Thermoquad vs. Six Pack/Six Barrel. Which is best ?

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Any temperature fluxuation and I had to tinker with that air door again.

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DOOR tinkering ...do it once ..and do-it correct ...with the RIGHT tool !

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The 6-pack is a proven performance intake for hot street/strip cars.

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The tq can be a good carb, however there's a shortage of good spreadbore intakes out there..

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However the secondaries were a pain to keep in tune. Any temperature fluxuation and I had to tinker with that air door again.

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F1Scamp Just conducted a test. Seems his new thermoquad car can't run with his six pack car. So he swapped the six pack on to his 71 340 Duster and ran it at the track. The car picked up 3 mph over the TQ. Now there was a elevation differance of about 2000 ft but that doesn't equal 3 mph. Keep in mind the TQ intake is all tricked out and the Pack is stock.

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In general I would guess the same results but would also bet on a close race either way. That being said, I don't think the above comparison is really fair to either setup, to do a real scientific experiment you need to eliminate as many variables as possible to prove a hypothosis.

A dyno test (track test on a car being second choice due to other variables with the car, track and weather) done on the same day with both setups being 100% stock (carbs and intakes) being the only variables as a baseline, then start experimenting with one change at a time and rechecking the results, that's about the only way to really reach any real conclusions IMO. Comparing a modified setup to a stock setup isn't fair in either direction since some modifications may actually hurt performance.

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bla bla bal, if the T-quad was/is so great somebody would re-pop it and make a mint. It's a good carb, I oved my T-quad 440, but a well tuned six-pack (and you have to tune any carb) will out run the T-quad. and they won't melt if you should have a good back fire or carb fire.

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In general I would guess the same results but would also bet on a close race either way.

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Oh no doubt, a well tuned setup is in the 15-20 hp range.

Aside from the HP difference I also value simplicity, (fewer things to go wrong) and ease of tuning.

From those 3 standpoints alone 6-pack loses.

For looks its had to beat a six-pack or dual quad setup though

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That being said, I don't think the above comparison is really fair to either setup, to do a real scientific experiment you need to eliminate as many variables as possible to prove a hypothosis.

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He loaded it up and it backfired, Don't know how he did it but the carb never worked after that. I even rebuilt it and had a pro take a stab at it.

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Relax, all right? My old man is a television repairman, he's got this ultimate set of tools. I can fix it.

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So how many power valves do you have to replace on a six pack after a backfire?

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Only one just like any other old holley out there...And if it's backfiring your not getting fuel mileage or performance tuned like that !!! ...I'll take the 6 pack thank you...I can show you the good gas mileage I get right up to the point where the other two carbs come in... ..

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Hey Scott, Here's the thing... Chrysler thinks its 15hp better, NHRA thinks its 14hp better and some guy I know thinks his car doesn't go as fast with a thermoquad. How is that for scientific?

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Well, since we are going on looks alone I think this one is the clear winner

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Good idea Tom! I can give you a 440 TQ intake if you need one, I'm pissed at it anyway, stubbed my toe on the turd the other day

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If someone out there has a B engine spreadbore dual plane aftermarket intake I could borrow I bet we could close in on the pack.

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Well, since we are going on looks alone I think this one is the clear winner

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Speaks for itself!!

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I have ran 2 440s with the Edelbrock dual quad package. 2 500 cfm carbs with a 1 to 1 linkage. Great great and GREAT performance and looks! I know it not a mopar OEM offering but it is an era correct hi po set up. Its about half the price of a sixpack and easier/less expensive to tune. Id LOVE to see a shootout between the Six Pack and the Edelbrock CH28 with 2 4bbls.

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They (Chrysler) did offer a 2-4bbl inline setup
for the RB motor in the late 50's - early 60's.
The EDDY piece you have is a good design, lightweight and WITHOUT core shift (very little restriction in airflow). The shootout would awesome - try all three!!

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Since this is a question and answer forum, doesn't economy vs performance come into play. There are a lot of 4 barrel cars out the and not very many 6 pak cars. I will be replacing my Holley 750 DP with a Thermoquad. I'll bet I get much better gas mileage and more power(faster) at the strip. I have already tried the race on an engine dyno and the car was a pig at the strip. I changed cams, put on a dual plane spread bore manifold, took out the 4.30's and put in 3.23's. I realize now that a big part of my problem is a 410 stroker with Diamond rectangular port aluminum w2's. No torque down low. I'll let you know after I go to Sacrmento in September. Top gun dragstrip @ 4000' won't tell me much. The car ran 13.54 @100 mph at Top Gun in June. It didn't even start to run until 330'

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Would you up the gear to 3.90 for a comprimise with the TQ. 3.23's may be a bit too high, I could be
wrong, since I don't know how high your torque
band is and converter's stall speed if an automatic.

