STARTING TO BUILD INTAKE MANIFOLDS

Bill Hincher · Post by **Bill Hincher** » Tue Nov 28, 2006 2:37 pm

I want to start building a decent intake manifold with a place to except an extra injector, but I need to know what kind of improvements you guys would like to have, like where to locate it, away from the brake booster? away from the steering? high up? down low? what about throttle body location? and what kind of throttle body would you guys like to use.
Exhaust headers will follow

Your input is appreciated

Bill

Bill Hincher · Post by **Bill Hincher** » Tue Nov 28, 2006 7:24 pm

from the tests i have run , I can shorten the intake runners to about 5 " but the plentium should be much bigger and the taper in the runner has to be the same.
What I have to find is the velocity of the air behind the throttle body to aviod a flat spot on acceleration, if the velocity drops below 300 ft per second, the throttle body must be a two stage, which would also work well with the injection I plan to reccomend.
The volume of air ( cfm) doesnt seem to change the engine output after 550 CFM, throttle bodies bigger than that just slows the air down
The problem with very short runners is that the mass of air has been organized in forward motion toward the cylinder. When the intake valve snaps shut, the air flow is reversed, at a given point in the intake runner the organized air mass collides with the rebounding air mass and stalls. A third organized air mass ( from the plentium) over comes the collision of the first two and this third wave is timed to the opening of the exhaust valve so that when valve overlap occurs the fresh intake is pulled harder by the ehaust escaping out of the exhaust.
Thats what I was talking about when I suggested change of crankshaft stroke, changed the timing of the engine.

Post by **DJpowerHaus** » Tue Nov 28, 2006 7:35 pm

What are you making these out of? I want to see a machined nylon manifold

jeffball610 · Post by **jeffball610** » Tue Nov 28, 2006 9:10 pm

All of this sounds very impressive. But why not stick with simplicity? Why do you watn the extra injector? We can run 1600cc injectors if we want. Most people will not run more than 750cc injectors. Running meth injection or water injection would be cool. But you should run that before the TB I would think. I know alot of DSM guys run Mustang 75mm TB. The stock 1G unit is 60mm and the 2G is 52mm. Accufab also makes a 3" TB that sells for about $250.

Check out what other intake manifold manufacturers are doing. I know Magnus, Forester, AMS, Dejon Tool, Buschur Racing, Extreme Motorsports, and BJ's all make intakes for the 4G63. I don't think you should limit yourself to the 4G63 if you plan to make your own intake manifolds though. I think you could make a good unit alot cheaper than most of the other guys. They all sell for $600+. I think a $400 or less intake would sell faster than you could make them.

Post by **DJpowerHaus** » Tue Nov 28, 2006 10:53 pm

jeffball610 wrote:All of this sounds very impressive. But why not stick with simplicity? Why do you watn the extra injector? We can run 1600cc injectors if we want..

YESS!!! I was trying not to say it, but a definate good point.. plus 1600cc injectors are usually cheaper.

And Matt.. the Magnus is probably bad, but it has put down numbers hence its popularity.

Bill Hincher · Post by **Bill Hincher** » Tue Nov 28, 2006 11:11 pm

I live in my own world Jeff, I don't pay much attention to the other guys, unless of course I see thier rear liscense plate a lot, and then I realize they know more about it then me

The balance of design has to be truely balanced, from the tip of the exhaust outlet at the turbo to the air intake at the air cleaner ( thats right, backwards) You cant hang the greatest latest bullshit speed toy made by ' remco' on the intake side and not balance that with the exhaust header tuned to the given cylinder head and camshaft design. YOU gotta be smart, do your homework, make good descisions and LEARN

The extra injector would allow anyone to use the stock ECU and injection as a unit, with an add on injector to kick in with with boost not built into the stock unit. in other words a 4 barrel carb

Lots of guys would love to build a drifter, but the money is a problem, so the more affordable you make it, the more guys you get involved, the bigger the sport gets, you gotta keep the entry level guy in mind

Doc Holiday · Post by **Doc Holiday** » Wed Nov 29, 2006 2:03 pm

Bosses for nitrous would be nice, and if it was angled down, it would allow more room for a brake booster. Different sized bolt on plenums depending on displacement (or possibly just room?). Some sort of bracket for the throttle cables. It doesnt need injector bungs. Throttle body? Most guys feel the stocker is fine. In fact, throttle cable brackets on both sides might be cool, so you can run the TB in the factory orientation, or upsidedown. Hell, flip it sideways and run the throttle cable underneath, I dont know. Are we talking cast? Or sheet metal? Im assuming cast. It'll need several tapped holes for various vacuum sources. One big one for the vac to the booster. While yer at it, maybe a cool light bar with some black lights, and a coffee maker would be pretty cool too.

jeffball610 · Post by **jeffball610** » Wed Nov 29, 2006 3:10 pm

I agree that matching components is the key. If you just want a manifold that fits in the car and faces the RWD direction, you might stay with the DSM specs. I think you could shorten the runners and inlarge the plenum for a balanced intake. Most of us running turbos, run them in the upper revs. That's why the short runner manifolds like Magnus and others make "power". The extra injector is not needed when running a stand alone or piggy back fuel computer. You can set whatever fuel needs you need. Running E85 with 1600cc injectors is not out of the question. There is a guy locally running 10s on it. That's at 5000+ft elevation. Whatever you make will probably be great Bill.

Bill Hincher · Post by **Bill Hincher** » Wed Nov 29, 2006 4:47 pm

I agree..lets keep it simple I also agree that a bung should be in place for nitrous or an injector, so that would be a ' covered option' that could be opened if you wanted it, the issue of throttle body mounted at the center of the plentium is an option, to the outside toward the inner fender well. Is that a good idea from an air distribution standpoint?

