Re: Demon idle mixture tuning question
[Re: ZIPPY]
#322850
05/19/09 05:55 PM
05/19/09 05:55 PM
|
Joined: Jan 2003
Posts: 32,394
Quicktree
I Win
|
I Win
Joined: Jan 2003
Posts: 32,394
|
Quote:
I tried splitting the difference between the front and back, and it makes over 1" of vacuum less than doing it the other way, and just idles a whole lot weaker.
then adjust with the idle screws to get it back.
|
|
|
Re: Demon idle mixture tuning question
[Re: ToddP]
#322855
05/19/09 09:26 PM
05/19/09 09:26 PM
|
Joined: Jan 2003
Posts: 17,836 S.E. Michigan
ZIPPY
OP
I Live Here
|
OP
I Live Here
Joined: Jan 2003
Posts: 17,836
S.E. Michigan
|
Quote:
I have noted that for whatever reason,(seat angle?) demon metering blocks, idle mixture screw go fat after about 3/4 turn. Regardless of ifr or iab.
Holley,blp, quickfuel seem to be correct at around 1 1/2 turn.
I would say that this is normal for Demon carbs.
Thanks, and also to the others who said they noticed something similar.
This is the only Race Demon I've had the pleasure (?) of working with. On all the Holley stuff I've worked with I was always able to get all 4 fairly close to the same, maybe all within 1/8 turn or so, but this carb is not having it....so I guess I better forget some of the Holley experience if it doesn't really apply.
I like the idea of maybe closing the secondaries a bit/opening up the primaries to see if that has any effect on it. Have not tried that yet
Idle quality is acceptably decent and all the way it is, I was poking around to find ways to make it a little bit stronger. It's 451ci and the cam is a 262/264 @ .050 on 110 so I'm not expecting any miracles.
|
|
|
Re: Demon idle mixture tuning question
[Re: 602heavy]
#322858
07/02/09 04:41 PM
07/02/09 04:41 PM
|
Joined: Jan 2003
Posts: 17,836 S.E. Michigan
ZIPPY
OP
I Live Here
|
OP
I Live Here
Joined: Jan 2003
Posts: 17,836
S.E. Michigan
|
Quote:
adding bigger idle air bleeds will allow more turns on screw and with the bigger bleed will atomize much better.
That was what I was wondering about too on the first post, but being that I never experimented with air bleeds, really didn't know either way. Interesting, might have to mess with it some more then.
|
|
|
Re: Demon idle mixture tuning question
[Re: solidcam]
#322861
07/02/09 04:59 PM
07/02/09 04:59 PM
|
Joined: Dec 2008
Posts: 1,200 UK
602heavy
pro stock
|
pro stock
Joined: Dec 2008
Posts: 1,200
UK
|
Increasing the IFRs is the wrong way to go , these are fitted with .037" & need taking down to .030 @ least , the IABs are around .067" , i had a Demon on 500" which pulled 16" vac , the IABs came out to .062" with IFRs @ .025 , the throttlke blades were also cleaned up , put a .050" restrictor in the trans feed also (.080 stock) , if you move the IFRs to the lower position in the metering block just watch out for any leaks between emulsion well & idle restrictor as there's not much material here , best thing is to keep the IFRs @ the top.
|
|
|
Re: Demon idle mixture tuning question
[Re: 602heavy]
#322862
07/02/09 05:17 PM
07/02/09 05:17 PM
|
Joined: Jul 2005
Posts: 1,472 Overland Park, KS.
Joshs68
pro stock
|
pro stock
Joined: Jul 2005
Posts: 1,472
Overland Park, KS.
|
Jesse at bigs told me to set up my/his 950 1 1/2 turns out on the primary and 1 out on the secondary. I always thought they should be the same. I just tried without question and I must say this thing idles fantastic for a 470 w a 265@50 cam. dont know if that helps but what I am trying to say is that try it where it runs the best even though it may not follow the conventional path.
|
|
|
|
|