diffrent intake manifold

cruisen_15 · #1 03-25-2008, 02:49 PM

is there any power to be seen if you made a custom intake maifold with bigger pipping to the cylinders and better flow paths and less of a "air box in the middle" in other words make it look like headers but have t.b's and what not, by doing this you could get more room for something like the tomyx intake. is there any need for the emission stuff hooked up to the intake manifold that cant be converted to the custom manifold?

cruisen_15 · #2 03-25-2008, 08:35 PM

anyone shed some light please?

LetItSnow · #3 03-26-2008, 04:50 AM

How many "air box[es] in the middle" do you see? I count two. The manifold treats the engine like a pair of 3 cylinder engines until the IRIS valve opens.

You're looking at an active, two stage intake manifold. If you haven't done anything to your cams and heads, I'd say that intake manifold restrictions are not a concern.

If you're not going to do any substantial breathing work, then a new manifold design is a lost cause, imho. Bang for the buck, there are plenty of better things to do.

Do some research. Learn how stuff works. Find out where things actually can be improved.

Crazy_pilot · #4 03-26-2008, 03:32 PM

I know of one complete custom manifold, but that was for an airplane using an EG33. The guy didn't need it for performance, he wanted to trim 25+ lbs off the engine's weight.

It's Just Eric · #5 03-26-2008, 05:00 PM

Hmm....It would be intresting to see if any gains are had making the intake tubing equal lenghth, much like you are thinking Im guessing.

Honestly, when combined with a custom air box (I bet you can move the tb forward and have room for a nice scoop fed ram air) on a sstock motor I bet you would see SOME gains....But on a motor with some camn and headwork it would be more notable

this is probably one of your better ideas..and I say, if you have the money for mandral bends, and have acess to the tools youll need to do it..Go for it

cruisen_15 · #6 03-26-2008, 06:03 PM

yes i thought maby you could increase the tubing size and have flow paths to each cylinder with 1 t.b and have it like 3 inch and do a ram air or cold air setup, this would also work good for anyone doing a front mount intercooler, ive seen a shop do a custom manifold for an sti in person and i asked the dude how much hp it gained and he said 25 to the wheels and they are patenting it, i even got a pic of it on my phone, its setup for a front mount though, and the t.b is turned 360 deg.

Nevin · #7 03-27-2008, 11:18 PM

On a car with mostly stock everything, I can't imagine much gains at all from something like this. It's a great idea to try to improve something, but this just isn't where improving needsto be done. The intake "region" of the car (besides the MAF anyway) is not something that really needs improvement.

The throttle body twin intake throttle plates are 60mm and capable of flowing 900 CFM*.
Our 202 CID engines can only flow 420 CFM at 100% volumetric efficiency
at 7200 RPM. That is from the FAQ page.

Besides, if you wanted itb's or anything like that, you'd need to run a standalone to make it work. If you're gong standalone, then I could imagine this being worthwhile, but until then, when you could actually tune FOR the changes, it would be quite hard to optimize your newfound power.

It SOUNDS like a fine idea, but there would be a lot of CAD time needed to design a manifold better than the manufacturer did. Ours is a design that is quite unique, and very effective at what it does. Being able to design something to "out do" it at the same power levels, same driveability, etc... would be very hard indeed.

cruisen_15 · #8 03-28-2008, 12:12 AM

nevin, i see where your coming from, but when you say how can i build something better than factory? just look at the tomyx intake, its way better than stock and added h.p, now doesnt that defeat your idea that making the flow better then factory would be unlikely? jsut my 0.02$

Nevin · #9 03-28-2008, 12:04 PM

The idea behind the factory intake setup is to make the car quiet while driving. THat's why things are made of rubber, have helmholtz resonators, and weird accordian looking dealies. Sure you can make more noise, and a bit more power, but things are less important before the TB than they are after on an N/A motor.

You could very well make more power at a certain RPM with a different intake manifold, but I guarantee you you will not make more over the same powerband. Resonance is extremely important, and unless you have the data to construct something that takes this into account, you CAN make more power, but you very well won't have a very "everyday user-friendly" car. If you CAN make more power, you'll more than likely need more revs to do it, and doing things like that starts getting tricky.

I am all for the idea, but there are simply a LOT of factors when designing something of this caliber. If you do it right, pay attention to the details, and don't overlook anything, you could have a very good piece. That's all I'm saying. Just do your homework. And no, asking "how do I make an intake manifold" and then slapping something together does not work. hahah

Good luck, just the same.