Tsunami

is it a common practice? did a search and it didnt return much. I figure im gonna have some free time coming up over spring break and I will probably port my intake mani, but how about the exhaust too? Things to look out for? (ie twin scroll actuator). I know i wont see real benefits until it has a full exhaust setup but that is down the line. Thanks

Tsunami

kirss kross will make ya...
Bump Bump

krazydru784

are u talking about porting the wastegate? or exhaust manifold itself? i would not suggest parting the manifold itself cuz u dont want it too thin and to crack on you, especially with all that heat. if u are talking about the wastegate there are a bunch of threads on it...i juss did it too the max..so the stock flapper door would steal crate a seal over the whole...however with my full 3 inch exhaust allt he way i still have a bunch of boost creep so if u are going to do the wastegate i suggest u port that sucker huge..and weld on a new flapper door.

Tsunami

im talking the manifold. Back in DSM land where i come from its pretty common to flow more air to the turbine and help it spool faster, just curious if this is true for the rotary too.

13bpower

That is interesting. The point of the twin scroll actuator is to decrease the area which the exhaust can flow through. In turn increasing the speed of the exhaust flowing through it, leading to quicker spool up. Making the passage bigger would seem to work against this theory.

Porting the exhaust minifold would be a delicate process. I know some people on here have done it.

MountainTurbo

Doesn't the twin scroll only do that at low RPMS, then at higher RPM's it opens up?

Tsunami

1.yes the twin scroll does do that at low rpms, but thats when the intial 'spooling' of the turbo takes place.

2. My guess is that with the actuator design, exhaust gas velocity is increased by decreasing cross sectional area, but with the DSM design (no twin scrolls there) the porting of the entire manifold, turbine housing, and o2 sensor housing (combined with a rather free flowing exhaust) is designed to create such a free flowing exhaust system, that the gasses are nearly sucked out the back and cross the turbine on the way. Either way its tried and true on those cars.

Infini IV

I believe fc3spro.com used to have something on this. However, it would take sooooo long to port. Why not just upgrade to S5 manifold and turbo?

rx78788

just woundering how you port the intake manifold. what is exactly done. i know what is done for a bridge and periphrel ports job but how do you port a manifold

Infini IV

We're talking exhaust manifold/turbo manifold here.