# Tripower VS Quadrajet



## geeteeohguy (Feb 2, 2008)

I'm beginning a new thread in hopes of generating a discussion and getting some input. I have heard that a well set-up Q-Jet on a stock intake manifold can be made to outperform a Tripower setup on a stock intake. This debate has gone on for decades, but I'm trying to verify the facts. Here's what I know: all things being equal, in my personal experience, the tripower produces more power. I ran the stock Qjet and intake on my '67 GTO (stock 400 with 9:1 compression) and it ran fine. I installed a '66 tripower setup on it and it ran much stronger....felt like a 50 hp gain. I then re-installed the correct intake and carb, and it's been that way ever since. I recently read an old article in HPP where a gent with a '68 GTO with a 428 and a TH400 ran 13.40 or so in the 1/4 mile with his stock Q jet and intake. He made 3 runs, all in the 13.40 range. He then bolted on a '66 tripower, and making no other changes, proceeded to run off three consecutive 12.8's or so.  He picked up a full half second. This was on the same day, under the same exact conditions. In my opinion, the tripower flows for cfm, and gets a denser charge of fuel to the cylinders due to the shorter runner lengths on the intake....you have a carb close to every cylinder. I think the confusion comes in because in '67, after the tripower was banned, the magazines were saying that a 4v 400 could beat a 6v 389. They wanted to sell GTO's, and wanted the public to know that the GTO was in no way diminished. It wasn
't: the '67 400 had more cubic inches and far superior cylinder heads and exhaust manifolds. It could beat a 6v 389 with a single 4v. BUT: what if the tripower were bolted on to that '67 400?? The 428 in the test showed a huge improvement. My own '67 showed a huge improvement, though it was a "seat of the pants" measurement, as I did not run the car at the track. It seems that the real racers out there are running a big 4 barrel carb. But, what I want to know is, can a Q-Jet on a stock intake be made to run stronger than a tripower? I'm open to all answers!!! Thanks.


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## Rukee (Feb 8, 2007)

erm, sure if the Tri-Power is not set up correctly, but for the most part a Tri-Power set-up flows more air then a 4bbl.


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## 68greengoat (Sep 15, 2005)

Unless this is a hypothetical question, the first thing that came to my mind is, will the gains of a tri-power outweigh the additional maintenance of a tri-power? I'm assuming a q-jet would be easier to maintain even if it cannot be built to outrun a tri .. Especially, if you're not planning on running it on a track..


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## geeteeohguy (Feb 2, 2008)

No, GG. This is a "hands on" question. I want to know what other people have experienced/what they're doing. In my experience, I've rebuilt the q-jet on my '67 twice in 120,000 miles and 28 years (original carb, has 242k on it) and I've rebuilt the tripower 0 times in 60,000 miles and 29 years. The tripower is a low maintainence unit, in my experience. I guess what I'm asking is, can a Q-Jet be "worked" to beat a "worked" tripower? (Jets, metering rods, etc.) My experience has been that the tripower produces more power than a q-jet, all else being equal. A buddy just finished the restoration of an HO spec '67 GTO, and he's running a '66 Tripower on it instead of the Q-jet he used to run. He too says it's faster than it wver was with the stock Q-jet.....this should be interesting.


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## BearGFR (Aug 25, 2008)

Well now, that's an interesting question. I've always been in the "Qjets are faster" camp, but mostly because "other people" I tend to believe have said so. "They say" that tripowers have fuel distribution problems due to the relatively large area the carbs are spread over and the resulting unequal length intake runners.

Ack-shully though, I 'spose the only way to get a definitive answer would be to run both on the same car at the same track on the same day, with both setups optimized as much as possible for the car, and just see what the clocks have to say about it.

Anybody out there in a position to do that? Or have results from it having been done?

Bear


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## geeteeohguy (Feb 2, 2008)

Bear, I think I would need to ship you my '66 Tripower so you could dyno that 461 of yours and see what comes up!!! Seriously, though, I'm curious. I'll try to dig up the HPP article and post the actual numbers...I read it again last week. I think a true Q-Jet Guru would know a lot about making power with a Q-Jet as opposed to myself. I know they are excellent, and can move a bunch of mixture. I think a definitive test like you mentioned would answer a few questions, too. (same car, same conditions, just a manifold/carb swap) and run the numbers. Thanks.


