Super Victor vs RPM Airgap Dyno results SBC

[Winston Wolf]

Got to do a dyno comparison between an Edelbrock Performer RPM Airgap and a home ported Super Victor 2925. The results were surprising.

GM 400 block, .040 over
Eagle Forged crank and rods. 6" rod length
Mahle Pistons with 5cc valve reliefs
75cc AFR Race heads 210 cc runner
Lunati 60133 Solid Roller 249/255@ .050 .585/.600
1.6 rocker intake/1.5 rocker exh
Edelbrock RPM Air-Gap intake, matched to 1206 gasket with 1" open spacer
950 HP Holley carb
37 deg total timing

Changed to a 2925 with an opened up plenum. Ports are matched to a 1206 gasket. Same timing, one size larger jets in the primaries, but no tuning. Below are the intake and the dyno results.

[bigjoe1]

Please tell us the results. I can not tell from the graphs


JOE SHERMAN RACING ENGINES

[rally]

I take it his graph shows the RPM Air Gap doing very well compared to this Vic Jr. I have said this before, never underestimate a good dual plane intake. A good dual plane with outshine that Super Vic in port velocity and cylinder fill. I am thinking of switching to the Factory ZL-1 intake for my 468 ci BB Chevy drag car. I shift this motor at 6500 RPMs, for best results. A single plane makes the difference in the 8000 RPMs range. Stock eliminator drag car use factory dual plane intakes. They work period.

[Winston Wolf]

Peaks are:

RPM Air-Gap

437 ftlbs @ 4350
402 hp @ 5200

Super Victor

436 ftlbs @ 4700
427 hp @ 5650

So, Same RWTQ, 25 more RWHP
They are putting down the same hp at 4500 rpms, by 5600 the Super Victor is up by almost 30 hp and at 6500 RPMs, the 2925 is still up by 22 hp
This is on a Dynojet chassis dyno.

[Winston Wolf]

I take it his graph shows the RPM Air Gap doing very well compared to this Vic Jr. I have said this before, never underestimate a good dual plane intake. A good dual plane with outshine that Super Vic in port velocity and cylinder fill. I am thinking of switching to the Factory ZL-1 intake for my 468 ci BB Chevy drag car. I shift this motor at 6500 RPMs, for best results. A single plane makes the difference in the 8000 RPMs range. Stock eliminator drag car use factory dual plane intakes. They work period.

Actually in this case, completely opposite. The Victor kills the Air-Gap and there is no way you would run the dual plane. And this isn't a high RPM screamer or anything.

[CamKing]

That's just what I would think would happen. You've got 400 cubes, and a 249/255 solid roller cam with 210 heads.
That combo is just screaming "single plane".
I'd bet that if you put a ported victor Jr on it, you'd pick up a bunch of torque, and only lose a few HP.
For a 400hp 350cid engine, the air gap is great. Anything above that, not so great.

[Bob Hollinshead]

427hp at the rear wheels at 5600rpm? Nice I wonder what some bigger heads would do.

[JoePorting]

Very predictable outcome. From 0 to 4000 rpm, the airgap is better. From 4000 rpm to 5000 rpm, they are about equal. From 5000 rpm+, the Victor is better. That's what we would think. The point is that the rpm airgap is a small port manifold with around a Fel-Pro 1205 runner, while the Victor when opened up to the Fel-Pro 1206 is a bigger manifold able to handle the increased air requirements in the higher rpm.

[aussie mouse]

I agree like Cam King said, the results are hardly surprising given engine and camshaft size.

But was the test a totaly fair comparison, you have a modified port matched Super Victor.

Did you treat the Air Gap to simlar port match etc ?, if not the comparsion is worth little

[Winston Wolf]

I agree like Cam King said, the results are hardly surprising given engine and camshaft size.

But was the test a totaly fair comparison, you have a modified port matched Super Victor.

Did you treat the Air Gap to simlar port match etc ?, if not the comparsion is worth little

Yes, the Airgap was also port matched to a 1206 gasket.

[Matt Gruber]

thanks for the report, Wolf!
i predict 11.4's w/2925.
then after adding a roll bar, 11.5's.
or 11.5's w/air-gap, no roll bar.

[mike walsh]

So I have a question with a statement!
Built a 351 Windsor, +.060, 248 @ .050 w/.540 lift, wndsor SR. heads, compression is at 11:1, long tubes w/H pipe then turn downs, light car about 2800 lbs, 3400 stall, 750 Holley dbl pmpr;
On the street the Victor JR. was a chore at part throttle,
the air gap RPM was much better off, in traffic throttle response was crisper.
The customer knew better than me so the Vic jr. was run.
Also I know this combo was never sorted out, the customer was more than happy with a 7:60 1/8th mile pass where he lifted after launching.

My question is, is this common or just that combo?

[Winston Wolf]

So I have a question with a statement!
Built a 351 Windsor, +.060, 248 @ .050 w/.540 lift, wndsor SR. heads, compression is at 11:1, long tubes w/H pipe then turn downs, light car about 2800 lbs, 3400 stall, 750 Holley dbl pmpr;
On the street the Victor JR. was a chore at part throttle,
the air gap RPM was much better off, in traffic throttle response was crisper.
The customer knew better than me so the Vic jr. was run.
Also I know this combo was never sorted out, the customer was more than happy with a 7:60 1/8th mile pass where he lifted after launching.

My question is, is this common or just that combo?

I can honestly say I cannot tell a difference driving it around on the street. I seems the same at part throttle and a steady cruise as the Airgap. I do have a 4k stall and 4.56 gears (200-4r OD trans) so I'm sure that could mask any low speed stuff. But it seems ok with the trans locked at lower RPMs (2000-2500) This is a heavier car too, 3600 lbs without driver.

[stealth]

wonder what a bigger carb then the 950HP would do..

[rfoll]

75 FT. LBS difference around 4000 RPM. If this gets driven on the street, I can't believe you wouldn't notice, especially if you had a manual trans.