Hey guys ive been digging around trying to come up w/ some ideas for a junior project in mech eng...i am going to try and redisgn my turbo mani to take adavntage of the split scroll design of the holset hx35...if any of you guys could point me in the direction of some information regarding exh pulses and collector design it would be greatly appreciated...

 

The thought that often runs through my head...."A divided housing turbo paired with a divided housing manifold, wouldn't it be the same thing as a 4-2-1 manifold and open turbo housing."

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bump for the info too

 

well to my understanding...a 4-1 merge collector creates an equal pressure to each divided side...now when properly setup...it takes adavatage of the exhuast puleses also helping to improve spool a few hundred rpms

 

yea but if it does as you say then with the 4-1 only does this once when they all come together where as the 4-2-1 would have two cylinders doings this and then the two remaining runerd would do it again multiplying the scavenging effect. Also with the 4-1 helping to pull other cylinder runners gases out, wouldn't you be using the pulse from one cylinder to try to pull 3 others out? The 4-2-1 would use one cylinder to pull another, and then another collector to help with the already joined runners. To me it seam like a better design.

"A divided housing turbo paired with a divided housing manifold, wouldn't it be the same thing as a 4-2-1 manifold and open turbo housing."
Can that statement be proven wrong? idk thats why i asked. To me there is no difference. Think about it, 4-2 manifold and a divided turbo housing = 4-2 and the third collector would be the housing esentially equaling a 4-2-1 design.
Same car 4-2-1 manifold with open housing...how is it any different than running a divided setup manifold and turbo?

 

my understanding of it..is that it seperates the pulses into 2 seperate systems...so one pulse is firing at the wheel at any given time...when runnnin a 4-1 collector this merges all the pulses together 1 after another in a eq pressure seneario...in the split scroll it wouldnt neccasirly be equal pressure at any given point...

looking for some more insight

 

School me up on the split scroll design. Are both volutes the same, or is one bigger than another? Do you have to run independant wategates on both volutes?

If they are different A/R's and independant of each other in the wastegates, I can see how a well-designed manifold would improve spool. It could be like having two turbos in one.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by beepy &raquo;</TD></TR><TR><TD CLASS="quote">School me up on the split scroll design. Are both volutes the same, or is one bigger than another? Do you have to run independant wategates on both volutes?

If they are different A/R's and independant of each other in the wastegates, I can see how a well-designed manifold would improve spool. It could be like having two turbos in one.</TD></TR></TABLE>

each side is the same in size, they just hit the exhaust wheel in a different place. You do not need dual gates, but you do need to draw gasses out of both tangs to be able to reach a steady consistant boost level. so dual gate is ideal but a merging to a big single gate will work also

With "equal" runners, a divided tang housing is supposed to help by like at least 500rpms from what i've heard/seen

 

someone has to have some solid evidence on cylinder pairings for optimal performance...and why this actaully all works

 

read through this thread, around page two starts taling about it.... https://honda-tech.com/zerothread?id=1515492

 

nice find...i viewed that the other day...and hadnt been back...

thanks for the insight...

im tryin to optimize my holset hx35's divided housing...hence the post

 

Divided style manifold will do that.