holley V's Demon on the track

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A360

Benton
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Howdy all
Thoughts to those affected by Ike

Anyway some of you may have read the issue I had been having with a Demon I picked up on the cheap.

http://www.forabodiesonly.com/mopar/showthread.php?t=36690

After a few months of trying to get the Demon right I finally got it right.
So I thought.

Went to the track to give it a go had 4 runs averaging 12.85 @ 105mph
Went again last night the only change was I swapped the Demon for a 750 Holley DP and again has 4 runs ave 12.68 @ 109mph.

So basically you don't know unless you give it a go.

cheers
 
If I read your other post correct you are jetted 80/81. If you have a pv then the ratio is still wrong IMHO as you should have 7-8 size difference front to back. I'd try a 76/84 combo in the Demon and go 1 size up all the way around to see if the mph slows down or picks up. once you start to slow down - jet 2 sizes down and burn rubber.
 
I started with the demon with 72 -87 then went two sizes progression till I got to the 80-81 with best results.

with the holley I squared the jets up straight away 80-80 and it ran best of
12.67 @ 109.7mph I will fiddle a bit more but I am happy with that at the moment.

I have a private track day I have been invited to and will be taking all my jets and both carbs down to some finer tuning.Apparently I will get as many runs as I want so it will be a interesting day.

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A360 said:
I started with the demon with 72 -87 then went two sizes progression till I got to the 80-81 with best results.

with the holley I squared the jets up straight away 80-80 and it ran best of
12.67 @ 109.7mph I will fiddle a bit more but I am happy with that at the moment.

I have a private track day I have been invited to and will be taking all my jets and both carbs down to some finer tuning.Apparently I will get as many runs as I want so it will be a interesting day.
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Wow. That shouldn't work. The reason that there is a difference of 7-8 jet sizes between the primary and secondary is because the power valve flows fuel into the primary at the same rate as a size 7 or 8 jet. If you vary from that difference then one end of the carb is going to be lean compared to the other and it can cause all kinds of problems. You should be jetting for max trap speed, not best E.T., because trap speed is a better indication of how much power the engine is making. E.T. is affected by more variables.
 
Wow. That shouldn't work.
Click to expand...

Agreed ,all my other carbs over the years have had a significant diff between front and rear.

Although the 109.7mph speed is the fastest yet in this car.

I plan to do up a spread sheet of the diff jet combo's on the two carbs I use at the private test day with all the 60',mph's etc.
 
I,d be interested as I,m running 750 holley with v.s it ran 12.88at108.2 .I believe the jets are 72-68..
 
A360 said:
Agreed ,all my other carbs over the years have had a significant diff between front and rear.

Although the 109.7mph speed is the fastest yet in this car.

I plan to do up a spread sheet of the diff jet combo's on the two carbs I use at the private test day with all the 60',mph's etc.
Click to expand...
The best thing to do is look up the jet sizes that the carb came with from the factory and start there. Proceed exactly as 388dart said.
 
pettybludart said:
I,d be interested as I,m running 750 holley with v.s it ran 12.88at108.2 .I believe the jets are 72-68..
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Wow, if you mean 72 in the primary your primary side is WAY richer than your secondary. The secondary side should be 7-8 sizes bigger than the primary.
 
Your right 2shelbys it,s 72-78 in the block.I,ve ordered the conversion kit,power valve and also the holley jet kit.I also got the secondary spring kit.Now it,s time to read up on what will be best for my set up.
 
pettybludart said:
Your right 2shelbys it,s 72-78 in the block.I,ve ordered the conversion kit,power valve and also the holley jet kit.I also got the secondary spring kit.Now it,s time to read up on what will be best for my set up.
Click to expand...
Sounds like a plan.
 
I can,t wait to see A360,s spread sheets.I,m sure it will be some help with setting up my carb for better runs.That,s if I get out again this year.Friday nite at the track 3rd pass got stuck in 1st gear and it,s back in garage haven,t looked at it yet.I think shifter fork is #%&*!
 
Well I got back out to the track Wed.nite.best run was..
R/T.012
60ft.1.87
330ft.5.39
1/8 8.312
mph 84.51
1000ft.10.83
1/4 12.96
mph 105.97

It was a little cool out maybe 62 degrees.I lost my top speed of 108,but i,ve got my 60ft. down a bit.I was playing with secondary spring.Gotta go back next friday.Hopefully it will be warmer out.
 
Hi Fellas

Did not get to the track just after I posted I wiped the lobes off my cam and have been doing a low budget rebuild so I can get to the track before the end of the season.
Sold the Demon to pay for gaskets etc ,so back at the track next Fri

Interesting to see the times with the fresh engine ,I got a new cam in there ,probaly way too big but track times will tell.

Specs at link below

http://www.forabodiesonly.com/mopar/showthread.php?t=56635
 
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