inqbus383

I just replaced my Holley 750 with a Barry Grant Speed Demon 740 VS EC and the difference is amasing. After only leaning out the idle mixture, It drives like pure evil. It now HAS off idle power. It runs perfectly cold. The stumbles and hesitation are gone. Runs much smoother at all rpms, and most of all, its got loads more power and torque. Where before in the rain(with excellent rain tires)it would grip until about 3500rpm at WOT, now it breaks free at 2500 rpm. We estimate about 15% more power in the low end (below 3500). Testing of higher rpms will have to wait untill its dry out :D . The Demons are very well designed carburators, score one for Barry Grant!

I did the same tuning on the old holly, and it ran fine. The new carb just exceeds my expectations. Can't wait to have a shop tune it fully!


[Modified by inqbus383, 7:46 AM 2/1/2002]

mountainmotor

Sounds good! Are you interested in selling the Holley?

Paul 75 L82

Here's a few tips that I did that even made it run better. I went to the next step up on the power valve. One step lighter on the spring for the secondaries, and set my 4 corner idle screws with a vac gauge at the highest reading. After that It really kicks as*. I just love my Demon. All of the new issuses of the magazines are putting Demons on thier test motors. And I know why.

Alwyn678

To make money of Course...do not think for a moment that they are not getting PAID :yesnod:

Brutal64

I have two friends who changed swapped their Holleys for Demons and had the same experience as you. I'll be switching over soon myself. :yesnod:

lars

inq -
If you send me an e-mail address other than a hotmail account, I'll send you out the article we did on how to build an awesome all-steel fuel line for the Demon setup you have.
As a note, we've been measuring 20 more hp at the rear wheels with the Demon as opposed to a well set up Holley.
V8FastCars@msn.com

68shark

How much does this cost and where did you source it?? Eckler's or other national outfit? Sounds like great performance!! :cheers:

mountainmotor

Lars that is alot of rear wheel HP much less crankshaft HP to be gained with the same CFM carbs.I assume this is apples to apples double pump to double pump.What is making the difference?
I doubt a Demon 750 will make any more power than a Holley0-80528-1 or even the old 4779 when tuned properly
my opinion anyway


:)


[Modified by mountainmotor, 10:40 AM 2/2/2002]

gdh

I have the same question that MountainMotor just asked as a friend of mine posted a small gain when he compared the 2 on the dyno (Holley dp and Speed Demon) but he couldn't get the 25hp gain. He was telling more it was in the 5 -7 hp range. He really likes the Speed Demon but thinks that they are overpriced for the hp that he gained. I will call him tomorrow to check again because if a 20 - 25 hp gain is to be had comparing similar units, Holley may be in for a serious wake up call.


[Modified by gdh, 11:11 PM 2/1/2002]

Alwyn678

:eek: :eek: Now that may be worth it.....williamyelton@aol.com


[Modified by Alwyn678, 3:22 PM 2/1/2002]

inqbus383

I paid 406$ including shipping from summit. I don't think I could get the idle any better with a vacuum gauge. The idle adjustment screws were actually very sensitive, too rich and it would surge, too lean and the idle wouldn't settle down. My email is aro@u.washington.edu, I'd love to set up a stainless fuel line. Thanks lars

mountainmotor - I wouldn't mind selling the holly, but it is a good test carb to keep around.

gkull

I went with the BG dual feed and fuel log. It's all 8 AN fittings. For about $80 from summit. Then you have to get an 8AN inline filter............

A little off of the subject. But the trickest rear spoiler I ever saw and it was home made was a local auto-x/roadracing 78. They had made a tall clear plexy glass spoiler with turn buckle angle adjustable. Just like what's used in 1/4 3/8th and 1/2 mile circle track cars. since it see through you don't loose any rear vision.