Moparchat - Home of MOPAR enthusiasts worldwide!



Go Back   Moparchat - Home of MOPAR enthusiasts worldwide! > Technical Forums > Performance Talk

Click here to search for Mopar cars and parts for sale.


Reply
 
Thread Tools Display Modes
  #1  
Old 05-30-2003, 10:11 AM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Help understanding carb specs.

Does anyone know of a good reference for understanding all the specs of a carb?

I.E.
IDLE AIR BLEEDS SEC:
BOOSTER TYPE:
METERING BLOCK # P.
IDLE FEED RESTRICTOR

I'm looking at the Demon carbs specs page http://www.bgfuel.com/demon/29.aspx
and realized how little i know about carbs.
I'm trying to find a carb that will work on my 383.
but thats a question for another time, right now i just need to understand the specs.
Reply With Quote
  #2  
Old 05-30-2003, 10:15 AM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

Go to your local speed shop and buy the books they have, on Holleys and Carters and Edelbrocks and of course Demons. Any or all of them, I do. Just bought a Demon book a week ago.

Get an old carb from a friend and take it apart and look at the book and pick out the idividual parts and just check them out. Then put it back together and try a different brand carb and do it again. Practise, practise, practise.
Reply With Quote
  #3  
Old 05-30-2003, 10:25 AM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

do you know what the price range is for the demon carbs?
from what i have seen and understood those carbs are awsome.
But i'm guessing your gonna pay for it also.

amxauto-x what carbs are you currently using?

I'm gonna go get the holley book today.
Reply With Quote
  #4  
Old 05-30-2003, 10:46 AM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

Talk to cuda66273, his business; http://www.4secondsflat.com/

$450 and up, I'm thinking. I'll be getting a 650 or 750 Demon soon.

I've used Holleys, Carters and Edelbrocks. The Carters are much better than the Eddys. Holleys are ok. Never used a Demon.

I've got Eddys on the van and AMX. Will put the Demon on the AMX. Have a Carter on the Ramcharger.
Reply With Quote
  #5  
Old 05-30-2003, 12:13 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
IF this car is in any way a street car - partly or wholy - consider the ... TQ !!
Reply With Quote
  #6  
Old 05-30-2003, 12:16 PM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

Oh ya, why did I forget that one. Never had one, but I was doing the car thing in the '60s and '70s when those were very prevalent on Mopars. And real good too.
Reply With Quote
  #7  
Old 05-30-2003, 12:38 PM
cuda66273's Avatar
cuda66273 cuda66273 is offline
Banned
 
Join Date: Dec 2001
Location: Beaverton Oregon
Age: 71
Posts: 3,685
Default

Demon makes 5 different models....each one is specific to the application.

They range in price from $259 to $1200

If you go to http://www.4secondsflat.com/Carb_and...rder_form.html

Copy and paste the info into an email I'd be happy to recommend the correct Demon for your engine combination.

You may also want to read the bottom section of this page:
http://www.4secondsflat.com/fuelsystems.html

Don
Reply With Quote
  #8  
Old 05-30-2003, 12:47 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
Default

Damn Don....

over 12 HUN for a carb !! ....... it is FI time !!

For under a hun you can do all the trix to a TQ !!
Reply With Quote
  #9  
Old 05-30-2003, 02:38 PM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

Forgive my stupidity but what does TQ stand for, or is that the actuall name of the carb manufacturer?


Thanks Don! I'll probably be sending you an email for your recomendation.
Reply With Quote
  #10  
Old 05-30-2003, 02:43 PM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

Quote:
Forgive my stupidity but what does TQ stand for, or is that the actuall name of the carb manufacturer?
I was waiting for that one It is the Thermoquad carb made by Carter. Back in the real muscle car days. Early '70s. It is a speadbore type. With small primaries and real large secondary throats/venturies.

Not a bad questian. Not everyone has heard of everything
Reply With Quote
  #11  
Old 05-30-2003, 03:17 PM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

Are there certain TQ'S i should stay away from?
A guy i know was saying something about the ones with the silver top and bottom caps on the bowl and a black center band i should stay away from. He did not explain why.
Reply With Quote
  #12  
Old 05-30-2003, 03:20 PM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

All Thermoquads are built like that. The middle section is a plastic. Some have been known to warp. You have to be carefull of what you buy.
Reply With Quote
  #13  
Old 05-30-2003, 03:23 PM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

i'm guessing they make replacement bowls though, correct?

