I'm talking torque which shows up as real street preformance improvement and you are talking horsepower, which for the street race is next to useless. When will you guys understand that horsepower is a top speed indicator, and just how much time do you run a street rig at top speed, want to try next to never. Torques is what makes acceleration and that is the number you want to increase and keep peak torque around 3000 RPM max and a big flat torque curve starting at around 1500 to 1800 and extending to 3500 to 4000 RPM Horsepower is for racers and torque is for the street machine. Yet all you know it alls talk is horsepower.

 

Roger that. I have C6AE-R heads, and my cam is an unknown. My main curiosity is if I'd stand to gain noticable torque with a manifold thats got the larger ports to match the larger 2.2 R-code ports. If it is'nt, then it wouldn't justify shelling out the $470 for a BT, and at the same time save some dissapointment in the fact that I could get similar results from a much more wallet friendly manifold that is used primarily for smoking tires and rapid acceleration.

 

Does the iron 428CJ intake have the exhaust x-over?

 

Something to keep in mind.....HP is a function of torque.


HP=TQxRPM/5250
TQ=HPx5250/RPM

Think of it this way....Hp is the RATE at which torque is made. The more hp you have the more quickly tq is available.

500lbft x 2000/5250=190.47hp
500lbft x 2500/5250=238.09hp
500lbft x 3000/5250=285.71hp

If you can maintain a flat, broad tq curve, the hp will climb. if you could build a motor to make low rpm hp, you'd probably never get the car/truck to hookup on the street.

300hp x 5250/2000rpm=787.5lbft
300hp x 5250/3000rpm=525lbft

It really isn't one or the other that will get you vehicle moving, as hp and tq are almost one in the same. They are just different ways of expressing the way energy is used to do work.

 

There is no reason to believe that a manifold that makes more horsepower will not deliver more torque as well. As long as they are rationally comparable (no dual plane versus tunnel ram stuff) a good intake can outperform a weak one at every single point on the RPM curve from idle to window.

The idea that you need to give up on horsepower to get low end torque is simply not true. The Engine Masters test have bourne this out very clearly. I have run both huge single plane and modest dual plane combinations. After a huge amount of testing I can say the differences are there, but nowhere near as dramatic as you may think. The current one had an insanely huge Dove single plane and still made 500 lbs/ft at 2500RPM - 427 cubes and 10.5:1.

 

If what you say is true, then it doesn't hold up to the dyno #'s on a recent article in Car Craft, Aug. 08. 2 stroker FE's, one built for street one for strip (the street version running the Edelbrock Performer RPM, the strip version with a Edelbrock Victor). The street version has a HP high of 504 @ 6100 and torque high of 503 @ 3800. The strip version makes 551hp @ 6300, and 519ft/lbs @ 5300. The strip version doesn't make 500ft/lbs until around 4800rpm, almost a thousand rpms later to make the same torque as the steet version, thus the torque coming much later instead of earlier. Also of note the street version made 458ft/lbs @ 3000rpm and the strip version made only 439 ft/lbs @ 3000.

 

The last thing I said was Torque, and the articles I referred to, if you bother to read, mention torque increases thru out the rpm range. My recommendation of the rpm intake is based on personal experience, and numerous articles. your attitude sound like a bunch of opinion, and the rest of us are all ignorant, but your next to God!! Theres been plenty of other posts on this forum where folks are not impressed with your mr perfect style. YOu chose to assume we all talk HP. You have good comments some of the time, otherwise your attitude just pulls this forum down.

 

Without dyno numbers or time slips on the track your feel is even less than opinion. My opinion is backed up by the numbers seen on the dyno in the shop I worked at and on the track while racing. Seat of the pants feel tells you nothing and magazines sell advertizing and aim to make those advertizers happy. So who's ignorant now?

 

What other factory aluminum manifolds resemble the cast iron 428 CJ other than the PI? In a comparison between a PI, an Edelbrock F427 and a Sidewinder, which one would be the most beneficial for the street? They're all dual plane with large runners. Which would most likely have been found in a scrap yard?

 

Interesting that you say the 'S' intake is better than the rpm, yet theres plenty of engine builds showing good torque increases over 20+ ft lb at 2500 rpm, right in the torque range you think only you understand. I'll bet you think your right and all these other dyno tests are wrong. Tell that to AFR.

 

The Edelbrock RPM manifold EDL-7105 from Summit Racing is only $339.95 and is as good as or a little better than the Ford Sidewinder intake. The Sidewinder is a great manifold, but very hard to find. I have one, but do not want to sell it.
I doubt that you will find any of the above in a scrap yard.
Buy the Edelbrock and enjoy your engine. In a years time, $340 is less than a dollar a day. Treat yourself and buy the good manifold. If you can find a sidewinder for less money, then get it. Both are great manifolds for your application.

 

Well the deal is, is that a fellow Ford guy has a factory aluminum intake which he said is an aluminum version of he 428CJ, which I though was a PI. But he didn't say what it was. Anyways he said he'd sell it to me for $300. If it's a PI or a sidewinder I'll do it when I get the $$'s. If it is some early factory 4 barrel with smallish runners, I'll pass and opt for the RPM. So far by what I've read not only here but elsewhere, is that the PI, Sidewinder, Blue Thunder, and E-brock RPM are the best single 4v "street" intakes, with increases in both HP and torque across the board.
Currently I have an Edelbrock Performer 390 for sale if anyones interested, good condition, $100.

 

The PI manifold is as close to the CJ as you are gonna get. Ford said the horsepower and torque gains are identical.

 

Dust, the factory aluminum intakes are tough to find in a scrap yard. Most of them have been grabbed long ago. I wouldn't hesitate a bit to use an iron CJ intake on a truck. If your pal has an aluminum one that is not a P.I. or sidewinder or Edel F427, he might have a 427MR intake. These are single 4 barrel intakes that look a lot like the P.I., and could be mistaken for one if you don't know the casting number. They're a very nice intake. There are also some aluminum intakes that were installed on 352s and 390s, that were made before '67, that are very nice, but they have the larger, 'tall to the bottom' size ports. If you have the matching ports in your heads, you'll be fine.

If I were building Keisha's engine and were going to use the D2TE-AA heads that are already there, my first choice would be the Blue Thunder 427MR. It will match the D2s ports just fine, and being a dual plane will still have perfectly good low speed manners. My next choice would be a Ford 427MR intake, then a sidewinder, then an F427, then a P.I. My last choice in aluminum is the Edel RPM. All of the dual planes work very well, the reason the RPM is my last choice is because I just don't like the appearance of them....but all of the nicer dual planes are within 5% or so of each other. That shows you that Ford knew what they were doing when they made these things. If the Iron CJ intake is available, thats fine too. If Keisha is on a budget headers are most important now, and the stock iron S or T intake would be fine till more cash could be found. DinosaurFan

 

I have the Edelbrock rpm, Sidewinder and Ford Medium riser aluminum intake manifolds, and I think they all look good, but beauty is in the eye of the beholder.