In a motor built for track only, and 3500-7500, when do you begin to see gains with a tunnel ram setup over a single carb setup? And how substantial are those gains?

The reason I ask is, I wonder if my motor is being choked by the 750 dominator and victor jr intake, especially considering the manifold has a 4150 type flange, and thus requires an adapter to mount the 4500 flange dominator.

If I were to rework the setup, I'd either sell the dominator and adapter and get a barry grant carb (something in the demon series) OR sell the the intake and adapter and pick up either a Brodix intake with dominator flange that would match my heads, OR sell the whole shebang and go to a tunnel ram and dual 500 or 660 setup.

But I don't know which setup will net me the most benefit.

Engine: 407 Ci, 40 over 400 splayed mains, poured with rock block (half), steel crank, Eagle rods, Wiseco pistons, molly rings, solid roller Reed cam Duration at .050 is 262/267 ADV Duration: IN 296 degrees, exhaust: 302 degrees Lobe Lift: IN .412" EX .417" Vavle Lift: IN .618" EX .625" @1.5 RR Valve Setting: IN .020" EX .022, zero decked block, Brodix Track I heads, 2.01 intake, 1.65 exhaust, intake runners 215 cc, triple valve springs, compression ratio 13.2 to 1, receiver grooved heads, block wire head gaskets, Victor Series intake, 750 Dominator carb., Hooker 2 inch longtube headers, 3 inch X pipe with 1 chamber Flowmasters. Transmission: Turbo 350 trans. with reverse valve body, 4400 stall converter. Rearend: 12 bolt GM differential, 456 ring and pinion with mini spool. Ignition System: MSD ignition, 7AL-2 with two-step, with rev. limiter pills. General Information: Channel for 4 link suspension. Car Weight: 3090 lbs. (without the driver) Brake line lock, trans. brake, B & M rachet shifter, Southside traction bars, 8 point cage.

Car will run high 6's in the 8th on motor only as it sits.

I am sure some of you have an opinion on this... let's hear it. A desktop dyno sumlation possibly?

Hey neigbor!

I think there is a reason you see very few if any SBCs running tunnel rams at the track. While your combo sounds pretty hot, I doubt that a single carb with the right intake would be choking it and would be much easier to setup correctly than two carbs on a tunnel ram.

IMO 750 Dominators are not a very popular carb . . . have heard there are some "challenges" with them, but cannot remember exactly what. I will say though that putting a 4500 carb on a 4150 manifold using an adapter will cost some power - not the best way to go.

I personally think that a properly prepped Vic Jr manifold with a good 4150 style 950 HP carb would be plenty for your ride.

Originally posted by Eric68:
IMO 750 Dominators are not a very popular carb . . . have heard there are some "challenges" with them, but cannot remember exactly what. I will say though that putting a 4500 carb on a 4150 manifold using an adapter will cost some power - not the best way to go.

I personally think that a properly prepped Vic Jr manifold with a good 4150 style 950 HP carb would be plenty for your ride. Well, that's kinda what I was thinking. I bought the car setup as it is, and I REALLY don't like that adapter setup. it has quite a taper to it...

That victor jr is costing you a pile of power and torque. I would look into larger intake with a dominator style flange like super victor, brodix hvh, or dart wilson. You have to remember that the victor jr has been around for a long time. It is old technology. Also tunnel rams make a lot of power when prepped properly. It just takes a little "tinkering".
Just my thoughts.

Originally posted by 427ss:
That victor jr is costing you a pile of power and torque. I would look into larger intake with a dominator style flange like super victor, brodix hvh, or dart wilson. You have to remember that the victor jr has been around for a long time. It is old technology. Also tunnel rams make a lot of power when prepped properly. It just takes a little "tinkering".
Just my thoughts. Hmm... I looked at a brodix intake the other day, I believe it was the hv1003. There was a brand new one on racingjunk.com for $100 but it was for a "toilet style" setup.

Does anyone have a desktop dyno where they can put my combo in and simulate different types of induction? Tunnel Ram, super victor, brodix, etc?

