Which Replacement Carb?

jhv48 · #1 (**permalink**) 12-11-2009, 03:50 PM

Ok, I've got a Roush 427 SRTW in my SPF and have the new 3 inch mufflers to replace the stock 2 inchers.

Now I want to get rid of that vacuum secondary Street Avenger carb and get a real DP.

On my previous Cobra, I changed out an Edelbrock carb for a Speed Demon and it really woke up the engine.

Want good street manners and to not stall out on hard cornering or stopping.

Which DP would you guys recommend and why?

Gunner · #2 (**permalink**) 12-11-2009, 04:01 PM

I think it's hard to beat a Barry Grant. Proven Holley model but improved in every way, more reliable and endlessly tweakable without having to modify every part (e.g., replaceable air bleed inserts, Idle-Eze, etc.) Even Holley now makes BG clones (the HP series). The only thing you can get is cheaper.

That said, there's nothing wrong with a well-tuned vacuum secondary carb for anything short of full-race use.

mdross1 · #3 (**permalink**) 12-12-2009, 03:03 AM

Quote:

Originally Posted by Gunner

I think it's hard to beat a Barry Grant. Proven Holley model but improved in every way, more reliable and endlessly tweakable without having to modify every part (e.g., replaceable air bleed inserts, Idle-Eze, etc.) Even Holley now makes BG clones (the HP series). The only thing you can get is cheaper.

That said, there's nothing wrong with a well-tuned vacuum secondary carb for anything short of full-race use.

Vacuum secondary carbs never worked for me,could never get them to hit like a dbl pmp.Both my big block cars have the HP Holley 850 dbl pmp.Thinking about sending one out to Dan Davinci for his magic touch.

CHRIS DAMSCH · #4 (**permalink**) 12-11-2009, 04:09 PM

Pro Systems is a nice carb.

www.pro-system.com/

Gunner · #5 (**permalink**) 12-11-2009, 04:12 PM

Quote:

Originally Posted by CHRIS DAMSCH

Pro Systems is a nice carb.

Let's just say I'm leery of small makers in complex systems - if they aren't here next week, you're SOL on parts, support, etc. Staying with a more standard setup for which you can get parts at Pep Boys on up has a certain comfort.

I'm also leery of car parts so specialized and exotic that you have to ask for a price quote...

greg schroeder · #6 (**permalink**) 12-11-2009, 04:56 PM

Get a mechanical secondary Pro-Systems carb. It will blow away that Avenger. Just call Patrick over there and tell him what engine you have and what you want. He'll ask what your zip code you're in to dial in the carb for your local weather. He'll recomend the proper size carb for your engine too.

http://www.prosystemsracing.com/custom.html

The unit I put on my car was the 1040 cfm on a single plane intake Roush 427R, 3.73 rear gear and 28 inch tall rear tires, Tremec TKO with .64 5th gear. The application is extremely streetable, instant throttle response and very accurate form just about any RPM.

Zoom This · #7 (**permalink**) 12-11-2009, 05:23 PM

I had so many problems with my 850 Holley DP for years on my 418W. I finally chucked it for a Barry Grant Mighty Demon 650 DP. I gave up about 12 HP at the top end but gained back 19 pounds of torque in the mid range. Not a bad trade off plus better throttle response. Now if I were to go drag racing I'd opt for a BG 750 DP Mighty Demon. Vacuum is less than 1 inch under full throttle chassis dyno pull until 5K rpm, then tops at 2 inches vacuum to 6K rpm.

RedBarchetta · #8 (**permalink**) 12-11-2009, 07:18 PM

Quote:

Originally Posted by Zoom This

BG 750 DP Mighty Demon

That's what I run now. A very reliable carb for six years running. The Pro Systems units are stout, too. From what I've heard their crew knows how to make 'em work out of the box (so long as you relay the correct specs).

-Dean

Hotfingrs · #9 (**permalink**) 12-12-2009, 02:51 AM

Quote:

Let's just say I'm leery of small makers in complex systems - if they aren't here next week, you're SOL on parts, support, etc.

