# Tri Power or 4 BRL



## SIXT5GTO (Mar 9, 2010)

I wanted to keep make the 65 as close to stock as possible but was still thinking about putting a tri power set up on the car or find a 4 brl set up for it.
I have always liked the tri power but would be the recommendations,
I hear the tri powers are hard to keep tuned , have more problems and it would lower the value of the car. I was not quite sure about the last one, 
This is the wife's cruiser, She does not mind the go fast stuff, so I just want to keep the thing where she can drive it when she wants,
I am not always around to work on the thing.
Thanks


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## Koppster (Jul 27, 2008)

I'm not an expert but I think the "hard to tune" thing is a myth or probably comes from the 64 vacuum linkage units. My understanding is the later 65-up mechanical linkage units work just fine. They are expensive and you really need to do your homework to make sure you aren't buying a pretty piece of junk that will need big time rebuilding. And.....when you get in to tripower there's a whole new numbers matching and tag game for the carbs. 

As for value, tri-power will likely increase the appeal for your car, most folks associate tri-power with GTOs.

Horsepower-wise, I've seen specs that show the 4-bbl's produce as much if not more horespower "depending" on the carb and engine configuration.

If you go 4-bbl, I'd recommend you spend some bucks and get Cliff Ruggles to build a Rochester Quadrajet for you. I have an Edelbrock and it is "okay" but I plan to replace it with a Rochester.

Again, I'm no expert, just repeating what I think I've gleaned from the real motorheads on this forum and others.

Rick


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## Rukee (Feb 8, 2007)

I'd do the tri-power, once set-up you really don't mess with it. Been 16yrs on mine with only filter changes.


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## 05GTO (Oct 6, 2004)

The only time I see a 64 or 65's value lessened by a tri-power is when you have a PHS numbers matching 4 bbl car that someone has changed. In some cases the car will retain the highest market value if the correct carter afb 4 bbl carb and manifold are included with the sale of a tri powered car.

A PHS documented tri-power GTO will always bring more dollars than a 4 bbl car!


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## jetstang (Nov 5, 2008)

A good 4 barrel will out perform a tri power setup. But, the cool factor of a tri power outways any performance disadvantage. Tri power will get really good gas mileage if you keep your foot out of it, as you are only running off of a small 2 barrel carb. The transition between 1 and 3 carbs is where the tuning issue is, but once you have it set, you should be good to go. I would think you would have to jump on it about everytime you drive it to make sure you keep fresh gas in the outer carbs, so they don't gum up from evaporation and old gas.


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## geeteeohguy (Feb 2, 2008)

I have run both 4 barrels and tripowers since the 1970's, and I prefer the tripower. In my experience, they produce more power, particularly in the midrange and top end. Unreal. My '65 is a born-with tripower car, and has never had anything else on it. The set-up is reliable and extremely low maintenence, as any tri-power guy will tell you. There is only one choke, and one idle circuit (middle carb), and the linkage is adjustable to your liking. Mine is set up stock, the two outer carbs kick in at about 75% throttle. You could drive the car all month and never even know the other two carbs were out there, waiting. The power kick when you nail it is UNREAL. That said, I've had Carter 4 bbl GTO's that ran really well, '65's and '66's, but they ran harder when I put a tripower on them. My latest experiment is with my '67 GTO, which came with a Q-jet. I ran a tripower on this car for a short time about 15 years ago, and the tripower (a '66 unit that I have laying around) produced , in my estimation, about 30-50 HP on the midrange and top end. HUGE improvement over the Q-jet. There was an article back in '67 in Hotrod or Carlife magazine that said the new '67 Q-jet was just as hot as the old '66 Tripower set up. It was. What they DIDN"T say was the '66 was a 389, with old-school heads, etc. , and the '67 was a new 400, with the big valve heads and more inches. When I put a '66 tripower on my stock '67 400, it put out a lot more power. I then put the Q-jet back on, because I liked a "correct" engine bay. The Q-jet will get good fuel mileage due to its tiny primaries, even better than the tripower, if you keep your foot out of it. That said, what you run is up to you. Tripower GTO's are like SS El Caminos or '32 Fords: there are a whole lot more of them around now than when they were new, it seems! The newer, hi-tech non stock carbs and intakes are probably another story. I see a lot of that stuff at the drags and online, and the real aluminum-head, stroker, forged-rod guys all seem to run huge 4 barrels. I am not in that league. (But, if I ever build that drag car, who knows????)


