I have been trying to search but havnt found anything. Is there anybody out there with a Pulse Converter manifold? Or does anybody make one? I believe such a mnaifold will help significantly with spool because each runner length according to the firing order thus making one continuous pulse to the turbine inlet. Please if anybody has any idea, let me know. Thanks


*EDIT* Mr. Buschur I hope u read this.

Krunal

 

interesting ...

 

Pulse convertor manifold? Is that a new term for equal length?

 

Nah. It isnt an equal length.

 

FWIW: Your factory exhaust manifold IS a pulse converter design.

 

mmm issit? hmm and is it pulse converter with with scroll like... does the twin scroll flow one pulse through one channel at a time or does it seperate two pulses at the same time or seperate two that are slightly staggered? stock mani sounds good to me now... i really wanna get the 20g just to get the benefits of keeping the stock mani...

 

The optimum configuration of a pulse converter manifold keeps each pulse evenly separated. Naturally, this requires equal length runners, which is where the factory exhaust manifold falls short. Nevertheless, the factory manifold and any other manifold that keeps the pulses separate until the collector is a pulse converter design. The pulse converter design is best suited for applications that will vary in rpm and require good spool characteristics.

The other design is a constant pressure type, which is basically a log manifold, where each very short runner empties into a larger chamber, which has a single outlet. This type is better suited toward applications that are going to run at a steady, higher engine speed - like a turbo diesel generator engine.

 

So "Pulse Convertor" is another term for a divided manifold & turbine housing. As Ted said the stock turbo set-up is considered one, but lacking equal length runners.

The entire purpose behind an equal length manifold, divided or not, is to ensure that the exhaust pulses reach the turbine inlet in consecutive order to the combustion events. This keeps velocity up as the exhaust pulse enters the turbine and aids in scavenging of the next cylinder to fire. IMO diesel technology drives the turbocharger industry and much of this was developed with diesel engines in mind, mainly the Inline 6 which is the vast majority of diesel engines running today. Typically the front 3 and rear 3 cylinders are paired together. This results in an exhaust pulse every 240 degrees of crank revolution for each divided side, where as a 4 cylinder has one pulse per side for every 360 degrees of crank revolution. Boost response was/is a big issue for turbo diesels since they are pretty much lifeless without boost.

Some of my friends have run divided and un-divided set-ups only to say that they felt no difference. Of course these are cars so transient response is not really a factor and over time undivided set-ups have proven to reign king on drag cars. For the road racer the story may be different. I'm building a divided set-up for a large turbo on an EVO right now, once it is complete I will see if the owner can post with some feedback on his opinions.