Kacyc3

if someone that had an efi car and still had stock cold air setup would make this really easy to see the difference.

commander_47

Well, then your choice is obvious.

If you have the clearance go with the Edelbrock RPM 7104. There is no other choice.
501 peak torque, 465 hp

You could downgrade to the straight Performer 2101
494 peak torque, 456 hp.

The 2601 air gap spreadbore will give you:
504 peak torque, 458 hp


Performer RPM air gap 7501 (this is what I run) with square bore will net you:
508 peak torque, 474 peak hp

Performer RPM 7101 square bore gets you
504 peak torque, 470 hp


You can only get the most from your setup with the Performer RPM. To get more you have to go squarebore.

IMHO the loss of HP with the 2601 isn't worth it.

Torqued Off

Down to:

Performer RPM Quadrajet OR Performer Air Gap (non-RPM)

I will never push RPM past 5500. The Air Gap actually has better torque at 3000 and better peak torque than the RPM, so makes me think its better for me. I could care less what happens at 6000 where the extra HP is made.

Just a little worried about colder weather problems with Air Gap.

I did talked to Edelbrock and they claim that the runner design of the Air Gap is improved over the 2101 Performer?? The port dimensions are identical.

commander_47

Down to:

Performer RPM Quadrajet OR Performer Air Gap (non-RPM)

I will never push RPM past 5500. The Air Gap actually has better torque at 3000 and better peak torque than the RPM, so makes me think its better for me. I could care less what happens at 6000 where the extra HP is made.

You will have to measure, but I do not believe the air gap will fit under your stock hood even with a drop base air cleaner.


Just a little worried about colder weather problems with Air Gap.

I have never had an issue. Starts right up and idles perfect. I have an electric choke.

I did talked to Edelbrock and they claim that the runner design of the Air Gap is improved over the 2101 Performer?? The port dimensions are identical.

It is a limitation of the small front venturis and squeezed front intake on a spreadbore

Shark Racer

I agree on measuring:
Performer: 4.05
Performer Air-Gap: 4.32 (0.27" taller)
Performer RPM (air gap or no): 4.72 (0.67" taller than performer)

REELAV8R

With my 77 and the Performer (2101), stock air cleaner installation, I have room for 3/8" under the carb and 1/8" clearance from the hood.
So total 1/2" with no clearance.
So an airgap would fit but I could not get an insulating 1/4" carb gasket under the carb and still have clearance.

BKbroiler

The RPM airgap with a drop base air cleaner and 3 inch element fits under the hood with no problem.

Torqued Off

BK, did you say you are using the K&N drop base? I have a factory drop base, this its the unit made for the L88 hood setup, got it a Carlisle. It has a pretty significant.

My only question for you is do you think the drop base restricts the airflow into the inlet. A previous post said you need at least 3/8 from top of vent tube to roof of air cleaner lid. Other forums and posts suggest that airflow can be restricted with a large drop base air cleaner. What do you think?

BKbroiler

My drop base is a cheap generic unit, about 1.5 inches deep. I'm not sure of the vent tube to lid clearance (I am using a Qjet). But based on the way the car runs, as good as 12.15 at 110mph in the quarter with the air cleaner on, I don't think its starving for air flow. It will run up to the 5,800 rpm shift points with no drop off in power.

7t9l82

i have the r.p.m air gap with a 1/2" spacer 750 double pumper and dropped base air cleaner with NO issue.

Torqued Off

OK, that answers that.

Torqued Off

I think you are confusing this, I am asking about the newer Performer Air Gap.....not the Performer RPM Airgap that is so popular.

The 2601 manifold is like a 2101 Performer, but with Air Gap. In the Hot Rod reports, it actually does better than the RPM QUadrajet in terms of Peak Torque and Average Torque, it loses out slightly in Peak HP, but I am very skeptical that this is accurate, because I can't figure out WHY it would be better. The port dimensions are identical to the 2101, the height is only .25 inch taller. So whats the magic? I question the dyno runs, did they allow the engine to fully warm up, and when it does, and the manifolds are hot, do the numbers still do as well?? Logically, I can understand the Air Gap concept, but can it really make more torque than an RPM manifold in the same RPM range....and will it maintain than when fully warmed.