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## dimitri (Feb 13, 2009)

In the early 80's with my 68 GTO 400 I got a H-O Power Kit which included instuctions on how to modify my Qudrajet and different springs, jets, rods, etc. This also included a kit for the distributer. I did this to my engine and was very happy with the results. A friend of mine had a tri power intake set up that he was not using. I took off my quad set up and installed the tri set up. What a big difference in power the tri set up had over the quad. I ran it that way for about a year and changed back because I could not afford the fuel it was consuming. At full throttle you can see the gauge drop.


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## freethinker (Nov 14, 2009)

geeteeohguy said:


> I guess what I'm asking is, can a Q-Jet be "worked" to beat a "worked" tripower? (Jets, metering rods, etc.) .


 it boils down to this.a qjet flows about 750cfm. a tripower flows about 900cfm.


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## jetstang (Nov 5, 2008)

You guys made me think about this, and yes a tri power of equal CFM will outperform a single carb. The middle cylinders are richer than the outers with a single carb set up, as the runners are shorter in the middle, thus compromising both. Now, most cars don't have TBIs, they have MPFI, injector for every cylinder, making every cylinder equal and optimizing power by not compromising anything. Now, the DI-direct injected motor is computer controlled to inject the fuel at the correct time, not just squirting fuel and waiting for the valve to open. GM is getting 305 BHP out of it's stock DI motors, so HP is really in the 400 range, question really answers itself.. Technology is pretty cool.


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## 68GTO4004Spd (Jun 19, 2008)

I don't know for sure if you can get better performance out of a tripower or a quadrajet. I do know that the guys with f.a.s.t (factory appearing stock tire) racing lay down some fast lap times with well turned quadrajets. Check out this guy running 11.62's in a Firebird with bias ply tires in the stock class.

F.A.S.T. - Factory Appearing Stock Tire - hide FAST Racers - FS Rick Mahoney


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## Rukee (Feb 8, 2007)

dimitri said:


> In the early 80's with my 68 GTO 400 I got a H-O Power Kit which included instuctions on how to modify my Qudrajet and different springs, jets, rods, etc. This also included a kit for the distributer. I did this to my engine and was very happy with the results. A friend of mine had a tri power intake set up that he was not using. I took off my quad set up and installed the tri set up. What a big difference in power the tri set up had over the quad. I ran it that way for about a year and changed back because I could not afford the fuel it was consuming. * At full throttle you can see the gauge drop.*


I always say mine will pass anything on the road, sept the gas station!! :willy:


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## likethat (Oct 5, 2007)

I say Qjet. Just pm me, so I can send you my shipping addy for you to send me those crappy tri power set ups. I will recycle them.


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## xconcepts (Jan 4, 2009)

I replaced my 750cfm 4brl Q-jet on my 66 to the original tri-power and felt a decent gain, I would agree with about 50hp.


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## Tropical Goat (Jan 30, 2011)

Well!..This is certainly good news to me!
I too, have always heard that the Q-jets were the way to go, as far as performance goes. ...much to my dismay, I might add, because I've always loved tri-power.
Looks like I've just added a new sub-project to my goat. I can handle the maintenence.
...I just wanna hear that banshee WAIL!


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## SIXT5GTO (Mar 9, 2010)

Are there any special consideration when running a tri power on a two speed auto car with the 3.08 gears.
I want to make the car look stock but dont know how well a reworked stock carb and intake will perforn compared to a holley street advenger 670CFM with Edlebrock performer manifold. I under stand the stock maniford will probaly give me a better low end.
The car does have a after market cam in it. best power seems to be at 3000 - 5200(the shift point)
With this drive train will the Tri Power still be the best option for performance.


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## geeteeohguy (Feb 2, 2008)

Yes. Tripower came on many GTO's with the two speed and mild gears. It will walk all over your Holley street avenger. And, contrary to misconception, they are low maintainence, dependable units.


