Ford Focus Forum banner

1 - 20 of 24 Posts

·
Registered
Joined
·
402 Posts
Discussion Starter #1
Does any one have a spare intake manifold? If so can you measure the length of the runners for me? also can you measure the distance between each center of the ports.
 

·
Registered
Joined
·
5,446 Posts
yo matt, props for having the balls for trying the intake spacer thing out...everyone else just shot down my idea. I really wish i could help more, but i'm in NY, my focus is in TX, and you're in freakin OR...kinda big triangle. BTW, i'll lend monetary support if you make me one of whatever you make in the future
 

·
Registered
Joined
·
402 Posts
Discussion Starter #3
Im experimental. lol. I like the challenge. Thank you for the props. im getting ready to experiment with a new manifold too. Same runner length as our stockers just round tubes with more volume. and a round plenum. I just need the measurments of the runner lengths on the stockers. for the adjustable tubes. im playing with differ tube lengths as well. to see what performance changes it makes.
 

·
Registered
Joined
·
5,446 Posts
taking the HCI article's advice? Sweet, it looks like it'll be somewhat tricky to fab up in a streetable version, but if it works, i want one.

Intake manifold was such a big deal on V8's and here we worry more about the freakin intake TUBE than we do the mani itself...upsetting, horribly upsetting. Untapped potential out the wazoo. 3.8's could gain 30-40% more hp and tq by the industrious use of phenolic, a dremel and the balls to hand port the intake. I'll continue ranting about ignoring the intake mani for a few days, so just put up with me
 

·
Registered
Joined
·
402 Posts
Discussion Starter #6
i have a fealing this Intake mani is going to work. I just removed my intake mani. and measured the runner length. so i inverted the custom one. the TB sits on the side. much like the new toyota celica intake. but the runners are the same lenth as our stockers. just with round tubes.
 

·
Registered
Joined
·
5,446 Posts
sweet...you still got plans to try out an even longer runner length?
 

·
Registered
Joined
·
19,264 Posts
dammit Nader.... why you gotta put your bid so high!


I just won't go above $50 for it...
 

·
Registered
Joined
·
402 Posts
Discussion Starter #10
I pulled my Intake mani off today and so i could get the specs. 3 hours to get off. 30 mins to get back on. learning experience. but im makeing a cutom mani with 1.5" ID tubes and one with 1.25" ID tubes. the one with 1.25" ID tubes is almost done. i just need to add the mount bracket. But i cant wait to try it out.
 

·
is THE most interesting man in the world!
Joined
·
3,514 Posts
I saw a nice aluminum spacer a few weeks ago, made to go with the Ford Racing header. VERY sweet! Go with it man.
 

·
Registered
Joined
·
402 Posts
Discussion Starter #13
the stock runners are a little over 16 inches long. i wunder if a vertical plenum would do any differ then a horizontal.
 

·
Registered
Joined
·
1,176 Posts
i am very interested to see how this works out.

 

·
Registered
Joined
·
411 Posts
if you do a in line plenum....it will be a tunnel ram, from what I hear, it might not be streetable...haha

to do this, you would take the runners into a "cone" collector, the collector needs to be the same volume as the runners. then you put the TB on top of that. if you have it set up right it should in theory cool the intake charge also.

16 inches!!! that is long! wow

I just drew one up on cad and guestimated an 8 inch length and it looks pretty cool...back to the drawing board.
 

·
Registered
Joined
·
517 Posts
How are you doing the transition from a round tube to the rectangular intake port? Glad to see someone is trying this out!
 

·
Registered
Joined
·
101 Posts
Okay, here are my thoughts on a custom intake manifold:

1- Material: personally I would try carbon fiber or kelvar weave on a male mold, with a lot of epoxy so you don't get air leaking through the cloth. This way you can make a nice smooth shape to transitiion from the TB to the plenum [aka collector] to the runners. If you don't like that I guess sheet metal is ok if you are good at welding.

2- Plenum size: I'm not really sure on this one. I personally think the total volume of the intake system after the largest restriction should be more than twice the engine displacement, that's only a rough guess though. Otherwise I think a larger plenum [up to a certain extent] is better for flow characteristics, but a small plenum allows for better transient throttle flow [ie throttle response] due to lower system inertance.

3- Runner length: This depends upon where you want to make the best power. Shorter runners are better for high end power and transient throttle, while longer runners make better low RPM power but make for worse throttle response. For the street I think longer runners are better.

Those are just my thoughts and what I would do. Engine tuning realyl isn't my speciality so I could be wrong, just a disclaimer.
 

·
Registered
Joined
·
243 Posts
If you can find one the December 2002 issue of HCI Magazine did a good article on various manifolds made (and not made)these were used on Turbo applications, but they should give you a good visual etc...
 

·
Registered
Joined
·
411 Posts
Originally posted by mattndew676:
that article is tbhe one im going off of. i am useing fiber glass and a PVC tube as the plenum. Im useing Coolchem sealer to Make the seems air tight. Coolchem is the toughest heat resistant glue you can find. This is just a proto Manifold. so far the design is a vertical tube with the tubes comeing off the bottom. But my tubes start on the bottom and run up, in stead of down.. I would like to build it like a tunnel ram but i would have to mod the hood.
<font size="2" face="Verdana, Arial">I can't find the formula for runner lengths...but I think I was wrong earlier about the collector being the = ammount of volume as the runners. I am under the impression that you take the runners and divide by 2, then you get the volume of each...the runners and collector seperately.

Welding a intake manifold and installing it with a phenolic spacer between the head and mani is the most optimal way....reduces heat soak induced by the head.
 
1 - 20 of 24 Posts
Top