: Polk Performance sheetmetal intake manifolds!
02-05-2003, 02:27 AM
I'm working with Danny (turbomiata) on getting some stuff made for the SR20DE/DET and the QR25DE as far as intake manifolds and fuel rails are concerned. I will have a QR25 manifold made up in the next few months for a project car we're working on. The SR20 stuff should be coming soon too. Here's a pic of a manifold from these guys. Their work is amazing! I think this is a 4G63 manifold..
Check them out at www.polkperformance.com. Call and ask for Danny or Don. They are also going to offer head work for the SR and QR engines. From mild to wild... they will have it!
02-05-2003, 03:01 AM
You would not by any chance happen to know how much this will cost? And did they make that throttlebody also.
02-05-2003, 03:12 AM
will the nissan apps have square runners too?
02-05-2003, 03:27 AM
I don't know about EXACT costs.... but I think it will be around 850.00 or so with a fuel rail. They can do oval, round, or square runners. But, it's a nice manifold... worth the money for sure. Doesn't have that nasty stock injector boss/flange with runners welded to it. I likes!
02-05-2003, 03:41 AM
i dont know why the DSM's like square runners. i ran into a fabricator in cali once. he produced a similar intake mani for a 4G63. i asked "why square runners?" and he responded "they work." absolutely no scientific explanation at all:(
Doesn't have that nasty stock injector boss/flange with runners welded to it. I likes!
hehe, i was going to weld one of my stock flanges to a intake mani of my design. TIG'ing to cast AL makes me cringe:rolleyes:
02-05-2003, 03:45 AM
lol... yeah... that's what Don says... it works well for them! I was going to buy an o2induction manifold last year.. but I just couldn't get past the cast flange/boss thing. If I'm going to spend that kind of money on a manifold.. I want it to be like this one.
02-05-2003, 03:51 AM
yeah, its definitely a nice looking mani for the $!
02-05-2003, 10:29 AM
now they need to make a larger runner replica of the GTi-R manifold with larger throttle bodies :D i can dream cant i?
AZ WHITE SE-R
02-05-2003, 11:46 AM
Is there going to be a low port manifold made as well? How about being sold without the feul rail?
02-05-2003, 12:30 PM
Not sure on the lowport head... I'm sure if enough people showed interest.. they would try it out. I'm also sure that they can sell you one without a fuel rail. Why wouldn't you want the rail though? You will have to make one otherwise.
02-05-2003, 02:38 PM
i dont know why the DSM's like square runners. i ran into a fabricator in cali once. he produced a similar intake mani for a 4G63. i asked "why square runners?" and he responded "they work." absolutely no scientific explanation at all
This is Don Polk using Danny's login...
The reason for the square runners is the factory head has square ports on the entry. The intake follows the radius on the corners just like the head. If you will notice the intake has a tapered runner from the plenum to the head. This helps out by keeping velocity as high as possible. I have seen other custom intakes and flowed benched them against the tapered ones. The non-tapered ones do not have as much air speed as the tapered ones do.
Velocity is a big deal in making efficient power. It is not as big of a deal with a turbo car, but still helps to keep it high.
As for the Nissan intakes.....We have not done one yet, but will soon. It takes time to design a proper intake that will perform well. It is not a simple task to do it right.
02-05-2003, 03:01 PM
02-05-2003, 03:12 PM
holy crap i need one
also i need sun dnyo numbers
02-05-2003, 03:50 PM
well, that, and round runners make it so that the air in the middle is farther away from any edge, reducing velocity. unless you are making mega huge amounts of power, a sqaure design is mo bettah.
02-05-2003, 04:53 PM
Will this be for turbo or NA or both? I would love to see a properly/scientifically designed intake manifold for our cars. One with proper plenum size, runner length, and correct taper. Something that is harmonically tuned to produce mid-top end gains, not just a throw together.
02-05-2003, 05:02 PM
any ideas on when they might go into production??
02-05-2003, 05:03 PM
I am officially showing interest on the lowport manifold.
02-05-2003, 05:13 PM
Originally posted by scmser
I would love to see a properly/scientifically designed intake manifold for our cars.
You know... I wonder how many of those intake manifolds on the market are actually designed and not just put together. I have some friends who designed an intake manifold for the SAE formula car at school. They did all kinds of computer models of various designs, ran computer simulations on them to determine pressure distribution through the manifold, harmonics, and of course, they were designed specifically for the motor in the car (cbr 600 f4 motor). They also tested each model in ADAMS which is the same software that Formula 1 teams use to model their engines. For an NA motor, you have to be careful with a log style manifold because you can starve a couple of the cylinders of air; the first cylinder because the air is going to fast and goes by, and the last because there's not enough velocity to get there. Or something like that. For a turbo, I'm guessing it's not as critical. Makes ya wonder though how many companies actually spend the time to properly design one....
02-05-2003, 05:26 PM
I'd like one for my B14 :)
02-05-2003, 05:46 PM
I'd be very interested in some dyno numbers (low boost and high boost) when a prototype is developed.