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## peahrens (Jun 7, 2010)

Regarding maintenance on the tripowers, I rebuilt my '66 front and rear carbs in '92 and put on a replacement 2bbl Rochester then (wanted to start fresh). Had two problems over the years; 1: some leakage around the top/base flanges, 2: one end carb got gummed up and had to be rebuilt again. I'd never rebuilt carbs before and it was reasonably straightforward. Last year I rebuilt them all again as the engine was pulled for a rear main seal and lifter work. I rebuilt the carbs again, and have a couple points to make there; since my center carb was not quite an original type, I had to order the 3-deuces kit (for the end carbs) and also the specific kit for the replacement carb number (I think it's a later Firebird or other). I didn't mind the extra cost as long as it went right. I bought through Ames, but talked with their supplier. He explained that their kits were very carefully assembled; things like leather cups that work with ethanol mixes, etc (if I remember right). Also, I tied to flatten the carb base to upper horn flanges to avoid leakage by sanding them a bit on a flat glass plate, a trick the garage suggested. The point is, there may be some maintenance quirks to be aware of to avoid problems. So far (only 300-400 miles) they work ok and leakage mess at the flange points is minimal.


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## geeteeohguy (Feb 2, 2008)

Any induction system will need some initial refurbishment if its 45 years old, be it a single two barrel, 4 barrel, or triple two barell. Once "set up", the tripower is a solid, trouble free unit. Only the middle carb has a choke and idle mixture circuit. The one on my '65 has been on the car since 1965, and I think I kitted the carbs in 1982. They have not been touched since. Yes, they look grungy, but they work great. I have a '66 Tripower setup that sits in my garage for years at a time, and then I'll throw it on an engine and run it....I replaced the center carb in 1979, but never even kitted the outer carbs. It is "ready to bolt on" as we speak. My personal opinion is, if you can run a tripower, do it. You'll love it!!!


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## daveh70 (Sep 4, 2008)

I'm a little surprised some say it's trouble free once set up. I've had my car w/the tri power a short time, about 4 years now. The center carb and tri power setup has needed 3-4 adjustments with various things. But when I had the 67 w/the quadrajet, it was serviced once and never again needed work the remaining years I had it. May be just luck...


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## geeteeohguy (Feb 2, 2008)

Dave, that's funny...My experience has been exactly the opposite of yours. As I've said, I haven't fiddled with my TP for decades, but I've rebuilt/repaired the Q-jet on my '67 maybe 4 times in fewer years. Must be the luck of the draw.....


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## jetstang (Nov 5, 2008)

Carbs are funny animals, any little issue will show itself. The 2 barrel is a dead simple carb. Quadrajet is a little trickier. If you get a good one, or a pro rebuild of either carb it should be troublefree, and run stronger. Fuel injection is self adjusting, while carbs need adjusting from time to time.


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## Eric Animal (Oct 28, 2007)

I saw a 66 GTO...389 with a 671 Weiand SC on it....and 6 Strombergs !!!!! Looked very cool and actually ran OK !......just sayin' E


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## geeteeohguy (Feb 2, 2008)

Another thing, I think it depends on the individual unit. Yes, the 2jet is simpler than the Q jet, but there are 3 of them...more to "go wrong", 'though the outer two carbs are really simple. In my case, I've driven the tripower car about 50-60k miles in the past 30 years...the Q-jet car has been driven over 130k miles, so twice the wear and tear, etc. My Q-jet had the typical thread rot at the fuel inlet and the well plug leaking issue, but that was taken care of years ago. A quality rebuild kit and a good float, and they are very, very reliable. My unit is the original one, with over 240,000 miles on it, and it works great. The last rebuild was back in the early '90's, and I removed and cleaned it externally a couple of months ago when I had the engine out for the reseal job. Bottom line, Tripower units are not some exotic, hard to tune, high strung system. They are reliable, effective, and flow more CFM than a Q Jet or most Holley's.


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## freethinker (Nov 14, 2009)

the biggest problem with the tripower is when the two end carbs dont get used that often. the gas just sits there and eventually evaporates and leaves behind scum that gums up the carb. gas with ethanol is even worse. ethanol turns to glue when it evaporates. the solution. burn more rubber more often. keep cycling fresh gas in those end carbs.


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## Eric Animal (Oct 28, 2007)

:agree I think that is even stated in the OWNER'S MANUAL :lol:


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## my66 (Apr 27, 2011)

I have a 400 with a tripower that will sit you back in the seat. I would love to know what Kind of HP it is pushing. Not sure where to find specs to see what they were rated and how much more the tripower improves it.


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## freethinker (Nov 14, 2009)

my66 said:


> I have a 400 with a tripower that will sit you back in the seat. I would love to know what Kind of HP it is pushing. Not sure where to find specs to see what they were rated and how much more the tripower improves it.



