Performer RPM vs Streetmaster for the street....

[westcoastgalaxie]

I have three intakes in my stock to choose from: Performer RPM, Streetmaster, and F427. This is going in a 62 galaxie spirited street use only. I run it to redline through the gears and have fun with it around town and up in the canyons, certainly don't baby it. Setup is a 416, 9.5:1, C1AE's CJ valves and pocket porting chamber at 68 cc, solid flat tappet cam 230 @ .050 w/ .525 lift, performer RPM intake, FPA tri-y headers, full 2.5" duals with H pipe, 750 speed demon, gears out rear are 3.5. Stock COM tranny with stock converter, next year or two I plan on swapping out tranny and going with a hotter converter likely 2200-2500 range.

I am looking over Jay's book trying to debate which intake to choose. I find it perplexing that the performer RPM would have such a dramatic drop from the base 428 to the next up. The differences to me are the heads and cam, all other variable seem similar. The C6' have smaller ports and would certainly not be matched to the intake, the flow was similar to the CJ's but the exhaust did out flow the CJ's. The cam was a split with more exhaust duration. Could all this add up to better low speed performance for the RPM on the base 428?

This is leaving me a bit discouraged as my combo is not a mirror of any of those. I am down displacement, running different heads, different cam, so an apples to apples comparison is tough. However I can't ignore the performer RPM is down close to 50 ftlbs and similar hp until around 3300 rpm compared to the streetmaster and maybe even more over the F427. F427 doesn't have the performance up top so I am ruling that one out. The RPM however is about 20 ish up on the streetmaster in the 3300 to 4500 ish range. With my driving style I view my range 2000 to 5500 so this is making for a tough decision. I am leaning towards the streetmaster as it seems more consistent across engines and I do like that power increase at slower rpms.

Your thoughts?

[machoneman]

Your 2,000 rpm low is mighty low even for some really tight corners you'd take on occasion. That and the idea that you will swap out to a looser convertor later would have me go for the higher hp intake rather than chase some really low rpm hp. JMO!

The good news is since you have all three intakes, save for the work and the price of gaskets, experimentation would be a lot of fun in my book.

[westcoastgalaxie]

Okay so let's bump that rpm range to 2500 - 5500.  That leaves 2500 - 3300, which worries me that I will have a bog down low, that it will be sluggish off the light or out of a corner. Maybe it isn't worth worrying about but that is why I am asking here as I tend to over think things, a bit of perfectionist. I wish I had a dyno like Jay to do some real comparisons, but as you say I could swap out and find out. Wish I was quicker at these intake changes and had the time to do so.

[jayb]

How much horsepower do you think you have?  Up to 425-450 the Streetmaster is pretty tough to beat.  Over that, I'd favor the Performer RPM...

[Drew Pojedinec]

I'd use the F427 due to looks alone in a 62 Galaxie.
With some porting/cleanup work I doubt you'd really notice a huge difference on the street.

[TorinoBP88]

My (recently broken      due to bad valve) 416 FE had a 232/238 solid cam on a 108*, 3.5 rear gear in  a 1964 galaxie. I have a PI intake in the car now (and now sitting on a rebuild stock 428).  Even with the PI intake and too low a compression in the 416 (about 9.2:1) and the cam timed a bit late, it was very drivable around town 1800 to 2400 rpm was starting to get happy and the engine made fantastic power from 3500 to 5500 (never went beyond that - although is was not slowing down any!). 

I have used the streetmaster on several engines, and it has s definite jump up in power about 2500 RPM and pulls strong.  Nice running intake, but will suffer in the all to important 1800 to 3000 'normal' driving range compared to most any dual plane. That cam you have is already boarder line for good torque below 2000 also.  If flat out drag racing is what you want, sure the streetmaster is good (of your choices).  And of course the RPM is all around great.

I would start with the F427 thought, looks the 'correct part'  for the car, and will run in the low and mid range at part throttle much better then the street master, and with a split intake will pick up throttle response.  You can play with either a 4 hole spacer or with an open spacer.

[westcoastgalaxie]

Well Jay current setup is guesstimated around 400 hp, 450 ftlb. That would be at sea level but I am in Denver so correct from there.

I know in your book you could not explain the loss with the RPM but do you think I might be on track with my thoughts above?

When port matching the streetmaster do you only go 2-3 inches into the port?

[jayb]

I really can't explain why the Performer RPM was down as much as it was at the start of that one test.  That kind of performance is not characteristic of that manifold, but the test was checked and run twice to get good back to back data, so I think it is real.  It may not behave that way on your engine. 

On the port matching going 2"-3" into the manifold is all that I ever did, so I don't think you would need to do any more than that.  Also FYI on my brother's Thunderbird engine, which now resides in his 68 Cougar, there is no shortage of low end torque with the Streetmaster; he can spin the tires from any RPM. 

