[Cliff R]

I would say yes. When they discontinued the P4B with it's wide runners swooping runners and went two directions.. A small runner intake with stock flange height (Performer) and an RPM that was over 1" taller with taller/larger runners and lacked provisions for factory divorced and hot air chokes. Not doubt the were targeting the "high performance" crowd with the RPM and closer to stock and "mild" combo's with the Performer.

At least one would have thought the engineers knew that most Pontiac engines were 400cid and larger and would suffer with a small runner intake past about 1hp per CID and larger.

The Performer at a glance reminds me of the ill-fated SP2P intakes they made for a while for SBC engines. What a "turd" that was.

I can tell anyone reading this that on my first 455 with 6X heads the Performer would actually work, it just didn't work well. On my 2nd go round with that engine after the KRE head swap it would NOT effectively feed it, Any attempt to go to full throttle had to be aborted because it caused a HUGE hesitation/stumble/bog and noticeable "surging" in the mid-range. I tried it briefly on the street before heading to our private track rental for intake testing. It was quickly removed, the iron intake put back in place and ALL issues went away. I decided to take it off the intake testing list.........

[PONTIAC LARRY]

That old P4B Q-jet version LOOKS like it would work as well as your good iron ported one but I suppose it does not though. Surely the old P4B works better than the regular (non)Performer on a 455 then ?

[b-man]

SP-2P Edelbrock intake was the smogger/economy intake, intended for use on low compression smog engines. Tiny runners limited rpms to around 3500, this intake was a product of terrible times back in the early ‘70s days of emission controls and the first gas crunch.

The regular Performer didn’t live up to its name.

It’s okay on 350 and 400 mild builds, but when it’s really not able to outrun a stock intake I’d say it’s a dud.

[Skip Fix]

Chevy racing dual plane for Holley and Qjets(I think an older one for circle track classes requiring iron) that has one carb slid forward some to center it better. I think Dave at SD did that on his Holley SD intakes converted to 4500s. Part of why the Tomahawk and Holley flow better with a Holley on the front runners than a Qjet they are more centered than the Qjet to make the turn into 1/3 and 2/4 runners.

[25stevem]

The performer works fine up to 5400 with anything 400 cid or less, or up to 5200 with a 428 to 455 cid motor .

The devil is in the details though, but it can produce up to 420 hp.
You can not use it with anything flowing more intake air then stock flowing 67 and up D port heads, or about 210 cfm@28”.

Even with the velocity produced by stock D port heads it needs a 1” spacer and a 780 to 850 carb.
If you run it without the spacer and not in conjunction with what seems like a oversized carb then air can not turn efficiently into the shallow side plenum at high flow rates and you end up being lucky to make 390 Hp on motors bigger then 400 cid.

The performer to me was designed from the word go to be a high velocity intake that will help make great throttle response on emissions era low comp cars with poor rear gearing.

Edelbrock very clearly states that the manifold is only good to 5200, and without a spacer and a big carb it might be best on no more then a 350 cid motor if you want it to pull to 5500.

Note that Edelbrock does not even want you to use bowl blended heads with the performer as seen in lower part of what I have posted!

PS.
That sweeping upper plenum runner feeding number 2 has on a P4B intake is a flow decreasing and fuel separating night nightmare!

[mrmark1957]

The regular Performer made more torque under 2500 - 3000 rpm than a cast iron 1973 EGR intake on my low compression 73 400 inch motor with 4X heads,a 204/214 degree cam and stock TH400 converter. The iron intake with that cam and 3.23 gears would barely spin the tires. Swapped to a Performer with no other changes and now could easily spin the tires, throttle response was better too. Felt the same from 3000 rpm to the shift point. Unfortunately I never took it to the dragstrip.

[Dragncar]

Originally Posted by Cliff R

Even the RPM has it's limitations for "big" power.

I've had customers attempt to use them on really high HP stuff only to experience distribution issues and resulting engine troubles. One customer in particular ran one on a 455 in a low 10 second application. After several times spinning the same rod bearing he went to a Tomahawk intake with a 2" spacer. Going from memory here, there is one runner on the RPM that gets crunched down a bit where another lays over it, but at the moment I don't have one in front of me to look at.

Anyhow, his intake swap immediately stopped the rod bearing issues. His engine dyno'd around 735hp at that time. The heads were 330cfm older Edelbrock round ports, so when moving that much air it's just makes more sense to use a bigger intake with straighter runners and a common plenum area vs a dual plane with a all different length runners and a divider in it..........

Was that engine a high CR race gas engine. Do you remember about how big the cam was ?

[Cliff R]

Yes and yes. The cam was (nearly as I can remember) solid roller, over .700" lift and 276/284 @ .050" on a 110LSA. Shift points were 7200rpm's. After pounding the same rod bearing out of it 2 or 3 times he swapped to a single plane intake and the problem disappeared. Of course it's just ad educated guess as to why, but the logical conclusion is that the RPM intake for some reason was deficient on that particular port causing detonation by leaning it out. Doesn't matter in the big scheme of things, the RPM was removed, replaced with a Tomahawk intake and no more issues.........

