Na cars are super duper peaky and from my experince even on the little D react awesome to increased plenum volume and larger tb's

 

I had a mazda 323 gt which had a 323 gtx turbo motor in it from the factory. I never really looked at the extact volume but it was ------- small. It also was a center t-body design, which is good if done right. This car was fun until about 5,000 rpms. After that it just didn't like revving, but it also was setup with about the smallest turbo in the world.

Randy

 

cut and rolled the plenum this week. straight side is 4" and the round is 4.5" and the distance fromt he straight to the round wall is 4" should be a good size i think looks proportional to everything else. guess i need to order my runners and start chopping off flanges off of the stocker and put in a few vacum taps

 

Uh-huh.

 

any taper on that thing?

also i wouldnt look to production cars for insiration seriously your on the right track and it seems like your listening to the right people though so ill leave that one alone.

 

i was thinking of a taper but i have seen so many without one i figured i would leave it. i could still taper it if its really a big deal. i could do it with a porta band i suppose

 

Box the far end, do not angle. Taper is good but not essential and you could mess it up tapering blind. If the plenum is as big as it looks, the pressure drop as it enters will kill off flow and just tumble-swirl as pressure builds. Each cyl will suck more or less evenly until you get a LOT of flow coming into a really high pressure plenum.

 

raised velocity stacks maybe?

 

I would try and fit some, yes.

 

well look at 4" on a ruler its pretty small. itll be a 1.8 setup with a t25 .48 .49 and 2 1/4 ic piping and front mount. i can go smaller but adding would be somthing i will not do.