WIDE OPEN VACUUM TEST......................

Posted By: Thumperdart

WIDE OPEN VACUUM TEST...................... - 03/19/14 05:50 AM

How many of you folks have done a dyno or street wide open test to see how much vacuum you have? After much thinking and research I`m thinking my 3.5 p/v COULD be closing at wot if I`m pullin more that a few inches of vacuum............Anyone?

Posted By: Aspen7695

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 06:35 AM

I run a TQuad on my stocker. At WOT I have zero vacuum.

Raul

Posted By: Thumperdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 07:20 AM

Quote:

I run a TQuad on my stocker. At WOT I have zero vacuum.

Raul

Is that wot in high gear wooded?

Posted By: Cab_Burge

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 08:00 AM

Put a vacume gauge in the car where you can see it easily and go for a ride

Probally not going to see any vacume with yoour parts, 1050 Dominator and so on

What does the wide ban say

Posted By: mopar dave

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 02:43 PM

with my 408 and a 950 I have 1.5-2"@wot. that's why I decided to try a dominator this year.

Posted By: Crizila

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 03:50 PM

Quote:

How many of you folks have done a dyno or street wide open test to see how much vacuum you have? After much thinking and research I`m thinking my 3.5 p/v COULD be closing at wot if I`m pullin more that a few inches of vacuum............Anyone?

Any vacuum basically sez restriction. I know some who do carb sizing that way. Through the lights, you wanna see no more than 1.5" for a race only application.

Posted By: Clanton

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 03:59 PM

Here is some good posts about it.
https://www.google.com/url?sa=t&rct=...JMNmT-xav9BPH2g

Posted By: gregsdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 04:06 PM

At 7,000 rpm and 100 percent VE, you pull 950 cfm with 470 cubes. Your VE may be over that, but not by much. I would think the pv would be plenty high, and your WOT vacuum will be 1.6 or less. Probably the only real test would be a AFR test to see what is going on. You could also put a new 4.5 in it and test it.

Posted By: Thumperdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 05:35 PM

Will install a vac gauge soon and test these things but I can`t get my wot rich enuff w/out jetting it to the moon so was just curious. I`ll get some 26 hsb`s also and go from there. Right now I`m bet. 12.8-13.2 at wot and VP likes to see low 12`s w/their now 101 unleaded.

Posted By: Baxter61

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 05:53 PM

Try sticking a plug in it and jetting up till your fat enough and record the jet number. Figure out the difference flow of your current primary jets and what its jets it took without the pv. That's how much your power valve channels need to flow.

Posted By: Thumperdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 05:57 PM

I tried that years ago before the wide band and just may again it`s just a pain testing on the street at 120+ mph............

Posted By: lewtot184

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 05:59 PM

Quote:

How many of you folks have done a dyno or street wide open test to see how much vacuum you have? After much thinking and research I`m thinking my 3.5 p/v COULD be closing at wot if I`m pullin more that a few inches of vacuum............Anyone?

if your pulling over 3.5" of vacuum at WOT you've got issues. 3.5" would indicate a very big restriction on the intake/carb. i'd look for fuel delivery problems.

Posted By: Thumperdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 06:15 PM

I personally don`t see it pullin that much and it was a suggestion to check it out but I leave no stone unturned and will VERIFY everything before I hit the track here soon...........

Posted By: Baxter61

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 06:53 PM

Quote:

I tried that years ago before the wide band and just may again it`s just a pain testing on the street at 120+ mph............

need a co-pilot?

Posted By: Thumperdart

Re: WIDE OPEN VACUUM TEST...................... - 03/19/14 07:23 PM

Quote:

Quote:

I tried that years ago before the wide band and just may again it`s just a pain testing on the street at 120+ mph............

need a co-pilot?

Come on.............

Posted By: Aspen7695

Re: WIDE OPEN VACUUM TEST...................... - 03/23/14 02:42 PM

Sorry it took so long to reply. I was racing at Las Vegas.. I have zero vacuum at WOT all the way down the track.

Raul

Posted By: sixpackgut

Re: WIDE OPEN VACUUM TEST...................... - 03/24/14 02:48 AM

I never use a PV lower than 6.5 except in the borrowed carb i used for drag week last year and i believe that was happening to me but it was actually helping.

There is no reason to have a 3.5 PV in a carb. Do not listen to anyone that tells you to use a PV that is 2" lower. That is complete nonsense