Reply to "Manifold Question - Performer vs A331 Torker"

> Ok - I feel like an idiot at this point. The intake that is sitting in the
> shop is an Edelbrock Performer - Not an Edelbrock Performer RPM Air Gap.
> My question is this - should I send it back and get the RPM Air Gap or stick
> with just the standard Performer?

The RPM Air Gap is a much better intake on a modified engine but is
considerably taller.

> The cost difference is only about $120. Any clue as to the HP difference
> between these two?

See attached dyno results below. If you plot the data, you'll notice the
RPM Air Gap is better across the tested rev range which is more important
than just peak numbers. Also, notice the standard Performer was only tested
with a 1" spacer as the dyno carb fuel log wouldn't clear otherwise. Note
that it really responded to the 1" HVH spacer.

> I know one of the comments from previous posts was asking about the air
> screen. If I decide to leave the screen in place, will the RPM Air Gap
> version fit with a dropped air cleaner?

No.

> I believe Dan mentioned that if I went with the standard Performer that it
> would need some work in the plenum area. How much would this help if I
> decide to go with the standard Performer

On a Ford aluminum dual plane, it helped a bunch on the nearly 500 HP
408C it was tested on. In those tests, the ported Ford aluminum dual
plane made 31 HP and 23 ft-lbs more than an unported Blue Thunder.
The ported Blue Thunder pulled better numbers on the flow bench
(attached to a cylinder head) and would have likely made better power
but was not tested. We did test the ported Blue Thunder this weekend
on Mike McDougal's 393C and it made 411 HP at the rear wheels through
the mufflers and small air cleaner so the porting worked.

> and what exactly needs to be done?

The problem with older dual planes is that half of the runners often
flow much worse than the other half when bolted to a cylinder head.
If you bring up the poor runners to match the good runners, it really
pays off. Note that we really aren't porting the runners. What we do
is cut down the plenum divider and radius the port entry in the plenum
to aid flow into the poorer flowing ports. This needs to be done on a
flow bench with a cylinder head attached and a carb in place. IIRC,
Dave McLain charged Mike McDougal $150 to port his Blue Thunder intake
(correct me if I'm wrong Mike). If you are interested in keeping a
stock engine screen, you may want to consider sending me your intake
and we can port it on the flow bench and dyno it in ported and unported
form. I believe I have a spare Performer here so if you want to hang
on to the intake and drive the car, we can port my spare intake and
exchange them after the testing is completed. If you want to ditch
the engine screen, go with the Air Gap intake. If you look at the
plenum of the RPM Air Gap, you'll see the divider is already cut down
and the runners are reasonably well equalized.

Dan Jones

Performer with 4 Hole 1 Inch Spacer
950 HP dyno carb, Pantera GTS headers and Magnaflow mufflers.
Note: Intake is actually the earlier F-351 4V version but appears identical
to the current Performer. The Perfomrer required a spacer for throttle
clearance so was tested only with 1" spacers. Baseline for Edelbrock
Performer intake was with a 4 hole 1 inch spacer which was needed to allow
clearance for fuel log. Good solid pull and for whatever reason the engine
didn't seem to mind the 1 inch 4 hole on this dual plane. Going to try the
HVH spacer next.

RPM HP Torque (ft-lb)
4100 300.0 384.1
4200 303.2 379.6
4300 312.9 382.0
4400 319.7 381.8
4500 324.6 379.2
4600 331.5 378.5
4700 341.3 380.9
4800 350.0 383.5
4900 354.6 380.0
5000 358.2 375.9
5100 362.0 373.0
5200 367.8 371.2
5300 369.6 366.9
5400 372.6 362.5
5500 377.5 360.3
5600 381.3 357.1
5700 381.4 352.1
5800 374.6 339.3
5900 371.9 330.6
6000 363.0 317.9
6100 370.5 318.4


Performer with HVH Spacer
950 HP dyno carb, Pantera GTS headers and Magnaflow mufflers.
HVH was also better on the Edelbrock Performer but not as drastic as with the
factory iron piece. Performer is better than factory cast iron intake or so
it seems on this engine.

RPM HP Torque (ft-lb)
4100 308.1 391.7
4200 310.7 390.1
4300 322.5 394.8
4400 324.6 387.8
4500 330.6 386.1
4600 339.2 387.3
4700 349.3 390.2
4800 361.1 394.7
4900 371.3 397.5
5000 371.1 390.1
5100 375.3 386.4
5200 378.2 382.4
5300 377.7 374.5
5400 380.6 370.1
5500 385.1 367.5
5600 388.3 363.8
5700 390.4 359.5
5800 390.1 353.3
5900 391.1 348.2
6000 382.4 334.8
6100 384.2 331.1


Performer RPM Air Gap 2V
950 HP dyno carb, Pantera GTS headers and Magnaflow mufflers.
Baseline for Performer RPM airgap intake. Like many of the intakes designed
for 2V heads, the RPM Air Gap will fit either 2V or 4V heads. Running with
no spacer. Going to try the 4 hole 1 inch and HVH spacers next. Good solid
pull with good numbers.

RPM HP Torque (ft-lb)
4000 312.4 405.7
4100 311.9 401.8
4200 320.7 399.9
4300 329.1 402.7
4400 335.8 400.9
4500 344.8 402.2
4600 350.7 400.7
4700 355.8 397.6
4800 362.7 396.7
4900 370.0 396.6
5000 376.2 395.1
5100 381.8 393.1
5200 386.7 390.4
5300 390.3 387.2
5400 392.9 382.1
5500 398.1 380.0
5600 396.7 372.1
5700 394.6 363.6
5800 392.6 355.6
5900 393.2 350.1
6000 396.6 346.9
6100 394.3 339.4


Performer RPM Air Gap with HVH
950 HP dyno carb, Pantera GTS headers and Magnaflow mufflers.
HVH spacer seems to run about in the middle of the bare intake or 4 hole 1
inch. Good all around performance making over 380HP and torque.

RPM HP Torque (ft-lb)
4100 310.1 400.8
4200 314.8 394.1
4300 324.0 395.7
4400 337.1 401.9
4500 349.7 407.9
4600 354.2 404.6
4700 360.2 402.3
4800 367.3 401.8
4900 373.6 400.4
5000 377.2 396.5
5100 381.3 392.6
5200 388.5 392.1
5300 392.9 389.9
5400 395.3 384.4
5500 400.1 381.5
5600 399.1 375.0
5700 390.8 360.2
5800 388.7 351.9
5900 386.0 343.7
6000 384.1 336.2
6100 386.9 332.9


Performer RPM Air Gap with 4 hole 1 Inch
950 HP dyno carb, Pantera GTS headers and Magnaflow mufflers.
Good pull and engine picked up about 5 horsepower and about 10lbs/ft with 4
hole. A good swap and about the best all around combo for these heads etc.

RPM HP Torque (ft-lb)
4000 312.9 409.3
4100 316.6 406.5
4200 324.3 404.7
4300 332.7 407.4
4400 346.3 410.7
4500 349.2 408.1
4600 354.1 404.4
4700 362.8 405.1
4800 371.3 406.4
4900 375.1 402.2
5000 380.3 399.3
5100 387.9 399.1
5200 394.1 398.1
5300 395.3 391.9
5400 398.6 387.7
5500 401.6 383.4
5600 403.3 378.3
5700 400.8 369.4
5800 401.7 363.7
5900 401.1 357.2
6000 403.1 352.5