[Cliff R]

Steve, the Performer is a complete "turd" on a 455 build. I've tested them several times, dyno and on the street. Couldn't make track runs with one on my last 455 at 500hp because it was too restrictive. So much so that it induced a HUGE hesitation/stumble going from idle to full throttle with good traction. The engine was also "surging" in the mid-range so I stopped testing with it and put the iron intake back in place with no other changes and ALL the problems disappeared.

I'd also add that it's highly likely the one Jim Hand was testing was modified a bit, and may have had a spacer on it as well.

In any case a stock one with a port match to a stock Felpro intake gasket is a "turd" on a 455 much past 400hp so I recommend for folks to avoid it for higher HP builds........

[Steve C.]

OK Cliff.

I'm relaying Jim's results as he reported to the Dallas Area Pontiac Association and testing that was done prior to a formal article in High Performance Pontiac magazine on the subject.

Only the water crossover was removed from both manifolds to allow an easy change at the strip. He reported nothing else was changed.
His transmission was set up to shift automatically at 5200 and two runs were made to get consistent times. The only difference in the engine was the manifolds.

He reported with the Edelbrock Performer intake manifold on his car there was no change in ET or MPH. That said, we both know different engine/vehicle combinations can and do reflect different results.

.

[Dragncar]

Whitmore told me back in the day Peformers were a good intake for a hot street 350 but would not use them on higher HP builds with 400s-455s.

[TA63]

Thanks for the input guys. I should have been a little more specific about my objectives with this car. Street driven 72 lemans with the T41 option. Looking to build a 400 to 450 hp 400 with a modest roller cam, which in my experience is much easier to do with an efficient head and intake setup. Planning on either ported #48's or speedmaster aluminum heads. I wanted to stay with a near stock height intake to make use of the ram air system I planned to fit to this car, hence the interest in the performer, or I'd slap a port matched RPM on there no doubt. The cam I am considering is a butler 224/230 @ .050 offering on a 114 LSA. Shes a factory AC car with auto trans.

[Skip Fix]

FWIW when I was building my RAIV motor after my machinist flowed the heads with just a pocket port-per BMCA rules that year- flowed it with a non ported Performer, then my gasket matched HO intake. told me to take that manifold back to super shops-even thought the Edelbrock tech said "it flows better than stock", granted it was untouched so I am sure that hurt flow.

The one on the mild 400 in my 81 TA I blended way up the runners.

[25stevem]

Here’s some dyno info in regards to the usage of a Performer on a ,030” 455 with low comp heads,

Here’s a brief detail about the motor,
It was built with a Comp Cams P286-AH8 flat tapped hydro cam.
1.5 rockers.
The intake was run with a 1” spacer.
Both cast # 96 and 6X heads in fully stock form where tested with the same exact chamber CC size.

You be the judge if a 455 built to use a Performer is a slouch or not.

[Cliff R]

"He reported with the Edelbrock Performer intake manifold on his car there was no change in ET or MPH. That said, we both know different engine/vehicle combinations can and do reflect different results."

Steve, I'm sure that at that time Jim was able to run equally as well with either one.

So take that information plus the testing I did with it on a more powerful engine with aftermarket aluminum heads and somewhere in between that intake gets very restrictive on a 455 build.

I was NOT able to use it for track testing as it failed street testing miserably. When you go to full throttle and get a HUGE stumble, then "surging" in the mid-range, and the ONLY part you've changes was the intake, well, common sense says to remove that part as it's NOT going to work well for what you are doing. Also keep in mind that I also tested a truckload of other intakes and NONE of them caused any issues anyplace with hesitation, stumble, bog or surging at WOT.

I can tell anyone reading this that IF you are limited to the height of the stock intake and your engine is at or past about the 450hp mark, the best intake for your engine is goind to be the stock cast iron or aluminum HO. ALL of the other intakes I tested except for the RPM (it's already over 1" taller than a stock one) REQUIRED a 1" spacer to work well.

I found the same thing on the dyno. At least a 1" spacer is required for all the single plane intakes available for these engines or you are leaving some power on the table. The higher level of power your engine is, the more it will benefit from a well blended 1" spacer on ALL single plane intakes.

The Performer RPM really doesn't need one and it really becomes a PITA to add one for most of these set-ups, especially if you are trying to get it all under the hood (without a HUGE hole in it) or use factory Shaker or Ram Air parts.......FWIW.......

[Skip Fix]

Also the Performer has a slightly different level than the factory intake. a click higher in front and about 1/2" lower in rear for those with a Shaker.