Jump to content
SAU Community
  • Welcome to SAU Community

    Welcome to SAU Community, like most online communities you must register to view or post in our community, but don't worry this is a simple free process that requires minimal information for you to signup. Be apart of SAU Community by signing in or creating an account.

    • Start new topics and reply to others
    • Subscribe to topics and forums to get email updates
    • Get your own profile page, build reputation and make new friends
    • Send personal messages to other members.
    • See fewer ads!

    Consider joining our newsletter for the latest content updates

    Click here to register

GT-R David

int  Ultra Rare Nismo Nissan parts, Nismo Cast Turbo Elbows RB26 , Nissan R32 GTR OEM Rubber Rear Spats

Recommended Posts

Hi, I'm selling a few parts that are realy realy realy rare to find.

These are intendet for the Nismo nuts out there.

I'm willing to ship worldwide at buyers expense. I can wrap it up realy careful but I'm not responsible for damage or loss of the parcel.
I will consider SENSIBLE offers.
Items located in Germany.

First of all. These beautiful Nismo Cast Turbo Outlet Pipes.
I personally have never seen a set of these before for sale, propably the only set for sale at the momet.

They come on Nismo S-Tune and R-Tune engines nowadays and are not sold seperatly as far as I know.
Very good condition. No cracks. Rear one has a fitting for exhaust Temp sensor as needed for some R34.
They are internally devided even though they are cast. Piece of art.
1700 Euro






Second item are the uber rare OEM Nissan Optional Rear Side Spats.
This are the Rubber ones that go behind the rear wheels, they are realy hard to get nowadays.
Condition is not as good unfortunately, but don't get scared by the pictures. As they are made from rubber and the guy before my painted them without primer or something, the paint peels of. Could be scratched of with a few hours of work.
Also the right one has a small piece cut off at the upper side. Don't know how someone could do that...
Because of the "bad" condition.
950 Euro






Please no discussions about the pricing. Nismo tax included.

Link to post
Share on other sites
2 hours ago, joshuaho96 said:

I still don't understand the point of dividing the wastegate from the exhaust turbine. Does it actually matter? I get the distinct impression from modern designs that the answer is no.

It makes good sense from a fundamental flow point of view. The very best turbine outlet is a pure cone, growing at 7-10° from the turbine outlet diameter to the main dump pipe diameter. Nice and straight, no bends. That's the ideal - straight from the mouth of a Garrett R&D engineer. These details are all about obtaining the best pressure recovery (across the turbine - not trying to maximise pressure in the exhaust, which is what we normally mean when we talk about pressure recovery after a disturbance).

The shallow cone angle is intended to prevent any unpleasant separation effects (that you get with wider cone angles), but this is one area where I suspect that the difference might be tiny. The turbine exit flow will be coming out with a large amount of swirl and will want to expand (purely from centrifugal force) and will push up hard against the wall. A wider cone angle would probably be indistinguishable from a shallower cone angle. But....

That horrible swirling flow is fine and dandy when it is trapped in a nice conical expansion. But when you drop it out into a suddenly opened up space (like the common turbine and wastegate outlet cavity in many integrated turbine housings) then you get a mess. The turbine flow does not have the opportunity to depart the turbine cleanly and instead causes horrible turbulence features that impeded what's coming out of the turbine. Worse, in many of these housings the wastegate flap is set up to open so that the wastegate flow is aimed directly across the turbine outlet. The two flows do ugly things to each other once the wastegate is open.

Any divided dump pipe will attempt to prevent the wastegate flow from bashing into the turbine exit flow. There is some small chance that the divider might impede wastegate flow, but so long as the wastegate is large enough, this will only happen at low angles and the wastegate can always open a bit more. If the wastegate is a bit undersized, then it could be worse (for boost control). The divider will make the big cavity in the turbine outlet section a smaller cavity, which will edge it closer to the "ideal"....but only edge. Not actually a large improvement. But getting the wastegate flow out of the turbine flow is the main goal anyway.

The main problem is that nearly every dump pipe is a horrible compromise wrt to the ideal. There is usually a 90° bend downward directly out of the turbo, there is almost no conical expansion, etc etc. Even a pretty nice looking divided dump will still have that.

The main argument against divided dumps is that a big open dump offers more open area and a better pressure drop across the turbine, being better for spool. It might well be true. The argument goes on to say that the smaller diameter of the turbine dump on a divided dump causes higher velocity and therefore more frictional pressure losses (and therefore reduced efficiency) when on boost compared to an open dump. But that's probably not true. If the wastegate flow is interfering with the turbine exit flow, then the difference in the dump pipe friction is going to be small in comparison.

All in all, the best thing is to use an external gate so that you don't have to even think about this shit.

  • Like 2
Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...