Thanks guys for all your help.

its greatly appreciated!!
Reply With Quote
  #14  
Old 05-30-2003, 03:26 PM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

There is a Thermoquad guy here that'll have to tell you all about them. I've only seen them, not worked on them.
Reply With Quote
  #15  
Old 05-30-2003, 03:46 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
Default

I think that I know a little about the TQ's............. in fact - I have been accused of being the Captain of the ThermoSquad !!

As far as what was mentioned about the bowls......warping and cracking does occur but not that often.

And there are "better" ones to start with. Normally the ones in the early through mid 70's are a better HP piece.

Is this car going to be a streeter?
Reply With Quote
  #16  
Old 05-30-2003, 04:14 PM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Default

Demon-Sizzler is they guy with tons of TQ knowledge and builds them for people.

The TQ is a very good carb. Remember, it is a spread bore design, so it will not fit on most intakes, without an adapter plate. I really like the old TQ carbs, but, they just won't work for my application.

There is NO TQ that can touch the $1,200 Demon that is for all out race.
Reply With Quote
  #17  
Old 05-30-2003, 04:28 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
Default

Well Ed............I would really hope that the Demon carb can out-perform a TQ !!! .......... on a race-only test.

Especially since that TQ was a OEM item, was emissions designed and that a total HP prepped TQ should be only about 1/4 the cost of that Demon-Berri.

BUT on a street/strip combo test(ET and speed, fuel mileage, driveability, plug life etc) - where everything is considered - I submit to you that the TQ will spank that Berri.

Why won't a TQ work for your application?
Reply With Quote
  #18  
Old 05-30-2003, 04:53 PM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

yep, its gonne be a street.
Reply With Quote
  #19  
Old 05-30-2003, 05:52 PM
Bigfoot Bigfoot is offline
Inactive User
 
Join Date: May 2002
Location: Edmonton/Alberta
Posts: 178
Default

The best thermoquads to get are from 1972-75, easy to work on, easy to tune and you can still get parts except different jets or rods. The jets and rods can still be had from DemonSizzler or other private parties, you just can't go into autozone and find them. If you have a 318 or 340/360 then look for the ones with the small 1 3/8" primaries, if you have a big block then the 1 1/2" primaries are the way to go. I have a 340 model on my factory smog 1980 318 and I changed the primary and secondary jets down a couple of sizes and it works great. Starts right up, even at -25 deg below zero and gives excellent gas mileage with a good tuneup and your distributor setup correctly. I think I get 18-20mpg in the city and 24 on the highway as long as I stay out of the secondaries and I don't go rodding around allot. I rebuilt my very first one on a saturday morning and had it running great by 11 am, simple to work on.
Reply With Quote
  #20  
Old 05-30-2003, 08:05 PM
mynihilism's Avatar
mynihilism mynihilism is offline
Inactive User
 
Join Date: Apr 2003
Location: Hutchinson
Age: 45
Posts: 39
Default

cfm wise, how big to the TQ'S come?
Reply With Quote
  #21  
Old 05-30-2003, 08:24 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
Default

Typical OEM sizing is 800 and 850 but they can be made to flow from 600 to 1000 cfm with some simple mods.

A bud of mine has a project going that we will be using a TQ on a slant 6 - using only 1/2 of the carb.

I have a planned project where I am going to use a PAIR of TQ's on a 496 BUT will be reducing the primary sides down to 1" or 1 1/4".
Reply With Quote
  #22  
Old 05-30-2003, 10:27 PM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Default

Quote:
Originally posted by Mister Fiberglass
Well Ed............I would really hope that the Demon carb can out-perform a TQ !!! .......... on a race-only test.
Hey now, you are the one that tried to compare the TQ against a $1,200 Demon...

Quote:
Originally posted by Mister Fiberglass
Especially since that TQ was a OEM item, was emissions designed and that a total HP prepped TQ should be only about 1/4 the cost of that Demon-Berri.
Again, you are trying to compare the TQ against the $1,200 Demon. Try comparing Apples to Apples, in this case try comparing the 850 TQ to an 850 Demon.

Quote:
Originally posted by Mister Fiberglass
BUT on a street/strip combo test(ET and speed, fuel mileage, driveability, plug life etc) - where everything is considered - I submit to you that the TQ will spank that Berri.
On a street/strip combo, the only advantage that the TQ has is MPG. The comprable Demon will eat it alive, when it gets to the track.

