LEXUSV8NZ said:
No way to improve on them?
Modify (Or make a suitable set) to go onto a 1 or 3uz
(And ditch the cats of course)
Logan
I am thinking that TN meant that the entire engine package was essentially perfect from the factory and not necessarily the exhaust.
The exhaust is very nice for what it is... an emissions compliant 500hp system... no small feat.
That said there is always room for improvement but of course the better the starting point the less potential gain is available. At this power level on that engine this exhaust system is probably between 90-95% efficient. So, there MAY be another 25-50hp available in a PERFECT system... but is it really worth the effort to TRY? It would take optimized primary length, primary diameter, A/R ports, primary step/no step, step size, step location, port exit angle, bend minimization (number and severity), gas control at all these points, collector shape (lots of variable here), merge angles, collector exit size-lenght-taper, secondary diameter-size-length and then ballance of the system.
I hope I am conveying the VAST area of variable presented in a system. Anyone that claims to have tested all possible configurations is either ignorant or a liar. On top of that the RPM range that is to be favored and the RPM ranges that are to be at less than max efficiency also effects nearly every variable above.
As far as modifying these... no... not an option... first of all BMW would probably charge at LEAST $5000 for a set. They are V10 manifolds. They are engine/chasis specific.
Now, using the same idea... IE, maximized shorty style headers is exactly what I hope to accomplish with my (stalled) header project.