F.I. systems. Guess I'll have to bite the bullet and put F.I. on my next project. Cheers, Lone Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted October 5, 2000 Share Posted October 5, 2000 Drew I would love to get some info on your setup, I am definately considering the same setup. Did you use one computer, wiring harness, etc. Details bud, or even maybe a tech write up? Help me get a start here Mike Quote Link to comment Share on other sites More sharing options...
Guest Drewz Posted October 5, 2000 Share Posted October 5, 2000 Happy to help anyone I can. The Tbi.s in the pic. are 2.8 chev, computer is Gm 256, wiring is off of and uses all stock Gm parts and plugs. All sensors are factory and cheap. Harness was simple but making it with all the conectors was a diff. story. Had to buy a chip burner and about to purchase a Gm adapter to hook my laptop to for on the go tuning.If anyone wants more info. for any reason feel free to ask. Later guys!!!!!!!!! ------------------ The only stupid question is one you wanted to ask but never did!!! Drewz Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted October 6, 2000 Share Posted October 6, 2000 How much was the chip burner and what was involved in reprogramming it, and also what was involved in the wiring harness. Actually if you want point me to some of your resources I am willing to research it as well, or give me as much information as possible and I will do a tech write up, giving you credit where due of course Mike Quote Link to comment Share on other sites More sharing options...
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