well hopefully scott aka the mad porter will see this and chime in .this is what i was told by him personally and why i used the combo i did in a heavy truck. i believe scotts word to be be good as gold when it it comes to making a bbf run

 

I know Scott is great with old iron heads. I just can't believe that he told you the Stealth won't come on until 3500 RPM's. That is crazy talk. I need to let him ride in my truck. Now there are some differences when it comes to building 429's vs. 460's. The easiest way to think about it, is to realize that a 460 is taking as much air at 2800 as a 429 is at just over 3000 RPM's. So the combo should be matched with that in mind. There are other things to consider as well, including rod:stroke ratios etc, but that's a little too in-depth for this discussion. So, for a 429 that is mostly a low RPM torque'r that will rarely see more than 3000 RPM's, then yeah, the Performer should be adequate and the Stealth might be overkill. I would still bet that the Stealth would out-torque the Performer even on that type of engine, though.

 

i intend on using this for mud drags .im running the comp X4262 cam on a 109 lsa with dove ported heads 10.1 c.r. and also running a 2500 stall convertor . i also questioned him about this as i was gonna buy the stealth and thats what i was told.i know that he was very pleased when we took it for a drive and seen how well it pulled .maybe he will read this thread and chime in on his reasoning

 

The single plane torquer although a good intake is ill suited for use in a truck where torque is the name of the game. The single plane intake will trade torque downstairs for HP on the top end and if you do not have the cam to utilise it will make less overall average torque and HP than the performer. This is especially true if you use a 2" 4 hole spacer to add needed plenum volume to the performer.

Intake manifolds like all other components on a performance 460 should be chosen based on the choice of ancilliary components used for the build. A torque biased combo will be best suited when an intake with small runner cross section and high velocity is chosen.

The best intake by far for torque under 2.5K is the stock iron ford intake. Its problem is lack of plenum volume and the size of the holes on the carb pad.

Next in line is the performer intake which gives up a tick of torque below 2500 RPM but will add some 25 HP over the iron intake (stock pass car) and with a good spacer will add some 15 to 20 more HP for a total of some 40 HP. The performer has two different runner cross sections for a broader torque curve to some 4K. I use this intake on builds that utilise less than 220 degrees of duration @ .050" lift. 450 HP top side limit is about average.

Next in line is the performer RPM which starts to shine when you use more cam duration. I use it when duration @ .050" lift is above 220 @ .050" lift. It has larger runner cross section and will give up some low end torque and response below 3K vs the performer especially when the performer is paired with a spacer. I use it from 450 to 550 HP

The stealth is a higher RPM intake and I compare it with the RPM airgap which has smaller runner cross section than the stealth but larger than the rpm and performer. The airgap is by design meant to be port match per intended use. On a bench the airgap will out flow both stealth intakes due to its better runner velocity and larger plenum area. I use these higher RPM intake on builds that utilise a cam of 226 degrees duration @ .050" lift and above. I have yet to test the airgap against the stealth but my gut and experience along with some anecdotal track time evidence show it to be as good if not better than either stealth intake. Testing will bear this out and have the final say over my educated guestimate. If you do not have enough cam to utilise the higher RPM capabilities of the larger dual planes the trade off in low and mid range torque will not be off set at the higher RPM ranges these intakes are designed for. I use these from 550 to 650 HP which is about their limit.

With regard to testing all of the intakes on a combo with a 216 @ .050" lift cam I feel the results are suspect at best. You can not test a single plane intake such as the victor on a combo like this and expect it to be anything other than a rutting pig. The results show nothing more than which intake is best for a given combo but not overall. We have debated this ranking of intakes on the network 54 BBF forum and the statements I make here are more in line with consensus there.

The statement that a dual plane dual 4 barrel BT intake makes more HP is ludicrous at best. A victor is 40 to 50 HP better than ANY dual plane intake ever thought of being when a combo has the cam to utilise the RPM band the victor was designed for period.

My experience and the experiences of many engine builders I trust implicitly (from our BBF network 54 forum) bear out the fact that the stealth intake is a very good HP intake but it is softer on torque below 3 to 3.5K vs the stock intake and the performer by some 20 pound feet. From a driveability stand point it offers less runner velocity and response because its runner cross section is huge compared to any other intake mentioned here including the victor. For accelerating with a loaded trailer from a stand still I would bet the performer/spacer combo would outpace the stealth to the legal speed limit.

I steered my client to the performer because of the displacement and intended use. The fact that the performer pulled like a SOB well past the cams usuable rpm range bears this out in my mind. Hell the intake pulled well past the point of valve float onset and pulled like a freight train at that.

I am not convinced that a stealth would be a better overall intake for a mild combo like richards (or kevins) (both utilise the same cam by the way). I had both the stealth and airgap in stock at the time richards build was going together and felt that the performer was a better choice. Factors such as C/R, cylinderhead flow, cam specs and header design were part of my decision as well as fuel economy and I stand by it. Remember high runner velocity makes for great average torque and HP not fat flow numbers with big runner cross section. How a combo feels on the road in my butt dyno is a far greater indicater of client satisfaction than any dyno results believable or not.

By participating in engine masters I learned that average torque and HP with in a given RPM band are more important on a street biased combo than peak numbers be they torque or HP. Average numbers accelerate a combo far better than a peaky combo with poor overall performance across the lower end of the RPM window of operation. The heavier the vehicle the more important this is.

For kevins situation spending another $200.00 USD to add mabey 20 HP and give up 20 pound feet seems a waste of money when the performer and a spacer will do him just fine.


Scott J. / RHP
http://reincarnation-automotive.com
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The test engine was very comparable to what A LOT of guys are running. Something in the 210-220 intake duration range. In fact I think the vast majority of guys have built or are looking to build something like that. I think that test proved that the Stealth will outperform the other dual plane intakes on a moderate 460 buildup. Of course the single planes didn't fare too well. I don't think anyone would expect them to on that engine. It's too small and too low revving. Still, though, it looks like the Stealth is the better intake than both the Performer or Performer RPM in moderate effort 460's. The ONLY place I can see those two doing better than the Stealth is on a 429 that is a VERY VERY mild build.

 

A dyno measures numbers only.

The subtleties of tip in, transitional response,average torque and Hp throughout the measured RPM ranges etc are real world criteria that a dyno can not measure. I have seen countless dyno sheets that had better peak numbers that still did not cut the mustard when the combo went from the cell to in between the fenders.

I have been fortunate to have tested most of these intakes and trust my butt dyno more so that a test that offers no numbers or average figures to back the ranking.

A good portion of builds I see on this forum are reletively low in static C/R for the cam specs chosen and this makes manifold choice even more crucial in producing a good flat torque curve. Kevins build for example is 9.66 to 1 with a 75 cc chamber if the pistons are at 0 deck. If they are the usual .015" to .020" below with out a block decking then the c/r drops to the low 9's. Poor quench characteristics coupled with lower C/Rs in the 8's and even some in the high 7's are even less suited to the higher performance intakes than kevins build would be.

 

All very good points. I've always tried to tell people that there is more to engine building than cross-sectional area's, peak flow numbers, etc. It ALL factors in. I have no doubt that you considered EVERYTHING when making the recommendation for Kevin's engine. That being said, most things are a compromise. Torque at the expense of hp. High end power at the expense of low end grunt. Driveability at the expense of max power. That's why I think, in most moderately built 460's, the Stealth is the best compromise. The best of both world's. It's not great at the lowest low end of torque and it's not the best on the high end of power. But if you want a good strong powerband from 2000-5500, it is probably a very good choice, regardless of whatever else is used on that engine.