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## SIXT5GTO (Mar 9, 2010)

Good to know that I can set up the tri power and it will work fine,
I will have to see what the wallet can handle, I like the tri power but it is a 4 bbl car.
I guess I will see what I can find to replace the after market high rise
Thanks for the information.


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## Eric Animal (Oct 28, 2007)

Add the TRIPS and save the 4bbl for resale so much fun look cool and sound great!! arty:


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## Rukee (Feb 8, 2007)

jetstang said:


> A good 4 barrel will out perform a tri power setup. But, the cool factor of a tri power outways any performance disadvantage. Tri power will get really good gas mileage if you keep your foot out of it, as you are only running off of a small 2 barrel carb. The transition between 1 and 3 carbs is where the tuning issue is, but once you have it set, you should be good to go. I would think you would have to jump on it about everytime you drive it to make sure you keep fresh gas in the outer carbs, so they don't gum up from evaporation and old gas.


Yea, not sure what planet a 4bb will out perform a tri-power set-up, but not on this one. Stock for stock a tri-power will always out perform a 4bb.


...and keeping fresh gas in the outer carbs is just one of the benefits! :cheers


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## my62toy (Jul 15, 2009)

I personally went the stock 4 BBL route, mainly because it is different. There appear to be far more tri-power GTOs out there than ever left the factory. Given my car is a 2 door post and had few options to start with one has to believe the original buyer would not have added tri-power while giving up niceties like power brakes. Unless of course they bought a race car! I do like the clean look of the single Carter AFB on a stock blue cast iron manifold. My choice for what it's worth!


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## johnnylightning03 (Nov 27, 2007)

Eric Animal said:


> Add the TRIPS and save the 4bbl for resale so much fun look cool and sound great!! arty:


:agree that is exactly what i did. i figure a good tri power will be harder to get and more expensive in the future. so now i have both and it is obviously a bolt on reversible swap. mike wasson from pontiactripower.com can answer any questions, has all the parts and a instructional dvd. check him out. :seeya:


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## daveh70 (Sep 4, 2008)

If I were the buyer, I would prefer the original 4 brrl if that's what your PHS says. But I wouldn't mind much if you made it a tri-power and also gave me the old manifold and carb.


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## SIXT5GTO (Mar 9, 2010)

thanks for bringing up a lot of points that I have been thinking about,
I like the four bbl because you do not see many cars set up with them and it is a 4bbl car.
So I will tri to find the parts for that first and then work on the tri power just because i like the set up and I am sure I will be able to talk the wife into letting me drive it now and then,
Where should I look for the parts for both. 
Thanks again everyone


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## Koppster (Jul 27, 2008)

Relevant thread, look at post 34, published article on shootout between tripower, quadrajets and AFBs:

Tri-pwr vs. Q-Jet - PY Online Forums

Here's another good link with some data on tripower vs four-barrel horsepower and maintainability:

Tripower Myths - Pontiac Tripower.com - Your One Stop Tripower Shop


Bottom line, I can't find an authoritative source that shows 4 barrels out-performing tripower. I believe the specs I saw were for dual quad vs tripower.