Quote:
Originally posted by Mister Fiberglass
Why won't a TQ work for your application?
Well, it won't work on my intake, as I don't have a spreadbore intake. I have a Weiand Stealth, so taht I can try to maintain proper hood clearance for my RamCharger hood. If you had the adapter plate to the intake, the TQ is too tall and will cause the air cleaner to destroy the fiberglass assembly.

So far, the best intakes will not fit the TQ without an adapter plate.

Don't get me wrong. I really like the TQ and have run them in the past with NO complaints, just ear-to-ear grins. It only bothers me when supposed experts try to compare a TQ against a $1,200 Demon and then come off with "I would really hope that the Demon carb can out-perform a TQ !!!". That's when it bothers me.
Reply With Quote
  #23  
Old 05-30-2003, 10:48 PM
littlecampbell littlecampbell is offline
Banned
 
Join Date: Mar 2002
Location: canuck land
Age: 73
Posts: 750
Default

Hey Dandy Don....I see your virus is cleared up... or have you been visiting a few of them Surrey girls again?
Are you gonna try and make it to Mission in August?...Sorry to butt in on the thread....
Reply With Quote
  #24  
Old 05-30-2003, 11:03 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
Default

Now Ed.......... what is your defination of "eat it alive" ?? What motor do you have? Is this a street application at all?

Why does all of this bother you? Shouldn't a piece that is race-designed and cost 4 times as much BEAT a piece that is a basic OEM part - IN a race-only comparison ?
Reply With Quote
  #25  
Old 05-30-2003, 11:23 PM
ehostler's Avatar
ehostler ehostler is offline
Registered User
 
Join Date: Jan 2000
Location: Annandale, VA
Age: 57
Posts: 15,212
Default

My motor is all street (gears in the back won't let me race, yet).

Again, you are trying to compare a TQ to a $1,200 King Demon... Try comparing the TQ to the comprable Speed Demon that is about $440.

If you could read my entire post, you would see that the reason it bothers me is because you keep trying to use a $1,200 King Demon as the reasoning to go with a TQ. You refuse to compare Apple-to-Apples.

An 850 Speed Demon is close to the 850 TQ and the 750 Speed Demon is close to the 750 TQ. The Speed Demon will cost between $400 - $440 and be setup for your specific application with great support. The TQ can be had for about $300, when you can find one. Then it needs to be properly rebuilt. You will also need the $50 - $75 strip kit, to tune it. You will spend a day at the track, to get it properly tuned (if you're lucky). What you end up with is a great carb. It has great MPG and a respectable ET. The Speed Demon will give you a better ET and have respectable MPG. It's a slight handoff, however, the Demon will actually fit my intake and maintain proper hood clearance. The TQ will require an adapter plate and then it won't have proper hood clearance and it will bust the factory fiberglass RamCharger. That is a handoff that is unacceptable.

Again though, it comes down to comparing apples to apples and not using a $1,200 King Demon as your prime reasoning in justifying the use of a TQ.

If you try to maintain your objectivity and compare Apples-to-Apples (as Demon-Sizzler does), then I won't try to refute what you have to say. However, you are unable to maintain objectivity.

Demon-Sizzler has a great thread on the proper tuning of a TQ. It has earned its place in the tech archives, because he was very good at what he intended to get across.
Reply With Quote
  #26  
Old 05-31-2003, 01:17 AM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
LOL

......and the motor that you use is ? .....and you define "eat it alive" as ?

Objectivity?........... I will admit that the Berri carb will outperform a TQ on a race-only format. Being somewhat of a TQ fan........and admitting that.......that is not exihibiting objectivity, fairness, honesty and open-mindedness ?

TOTAL "objectivity" ??........why not then compare a OEM vac-secondary Berri against that TQ ??

Where do you get those TQ costs? Good core carbs are between 5$ to 80$ ......... with a total rebuild at about a 150$ with all the good parts. BUT those strip kits are MORE than you mention.
Reply With Quote
  #27  
Old 06-02-2003, 12:01 PM
cuda66273's Avatar
cuda66273 cuda66273 is offline
Banned
 
Join Date: Dec 2001
Location: Beaverton Oregon
Age: 71
Posts: 3,685
Default

I think I'll stick my nose in here and give you my 2 cents worth....