If you don't mind me butting in, I asked this question about my big block, the other month on DDR site and it appears you'll get a lot of conflict. Several people informed me to us a single plane intake, such as a holley strip or a team G and a single carb, while others told me that if you plan on draging the car, a tunnel ram, when setup properly will give you a good amount of extra HP. When I ran some numbers on the program I use, a tunnel ram, can drop me into the low tens, just by adding one on.
But the question is, do I want to spend a lot of extra money buying one, when all I would have to do is spend 1/2 that amount and buy a new intake and a larger carb.
So I guess the real answer is really up to you? Do you want to spend, at least 800.00 for a tunnel ram set up or more, or do you want to spend less and have a lot less headaches with the setup?
A friend told me, he bought a ram, bought two new holleys, out of the box, bolted them on and it made a big difference after getting the setup just right.
Good luck with the end results. They sure do look neat though.....
Bruce graemlins/thumbsup.gif
www.hobbystage.net/camaro/rolandracing (http://www.hobbystage.net/camaro/rolandracing)

I agree the victor jr. is not helping. They were made for a heavier car and a milder motor. Your convertor will hurt you if you do go to a tunnel ram (if it's really a race only deal think about stepping up with a different convertor, it will help) The car is light enough but most tunnel rams are a little light on power at 4400 rpm. Try a good single plane and think about a different carb.

Well, I picked up a used Weiand tunnel ram off ebay for about $100. Whether or not I'll use it, I don't know. I also found a brodix intake hv1002 that sounds pretty good and should match the heads I have pretty well as well as having a 4000-8000 rpm range according to the manufacturer. It has a dominator flange so I could keep my carb without the adapter as well. I dunno if the 750 dom is enough carb, but unless I can sell it and the vic jr, funds don't permit another $600-$900 expenditure on a carb right now..

Also, I was reading that the track1 port size is 221, not 215 as I was originally told.

Originally posted by oger:
I agree the victor jr. is not helping. They were made for a heavier car and a milder motor. Your convertor will hurt you if you do go to a tunnel ram (if it's really a race only deal think about stepping up with a different convertor, it will help) The car is light enough but most tunnel rams are a little light on power at 4400 rpm. Try a good single plane and think about a different carb. What converter would you recommend and why? I have seen tunnel rams that have different rpm ranges (3000-8000, 5000-10000, etc) so I am not sure how my 4400 will hurt me with a tunnel ram.

I'd like to sell the rear end and go to a 9 inch so I can play with gear ratios a bit easier too. The car was setup originally for an 8th mile track, but all we have around is here 1/4. I'm a little concerned about running out of gear, especially if I add a fogger down the road...

So would a 4.10 gear change your converter recommendations?

The hv 1002 would work good for your application. Also have you ever thought about letting a reputable carb shop work on that 750 dominator. Amazing what they can do. Might also save a few coins.

Originally posted by 427ss:
The hv 1002 would work good for your application. Also have you ever thought about letting a reputable carb shop work on that 750 dominator. Amazing what they can do. Might also save a few coins. no I would have no reservations about having a good shop work ont he dom for me. Any recommendations?

I may have missed something, but have you run the carb as is right now? How did it do?

If you haven't, I'd wait and see how it runs first.

I have used them with 5500 convertors and found in all cases the car was faster with a single 4bbl. Mine were always the higher rpm models but even the ones designed for lower rpm (unless you can find one made for a boat) have an awful lot of volume to do much even at 4400 rpm. We ran them with 4spds even in a 4000# car it picked up almost 5mph over a single 4bbl.

Originally posted by oger:
I have used them with 5500 convertors and found in all cases the car was faster with a single 4bbl. Mine were always the higher rpm models but even the ones designed for lower rpm (unless you can find one made for a boat) have an awful lot of volume to do much even at 4400 rpm. We ran them with 4spds even in a 4000# car it picked up almost 5mph over a single 4bbl. ok, ya lost me. at first it sounds like you are saying the single carb was faster, then at the end you say you gained 5mph OVER a single carb.. ?

I think he left the word "than" out..

pdq67

a 4400 converter is to too low for an intake that has a 5000 - 10000 RPM band. In general, you want your converter stall RPM close to your peak TQ, not the lowest RPM in the power band.

What I am saying is in a 4spd car if the rest of the motor is set up for the rpm range a tunnel ram can help especially in the mph. The point is tunnel rams and automatics usually don't work well together.

hmm, well I think I am going to put the vic jr, adapter and 750 dominator up for sale and give something else a try smile.gif I'm going to post them in the classifieds if anyone is interested in them