Pro System Carb and Power Valve

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posted

quote:
Originally posted by TOP38:
quote:
Originally posted by mopar man:
So are you saying that my Pro systems carburetor that they just built me with a power valve in front is not necessary? I thought I would run it like that see how it responds. This is a full drag car 8500 RPM

Are you asking me??? If so, I was pretty clear in my post above.

However I will add this, for foot brake folks, when staging, if they are only lightly loading the converter,,, keeping the manifold vac high, a power valve could actually help but that not to say a carb cannot be built to work cleanly without a PV.

A power valve will only provide a leaner AFR under light engine loads (high vac conditions) when the main circuit is flowing fuel. Once load increases enough to drop manifold vac enough to open the valve, its just there for the ride.

As for a drag car, fuel slosh in the float bowls can under either the PV and or jets, and since the PV is higher than the jets, its more likely to get uncovered during a run vs the jets. Give this fact and that fuel slosh is not a constant! from run to run, why add more potential issues that could cause inconsistencies? That's my two cents.

I've never ran a power valve in my drag motor either. And this is a trans brake car. I just figured the carb builder at Pro systems knew what he was doing?

Posts: 10 | Location: cedar rapids, iowa | Registered: September 16, 2009

Ignored post by mopar man posted

DRR S/Pro

posted

quote:
Originally posted by 1320racer:
you're making a blanket statement, he does NOT put PVs in all "drag cars" and specifically not in all bracket cars running a dominator.

That said, I have yet to find one custom carb builder who's carb outperforms Pro Systems comparing same size carbs.

No I did not make a blanket statement. I never said "ALL" anything and in no way am I disparaging his product. The one my friend has is running pretty well for the 12 passes he has made with it. I believe there is more in it that we will find with testing. I almost bought one from him myself many years ago. Instead I decided to build and tune my own.

If you don't mind me asking what is your 1/8 et and mph on your car? Not a trap just curious.

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Ignored post by CURTIS REED posted

DRR Elite

posted

Which car?

quote:
Originally posted by mopar man:
I've never ran a power valve in my drag motor either. And this is a trans brake car. I just figured the carb builder at Pro systems knew what he was doing?

I suggest you call Pro Systems and speak to either Patrick or Brad and ask them WHY your carb has a PV.

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

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posted

The Firebird

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Ignored post by CURTIS REED posted

DRR Trophy

posted

quote:
Originally posted by 1320racer:
Which car?

quote:
Originally posted by mopar man:
I've never ran a power valve in my drag motor either. And this is a trans brake car. I just figured the carb builder at Pro systems knew what he was doing?
I suggest you call Pro Systems and speak to either Patrick or Brad and ask them WHY your carb has a PV.

i already did and he said these carbs have a lot of signal and would be cleaner at part throttle

Posts: 10 | Location: cedar rapids, iowa | Registered: September 16, 2009

Ignored post by mopar man posted

DRR Elite

posted

specifically what carb did he build you and for what application?

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

DRR Elite

posted

quote:
Originally posted by CURTIS REED:
The Firebird

as I've stated many times here when discussing the performance of my footbrake launched Firebird, that it is run with a restrictor plate, dialed in to run 9.0x/5.7x because the NHRA Division 1 cutoff for Pro ET is 9.00.

That said, I have run as quick as 8.72/5.50 and this is with a Pro Systems 4150/1000HP...

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

DRR Trophy

posted

quote:
Originally posted by 1320racer:
specifically what carb did he build you and for what application?

1200 CFM dominator. 2800 LB drag car trans brake small block 850 lift cam. 8500 RPM

Posts: 10 | Location: cedar rapids, iowa | Registered: September 16, 2009

Ignored post by mopar man posted

DRR Elite

posted

so it's an 1150 dominator?