Obviously someone doesn't know about Pro-Systems. I've had the stock Holley's, the BG's, the Biggs and a couple of other "built" carbs. I will run nothing but a Pro-System carb from now on. Patrick has built 2 carbs for 2 different engines and they have been nothing short of fantastic. Take a look around and see what the guys making the most power at the track are using.

Hotfingrs · #10 (**permalink**) 12-12-2009, 06:50 AM

Davinci cost a friend in Delaware his engine....

Bill Wells · #11 (**permalink**) 12-12-2009, 07:10 AM

Ditto to those that have mentioned Pro-Systems > They have done 2 for me : 1 for a blower and the other for a non blower carb - no choke on either and always starts right up ,even after long storage.

when they arrived I had them checked on a chassis dyno and they were right on right out of the box - no adjustments needed, jets were perfect, air to fuel ratio perfect range. we adjusted idle setting and that was it .

Patrick will give you the best custom carb for your engine specs and needs . Bill

Jim Vander Wal · #12 (**permalink**) 12-12-2009, 07:15 AM

ProSystems.

Nothing small time about these guys. Holley HP 4150 based, parts are everywhere.

Patrick and his team wet flow every carb and you can send in your engine and car specs so the carb is built for you.

Great service and support. Reasonable prices too.

Jim

mrmustang · #13 (**permalink**) 12-12-2009, 07:21 AM

Based on the specs of the engine, I suggest a simple yet dyno tuned Holly 750CFM double pumper from their HP series.

http://www.holley.com/0-80528-1.asp

Again the trick is to find someone with a chassis dyno who can properly tune it for you. Once you bolt this one on, you'll never go back to anything else.

Bill S.

jhv48 · #14 (**permalink**) 12-12-2009, 07:45 AM

So far, you guys are thinking the same as I am.

I can get a Holley HP already jetted and modified for my engine from Pro Systems for about $700 and simply bolt it on.

Or I can get a new HP for about $450 and then spend another $300-$400 on tuner and dyno time to get it dialed in properly.

Pro Systems is looking like the way to go!

I had a BG on my last Cobra and, after dismantling it and cleaning out all the shavings, it ran like a champ. But it took me about three weeks and $$$$ to get it dialed in properly. Looking to do it the lazy man's way this time.

DAVID GAGNARD · #15 (**permalink**) 12-12-2009, 01:36 PM

Quote:

Originally Posted by Hotfingrs

Davinci cost a friend in Delaware his engine....

I've got a high dollar 750 cfm Davinci paper weight.......all but cost me an engine also..........

Have had nothing but good luck/service with my Demon carbs, love em............

David

Tom Kirkham · #16 (**permalink**) 12-12-2009, 06:02 PM

How much for the paper weight?

DAVID GAGNARD · #17 (**permalink**) 12-13-2009, 04:28 AM

Quote:

Originally Posted by Tom Kirkham

How much for the paper weight?

Tom:

They built this carb for me in the early 90's and I had to send it back to them twice for problems. Finally I gave up on the carb....

Since then,I've used it for parts, but the main body and the bare bowls are still there. I robbed the jets/needle & seats and floats out of it to use on other carbs........

You really DON'T want whats left!!!!!!!!!!! Don't know what they did wrong, but all it did was dump fuel in the engine at about 3 times the rate it should have.............

David

Tom Kirkham · #18 (**permalink**) 12-13-2009, 07:08 AM

Do you still have the metering blocks?

Can you post some pics?

Hotfingrs · #19 (**permalink**) 12-12-2009, 08:19 AM

The last BG I had, I could never get the A/F ratio right on a chassis dyno. No matter what was done it wouldn't run right, that's when I got my first Pro-Systems and never looked back.

mdross1 · #20 (**permalink**) 12-13-2009, 07:42 AM

I have used Holley carbs for over 35 yrs,and never had any tuning issues.Also have all the tools and fixtures to make it a pleasure to do so.No dyno needed,seat of the pants,reading the plugs,and a few rowing through the gears tells me all I need to know.Have found Holleys to be sensitive to fuel pressure,to much,and it will wash the motor down.Have to have a regulator with HV pump.