I know of one guy running a cosmo 13B turbo with a full bridgeport. He has two piece apex seals from Adam @ RX7 specialties in calgary. He Dyno'd at 705 RWHP. The car has a microtech lt8 management system. My father in-law in going to be running the same set up as Forcefed Performance has except that he will have a smaller turbo than marko. But should still be making 500+ rwhp in a full drag car set up. The corner seals are larger than others being produced so that as they wear down they wont fall into the bridge and **** your engine.

I think the air/fuel charge that escapes into the ex-manifold has a big part in the mid-range power gain. I think it contunues to burn in the turbo and manifold adding to heat and exhaust gas volume.

In japan they have been using bridge port huge j ports and pp engines with turbos. Revolution uses big street ports with 32mm pp . They make a intake manifold which splits the secondaries to both factory secondaries and pp, with t51 spl 680ps at 1.2kg. Before Scoot switched to a 4 rota there demo car 13b streetport primaries and pp seconaries ( factory pp size ) made 720ps at 1kg with t51spl.

I have made manifolds for s4 engine which used factory primaries and pp secondaries, The shop i made them for is yet to complete there customers cars.

Later this year i should get my own project engine for my car going. Its going to be like the Revolution port setup.

Knightsports was playing with Jports for awhile but that was sometime ago. The revolution car made 625 at 1.6 kg/cm3, the main reasoning for the configuration was that it was a legality trick for racing class rather being superior to other setups, not sure the cost would warrant anyting you would gain over other porting with stock manifolds It works pretty well, but the same effect can be had with a half bridge and the power band is very similar. KKM did a 8mm bridge and made 619 at 1.5kg/cm3, which is right on par with the crossport car, both cars did that on premium pump gas. The scoot car was making 710 at pressures around the 2.2 kg/cm3 mark, the T51 spl has to be run at pretty high boost pressures to make power, its a huge turbo..

I know RE wing has gone to a bridgeport with a T88-38gk and is now over the 700 mark, they are the fastest street tired fd in Japan currently, in the 1/4 mile according to the gossip mill there.