Silvia Club of NSW

Not exactly sure how much it would help with reversion as most tube type exhausts only come together at the collector, so the gas velocity has pretty much already been dictated by bends and tube size...

The link Dave posted show a picture of the split exhaust housing. I was always under the impression that devider went a fair distance into the turbine housing.

The only way I can see this whole thing working is when the pipes all come into one at the collector and into the enterence area of the turbine housing the area seems to grow which may result in loss of pressure.

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

interesting point, yeah each exhaust pulse would be exiting a nozzle half the size. so theres faster nozzle velocity, but each nozzle only needs to support 2 pulses, so flow wise they should be similar. win win situation !

each firing sequence would be in alternate sides maybe this would also aid gas flow???

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

thats exactly it, at the collector they all come together and its not always a smooth transition.

that divider goes ALL the way to the turbine blades, it doesnt ever merge together. this should make more sense in explaining how it helps reversion, and also you can see that loss of pressure/expansion doesnt occur

yeap the manifold is made based on the firing sequence, although i have no idea what it is off the top of my head

Yeah on Tomei's site you can see how they do the proper firing sequence for a SR20 and split pulse design;

http://www.tomei-p.co.jp/_2003web-catal ... ld_en.html

Again a waste because there are no T2 split housings. But yeah a split pulse certainly seems a sweet idea. Even the EVOs are split. I wish someone out there in the world would test the split pulse housings that ATP are offering!

oh crap. what have i done!

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meh

hahaha... you started a conversation with the blind leading the blind and best calculated guesses

Interesting Busky that they took no 1 over the far side and increased the length rather than bringing no 4 over to even it up....

Curious why they didn't take the devider right up to the face of the flange...

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

Well it seems Tomei chose unequal length to have the shortest runners possible for response. Tomei put cyl 1 onto the far side of the collector because it may have been difficult to put cyl 2&3 on the opposite side?

And yeah not sure why the divider plate doesn't go all the way to the flange. There must be a reason because the stock manifold is exactly the same!

only reason I could think of is to share some of the pulse across both sides of the devider to keep the load even, but that would kind of defeat the purpose.. so stuffed if I know.

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

Yeah no Idea on that one. Some have actually ground away the divider plate in the stock manifold with no effect on power or spool. IIRC, one said it was actually a backwards step.

probably because there are no split pulse turbo housings to take advantage of it
I'd say the divider is there more to direct the flow in the right direction than to keep the pulses "split"

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The Engine Whisperer - fixer of things

You may be on to something there. If the pulses are not fighting each other (i.e try to push each other out of the way) and they use a fixed devider to guide the flow it may promote a more even flow with reduced turbulance...

However if there was no split turbine housing why not take it all the way to the top if you one day get a split turbine housing???

Food for thought... The new manifold I am getting made will have 1 & 2 + 3 & 4 connected so I could run a devider 90 degrees to the nornal direction...

Just a thought if an external waste gate comes off one side of the manifold / devider that might upset the balance of things.

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.

if you ran the divider all the way to the flange level you'd end up with an area smaller than an exhaust port on each half, so it would be restrictive.
By running it only part of the way it'll direct the flow nicely but allow more area through the flange for flow.
On something like a T4 housing there's plenty of room for a full split pulse design without restricting flow.

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The Engine Whisperer - fixer of things

Good point may not work so well on a T25/28 style flange but on the larger T3 it shouldn't be a problem. Guess that is why I have never seen the split design on the smaller exhaust housings.

I was talking to the guys from Liverpool about the big angle the pipes entered the collector on the existing manifold and suggested that maybe we could go with a shallower angle to reduce the collector volume and reduce the turbulance, they didn't seem to have any problem with that...

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I didn’t break it, I just modified the operational status...
There are 10 types of people in this world, those that understand binary, and those that don't.