home made intake manifold?

[harjms]

Has anyone made a home made intake manifold before? i have access to a machine shop so making it and getting material is not a problem. the only problem i have is getting it to match our heads. Is there a place that shows a diagram or blueprint kind of thing that shows how far each runner is from each place and how big the openings/TB inlet is??

Since i saw this on ebay for 270$ http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=7950140808&category=33742
i thought i could build one just like it for cheaper and still be made out of good material.

plz if anyone could help me out that owuld be great

 

[CyberEye]

I've been using Mechanical Desktop and playing around with some models lately. Doubt I'll do anything with them anytime soon but i was bored . Just go to your parts store and get the gaskets. Then just match the port size and throttle body opening off the gaskets.

 

[12's]

I am not sure that particular manifold will help you. Depending on how it is made, a stock one can be better. I know of a few people who made some and the power wasn't any better. One was the same and the other lost power. You might be better off with a 1g one.

 

[harjms]

hmm well thanks for the tips...i think i might stick with my ported one...i just thought it would be neat for me to have a custom piece on the car...but if its gonna be a design flaw and holding me back...no thanks...


thanks again

 

[gixrman]

You want to come up with a cool intake? design a variable lenght runner manifold that is RPM/boost based that way you have the best of both worlds. And you'll problly earn your masters in mechanical engineering while your at it!!!!!

Something like the cyclone but actually works for high HP.

 

[myblack98gst]

http://www.jmfabrications.com/dsm.html

this place sells the flanges for the head and the TB..

there is a thread in this forum from polk performance that shows a custom made intake manifold tests. and gives the dimensions for each intake tested.


I am about to endevour into making a manifold, personally I do not see it being that hard. I can make the tapered runners. and the penum to match his ci. and have access to a VERY good tig welder.

 

[FORMONTOYA]

design a variable lenght runner manifold that is RPM/boost based that way you have the best of both worlds.

just like it is done in formula1.


jim

 

[jott5555]

no this does not look like the dejon tools one.. there are severl diffrences the tapered runners on the dejon ect.. as far as the one from jm fabrications if you look inseide the pelum the runners inlets are looks like 1/4 of a inch above the plemum wall..

im not sure how well thats going to work..

i would rather spend the money on a proven product then waste my time and money makeing my own only to bolt it up and loose hp..

 

[thegreatms]

as far as the one from jm fabrications if you look inseide the pelum the runners inlets are looks like 1/4 of a inch above the plemum wall..

im not sure how well thats going to work..

I was under the impression that it is better for the runners to stick into the plenum slightly. Also, they have that nice trumpet end thingi that helps the air go in smoothly.

 

[Echo5Zulu]

I also designed one up from a mix of other intakes that I had seen. Had all the parts CNC'd out for free at a shop I used to work at. Now all I have to do is free up enough time to weld it up and install it. I'll post the results someday when I get it finished. Fun stuff and I allways encourage innovation and imagination. Anyone have any first hand experiences to share with a homemade mani.? Times, hp, tq? I only hear about people talking about their buddies doing it but never first hand.

 

[miteclgst]

There is a lot of calculations and designing that needs to be completed in order to build a quality manifold. It isn't just getting a bunch of pipes and welding them together. You need to figure our how long your runners will be, there are equations for this. You need to figure out what size plenum you need. You need to design the taper in the runners that is required to achieve maximum power. You need to set the injector bosses at a specific angle so that they spray directly onto the valve. You need to know how long your runners will stick into the plenum so you get a "velocity stack" effect. You need to know how far to extend the manifold past the first and last runners. Plus you need to do all of this designing so that it will inside of the area available in the already cramped engine compartment.
I hate to be the one to say it but there is a reason why you pay for so much money for the manifolds, you need super strong welds and a lot of number crunching. The guys who make them spend a lot of R&D time. Just search the intake manifold shootout that they had on this site. There isn't a great deal of power to be made with a SMIM, the focus would be to gain as much power as possible by creating the right design.