So, is there a really nice aftermarket intake manifold we can buy for the N/A guys? Or are we just stuck with porting out the stock manifold???? Did anyone ever get a ITB setup?? Is it just a lost cause or what?? Fill me in, I've been out of the loop for a while. By the way, I don't want to hear about the POS OBX or Venom manifold. :)

there was a company a while back called fast fabs that produced a decent upper plenum for us... but they are now out of business. the design was fairly simple though. shouldn't be too hard to reproduce. maybe another project for velocita??

Originally posted by 2point4
there was a company a while back called fast fabs that produced a decent upper plenum for us... but they are now out of business. the design was fairly simple though. shouldn't be too hard to reproduce. maybe another project for velocita??

i started to make one from sheetmetal when i was designing my exhuast manifold as well, I just ran out of time and money so the project never got finished.

DJ420a I think was one of the very few who ever bought the FastFab intake manifold.

Originally posted by 2point4
there was a company a while back called fast fabs that produced a decent upper plenum for us... but they are now out of business. the design was fairly simple though. shouldn't be too hard to reproduce. maybe another project for velocita??

If you only want a simple design, that's shouldn't to very hard to produce...

Take a look here:

http://www.rossmachineracing.com/intakepartspage.html

Using those parts, I could slap together a decent intake manifold for a few hundred dollars.

However, I myself am partial to something more along the lines of Magnus' design. The reducing diameter of the plenum increases velocity to even out the inherently asymmetric flow pattern of a side-entrance plenum.

I'm all for creating one for the 420A, but it's going to take time to properly design, analyze and test one -- and the finished product isn't going to be cheap. Expect to pay $700+ for a good intake manifold....


-http://www.symtechlabs.com/-

i would suggest doing just the upper plenum because our runner section is fuckin sweet when ported properly... and then we can slap in your phenolic spacer as well :)

would be cheaper for the masses and thus, more marketable

i planned on doing something similar to the fast fabs unit when i was still in the machinery trade... but i have moved onto other things for now.

yeah, I was planning on keeping the lower part if I made one. You could just take the lower part and put a velocity stack on the tops of each runner, then make the rest. I am not sure what would be most efficient for an upper plenum though, and I don't really have the money to trial and error this sort of thing. Any one have any reccomendations for the upper part?? Square?? Round?? How big?? It almost seems that you would get just as much out of the stock one if it was just extrude honed......That would be even less than building a new one. More thoughts????

Originally posted by powellds
yeah, I was planning on keeping the lower part if I made one. You could just take the lower part and put a velocity stack on the tops of each runner, then make the rest. I am not sure what would be most efficient for an upper plenum though, and I don't really have the money to trial and error this sort of thing. Any one have any reccomendations for the upper part?? Square?? Round?? How big?? It almost seems that you would get just as much out of the stock one if it was just extrude honed......That would be even less than building a new one. More thoughts????

Make an ITB manifold. That would be killa.

That's the ticket, right there. }(

Why does everyone say that there is a clearance issue?? Couldn't you just angle it upward instead of toward the firewall?

Originally posted by powellds
Why does everyone say that there is a clearance issue??

There isn't, really. The problem is that people want a manifold that will drop in like a stocker and it'll never happen. They ask for a contradiction - a stock replacement that magically adds power and fits all the dimensions of a stock manifold. You're asking why people that have no concept of creative solutions can't come up with a creative solution.

Yes, I will have to agree on that note, but really, it looks to me like the tb's would just have to face up instead of facing the firewall. I know there's a lot more to figure out, but nothing too crazy. If I had the moola, I would definately do it.

I actually plan on building and testing one out this winter. There's so many variable that have to be taken into consideration that its taken me almost 9 mnths of planning, about $600 in classes at the local tech, and another $300 or so on amozon just learnin about the stuff. The hard part about an intake manifold that makes grazy power is that it's almost an engine specific matter. Yeah you can throw somethin together that will work on 75% of all the engines out there but who's gonna want to pay upwards of $900 for somethin special when most ppl on here don't develope enough power to need anything more than a reworked stock mani? With good head work and an extrude hone done on the stock mani along with a jeep TB theres enough potential already. The design has to be close to perfect and match your engines airflow characteristics. The runners need to be a certian length and diameter, the size of the plenum determines throttle response and potential airflow, the plenum shape determines how equally the air stream is distributed, hence the tapered plenum, and even in a boosted motor where the air is being stuffed in the taper and length of the runners will affect the torque curve of the motor. It's not just a matter of air, but sound plays a very large role in making power, along with high and low pressure regions, type of fuel and its atomization qualities, characteristics of the camshaft.. The variables are endless... The prob with the 420A is that there are only a few companies out there that are willing to put the time and money into developing something like this that would have enough of a range of opperation that it could be economically produced for the general masses.

Wow, sounds like fun I'll tell ya. You need to get one made, and then have me one made. And then other people too. Best of luck to you and I hope you succeed.