Rick


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## jetstang (Nov 5, 2008)

Good article Koppster.
In the day, you were forced to use multiple carbs to meet the CFM needs of your motor. Now, you can buy a 1050 CFM dominator, or bigger carb. When I said a 4 barrel will outperform tri power, I wasn't talking q-jet, I was talking Holley or Demon. Tri power cars run good numbers, but with it being a mechanical secondary system, it is up to the driver to determine when to open it up, hence creating a bog if done to early. Mechanical secondary carbs are reserved for light cars with huge cams that have a weak vacuum signal for the carb. All other cars should use a vacuum secondary carb that opens when the vacuum signal is showing the car wanting more gas, thus opening the secondaries. If you have the carb set right you should never feel the a secondary hit, just smooth power throughout the power band. If your car surges when you hit the secondaries, that is a bog.
Here's the formula for determining carb size:

CFM = cubic inches x rpm x Volumetric Efficiency divided by 3456

so using that formula

438 x 6000 x 80% / 3456 = 608 cfm

A 600 CFM doesn't sound like a lot of carb for a 438, but big CFM carbs and guys go hand in hand, always want more even when not needed.. Supercharged engines need more carb, and this formula doesn't work.


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## geeteeohguy (Feb 2, 2008)

When I'm "clearing the stale gas out of the end carbs" (a Rukee-approved preventive maintainence procedure)I have never experienced a bog. If you open up the tripower in all the tripower cars I've driven, including my present '65, even at 2000 RPM, there is no bog. The tires start boiling and the thing snaps sideways, according to road-crown. I think for basically stock applications and for driver cars, Tripower is hard to beat. I also notice when I go to the drags, that pretty much none of the Pontiac guys run tripower. They have the huge 4 barrel and the tunnel intake, KRE heads, etc. Thanks for posting the link to the articles!!


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## Rukee (Feb 8, 2007)

:agree
mine has no bog at any speed, any gear when you give it the berries, it only wants to suck the paint off the hood!!


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## jetstang (Nov 5, 2008)

Rukee said:


> :agree
> mine has no bog at any speed, any gear when you give it the berries, it only wants to suck the paint off the hood!!


That's because you are the man! No, really!
You could supertune a Holley and have the same or better performance. It all comes into play when you are racing it at the strip and are trying to pick up a couple tenths. My neighbor picked up 3/10s by swapping back to his cast iron 4 barrel intake from an Aluminum one. His story, not mine.. But, he ran a 12.4, so he had the car hooked up.


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## Gran Turismo (Jan 12, 2010)

No debate' TRIPOWER end of story.:cheers


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## Koppster (Jul 27, 2008)

Jetstang

Jim Hand's book has a table that shows the results of his testing of a fair list of intakes. Bottom line, with one exception (Edelbrock Performer), the stock intakes outperformed the aftermarkets. That surprised the heck out of me.

Rick


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## geeteeohguy (Feb 2, 2008)

Not me. The Pontiac engineers knew what they were doing. I've found that in most cases, performance "upgrades" are inferior to correctly assembled factory set ups. Just my personal experience, as an auto tech for over 30 years. If performance is gained, reliability and integrity suffers, and vise-versa. Jetstang, if you ever drove a tripower, you would be a believer, too. Try it some time. As Rukee said, "stock for stock', can't be beat. Funny thing is, I haven't touched mine except for air filters for over 20 years. The spare '66 unit I have sits around about 10 years in between each project, and always seems to work. No rebuilding, no nothin'.


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## Eric Animal (Oct 28, 2007)

Gran Turismo said:


> No debate' TRIPOWER end of story.:cheers


The 4bbl guys are forgetting to figure in the 'coolness factor':agree


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## jetstang (Nov 5, 2008)

I need to read Jim Hand's book. I love the look of a Tri power, may have to try one when the funds permit. It makes sense I guess, 3 carbs make sure that all the cylinders get even fuel distribution, with 4 barrels the center cylinders are richer than the front and rear cylinders. Same reason a multi port FI makes more power than a throttle body FI.
When I was 12 I went to a garage sale and could of got a 66 GTO convertible with Tri power, but it had a CARB FIRE, and the paint on the hood was burnt up. They wanted $1500, but I probably could of got it for $1200, anyone got a time machine?