June 1995 issue of High Performance Pontiac. The article is entitled, "Four Barrel vs. Tri-power." The authors employed the services of Jim Taylor to assist. They took a well performing 68 GTO, 428 car, 4 speed with slicks. All launches were made at 1200 rpm and shifts at 5200. Car went throught the traps at 5400-5500 rpm.

The Q-Jet had was dialed in on the car. It was equipted with Edelbrock jets, rods, and high-flow needles. In other words, this carb was modified slightly to match the needs of the car.

The 66 tripower was stock except that the choke plate in the center carb was removed and the jets were replaced with 70s in the center and 72s in the ends.

Three runs were made with each set-up. Results:

- Q-Jet tripower 
run 1 13.28/101.7 12.93/103.9 
run 2 13.33/101.5 12.92/103.8 
run 3 13.29/101.8 12.89/104.1 
AVERAGE 13.30/101.66 12.89/103.93 

The author calculates the 2.27 mph gain to a 22 hp gain over the 4 bbl. He attributes the gain to the tripower's shorter and straighter intake runners and its greater CFM flow.


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## geeteeohguy (Feb 2, 2008)

freethinker, that's the article I read a while back... thanks for posting it. Facts are much more valuable than speculation. Again, when I ran the tripower on the stock 400 that's in my convertible, it felt like a 40-50hp gain. Nothing else was changed. The tripower is an excellent choice for a high performance Pontiac, IMO.


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## my66 (Apr 27, 2011)

thanks for the info. I will find teh article and read it.


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## daveh70 (Sep 4, 2008)

...and now I'm having a problem with the fast idle screw that won't make contact with the "fast idle cam" on the center carb. When I push the unit holding the screw on to the cam (or little metal circular piece), then the idle is correct. Idles way too fast now because of it. This happened once last year and the problem was a bad accelerator pump in the center carb. I'll have to get it checked out.


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## freethinker (Nov 14, 2009)

remove the linkage to the end carbs and see if that will allow it to seat. they have to be syncronized to close the carbs


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## BearGFR (Aug 25, 2008)

geeteeohguy said:


> freethinker, that's the article I read a while back... thanks for posting it. Facts are much more valuable than speculation. Again, when I ran the tripower on the stock 400 that's in my convertible, it felt like a 40-50hp gain. Nothing else was changed. The tripower is an excellent choice for a high performance Pontiac, IMO.


Well there ya go. In the past I've been guilty of repeating the "folklore" that a well set-up QJet would outrun a tripower, mostly because I'd heard it from other 'reputable' folks - I'd never seen objective tests or tried it myself.

Turns out this just might be one of those instances that illustrates the principle: "If the only tool in your box is a hammer, then every problem starts to look like a nail." 

Bear


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## Purple Haze (Feb 27, 2011)

This forum rocks !!......... you guys are making my decisions soooooo easy!! A 6-pak, RA exhaust and a Keisler 5 speed!!! Oh yeah!!!

Ric


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## jetstang (Nov 5, 2008)

Purple Haze said:


> This forum rocks !!......... you guys are making my decisions soooooo easy!! A 6-pak, RA exhaust and a Keisler 5 speed!!! Oh yeah!!!
> 
> Ric


Six pack is Mopar.. Tri power.. All is good :cheers.
Exactly the same reason why a Direct Injected motor works better than a throttle body. All cylinders get exactly the same fuel charge, not middle cylinders rich, outers lean.


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## Purple Haze (Feb 27, 2011)

Hey Jet................ I know what you're saying but........ it's sure-grip/posi-trac/limited -slip.......... all is the same right?? :cheers


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## jetstang (Nov 5, 2008)

Purple Haze said:


> Hey Jet................ I know what you're saying but........ it's sure-grip/posi-trac/limited -slip.......... all is the same right?? :cheers


LOL, not my words, it was coorporate advertising their product. Not trying to be a butt, but 6 pack is a mopar thing. Sure grip is Mopar, not sure on the others, but same point, same product, dif name.
:cheers


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## Purple Haze (Feb 27, 2011)

jetstang said:


> LOL, not my words, it was coorporate advertising their product. Not trying to be a butt, but 6 pack is a mopar thing. Sure grip is Mopar, not sure on the others, but same point, same product, dif name.
> :cheers


All is good............... my Mopar was just loaded on the trailer to Florida!!!! 64 3834spd, AC PW,PS,PB,radio with rear speaker & reverb.

here's my other six pack.(not me!!)


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