[Tim Corcoran]

Had no idea that the Tomahawk was good for low 10 second ET's good to know, I thought the Victor was more inline with that level of performance. I will be dyno testing a new mild street build with good flowing 6x heads and a mild hyd roller very soon and plan to test it with a factory iron modified by Dave with a Cliff Q-Jet and with a port matched Tomahawk with the Q-Jet and with a 750 and a 850 Holley on the Tomahawk too. I will post the results after testing is complete.

[Steve C.]

Tid bits....

Example of my 'worked' Performer RPM intake compared to a single-plane intake:

Both intakes port matched to the heads in use, with half-inch open spacer and a HP950 carb. 4.210" stroke / 462 CID

RPM intake 580.2 HP at 5800 rpm (peak) and a Victor intake 600.9 HP at 6000 RPM (peak).

RPM intake 589.1 ft.lbs. torque at 4400 RPM (peak) and the Victor 595.1 ft.lbs. torque at 4700 RPM (peak).

Down lower, the Performer RPM with 491.2 ft.lbs. torque at 3500 RPM and the Victor intake 487.0 ft.lbs. torque at the same 3500 RPM.

Quarter mile with the RPM intake: (running 8" converter and 90/10 shocks on the front and no sway bar in place); 1.60 60" times, 10.88 ET at 124.28 mph (date: 11-21-03)
I never ran it with the Victor intake, wish I had !


On the same 462 engine.....

Holley Street Dominator intake with runner & plenum work by Dave Bisschop.
Port matched to the heads.

No carb spacer:
577.9 hp at 5700 rpm, 581.0 ft.lbs. at 4400 rpm.

With 1/2" open spacer:
589.4 hp at 5600 rpm, 589.0 ft.lbs. at 4600 rpm.

With 1" open spacer:
589.8 hp at 5700 rpm, 590.8 ft.lbs. at 4400 rpm

I did a Tomahawk intake to match my HSD intake. They are very similar in performance.
I only dyno tested it on my 505 on the first dyno session and with the same Holley HP950 carb as above.
Results with the other intakes:

Victor intake with no carb spacer:
638-642 HP at 6000-6100 rpm.
635-640 ft.lbs TQ at 4500-4600 rpm.

Tomahawk with 1-inch spacer:
611 HP at 5600 rpm
629.9 ft.lbs. TQ at 4600 rpm

The Performer RPM intake with 1/2" open spacer:
615 HP at 5800 rpm
634 ft.lbs. TQ at 4400 rpm

On my 505 the Victor is 'King'. I never tested any other intakes on it with further dyno sessions.
With later cam changes I ended up with a best of 660 HP using the Victor intake. Making low end torque with it is no issue !


.

[Cliff R]

Not surprised at all Steve that the Victor would be king. It was also the best intake (topped with a Dominator and 1" Wilson spacer nearly as I can remember) for the 505 I did here at close to 750hp.

I've rivaled the Victor with engines making slightly less power with the T-II, 1" spacer and HP950 or Holley 850DP, but never outran it. For all engines I've done here over 650hp the Victor was THE way to go for best power numbers........

[Steve C.]

A bit of clarification and related to the numbers I posted. The Holley Street Dominator intake I used was not your run of the mill intake, it was modified by Dave Bisschop with plenum and runner work. And probably VERY similar to the prototype that Dave did for the production Tomahawk intake. The first production Tomahawk intake as cast for marketing reasons did not have large port exit openings, this in order to be used on 'factory' cylinder heads.
I presume the as cast versions of the intake today are the same but done so under different names and maybe slight changes.

It will take quite a bit of port work on them for big HP numbers. The HSD intake port opening will go about 2.300" tall and have about a 0.125" above for gasket seal. I sent my Tomahawk intake to Cliff to do the port match and runner work.

Dave also did a HSD intake for me modified for use for a 1050 Dominator carb using a cloverleaf spacer. On track back-to-back it tested very similar to a Victor intake with the same Dominator carb. Both intakes port matched to the heads in use.


.

[Skip Fix]

Chevy intake with the Holley pattern about 5/16 forward. So must help even entry into ports and plenum.

[25stevem]

That Chevy designed for marine, stock car and circle track usage if I recall right.

[Skip Fix]

Yep designed for classes requiring a cast iron intake. Iron copy with Q jet and Holley of the old Z28/LT1 intake.

[Against the Wind]

Hi, I am looking for some advice about intake manifolds. I have a 70 Le Mans that I built in the late 90's and am going to put it back on the road. It has a 455 that I raced in SG for many years. Nuzi refreshed it for me for street use. It has forged flat-top pistons with 73-4 SD rods and a cast crank. The cam is one of his hydraulic flat tappets. I don't remember the exact specs but it has about 245-250 dur at .050 and about .550 lift. The heads are 71 HO round ports that have been heavily ported. I currently have an old Torker intake on it that has been ported also and an old BG 750 cfm on it now. It has a turbo 400 and a 9 in ford with 390 gears that I let Nunzi talk me into. (LOL) I have several vast iron intakes and a 72 HO 455 aluminum intake and wonder if anyone thinks one of these old dual planes work better with my combo. Thanks, Lee

[Skip Fix]

"Original" Torker mainly for Q jet(Step down in the plenum under the primaries) and different front runners than rear or Torker II? With that much cam and using a square bore carb the Torker II is a better choice.