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View Full Version : Carb compare. Magazines Scared???



GUS68
08-02-2005, 05:19 PM
Hey guys!!! I have always wondered why all the big magazines have never compared different carbs and brands on a dyno or at the strip. For all of the MILLION small block rebuilds and dyno motors stories done, somebody must have a dyno motor lying aroung for a test. It would be easy to test a Edelbrock AFB against a Holley and a Demon and a Quadrajet and ect... As long as they are all of the same CFM. They could even tell the carb companys about the motor and have them send the carb they think would work the best. I for one would like to know the best bang for the buck. I mean if a $200 carb made 2 hp less than the $500 carb then I would probably go for the cheaper. On the other hand if there is some one looking for that .001 off of their et than they would probably go with the $500 carb. They could also do the same test on a car and run it at the drag strip. I have always wondered why this has never been done? :dunno: It would be easy!!! But I suppose the Mags don't want to piss off the BIG companys by showing one is better. Remember Money talks, and ... well you know.

D Rock
08-02-2005, 05:43 PM
I agree, a good carb comparo would be great if all of the carbs were tuned in good.

69boo307
08-03-2005, 08:33 AM
It wouldn't be easy at all. There are way too many variables involved, and every engine requires different 'feeding' behavior to run ideally. What makes the most power on one engine may not on another.

I don't think there's any way they could do a controlled comparison that would yield meaningful results. Unless you have the exact engine they used in the test, their results wouldn't help you. Even if you build the same combo it may not run exactly the same and would require different carb tuning.

JJSmitches
08-03-2005, 09:34 AM
How bout testing the carbs on one or several popular crate engines?
That could even it up a bit and it would be useful info for crate engine shoppers.

GUS68
08-03-2005, 05:55 PM
Hey guys!!! I would have to agree that each individual engine is different and would respond differently to different carbs. But common!!! Mags have been comparing things on dyno motors for ever. I have seen them compare different heads, different cams and different intakes on the same motor. Same as your motor? same as my motor? Probably not. I remember one mag comparing a 454 small block to a 454 big block, bet there was no variables there!!! How about the Mag that compared "Equally built" small block Mopar, Ford and Chevy motors on the dyno and then in "Equally built" cars at the drag strip. There will allways be viaribles ( even in the way I spell variable) :jump: . But at least you could see if one carb made more of a difference than the other, 15 horse on one motor may not be 15 horse on your motor but it might be 5 horse. But like I said, it will probably never happen because all the big Mags don't want to piss off the big carb companys, then they might not get any more free stuff.

sinned
08-03-2005, 06:39 PM
You are missing the point. A cam swap or heads, or headers is a pretty fair test; 90% of the engines out there will have similar results. Carburetors are very picky, what works one engine will run terrible on another. My engine runs great with a 750HP but may not with a 750 Edlebrock. Every engine will behave differently to a change in carburetors. Granted each combo could be tuned but it would take an enormous amount of time to go through the trouble of building each of the tested carburetors to engine in question. A "good" tune takes about 4-6 hours. Multiply that by 3-6 different carbs and you can see how even a magazine might have trouble coughing up for that kind of dyno time.

GUS68
08-03-2005, 07:26 PM
Yes I agree. Sooooo lets take a crate 350, call each carb manufature and tell them all the specs on the crate 350 and have them send us a tuned carb specificly for this motor the only thing is that it has to be a 650cfm, (or 750 0r 800 or.....) as long as all the carbs tested flow the same cfm. In theory the motor will make exactly the same horse no matter what carb is bolted to it if they all flow the same cfm RIGHT? So lets see how the measure up. You could also do this same test on a car at the drag strip!!! And dyno time ????? I have read articles where they dynoed a motor then switched heads!!!! Or cams!!!! How long did that take???? It would take just minutes to switch carbs.

LowBuckX
08-03-2005, 10:16 PM
I would love to see it. Take the biggest selling crate engine (me thinks ZZ4 350) Have 3 catagories 1)vac secs. 2) double pumpers 3) race units. Holley V BG v Rochester V Edelbrock/Carter

But THE test would have to be OUT OF THE BOX STOCK with only Idle adjustments.

You will never see this thought because page 13 in Edelbrock page 20 24 36 45 Holley page 60 BG All that advertising money at risk

USAZR1
08-04-2005, 11:11 AM
The magazines are already doing this to a certain extent on most of their dyno tests. They almost always try more than one carb to see its effects.

GUS68
08-04-2005, 04:30 PM
BUT..... They are either all Holleys or demons or ect....
It would be a cool test. Too bad all the Mags are all too scared to loose some advertising.

JMarsa
08-04-2005, 06:50 PM
Here's what I'd like to see: Have the manufacture's send a tech to tune them. Then have a prominant carb shop tune them.

--JMarsa

427v8
08-14-2005, 08:58 AM
I'd like to see air fuel ratios and performance in real world driving situations, Not just WOT drag strip conditions...

I do like the crate engine approach, but I think there should be 2 engines, a 350 and like 1 502.

Also the carb company should be able to send any carb they want, who cares about CFM if it runs better?

BRIAN
08-14-2005, 03:08 PM
I remember years ago they did such a test and even incl Weber and Predator set ups. I remember the Predator doing better than all except the Webers. Problem was the lack of an idle? circuit i think. They now have one equiped with one. Never seen or heard about them again??

cad
08-25-2005, 06:47 PM
I know this isnt directly related, but makes a good point for guys that just want to bolt on a carb for power, but are intimidated by Holleys.....Really surprising results IMO regarding size.
Here's one of them...
http://www.superchevy-web.com/technical/engines_drivetrain/completebuilds_testing/0304SC_dangerm8_copy/

Steve Chryssos
09-12-2005, 06:11 PM
Carburetors are like the engines that they sit on. Mass produced, they only work so well. But if you fully blueprint them, they work excellent. -Check all the passages for partial obstructions left during the die castings process.
-Size those same passages for the exact requirements of the test engine.
-Machine all of the gasket surfaces for perfect flatness.
-Dye or redye the castings after modification.
-Hand assemble the carburetor with zero tolerance calibration parts.
-Test the carburetor before shipping.
None of these things happen on mass produced $300 carburetors. So in an effort to domminate the competition, one or more of the manufacturers would supply "ringers". The magazine editors know that the results of the comparison would be anything but real world so they don't bother.

cad
09-12-2005, 06:39 PM
Excellent point.

Bird of Fire
09-18-2005, 11:10 AM
For Joe Average, any carburetor will work well IMO....most people think the carb is junk because they can't tune it for squat :)

68Formula
10-15-2005, 07:38 PM
Driveability aside, there are basically three factors affecting power.
1) Airflow
2) Fuel mixture
3) Atomization

A spreadbore may have a slight advantage because of the smaller primaries in the low end range.

Proper tuning on all of them assuming same airflow should show no differece.

Atomization could improve low end as well.

Pretty much for the same flow size their going to make the same power.