I know this isn't much of an answer, but I think if I were you I'd try them both for a little while, and see which one you like better.  Your combination may prefer the Performer RPM, especially since it is a heavier vehicle.  Hard to say for sure, though until you try it...

[Qikbbstang]

I'll throw in a bit of Devil's Advocate and state Jay's tests were all done on a dyno presumably at WOT and starting at an RPM point that may well be around your typical cruise and around town RPMs. Dyno tests are in another realm not off-idle or as you'd experience driving around town as you cruise about your business from idle to 45-60mph amongst traffic at some smaller fractions of throttle opening.
    I own a Gen 1 Lightning, the truck is simply a joy to drive around town and on the interstate it has power and throttle response to effortlessly haul you to the posted limit's by barely moving the gas pedal. Of course truly WOT gets you into the realm of blue-lights in the mirror in short order
    No kidding it's a pain to swap FE manifolds especially on a street car. Keep in mind Jay did hundreds of intake swaps, your having three to play with ought to be well worth the efforts to swap and feel them on the Butt-O-Meter.. I'm planning the same Mexican Manifold Dance with my 427: Ported PI, Perf RPM and Street Dominator/Street Master (have both will try one)

[rcodecj]

BB, I think you should try both the Street Dominater and the Street Master.
When I had both side by side, they looked quite a bit different to me.

[Qikbbstang]

LOL granted on the difference but still they both were single planes with collars in their plenums  designed for RV's in the midst of a gas shortage. The Street Master in all it's versions be they Ford, Chevy, Mopar in both SB&BB all use the same patented very unique laid-over runners that Edelbrock abandoned never to use again?. The SD reminds me of a shrunken Vic 427.  I kind of believe the differences will be marginal.
    Oddly the Perf RPM if you study it is actually a half single plane and half dual plane. I've long dreamed if Ford engineers back in the 60-70s had only had a peak at a Perf RPM's one plane being conventional dual plane and one plane (lower) being like half a single plane plenum/runners

[rcodecj]

LOL You never know until you try.
The ports on the Street Dominater were definitely larger.

Edit to say definitely

[Cyclone03]

I've run both in my Mustang,near same cam but ED heads @433ci.
I did the throat mod to the Street Master
I run a TKO OD 5spd so I do run the engine down to 1800-2000 rpm at times , at that RPM the SM just didn't like the throttle to be moved at all the 850Demon hated life there. I ran the SM with a 1" 4 hole spacer that worked better than an open.
I swapped the SM for an RPM and I could effortlessly pull from 45mph to traffic speed in 5th gear. My goal was 45 and up for shiftless freeway driving,the RPM does it with a 4 hole spacer.

WOT running through the gears my butt dyno couldn't tell.   

[westcoastgalaxie]

Thanks for all the feedback guys, interesting to hear some real world feedback.

[frankenfords]

I swapped from a port matched F427 to a port matched RPM to a ported (collar removed from plenum, runners blended into plenum, runners opened up to MR port size at head and blended up into port) Streetmaster on a fairly mild 428 build a few years back. Combo was .040 428 with CJ style dished pistons, heavily ported C6AE-R heads with 2.09/1.66 valves, about 10.1 compression, mild Crower hydraulic cam with 220-228 @ .050", 112 LC, .540ish lift, Holley 780 VS carb, 1 3/4 inch primary tube headers into 2.5 inch duals, C6 auto with 2,200 rpm stall, 3.89 rear gears with a tall tire. Ran this in a 3,900lb 65 F-100 SWB truck.

With both the F427, then the RPM intake, it had gobs of power as soon as the converter stalled out, would blow the tires off pretty easy (too easy). I think the F427 and RPM were on par with each other for that build. Swapping to the Streetmaster, it lost about 1.5-inches of manifold vacuum at idle, and was noticeably softer below the converter stall, but above about 3,000 rpm, it came on hard, and according to my seat cushion, pulled much harder through the mid-range up to the shift point (about 5,500 rpm). I was able to control the tire spin better too, so I felt it was a win on my combo, for what I wanted. Cruise rpm with this combo was about 3,000 rpm at 70 mph, and I noticed no change in driveability or economy in this range. I did have to diddle with the power valves, jets, secondary spring and timing a bit between the two intakes. The Streetmaster worked best for me with a 4 hole spacer on top of an open spacer, where I ran the RPM with just a 4 hole spacer.

For my current 428 build, same truck, with more compression, Edelbrock heads, huge solid lifter cam, 3,000 stall converter and wide ratio gear set in the C6, I kept the Streetmaster and am pleased with it.

For your combo, given that you have more weight over the rear tires than my truck and likely traction will be improved, I'd probably go with the F427, for as others have said, it will look 'right' in that engine bay, and will be in the sweet spot for your driving range.

Brett