lately, i've been less connected to the honda community because i've had 3-4 dsm's over the past few years. my dad (3rx on the board) still has 4 or 5 crx's and my sister drives a del sol. i had a civic with a type R motor...and it was a great car. someone offered me too much money and i had to get rid of it.

as far as this thread, the design of intake manifolds has always interested me after i started to pay attention to the OEM intake manifolds on 4g63's. their intake plenum is curved and quite a bit longer compared to a type r manifold...and with the way the head on a 4g63 is designed, the car makes better midrange torque/power and less top end power. obviously, the b/d/k series motors flow much better up top and it has everything to do with the intake/head design.

i for one, can't understand how a company without the resources of say skunk2/aebs/JG can design an aftermarket intake manifold that flows as well as an OEM honda intake manifold. the guy's at full race make insane power and clearly have their **** together...and they have designed an intake manifold which seems to be quite a bit difference from your average design.

(pic shown below)



I'm not questioning whether or not this manifold design works (it clearly does)...with the runners actually protuding into the intake chamber...i'm just wondering about the thought process behind the design itself. common sense (at least my common sense) would suggest that this design would cause additional turbulance which could hurt air flow.

questions, comments...etc....about this would be great. i'm not here to criticize the guy's at full race...and i want to make that clear. i know their intake manifold works and i've seen it make 700+whp on a few of their cars... i'm just wondering how that design can be so effective.

 

CFDs (Computational Fluid Dynamics) are cheaper then ever. This is very powerful software that will simulate anything fluid dynamics. This can allow much smaller organizations to come up with good designs without ever having to even build a prototype.

I also remember hearing that the internal finish of the manifold played a fairly important role. It costs money to do this.....

Lastly Honda and other companies do like most other companies, they design their parts with cost of manufacturing in mind. Lets say they could improve the design to give an extra 1% but it would cost 3 times as much to make (like what I was talking about in the internal finish thing). They won't do it, cause other wise they would price themselves out of the market. I have worked for companies doing engineering design work before, cost and easy of manufacturing is one the things on the top of my mind. Racing is truly performance orientated, cost is almost not an issue. It's almost an exponetial curve, towards the bottom end, a double in the price will get you twice the performance but at the top of the market a double in the price won't get you a lot more gain.


Hope this gives you some insight. This is just my opinion of the matter, I have no real data to back this up.

 

air properties have prove that a raised velocity stack will flow much more efficiently than a flat mounted stack.

air likes to make that "S" turn right in front of that stack and speed up into the runner.