Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: HYPER8oSoNic]
#779592
08/21/10 10:33 PM
08/21/10 10:33 PM
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Joined: Jan 2005
Posts: 12,424 Kalispell Mt.
HotRodDave
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I Live Here
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Kalispell Mt.
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The TQ will give more mpg because it mixes the fuel better in the very small triple venturi primaries, it will also be more responsive but a 500 inch BB with any 950-1000 carb should be very responsive. The one thing you can do with the TQ is bolt basically the exact same carb on a stock 273 and still have a very responsive motor, 6 pack, not so much.
I think air flow "up top" would be the same, but if I was forced to pick one I would guess the TQ with it's sewer pipe sized secondaries would flow more. Also it comes back to the manifold selection, a big single plane can bolt right on under the TQ and have a big plenum feeding all 8 cylinders from all 4bbls, the 6pack, well I don't know of any single plane for them, probably some odd balls out there but not many.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: ScottSmith_Harms]
#779595
08/22/10 02:15 AM
08/22/10 02:15 AM
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Joined: Jan 2003
Posts: 42,714 Spokane Washington
ScottSmith_Harms
Mr Wizzard
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Mr Wizzard
Joined: Jan 2003
Posts: 42,714
Spokane Washington
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Which carb(s) is better will be determined by the particular engine combo it's used on, every engine has different fuel needs. Keep in mind that carb cfm ratings are based on demand, most won't flow thier maximum advertised cfm unless under idealic circumstances. most carburetors flow much less than advertised during normal use. If you've ever had trouble figuring out what CFM carb your engine might need the formula below can be helpful: Multiply your engine's CID by the RPM of the engine, Divide the number by 3,456. Multiply the quotient by your engine's VE (volumetric efficiency). VE is a measure of how efficiently your engine pumps air. Generally a stock engine has a VE of .8, a race engine should be valued as .9, multiply this value by 1.35 for the minimum cubic feet per minute (CFM) rating that your engine can use. The CFM rating is used to classify carburetors, based upon how much air will flow into a WOT carburetor. The reason your results must be multiplied by 1.35 is that most carburetors work in pulses, and as a result intake will often be slightly above or below its average rate. The 1.35 modifier ensures that your carburetor can handle your engine at its maximum output. You want a carb that is equal to or greater than your final answer. Example, my engine: 340 Stroked to 426 cubes, max rpm 5,700rpm. 426 x 5,700 = 2428200 2428200 div/ 3456 = 702.604 x .9 = 632.343 632.343 x 1.35 = 853.66 cfmThis tells me that when my engine is at full song at 5,700 rpm it could need as much as 853cfm of flow to keep up with it. In my case an unmodified 800 cfm TQ may fall a bit short, but a 1,000 cfm TQ should do the trick with a bit of room to spare.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: DaytonaTurbo]
#779597
08/22/10 03:21 AM
08/22/10 03:21 AM
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Joined: Jul 2008
Posts: 30,491 Florida STAYcation
dOc …
The village idiot's idiot
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The village idiot's idiot
Joined: Jul 2008
Posts: 30,491
Florida STAYcation
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Quote:
Any temperature fluxuation and I had to tinker with that air door again.
DOOR tinkering ...do it once ..and do-it correct ...with the RIGHT tool !
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: dOc …]
#779598
08/22/10 04:28 AM
08/22/10 04:28 AM
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Joined: Feb 2003
Posts: 21,318 Manitoba, Canada
DaytonaTurbo
Too Many Posts
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Too Many Posts
Joined: Feb 2003
Posts: 21,318
Manitoba, Canada
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Quote:
Quote:
Any temperature fluxuation and I had to tinker with that air door again.
DOOR tinkering ...do it once ..and do-it correct ...with the RIGHT tool !
I never encountered a thermoquad that needed that tool. I know what it's for but I was always able to do it with a couple screwdrivers just fine.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: DaytonaTurbo]
#779601
08/22/10 07:43 AM
08/22/10 07:43 AM
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Joined: Jun 2008
Posts: 10,847 Oakdale CT
gdonovan
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I Live Here
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Quote:
The 6-pack is a proven performance intake for hot street/strip cars.
Oh? Its a good looking setup hands down but there is a bit of hyperbole in your statment.
Its been shown time and time again the six-pack loses to a decent 4-bbl intake and carb. Back in the day there were no high cfm carbs which was the whole point of having 3 x 2bbls.
Today were flooded with a mutitude of 800-1000 cfm choices including the TQ which is still hanging in there.
Pity it is not in production anymore as the resin fuel bowls really do help in keeping the fuel from boiling out.
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The tq can be a good carb, however there's a shortage of good spreadbore intakes out there..
Turning your statment around I could argue there is a acute shortage of six-pack intakes!
Matter of fact there is what, two or three for each engine series? And 40 year old designs to boot. There is a number of spreadbore intakes, including newer designs from Mopar Performance.
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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.
Can't say I ever had that problem and I ran my GTX with an O2 sensor and K&N monitor (back in the 80's!) so it was easy to keep tabs on the fuel mixture and get it dialed in fast.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: Mr.Yuck]
#779605
08/22/10 11:17 AM
08/22/10 11:17 AM
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Joined: Jun 2008
Posts: 10,847 Oakdale CT
gdonovan
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I Live Here
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Quote:
bla bla bal, if the T-quad was/is so great somebody would re-pop it and make a mint.
Tooling cost my man, tooling costs.
I'm sure Edelbrock looked into it since they have already turned out both AFB and AVS clones.
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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.
Prove it.
Hey the six pack looks great and if thats what floats your boat then go for it.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: sixpackgut]
#779607
08/22/10 11:21 AM
08/22/10 11:21 AM
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Joined: Jan 2003
Posts: 3,103 Phila Pa
scatpacktom
master
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master
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Posts: 3,103
Phila Pa
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F1Scamp Just conducted a test. Seems his new thermoquad car can't run with his six pack car despite them having the same engine. 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.
Last edited by scatpacktom; 08/22/10 11:24 AM.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: scatpacktom]
#779609
08/22/10 11:30 AM
08/22/10 11:30 AM
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Joined: Jan 2003
Posts: 42,714 Spokane Washington
ScottSmith_Harms
Mr Wizzard
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Mr Wizzard
Joined: Jan 2003
Posts: 42,714
Spokane Washington
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Quote:
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.
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.
You'd have to have one hell of an engine fire to melt a TQ body, I think allot of those "My TQ melted" stories are highly exaggerated, they are made of a heat resistant RIM injection molded copolymer, it's actually pretty hard to melt it short of using a blow torch on it.
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: ScottSmith_Harms]
#779610
08/22/10 11:53 AM
08/22/10 11:53 AM
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Joined: Jan 2005
Posts: 12,424 Kalispell Mt.
HotRodDave
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I Live Here
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Kalispell Mt.
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So how many power valves do you have to replace on a six pack after a backfire?
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Thermoquad vs. Six Pack/Six Barrel. Which is best ?
[Re: ScottSmith_Harms]
#779611
08/22/10 12:04 PM
08/22/10 12:04 PM
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Joined: Jun 2008
Posts: 10,847 Oakdale CT
gdonovan
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I Live Here
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Quote:
In general I would guess the same results but would also bet on a close race either way.
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
Quote:
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.
Which is also a good point, if I'm going to drop $1500-$2500 a induction setup I'd like some hardcore proof its faster than what I'm already running.
"Someones brother said" isn't going to cut it.
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