Fabricated Intake design

I am going to be building my own intake and am trying to figure out what the ideal design is. I plan on going with a side feed intake to keep the inner cooler piping away from the exhaust manifold and turbo. It will also look cleaner with the piping running along side the engine, over the trans, rather than over top of it.

A little info on the engine it's going on:

2.0L
Ported head with 1mm oversized valves.
HKS 272 intake/ 264 exhaust cams
GT3582R .82 A/R
Custom manifold that will be very similar to the Full Race manifold
It's just going to be a fun/clean street car so I don't want it to have no torque/low end but I do want it to make decent power.

RMR offers a lot of the materials needed as:
5" round plenum, D shaped plenum, or half round plenum
various sized velocity stacks, round and oval runners

Information I am looking for:
Ideal throttle body size?
What plenum and size? I have heard that ideal plenum size is 1.5*the size of the engine, so in my case a 3 liter volume plenum. The D-shaped or half round would make fitting the velocity stacks much more simple.
Round or Oval Runners and what length and diameter? Is there any performance difference between straight and curved runners or is it just the runner length that is crucial?

You should look into RacerXFabrication manifolds on mr2 forums. He's done a bunch of R&D for many different styles, designs, etc.

I'd either buy one of his or use what you can from him threads to build your manifold from.

Here's his main website:
http://www.racerxfabrication.com/index.html

Here's a kit you can buy specifically suited for our motors, you just weld it up yourself (had I he had this earlier, I would have gone this route since my little brother is a welder, but I bought his intake manifold when he first came out with them).

http://www.racerxfabrication.com/page1/ ... age45.html

This kit provides the flange which RMR does not have. He has outperformed RMR in various setups (up to like 8000rpm or so anyway...not sure about now).

Bryan

That RacerX kit really looks nice, though there is something to be said when you make your own runners and plenum.

Thanks I was unaware of that kit. That is definitely a viable option or possibly just order a few pieces such as the velocity stacks. I had considered cutting the flange off the factory intake and milling the runners down and the flange face down to make it look nice and use that to build off of. They have some nice looking exhaust manifolds as well. Anybody know how they fit in an ST185?

They fit. He makes them to fit too. That's why I bought mine.

Bryan

toayoztan":1gdoe3vv said:

They fit. He makes them to fit too. That's why I bought mine.

Bryan

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I was referring to their exhaust manifolds, you have their exhaust manifolds as well?

dragstang86":2g6vnxaz said:

toayoztan":2g6vnxaz said:

They fit. He makes them to fit too. That's why I bought mine.

Bryan

Click to expand...

I was referring to their exhaust manifolds, you have their exhaust manifolds as well?

Click to expand...

Ah sorry, no i don't have their manifold. I will be building my own.

The site/stuff is actually just made up of one guy I believe, mainly. He was involved in like aerodynamics engineering or something.

Bryan

toayoztan":2203cz52 said:

dragstang86":2203cz52 said:

toayoztan":2203cz52 said:

They fit. He makes them to fit too. That's why I bought mine.

Bryan

Click to expand...

I was referring to their exhaust manifolds, you have their exhaust manifolds as well?

Click to expand...

Ah sorry, no i don't have their manifold. I will be building my own.

The site/stuff is actually just made up of one guy I believe, mainly. He was involved in like aerodynamics engineering or something.

Bryan

Click to expand...

I plan on building my own as well but have trying to decide on what design to go with. Are you going to go with a top mount or bottom mount? I had been leaning towards something similar to the Full Race manifold but I think I am going to go with all V-band mounting.

Going with ram horn design. If I went with a bigger turbo, I'd probably go with the longer runner top mount design for higher flow capability.

My setup is a T3 single scroll.

Bryan

I looked at the picture of your intake on your build thread. Where does that support in the bag go?

http://mr2oc.com/showthread.php?t=412296

Here's the thread that'll tell you everything...the build process, results, etc, pictures of different one he makes.

He's done a lot more since then, if you do a search, especially with the exhaust manifolds.

That bracket bolts to the back of the intake manifold and connects to the back of the block.

Similar to the OEM style, but much smaller and simpler.

Bryan