I'm in the process of gathering parts for a street/strip ride. 565 cubes, street roller or big hydraulic roller, 11:1 compression, 320cc runner Pro Topline heads, etc. I have a shot at a nearly new Holley Dominator Ultra HP: http://www.holley.com/products.asp?product=0-80672
Is this streetable or made more for full-throttle operation? I can get this carb for about half of what it sold for new and it has nothing but dyno time on it. The guy bought it for a 632 (against the advice of his builder) and it's too small for that engine in full race tune. Thanks in advance for your ideas, help and suggestions.

I have a shot at a nearly new Holley Dominator Ultra HP: http://www.holley.com/products.asp?product=0-80672
Is this streetable or made more for full-throttle operation?

Yes & Yes. You'll probably need to do some work on the idle/transition circuits, but it can be made very streetable, especially on a 565.

540HotRod Jim has remarked a few times about using a 2 circuit rather than a 3 circuit dominator for the street. While carbs are kinda like women to me (mysterious, great when they do what I want, frustrating when they don't), I don't understand why a transition circuit wouldn't help. Anybody care to clear this up for me? TIA!

If it's a good deal...get it...you can tweek anything you need to.

My experience has been that for the street you don't want the 3 circuit ones. For sure it will run around, but the issue is it will run fatter than it needs to in normal cruising.

The 3 circuits were designed to help a car come up against the converter with less throttle opening. This allowed you to have more pump shot left when you nailed it. So as you open throttle and are in that weird little area where you are between idle and main circuits, the 3rd circuit will add some fuel to help get RPM up. Basically a "passive" accelerator pump. Works great as you go through that area.

But on the street you will find that you have the throttle right in that same spot under light cruise conditions and it will start adding fuel and be way too fat. I've played with changing restrictions in them, changing tube angles etc to change the place it activates and finally found it best on the street to plug it off completely on primary side. The secondary side is no problem. Just play with primary pump shot and PV to tweek how it goes through that spot. No big deal.

You have to have power valves IMHO to make them nice and clean on the street. Many carb tuners will tell you they can make them work fine without them, but I know of two excellent well known ones that reverted back to them to make them street friendly. Sure you can run without them, but the main circuits will be so fat under light load it's crazy.

I'm assuming that one has PV's since it has changeable restrictors for the PV's it says?

With a little work or picking the right one up front, a Dominator will do great on the street. Mine makes cross country trips with my 540 and gets 11-12 mpg with a .700+ solid roller. Never loads up and drives great.


JIM

Thanks, Jim. I was hoping that I could flush you out with "Dominator" in the subject title. The only new HP Dominator set up for 1 x 4 carbs with 2 circuit metering is 0-8082-1.
http://www.holley.com/products.asp?product=0-8082-1
My guess is that this would be a good place to start. I still have some parts (and funds, for that matter) gathering to do so I'll set and watch to see if one becomes available for a reasonable price.
Thanks again - as always, your advice is appreciated.

If it's a good deal, I'd still get it. You can add PV's if they aren't there relatively easily and it's simple deal to kill the 3rd circuit. I use annulars in mine, but they aren't really necessary. I got them mainly because this carb was on my old 427 first.

I also use the super soft linkgage to delay sec opening on the street.


JIM

Jim, good info as always!

MyBowTY- With a 3 circuit Dom, PV's front and rear will be the way to go. If that doesn't clean it up enough, especially during transition/low speed cruise, you can install transfer slot restrictors in the main body that will also help clean it up a bunch. I've got some baseline calibrations that will get you in the ball park if you decide to go that route.

Good luck.

Jim, this HP Ultra is 3 circuit, both power valves, etc. - pretty much as good out of the box as Holley makes. Keep in mind I'm an absolute newbie at carbs. Is the intermediate circuit something that can be opened/closed (or whatever you want to call it) without disassembly? If so, that would let me do a relatively quick change from street to kill when I hit the strip for the fastest speed/lowest e.t. possible. I'll notch the frame to allow 13" - 14" of rubber on the ground, so traction shouldn't be an issue at the strip. I'm after the same thing you are, albeit in a different way - one sub-10 second time slip plus a ride that "merges will into traffice" as I think you put it. You'll have me weight-wise but I should have you traction-wise with much wider tires. I'd like to do it with a stick, but I'm afraid I'm gonna have to leave that to you. I know that a lot of people are pulling hard for you to do that soon - I know I'm anxious to see it. Thanks again for your help!

I bought a used but nearly new 9375-1 and sent it to Quick Fuel Technology
www.quickfueltechnology.com/
Told them my intended use (Street Strip).
They set it up with a primary PV, and their own custom boosters with a special one in the front for better street manners.
As near as I can tell, they nailed the thing. works just fine on the street and on the dyno the fuel curve looked good and the jetting was dead on.
I have a 496 BTW.
Cost to modify it was $550
They are former Holley engineers.
Ron

That's what I started with ...a 9375. I did work myself. It's been on numerous dynos and there have been lots of comments about it's low speed manners even on the dyno. It just does well with just simple mods.

During the last dyno flog I tried a VERY expensive...I mean VERY....from a very well known ProStock operation that they had converted to a single four application. He basically builds matched pairs of carbs himself and dynos them to get them perfect. During some construction at his shop, one carb came up missing. So to him, the other one was useless..he didn't want to mess with building another match for it, so he reworked the remaining one to a single 4 setup for a buddy of mine. Anyway, I "commandeered" it to try.....

My 1050 was showing almost 1.8" of vacuum at 7400 rpm. Hoping carb was the main restriction, we installed the monster one. It only picked up 6 HP at peak and under 5000 rpm was actually down a good bit. Vacuum dropped to 1.5"-1.6" or so. Pretty much backed up machine shops idea that it would do no good and I needed more head and intake,

But it did have a beautiful fuel curve from 5000 rpm up..looked like you hit "repeat" button...........absolutely flat curve.

One of these days I'm going to add adjustable air bleeds to mine..I've had it for 10 years or so..it does get a little fat at the very top end.

JIM