That said, just for comparisons...

my 615 makes 1100HP, in my transbrake launched piperack has a .900 gross lift cam and turns 7500 in the lights. My Pro Systems 1250 aka 1300 has no PV

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

DRR Trophy

posted

quote:
Originally posted by 1320racer:
so it's an 1150 dominator?

yep he said it flowed 1192 cfm

Posts: 10 | Location: cedar rapids, iowa | Registered: September 16, 2009

Ignored post by mopar man posted

TOP38

DRR S/Pro

posted

quote:
Originally posted by mopar man:
quote:
Originally posted by 1320racer:
Which car?

quote:
Originally posted by mopar man:
I've never ran a power valve in my drag motor either. And this is a trans brake car. I just figured the carb builder at Pro systems knew what he was doing?
I suggest you call Pro Systems and speak to either Patrick or Brad and ask them WHY your carb has a PV.

i already did and he said these carbs have a lot of signal and would be cleaner at part throttle

That translate into the PV was part of his carb fuel curve design for that particular carb.

Posts: 2163 | Location: Tewksbury, MA,USA | Registered: November 03, 2000

Ignored post by TOP38 posted

DRR S/Pro

posted

quote:
Originally posted by 1320racer:
quote:
Originally posted by CURTIS REED:
The Firebird

as I've stated many times here when discussing the performance of my footbrake launched Firebird, that it is run with a restrictor plate, dialed in to run 9.0x/5.7x because the NHRA Division 1 cutoff for Pro ET is 9.00.

That said, I have run as quick as 8.72/5.50 and this is with a Pro Systems 4150/1000HP...

I know it runs well and would always give you credit there. I just couldn't remember what you had stated about the et and mph in the 1/8 without the plate. I was just wondering for a comparison, nothing to do with ProSystems. No biggie.

Curtis

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Ignored post by CURTIS REED posted

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posted

restrictor plate set for 9.0x ET MPH is 119/149. Restrictor plate opened 123/154

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

DRR S/Pro

posted

quote:
Originally posted by 1320racer:
restrictor plate set for 9.0x ET MPH is 119/149. Restrictor plate opened 123/154

Thanks that is pretty good mph.

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Ignored post by CURTIS REED posted

1st_Gen

DRR Sportsman

posted

quote:
Originally posted by mopar man:
quote:
Originally posted by 1320racer:
so it's an 1150 dominator?

yep he said it flowed 1192 cfm

Dry flow that will be a 1050 based carb. Measure the venturi if you can, probably be less than 1.72" after he dolls them up. Probably has a .600" ID booster insert in it as well. Power valve will do one thing, clean up the part throttle, especially in the burn out.

This message has been edited. Last edited by: 1st_Gen,

Posts: 240 | Location: Texas | Registered: October 01, 2007

Ignored post by 1st_Gen posted

DRR Elite

posted

quote:
Originally posted by CURTIS REED:
quote:
Originally posted by 1320racer:
restrictor plate set for 9.0x ET MPH is 119/149. Restrictor plate opened 123/154

Thanks that is pretty good mph.

it is especially for a 4150 and truth be told, the restrictor was not 100% open on that pass. I do believe a dominator would MPH better by at least 1mph.

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

green1

DRR S/Pro

posted

quote:
Originally posted by 1320racer:
quote:
Originally posted by CURTIS REED:
The Firebird

as I've stated many times here when discussing the performance of my footbrake launched Firebird, that it is run with a restrictor plate, dialed in to run 9.0x/5.7x because the NHRA Division 1 cutoff for Pro ET is 9.00.

That said, I have run as quick as 8.72/5.50 and this is with a Pro Systems 4150/1000HP...

I thought you said your car was faster than mine?

Posts: 2595 | Location: at the track | Registered: May 09, 2007

Ignored post by green1 posted

DRR Elite

posted

let me guess, you cutup/lightened your shyt box more just so you could run with me.

Great now show up or shut the fuc up.

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted

green1

DRR S/Pro

posted

Nope haven’t done any of that in over 15 years. He11 I was running 8.50-8.60s 15 years ago. Imagine how much faster I would be if I only had one carb and 4.56 gears.

Posts: 2595 | Location: at the track | Registered: May 09, 2007

Ignored post by green1 posted

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posted

well then STFU and put that POS in the other lane!

Posts: 13522 | Location: NJ | Registered: August 20, 2000

Ignored post by 1320racer posted