Which intake manifold?

[float_6969]

I was looking at the 2 different intak manifold designs that were used for the CA18DE (FWD and RWD) and it strikes me that perhaps the FWD intake manifold is a better design. My reasoning is that if you look at the FWD manifold



it looks like the incoming air would be more evenly diveded between the runners, with the 2nd and 3rd being fed a little more directly than the 1st and 4th. Also, this is how the RB20, and RB25's manifolds are set up.

Now with the RWD manifold it looks like the 1st runner would be fed well, and then progressivly worse as you get to the 4th runner.



So what do you all think? I know that you'd have to have custom intercooler piping made and such, but thats not too big of a deal really.

[ants13]

Looks like an a**e of a job to me, but if you've got the engine out it mite be worth a go, but looking at that picture the fuel rail looks a different way round,

It mite be worth a go. let us know how you get on .

[NeedCAforS13]

I don't think you could close your hood with piping going over the motor like that ryan :pface...

and if you notice on the rwd manifold, its angled to the left, so that the #1 runner is longer than the #2 is longer than the #3, and so on, so I think it works out fine:)

Sean

[float_6969]

Who needs a hood anyway!!! Yea, I didn't think about that. And I knew it was angled and I knew that was why it was angled, but I still thought I'd ask....

[pulsar gtr]

By the way, this kind of intake only came in northamerica and some in Australia, in japan, it came looking like th rwd but the throttle body points in the opposite direction, only the ca16de came centered in Japan and the first generation of CA18det none intercooled.. Actually personally I hate the center intake setup, I think it is very much less practical that the side looking intake, one good reason is when you have the intake pipe running over the engine especially on a turbo engine, all the heat from the engine will rise and make this intake pipe very hot, therefore you will be feeding the engine some hot air which will results in less hp , plus the air tank inside that intake is much less smaller than the air tank inside the side shape intake. (I refer to the inside of the intake space after the throttle space as the air tank)

PULSAR GTR.

[float_6969]

Well I don't agree on the heat thing so much. Most of the heat that is transmitted to the mani is done through the contact area of the head. I could see how the heat from the exhaust might heat up the intercooler piping though. I Guess maybe I should look at it like this; They only used that design on the older CA's and the newer ones use the current setup, so that should probabally tell me that there was a reason that the center feed mani was dropped.

[paul_s13]

The standard RWD manifold is fine, I know of a few 400+ CA's that use it without problems.

The only thing i would suggest is to fit a larger throttle body from an SR or KA.