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## danthepontiacman (Jul 5, 2008)

why should anybody be surprised that stock pontiac parts outperform aftermarket stuff? and 60's pontiac stuff well heck thats when pontiac was at the top of its game and king of muscle or atleast king cept for the high doller hemis and other to rich for common person cars. i got a darn tempest with the 326 2v and a auto with a 1:76 first and a 2:56 rear and man that thing still has power, you put it in first and hit it at 30 mph and it lunches foward and throws you in your seat, it accerates ok from a stop to and this is there weakest v8. THERE WEAKIST!!!


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## SIXT5GTO (Mar 9, 2010)

*Added the Tri Power*



SIXT5GTO said:


> I wanted to keep make the 65 as close to stock as possible but was still thinking about putting a tri power set up on the car or find a 4 brl set up for it.
> I have always liked the tri power but would be the recommendations,
> I hear the tri powers are hard to keep tuned , have more problems and it would lower the value of the car. I was not quite sure about the last one,
> This is the wife's cruiser, She does not mind the go fast stuff, so I just want to keep the thing where she can drive it when she wants,
> ...


Well after looking for a stock 4brl intake, all I could find was a tri power set up.
So now the car has a 1965 Tri Power, Removed the Edlebrock performer intake and Holley advenger 670, and HEI.
I have to say off the line is a great emprovement, and the top end is better now too.
I seemed to of lost some vacume and the trans will not hold in gear as long as it needs too. shift was 5500 now 4200RPM. Still working on that.
It was a lot of work to get the carbs to a state where the throttle plates would seat and let the car idle right. once set up, it is an easy system to tune. Getting all the carbs to that standard can be some work and the cost was quite a bit more to set up then a 4brl. It does dress up the engine and people seem to love checking it out and take a trip down memory lane. it is what most people talk about when thay get on the subject of when the GTO came out.
I think eather set up looks great on the car, but I am happy with tri power.


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## xconcepts (Jan 4, 2009)

Welcome to the TRIPS family


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## VettenGoat (Jun 19, 2007)

On a 65 you can't go wrong with tri-power. I missed that earlier part about the 4bbl and intake not be stock anyhow. So now you're closer to stock, running better, and cooler factor doubled. Whats not to love?


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## peahrens (Jun 7, 2010)

My '66 was a (per PHS) 4-bbl car but had become a tri-power at some point. It's not numbers matching so I wanted it pretty "correct" looking. I noted the firewall plate doesn't indicate the tri-power is wrong (just the PHS doc) so I'm happy that it's cool and pretty correct looking. Since everything wasn't perfect, when I rebuilt things in '92 I bought a new Rochester 2Bbl center carb from Year One and rebuilt the end carbs. The mechanical linkage is straightforward and center choke works ok. With some engine work last year I decided to re-do the carbs. I had to buy the right kits...from Ames supplier (whom I discussed details with); that meant I had to buy the tripower rebuild kit for the end carb parts and a separate center carb kit for the specific carb I had acquired...which the supplier said needed different parts than the orig center carb kits are assembled. I second the mention above about getting fresh gas to the end carbs. After the '92 rebuild one end carb malfunctioned because I didn't open them up often and the gas got cooked in the carb after running. Now I open it up each time I go out weekly. Another detail...I got the car with K&N air filters and stuck with them since they breathe well and I was not concerned about show points (I could have the repro foam air filters to slap on if needed but never bothered). A guy advised me early on..."it's your car...do it the way you want". I like that advice.


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## geeteeohguy (Feb 2, 2008)

peahrens, X2 on the K&N. I've run them on my trips since the early/mid '80's, and wouldn't consider using anyting else. The paper AC elements get dirty and restriced in no time flat. The foam filters.....better off on my lawnmower.


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## 66COUPE (Jul 23, 2021)

Eric Animal said:


> The 4bbl guys are forgetting to figure in the 'coolness factor':agree


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## 66COUPE (Jul 23, 2021)

And everyone that’s ever owned a GTO knows what questions is coming regardless of the year “ does it have a tri power???”


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