Bill Hincher · Post by **Bill Hincher** » Thu Nov 30, 2006 11:36 am

Its beautiful, its well thought out and its gonna work.........but mannnnnnnnnnnnnnn is it gonna be expensive.
That block of aluminium has to be $2oo bucks, and the machine work is at least $400 at best and thats without the butterfly's but I been shopping around and I got a guy who is willing to do it, but he is a retired machinist who works when he wants to, so I wont speak to getting it done until we firm up some drawings I can present to the machinist

Bill Hincher · Post by **Bill Hincher** » Thu Nov 30, 2006 12:29 pm

It dont get much better than this
http://home.earthlink.net/~redcat/pulse_ram/index.html

check this out

rarson · Post by **rarson** » Thu Nov 30, 2006 9:53 pm

In defense of the Magnus manifold, I drove a friend's 2g Eclipse with it and the driveability was fantastic. It was actually better than my small 16g with cams, but he was running a Hahn Super20g, stock cams, and I believe a 2g TB (I'm running a 1g). My car was quite a bit faster than his, so it could've been a tuning issue, but it seemed like his car just pulled a lot better from about 2000 rpm up to about 3300 or so.

Bill Hincher wrote:the issue of throttle body mounted at the center of the plentium is an option, to the outside toward the inner fender well. Is that a good idea from an air distribution standpoint?

I'd like to see someone try it. Intrinsic Performance is working over in the Honda camp on the K-series engines and they've made a center-fed manifold. From all the testing they've done, it's making more power than ITB's on the naturally-aspirated K-series' (they're hitting around 300 whp with it). It'd be interesting to see someone try something like that for the 4g63. I'd link to some pictures, but I'm pretty sure you'd have to be a member to see them. At any rate, there's a lot of info about it at www.k20a.org.

Still, I'd like to see an ITB setup for the 4g63 as well. Some roller barrels would be sick!

Bill Hincher · Post by **Bill Hincher** » Thu Nov 30, 2006 11:04 pm

Have you noticed the high performance plenums are D shaped, not perfectly round?
I cut up the stock intake manifold and looked for tapers, there are NONE the runners are striaght and so is the stock plenum
there is a lot of room for improvement.

rarson · Post by **rarson** » Fri Dec 01, 2006 8:30 pm

mattmartindrift wrote:HOWEVER, there are a MILLION improvements that could also be made through R&D

Yeah, I agree. I'm just saying, for what they are, they do work pretty well, a lot better than I was expecting.

What do you guys think of the Forrester Racing Heads cast manifold? At least with that one, you can put the TB on whatever side you like.

Bill Hincher · Post by **Bill Hincher** » Fri Dec 01, 2006 11:13 pm

yeah, the Forreter intake is definitly the way to go, the runners look to be about 5 or 6 inches and the bolt on penum looks great, the only thing that would be nicer would be to curve the runners , just slightly, forward away from the firewall.
the plenum could be made different tapers and size for tuning, but there again, its creating complications, keep it simple.
I wonder why the Mits engineers made the original soooooo long?

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Robert Venable · Post by **Robert Venable** » Sat Dec 02, 2006 12:15 am

About how long is the original runner lenght??

Bill Hincher · Post by **Bill Hincher** » Sat Dec 02, 2006 8:38 am

I measured about 14" long

GRNDSM · Post by **GRNDSM** » Mon Dec 04, 2006 10:24 am

I wonder why the Mits engineers made the original soooooo long?

You mean that you are not familiar with a DSM bible (AKA DSM technical manual)?

It is a book that was mistakenly sold to the public for just $1.99 and was known in the old days as the "The $2 Manual". It looked just a FSM, but all it had were technical explanations of how things actually worked and not how to replace things.

Damian S. included it in the infamous "DSM manual CD".

Anyway, in that manual they describe DSM intake manifold as having “inertia supercharging”, long runner design. It used by most OEM manifolds and is designed to give you better low end torque.

But seriously guys, what is wrong with taking FRH manifolds and flipping them around? They might not be the best manifolds for the DSMs, but they make such an easy RWD option!

Bill Hincher · Post by **Bill Hincher** » Mon Dec 04, 2006 10:50 am

I have to make the assumption the intake ram affect was designed around the camshaft timing events because the camshaft profile had to meet certian emmision levels.

IF you change any event in the 4 cycles ( like crankshaft, camshaft, intake manifold) you interupped the timing of all the events, that is why its so important to develop a complete package working together

Post by **DJpowerHaus** » Mon Dec 04, 2006 12:44 pm

GRNDSM wrote:But seriously guys, what is wrong with taking FRH manifolds and flipping them around? They might not be the best manifolds for the DSMs, but they make such an easy RWD option!

Brake booster.

GRNDSM · Post by **GRNDSM** » Mon Dec 04, 2006 1:46 pm

DJpowerHaus wrote:
GRNDSM wrote:But seriously guys, what is wrong with taking FRH manifolds and flipping them around? They might not be the best manifolds for the DSMs, but they make such an easy RWD option!
Brake booster.

Well, that is a good point. Since I am not working on a Starion, I forgot that this is the reason why I have a corner cut off on my BR manifold. But wouldn't it be just a matter of a simple modification (45deg cut and a plated welded in place)?

rarson · Post by **rarson** » Thu Dec 07, 2006 2:05 am

GRNDSM wrote:But seriously guys, what is wrong with taking FRH manifolds and flipping them around? They might not be the best manifolds for the DSMs, but they make such an easy RWD option!

Yeah, that's what I was thinking. I mean, from what I remember, they make pretty good numbers and are easy to flip.

I'm not building a Starion either, actually right now the only thing I'm building is housing equity. But hopefully sometime soon I can start a 4g63 RX-7 project...