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Old 09-20-2010, 04:32 PM
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BelvedereII BelvedereII is offline
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Default Got a Mighty Demon

I picked up a 750 from FBO, this summer we've been having air from 3700-4400 density altitude so Don figured on leaning it just a little bit. It came with 75 and 83 jets, I think they're supposed to have 76's and 83's from the factory.

Going from the TQ to a Holley 750 vac secondary carb my best time went from a 7.95 down to a 7.60. With the Demon the car made it into the 7.50's on a Saturday night then on Sunday afternoon with warmer air it kept getting better as the day went on; it finally pulled a 7.55 at 90mph. That was with a tailwind of almost 20mph so it was cheating a little on my aerodynamic wonder of a car! Other runs were at 89mph where the Holley was usually 88. Not a huge change, but the 60' times were a bit better.

Finally, got the car down the 1/4 mile at Topeka. Odd thing is, I wasn't driving it! A friend qualified for the Div 5 ET finals and didn't have a car as he was tuning his wife's car and those of 2 high schoolers. Since I couldn't make it this year, I loaned Rick my car. He richened up the carb 3 steps front and back and left it like that----new car to learn while racing wasn't exactly the time for fine tuning. As long as it ran straight and safely, it was okay. Sportsman allows for 12.00 and slower, on Thursday night the car ran an 11.99 and 12.00. Friday and Saturday it slowed down along with all of the other cars, up into the 12.0's, then Rick wound up red-lighting in the second round on Sunday and not worrying about breaking out he ran it to an 11.98. 60' times were 1.64, MPH through the traps 110. The car's 1/8th mile times were around 7.58. Shift light at 5400rpm 1-2, 5600rpm 2-3.

Not bad, this pretty much follows the Mopar Big Block book by Chuck Senatore; with 10:1 pistons, ported 906's, a MP .509 cam (mine's the Racer Brown SSH-44 with .510 lift and 242deg at .050), a 440 in a well set up car should run 11.80-12.30 (or something like that). I'm happy!

B II
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Old 09-21-2010, 11:05 AM
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Got the timeslips when I got my car back yesterday, best was an 11.95 and our track has posted pictures from the event. These area from Saturday, and they wound up with rain delays.....the Belvedere is just before mid-point of the line of images, between those of the Z28 and the late-90's nova hatchback:

http://www.midamericamotorplex.com/2...ic_gallery.asp

They'll roll down the list of events when more are posted, just look for the Sept 19th ET Finals listing. If there are pics from the 18th, they'll be up next!
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Old 10-06-2010, 06:29 PM
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Has anyone ever run a Demon back-to-back with similar carbs at the drag strip?

Seems to be a good number of options among the Holley variations, Quick Fuel and Edelbrock seem to be popular as well, I just picked the Mighty Demon a bit at random. I won't have many tuning opportunities this Fall, but will see what I can get done in a few trips.

B II
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Old 10-06-2010, 08:59 PM
cudabob496 cudabob496 is offline
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Always heard Holley is the way to go. A nice DP set up for the quarter mile is hard to beat. When comparing carbs, lot of other factors to consider, like
air temp, track conditions, etc.
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Old 10-06-2010, 10:08 PM
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BelvedereII BelvedereII is offline
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True enough, Cudabob, doesn't seem like there are a lot of people performing back-to-back tests at the track. It'd be nice to have a few on hand to run in an evening. Magazine articles are a small help, usually they are going to a new carb to replace their worn item. I've read a few where they test different carbs within the Holley line, each with a different CFM or design difference. I'd like to see a Holley DP, Holley HP DP series, Demon, Edelbrock, etc. all with roughly the same CFM equivalent, tested on a variety of engines. So far, hit and miss is mostly missing in the magazines. Here, it's non existent.

B II
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Old 10-08-2010, 10:39 PM
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pishta pishta is offline
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You buy one from Bob at FBO after you tell him your motor specs and you will not find a better carb out of the box.
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Old 10-09-2010, 11:45 PM
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Pishta, I got mine from Don at FBO. Would have loved to have had a brand new HP Holley 750 at the same time, have yet to see such a test or know of anybody who has done one.
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Old 10-10-2010, 01:05 PM
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Oops, I should have said Don of course. I dont know where Bob came from....If you set up a Holley HP with equal jetting (a little fatter on the Holley brand as they flow less according to Don, maybe 1-2 steps) They are probably equal. But the stock features of a Demon are upgrades on a Holley, like the better looking bowls (easier to clean exterior) superior finish and those big sight glasses. All in all, just a higher quality LOOKING carb. Getting back the quality control part, if its from Don, he'll back it up. I wouldn't buy a Demon from anyone else. Of course I wouldn't buy a carb ever again after moving to MPFI.
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Old 10-10-2010, 08:30 PM
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BelvedereII BelvedereII is offline
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Pishta, they're both 3-letter names!

I know Don has a lot of experience with the Demons and he sets them up all the time--I found a video online (youtube?) where he takes one apart and points out all of the features, pretty neat stuff.

I called Jim at Racer Brown this past week, going over my combination. He told me his local Dyno operator builds and tests a lot of engines, and has found Demons to run behind the Holleys in horsepower on the same engines, across the board. Maybe he's not getting properly set up/tuned Demons, but you'd think he'd at least have run into a few. The magazines, taking ad money from the manufacturers, may never publish such a test result.

Mine runs well enough, as long as it's consistent I'll like it!

B II
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