After flipping through some engine pictures yesterday, I noticed lots of 3rd gens have different intake manifolds.

One style has shorter runners, a plenum, and says "13B RE sequential turbo" on top.

The other style has long runners, no plenum, and no writing on it.

If you don't know what I mean, check out this picture. You will need to copy and paste the link into a new window... you can't just click on it!

http://www.geocities.com/bridgeporte...DManifolds.jpg

 

The one with the 13B-RE on it isn't a motor found in the FD3S. That motor comes in the Eunos Cosmo which wasn't sold over here. The 20B also comes from Eunos Cosmo's as it was an option for the car. I think the 13B-RE intake manifold has larger ports/runners but the engine itself has smaller ports. Not 100% sure though.

The one with no writing on it is the 13B-REW intake manifold, that's the motor that comes in the FD3S.

 

To add to this thread, FD's(or any other rotaries) that were NOT imported to the USA don't have provisions for the EGR, and certain emission control related items on the intake manifolds. One such example of this is some of the Japanease turbo kits don't fit on the USA model FD's because the EGR provision gets in the way of the downpipe, non-USA models don't have this provision, and therefore fit with no problems.