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If need be I'll be happy to prove it. I'll have a new car coming out soon that I think would be the perfect test bed. It's a 72 400 Charger,TQ equipt of course. I'd have no problem swapping a pack on at the track,I own the parts. The car doesn't have fresh air so that wouldn't be a factor. I have the ability to set the A/F ratio in either setup to the other. I'm well versed in both setups. Its 8 bolts to me Sounds like fun

I'd be willing to bet on the pack by about 3 mph. If someone out there has a B engine spreadbore dual plane aftermarket intake I could borrow I bet we could close in on the pack.

We could always toss a TQ on the Bee I'm sure that would slow it right down. I would have to see if I have any 440 TQ manifolds.

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Since this is a question and answer forum, doesn't economy vs performance come into play. There are a lot of 4 barrel cars out the and not very many 6 pak cars. I will be replacing my Holley 750 DP with a Thermoquad. I'll bet I get much better gas mileage and more power(faster) at the strip. I have already tried the race on an engine dyno and the car was a pig at the strip. I changed cams, put on a dual plane spread bore manifold, took out the 4.30's and put in 3.23's. I realize now that a big part of my problem is a 410 stroker with Diamond rectangular port aluminum w2's. No torque down low. I'll let you know after I go to Sacrmento in September. Top gun dragstrip @ 4000' won't tell me much. The car ran 13.54 @100 mph at Top Gun in June. It didn't even start to run until 330'

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...and doing it with the two-screwdrivers .. you [Edited by Moparts - Family Friendly Site - Keep it clean]-up the lock-screw ...plus if the spring snaps-back ... it can DISlodge or can break....

This tool here is soooooo much BESTer than the Miller part ...it makes the people's heads spin ...

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Wasssupy ? .. LOL

B.u.g.g.e.r.e.d - up gets an EDIT ?

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dude that hing is going to be a PIG w/ 3.23's you ran 13's before get ready for 14's ... at least you won't need a helmet

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Hay Y-guy .... watch what choo say

I am running mid-12's ...with a 2.76 gear ... ....

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So how many power valves do you have to replace on a six pack after a backfire?

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I have ran 2 440s with the Edelbrock dual quad package. 2 500 cfm carbs with a 1 to 1 linkage. Great great and GREAT performance and looks! I know it not a mopar OEM offering but it is an era correct hi po set up. Its about half the price of a sixpack and easier/less expensive to tune. Id LOVE to see a shootout between the Six Pack and the Edelbrock CH28 with 2 4bbls.

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How is the powerband and mileage with those 500's?

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How is the powerband and mileage with those 500's?

who cares about mpg? It's a 4 4 o! and if you go 2x4's do it right and get a set of holleys.
No idea but if I had to bet 2x500 eddys vs a 6-pack, I'll bet on the 6-pack. Now a set of DP's and a good 2x4 intake I'll take the twin holleys

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As it was explained beforehand, it's about VOLUMETRIC EFFICIENCY (thanks Scott for the great
tech on it! - ). Whether street,
race or in-between motor, it's about the VE. Build
power efficiently!!

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Well I can't tell you exactly when it will happen but I'm going to settle this question. Right now my dyno mule 440 is not in good enough shape to start comparing induction systems on a level playing field. You may or may not remember I bought a 2000hp Land & Sea engine dyno. I don't care how many hours it takes, I'm not paying for dyno time. Once things quit down around here I'll do the tests and and post all the results. Let the chips fall where they may. Dave

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Thanks Dave, keep us posted!!

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How is the powerband and mileage with those 500's?

who cares about mpg? It's a 4 4 o! and if you go 2x4's do it right and get a set of holleys.
No idea but if I had to bet 2x500 eddys vs a 6-pack, I'll bet on the 6-pack. Now a set of DP's and a good 2x4 intake I'll take the twin holleys

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THIS is the solution for the CFM advantage those pig-rich Berri Crabs have over the Plastic Fantastic !

YOU SEE how happy this guy is ....

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I would be happy with just ONE of those on a high rise intake. Why be GREEDY. They aren't AFB's!! Man-o-live!!

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I have no experience with a tq, but I cant complain about my 6pack, it just runs good. I have used a performer rpm airgap with a carter avs- I wasn't too impressed, then I went to the sixpack on a Weiand/mopar crossram- it ran a hell of a lot better, but didn't really pull below 3k. Then I swapped to a factory sixpack manifold, low end came back strong, but it did lose a bit up top.

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Why the crossram did that is because of the passages. They were tuned for 2.5k to about 6.5k.
The factory manifold is tuned for off-idle to 5.5k. Big difference!! The crossram needed gears
around 3.90 and up. The factory manifold would be comfortable with gears from 3.55 to 4.10
before rejetting for bigger gears.

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Great topic, and another ?

Which is a better manifold, the BB six pack or the small block manifold itself.

My slightly modified sb likes 7k max, ive run it to 7600 but it seems to fall of at 7.

Good Vid...pretty mild combo but the six pack works well..

http://www.youtube.com/watch?v=MxsguEwUgew

As far as stock for stock in the early 80s two friends, one had a very much stock 69 340/4 speed 3.91 Dart. Another an AAR Stock auto with 3.55s.

