Pro-Systems SV1 - any experience, comments, good/bad?

[rob07002]

Looking for some instant gratification for the balance of the summer/fall before going efi. The worked BG 850cfm Holley 4150 I use now is crisp and runs ok, but I know I'm leaving a lot of power on the table with my 540BBC. Anyone have experience or heard good or bad things about the Pro Systems SV1 carbs?

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

[Shaker455]

Rob,
I'm not going to bash it as I already took a swip at Pro-System in another post.

I have followed this and when it first came out alot of people jumped on it...I thought it was pretty wild too!

Now after it being out awhile the quite crowd found no gains.

I'll take another look back on the PY & PZ boards.

I think in the long run the Holley engineers were on the right track keeping four 2" and 2-1/8" (1250cfm) throttleplates sepperated to maintain a constant & strong signal.

So my advice is to stay with a traditional style Dominator....even if you get a custom unit that flows about 1400 cfm.

Looking at your Atco Drag Race clip I'd say an 1150 2-circuit Dominator w/ external linkage would fit your ticket well.

Post your combo, dist & timming?

Jeff

[rob07002]

Thanks for your input Jeff.

540 BBC
Dart big m block
Eagle forged crank & rods
10.5:1 comp srp forged
Dart 310 pro1 aluminum heads out the box, no porting
Dart single plane intake
850 BG 4150
Aeromotive a1000 pump
Comp cams solid .256/.250 @ .50 duration, 108 lobe center
2" primary syainlessworks headers
T56 magnum w. 2.67 first gear
Moser 12 bolt 4:10 gears
Aluminum driveshaft
Msd ignition
Msd pro billet dist
38 deg total timing

It doesn't see the 1/4 that often, so I want to maintain drivability, but know the current carb is a weak spot.

[Shaker455]

Hey Rob,

If you go to a Dom you want extrernal linkage as it will give you best driveability like a 4150.

I just did one of my custom 1065's for a customer in WI and he has reported back a better A/F and milage with his Dom over his 4150....I know that sounds crazy with a big carb but true...

Dominators are well sepperated from each venturi and do not crosstalk and the signal to each venturi is strong resulting in a more efficent unit.

With your MSD...where your initinal at?

Are you using the Black 18 degree bushing with what springs?

Do you have a rev limiter as your buddy said you were breaking up a bit and it may be your rev limiter you tripped as with MSD the chips trip off eariler then what's printed on the chip.

Do you have room under the hood for a 4500 Dominator? ...they are about 1/4 taller than the 4150 you now have?

Lets see some pics of your underhood?

[rob07002]

IIRC, the initial timing is 23 or 24 degrees. I'm not sure which bushing I'm using and would have to check.

You can see underhood shots using the photobucket link.

I don't have much hood clearance at all, so it would be VERY tight with a dom.

The breaking up was the tune. Too much total timing. I have a 7000 chip in the MSD and it did not hit it. We bumped it down to 38 degrees and it ran clear.

[Vegas69]

You are choking that engine with the heads and carb. I've tested my 489 with a vaccuum gauge at WOT with an 850 and I have 2-2.5 inches of vaccuum. I redline at 6800 so we are similar. You must have 3 or so.

I've heard lots of good things about Pro Systems and some bad. My engine builder which is a very respected West coast engine builder, said he's never had much success with them picking up over a properly tuned holley around the same cfm. Chevelles.com is the best place to research big block stuff.

[rob07002]

You are choking that engine with the heads and carb. I've tested my 489 with a vaccuum gauge at WOT with an 850 and I have 2-2.5 inches of vaccuum. I redline at 6800 so we are similar. You must have 3 or so.

I've heard lots of good things about Pro Systems and some bad. My engine builder which is a very respected West coast engine builder, said he's never had much success with them picking up over a properly tuned holley around the same cfm. Chevelles.com is the best place to research big block stuff.

Thanks for your input Todd. The heads were a deal I couldn't pass up so no going back. Plus, even though it's a big BBC, it's not huge and it will live most it's life on the street. I wanted it to be manageable. I also think bigger isn't always better and the smaller heads increase air/fuel velocity and bottom end power, while still flowing better than stock. I suppose I could have gone with the 325's, but I would have been paying full retail. The 310's will be getting ported this winter.

[Vegas69]

I hear you man. I have 325's on mine due to my first engine builder making the mistake. They were paid for so.... Big blocks make so much damn torque I haven't really found it to be an issue. I've got 10 inches of vaccuum at idle with a solid roller about the same size as yours.

[rob07002]

I hear you man. I have 325's on mine due to my first engine builder making the mistake. They were paid for so.... Big blocks make so much damn torque I haven't really found it to be an issue. I've got 10 inches of vaccuum at idle with a solid roller about the same size as yours.

Well, my plan has always been to see what I get out of this combo and go from there. We (my builder & I) knew going into this that we were building a very "mild" 540, but with some tweaks could handle whatever we threw at it down the road. The block and bottom end are rock solid, and we leaned toward the conservative when going with the cam, valvetrain and induction, save for the nice Comp Cams mag roller rockers.

Now that we have a baseline, which I still think with better air and mild tweaking to the carb, ign, and leaving harder will be a high 11 @maybe 120mph, we can improve upon this combo.

I have a Team G dominator manifold and 1150 Dom that someone is willing to lend me for the next track day, so I've going to swap them and see if I'm going in the right direction. This car is no lightweight either. I bet with the frame conn, rollbar, beefier 12 bolt, T56 Mag, and my fat arse, she is close to 3800 lbs.

Over the winter, I'll be pulling the motor and finally dyno. From there the heads are going to my guru in Long Island for porting and polish along with the intake. I'll be upgrading to beehive springs and may consider a bigger cam or going with a solid roller. Then back to the dyno with multiple carbs to find the sweet spot.

She should make in the 750 hp range with ease.

Todd, what kind of power you seeing with your BBC? I'm curious how much the heads might be hurting me in their stock form. What's your cam specs? If you don't mind disclosing.

[Vegas69]

Hey Rob, I always assume everybody knows all about my car. ha ha It's a custom ZL1 489 that makes 666hp at 6200 and 641 ftlbs. at 4700. I redline it at 6800 alot and it's a solid roller with 252/260 @.50 and .655 lift on a 110. 325 dart pro 1's with a mild port and 850 AED. I ran 11.95 at 119.5 in Vegas and 12.1 and 120.5 in Fontana last weekend. Hot both places with a head wind in Vegas. This is launching at 2200-3000 on road race tires with a race weight of around 3760-3780 with me in the car. I'm confident I can get down the track here a couple tenths quicker now that I've had the car out a couple times. Some real drag dot tires and some softer springs would make it a whole lot easier to get out of the hole. I'm running 1.9xx 60 foot times which suck...