In their day the TQ's we're a good carb and still are to a point...
But let's look at it realisticly....parts are really hard to come by and getting harder to find, whereas the Demon parts are readily availble from just about any parts house, jets, gaskets, power valves are all the same as Holley...esy to find and the modular design makes them infinately tuneable.

When you look at flow numbers keep in mind that Demons are WET FLOW tested...which means that the air flow is mixed with a liquid the same weight as fuel, this decreases the numbers because of the weight of the air going through the venturis. If you were to dry flow a Demon you'd see that the 750 will actually pull over 800 and a 650 flows close to a 750 Holley, Eddy or TQ.

We need to look at the whole product line...Demons are very specific to manifold signals generated by the duration of the cam which makes them far easier to tune as the carb is calibrated to read that signal and major mods aren't required to get good milage, clean crisp idel and excellent WOT.

If you want to keep your car to a stock appearance then find a TQ core, build it, tune it and be satisfied with the end result, but when you drive it from Californnia to Denver don't expect it to perform at 5000' without searching for correct rods to lean it down....the Demon?... any parts store, 5 minutes with a screwdriver and allen wrench and your done.

The TQ's are calibrated to handle the manifold signal delivered by the factory camshafts...change that signal and you've got tuning and performance issues.

Not trying to knock the TQ's at all, but it's just so much easier for most guys here to bolt on a Demon...wether it's a Road Demon JR. at $239.00 or a Mighty Demon at $499.00 and have something that's brand new, repairable and tuneable, than to struggle with parts and knowledge availability of a TQ.
Reply With Quote
  #28  
Old 06-02-2003, 12:10 PM
ajmopar's Avatar
ajmopar ajmopar is offline
Inactive User
 
Join Date: Jul 2002
Location: Stoney Creek, Ontario, Canada
Age: 54
Posts: 806
Default

Yeah, but I think a stromberg 97 will wipe the demon's butt at the track, they used to use them on top fuelers didn't they?
Reply With Quote
  #29  
Old 06-02-2003, 12:42 PM
amxauto-x's Avatar
amxauto-x amxauto-x is offline
Inactive User
 
Join Date: Feb 2003
Location: Wa. state
Posts: 1,821
Default

Yup, 8 of them
Reply With Quote
  #30  
Old 06-02-2003, 01:01 PM
Mister Fiberglass's Avatar
Mister Fiberglass Mister Fiberglass is offline
Banned
 
Join Date: Jan 2000
Location: MI, TN, FL
Posts: 1,988
LOL

And 2 cents is ALL it is worth .......what partz are really needed for the TQ that you can't really get or very EZily fab yourself? And I DO understand that the Holley fans NEED all that parts availability - those Berri carbs EAT most of those parts up on a regular basis !! Infinately tuneable? .... I submit to you that a TQ with jets and rods is FAR more precisely tuneable than any jet/power valve combo.

5000' in Denver? ... are you aware that a TQ is made that has an auto-compensate for that from the OEM. But with a regular TQ......all it takes is a simple 20 second tweak with a small screwdriver on that primary rod tree. 5 minutes on a Berri?.........now WHAT can you on a Berri in TWICE that amount of time ?? !! :

Manifold signals?..........I would agree to a point BUT on most HP applications that are discussed here the TQ lives quite nicely. Now if you start talking a real fast 100% race cars........I would have to agree with you. Since 99.99999% of the race cars at the track agree with that ALSO.

And I am not trying to knock Berries.. ...... but I like to be different. And so do most people here on this BB do tooooo.

We all have Mopars.

OR should we all be the same as the rest of "them"?? - driving Chebbies, Furds and Ponti-yaks.

stromberg 97's ??.......... now THERE is a fuel-efficent piece.....
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Help in Understanding Democrat Tax Refunds Frank Off-Topic Forum 19 01-26-2007 09:19 AM
Understanding engineers Madman Stephan Joke Forum 1 01-12-2006 12:46 PM
understanding torque Youngin Ram Truck Chat 2 12-27-2001 07:21 PM
Understanding the Bass Player SUN RA KAT Joke Forum 2 11-24-2001 12:44 AM
Understanding terrorist PRO Off-Topic Forum 0 09-12-2001 02:04 AM




All times are GMT -4. The time now is 08:01 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
. . . . .