I know of no mods on the aar, the only thing we could tell on the dart was it had the big plastic spreadbore on it and it must of been lean as it got run hard and when running top end blasts you could eat a plug strap.

No getting back to the cars...I would say out of about 10 runs over a couple year period it was always the dart by a car length weather from a dead stop or a slow roll. stick/3.91 vs auto/3.55.

Both the aar and the dart were good running stockers and even in the early 80-s matching numbers, NOS, fender tags, never entered our minds just two cars on a country road doing what they were built to do...and them were some fun times.

Ive never run a tricked out T quad, but im leaning to one on a stock manifold/in a stroker motor in a driver project im working on.

I hate to ask the cost of a good 1000cfm unit, but then again it would still be cheaper then the full SP setup.

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That would be an interesting topic! I think that the AAR was lacking in the gear department to run
EVEN with the Dart. The AAR might have had close
to 200 pounds extra weight to run with. Maybe the
combo of these factors could have been corrected
and the race would have been even, who knows. It
goes back to airflow, and how efficiently the motor breathes!! Seems like the stick/TQ combo
had a slight advantage over the auto/sixpack setup. Had the AAR ran 3.91's also, things would have been REALLY interesting!!!

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Great topic, and another ?

Which is a better manifold, the BB six pack or the small block manifold itself.

My slightly modified sb likes 7k max, ive run it to 7600 but it seems to fall of at 7.

Good Vid...pretty mild combo but the six pack works well..

http://www.youtube.com/watch?v=MxsguEwUgew

As far as stock for stock in the early 80s two friends, one had a very much stock 69 340/4 speed 3.91 Dart. Another an AAR Stock auto with 3.55s.

I know of no mods on the aar, the only thing we could tell on the dart was it had the big plastic spreadbore on it and it must of been lean as it got run hard and when running top end blasts you could eat a plug strap.

No getting back to the cars...I would say out of about 10 runs over a couple year period it was always the dart by a car length weather from a dead stop or a slow roll. stick/3.91 vs auto/3.55.

Both the aar and the dart were good running stockers and even in the early 80-s matching numbers, NOS, fender tags, never entered our minds just two cars on a country road doing what they were built to do...and them were some fun times.

Ive never run a tricked out T quad, but im leaning to one on a stock manifold/in a stroker motor in a driver project im working on.

I hate to ask the cost of a good 1000cfm unit, but then again it would still be cheaper then the full SP setup.

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A GOOD 1000 cfm TQ setup would be equivalent to
the factory six pack setup, engine depending (cubes, compression, cam timing, exhaust tuning
and ignition setup/timing). The cost may be on a sliding scale depending on the engine also!! Either one you can,t go wrong!! Thanks for the
input, fellow members!! You have given me food for thought!!

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Hyper ..... put DOWN that fattie and step-back from that keyboard ....and "eat" some of that food-for-thought !!

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Mediators please step in at any time!! I have ZERO tolerance for the sarcasm OR stupidity.

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Hyper ..... put DOWN that fattie and step-back from that keyboard ....and "eat" some of that food-for-thought !!

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If this is the thoughts and professionalism of a
Thermoquad expert, no wonder why so many members RUN HOLLEYS!! Scott Smith you've got my vote.

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six pack will only open the outboards either too fast, to slow, or just what the engine needs (ie not fully open), depending on the spring.

thermobogs put all four blades on end when you firewall it, and the air valve open fairly fast without the dreaded "bog".. as long as a wanna be tuner never touched it.

so my vote goes to the T-bog.

YAY!

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I am a very firm belelver in the T-Quad, I love them and I put them on everything but even I have to admit, they are THE ugliest carb EVER made!

I think the Holley HP carbs look the best but I can never get them to run right and they sure drink gas too.

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Any temperature fluxuation and I had to tinker with that air door again.

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DOOR tinkering ...do it once ..and do-it correct ...with the RIGHT tool !

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Thats an intelligent statment a lot of the buick guys use them in place of the QJ for more flow on the 455

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Oh yeah .. the Buick guyz love 'em !!

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...but for racing or hot street car you dont see a guy putting a t-bog with adaptor on sigle plane m-1 intake....

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No you don't, because the M1 is Thermoquad ready, no adapter needed! The same is true of the Street Dominator.

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Heres the Holley street dominator with my 910cfm t-quad. Also like the sound of the big secondary air doors slamming shut when i let off of WOT!!

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Makes an EVEN BETTER sound opening up thru the gears!!

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Not to steal the thread from the OP, but if you guys had a choice, would you choose a stock holley with vac secondaries or a T-quad?

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stock holley? like the small vacuum units they used? Or a nice 750vacuum or bigger?

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Yes I'm referring to the small vacuum units that came on most of our cars stock. I have no idea how well they work since I haven't had any experience with them.

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