I was wondering if anyone has tried both the edelbrock performer or EPS intake manifold on a mild cammed 350(around .460 lift) and also tried an edelbrock RPM AIR GAP.
I currently have an EPS intake and after talking to many engine builders they insisted that if I should have a minimum of an RPM intake for the 350.
I looked through the edelbrock catalogue and there are dyno tests of a 350 with a performer intake and mild cam(.420/.442 lift) that made around 20 lbft torque more under 2500rpm than the 350 with an rpm intake(non air gap)and hot cam(.501/around.512).
Theoretically it seems sort of stupid to compare these 2 setups because one cam forms airflow at a certain rpm(= power) while another cam forms airflow at a much higher point.
I am just wondering if anyone used the SAME CAM (mild to moderate cam) for both intakes and if there was an overall greater torque feel or proof that the RPM AIR GAP produces better OVERALL power as well as better response in the lower rpms(aroune 1500 or lower).

Because sure the rpm air gap produced lower trq #'s down low than the performer with the dinky cam, but what if the crazy (.510+ lift cam) was dumped for a closer (.450to .460lift) cam..the numbers should be greater????correct

also rpm intake and rpm air gap are the same height HOWEVER
-rpm intake port dimensions are 1.16'' x 1.92''
-rpm air gap port dimenstion are 1.14'' x 1.95
I dont know if this is a very dramatic point but i just thought ide throw it in.

 

Cam LIFT doesn't determine the correct intake to match it; DURATION does.

.510" is not "crazy" lift. I'm driving around a 305 with about .530" lift, and it seems pretty normal to me. Gets over 20 mpg on the highway with 3.73 gears.

You're exactly right that you should pick an intake that does its best work in the same RPM range that the cam does. That's what "component matching" is all about. But of course, there's more to picking an intake than just the RPM range it's designed to work in; things like hood clearance, emissions, cold-weather manners, etc. will usually enter into the picture too. But in fact, the particular cam you have will work reasonably well with either of those intakes; probably the best with the RPM, but still OK with either the Performer or the Air Gap.

Another intake you might want to take a look at is the ZZ4 one.... you can pick up brand-new take-off ones from people who bought the motor and put something else (FI or whatever) on it, and have the intake left over.... it's 50-state emissions legal, and fits somewhere in between the Perf and the RPM in terms of the RPM range. It also complements the cam you have real well. Look at the ZZ4 cam specs (208/221° @ .050") for comparison.

 

its easier for me to get the performer rpm air gap than look around for a zz4..So for the intake i will go for the rpm air gap because I guess the diff from the performer rpm is the air gap which should theoretically result in a cooler charge..so unless I knew why a performer rpm is better than the air gap version....I am going with the air gap rpm

 

I'll give you one good reason; it won't fit under your hood.

Try ebay.... air intake, search on ZZ4... or www.sdpc2000.com or www.paceparts.com .... one click and you're done... doesn't get a whole lot easier than that

 

i will look for the intake on the net...you said it was better than a performer but better in the lower rpm's than the performer rpm.
That is what I need.
However I am fully aware it wont fit my hood with the 14x3 element. I know what is going on with my parts...the rpm air gap manifold is only 0.45'' taller than the eps. THat is not that bad.
A smaller 10x2 filter or a chopped 14x3 to 14x2 will do the trick. and I knew that already...So lets focus on the intake and how it will work with my setup rather than how things like hood clearance because I can always fix that.
Thanks

 

I would strongly recommend against any type of "drop base" air cleaner. To get a picture of why, imagine what happens as you hold the lid still, as high as it will go under the hood; and move the carb upwards. You will see that the clearance between the carb and air cleaner lid gets smaller and smaller. Even with a "good" drop-base, like the old Chevelle/Camaro big block one from the 60s and early 70s which at least has a base that's properly designed for flow UNLIKE the aftermarket ones, you still will end up narrowing that space to a little slot; which pretty much negates the point of a larger intake.

I don't happen to have the Air Gap in stock; but I do have a stock L69 intake, a Perf RPM, and a ZZ4 intake. The ZZ4 is about ¾" taller than the stock one (the ZZ4 is now on my car), and the RPM is about ½" taller than that. So the RPM is about 1¼" taller than your stock one. That should give you some idea what you're working with.

 

I was just confused because the edelbrock website has the height for the eps being 3.74'' in the front and 4.80'' near the back

the rpm air gap is stated as 4.20'' in the front and 5.25'' in the back.
That is an average difference of 0.46'' taller than the eps.
I do not know if these #'s are accurate or not so hopefully RB83L69 you can understand my uncertainty when you say one thing and the product websites say another.

 

I can't accept much responsibility for what people put on web sites.... all I know is what I see when I set them on the floor next to each other, preparing to make the exact same decision you're working on right now. But for all I know, I could be wrong I suppose.

But, the Performer I have isn't the EPS, it's just the regular Performer. Maybe they're different. A regular Performer is very very close to the same height as the stock one.

 

ok I understand. But that is totally correct..the performer is 3.50'' and 4.60'' compared to the eps 3.74'' and 4.80''. It not the biggest difference but its enough to cause possible clearance issues.
I am strongly thinking about that zz4 intake but I have honestly never ordered anything from the internet but i will call around performance shops and ask if they have any lying around.

Thanks a lot for all of your replys RB83L69

 

RB83,
What manifold designs DO fit under a stock IROC hood? Performer RPM without the airgap? I wouldn't want to be forced to feed my AFR equiped 355 with a standard Performer.

 

Go RPM all the way. I heard that the performer is just a btter than stock one. The rpm is for max power and torque. We went from a perfomer to a RPM on my 66 truck with a carbed L05 and a mild cam 210-216 .440 .454 and it made a notiable increase in top end power with no loss to the low end.

 

I had an EPS topped with a Road Demon and a 3" drop base air cleaner under my stock Camaro hood.

 

RB,

The EPS and performar manifolds are different. As stated, the EPS is a bit taller. The EPS port designs are such that they are wider and shorter, both by .001" Edelbrock claims these changes make for peak torque around 3500 rpm on a 350 sbc.


wesilva,

Call me crazy, but i think the RPM and the AirGap version are the same heights. The ports are just a bit different

An alternative to the RPM air gap is the Dart Kool Can intake. Very similar looking. They can be snagged for around $150 on eBay.