Hypergear Turbochargers and High flow Services Development thread

[hypergear]

2 hours ago, SKYMAGGOT said:

Is there much lost by plumbing in the wastegate with the 3 inch exhaust?

Yes alot. 

 

[hypergear]

New result to share. This is an ATR45SAT ball bearing bolton turbo running of an external gate from factory exhaust manifold. Car is an R34 GTT with a freshed up Rb25det NEO engine. Car made 420rwkws @ 25psi of boost E85 fuel, 240rwkws @ 4000RPM, Nice and responsive. 

 

 

 

[LaurelPWR]

New result to share. This is an ATR45SAT ball bearing bolton turbo running of an external gate from factory exhaust manifold. Car is an R34 GTT with a freshed up Rb25det NEO engine. Car made 420rwkws @ 25psi of boost E85 fuel, 240rwkws @ 4000RPM, Nice and responsive. 

 

 
 

Is there a twin scroll housing that would fit this turbine?

[hypergear]

I can supply a .84 rear housing in twin scroll. It won't be as responsive. If you have a twin pulse twin gate manifold, you can use the .63 single housing with an ATR45SS-1 to make 450rwkws+ while still have similar response as above. 

[LaurelPWR]

I can supply a .84 rear housing in twin scroll. It won't be as responsive. If you have a twin pulse twin gate manifold, you can use the .63 single housing with an ATR45SS-1 to make 450rwkws+ while still have similar response as above. 

Have you tested it with the .84 twin scroll rear on a true twin scroll twin gate manifold?

I would be genuinely surprised if it was less responsive [emoji848]

[Dose Pipe Sutututu]

4 hours ago, LaurelPWR said:

 

Have you tested it with the .84 twin scroll rear on a true twin scroll twin gate manifold?

I would be genuinely surprised if it was less responsive

 

Same thought, a true twin scroll and proper divided setup would be more responsive than a single scroll.

[Lithium]

20 minutes ago, Dose Pipe Sutututu said:

Same thought, a true twin scroll and proper divided setup would be more responsive than a single scroll.

Interesting thing happened around here recently, a guy with a 2litre Subaru running a twin scroll manifold and a open housing .63 GTX3076R decided he was happy with the power he was making but wanted more spool so swapped to a .61a/r divided hotside - using the same exhaust manifold, but changing the up-pipe to suit the twin scroll housing.  The car improved spool by a couple hundred rpm and lost around 50kw @ wheels.

After going through a bunch of diagnostics and deciding there were no other issues or changes other than the housing/flange setup he tried changing to a .83a/r twin scroll housing and it got back within 20kw of the .63 housing, but was also no better spool than with the open housing option.

Again, after further head scratching and messing around he decided to swap back to the original up-pipe and .63a/r housing and boom!  Back to the same power and response he had before trying the divided path.   Definitely not what I would have expected, but it's a thing that happened - unfortunately I am not directly involved so I have no more detail than what I've shared here, I wouldn't count out the possibility there is some other variable at play but realistically the options are pretty minimal... especially when it came back to "full power and response".   The car is definitely performing overall better with the .63 hotside.

[Dose Pipe Sutututu]

Only thing I can think of with the EJ, is the turbo manifold of equal header lengths or is it the usual unequal length business?

[Lithium]

3 minutes ago, Dose Pipe Sutututu said:

Only thing I can think of with the EJ, is the turbo manifold of equal header lengths or is it the usual unequal length business?

The twin scroll turbo manifolds are equal length, which is why a lot of the later Subarus don't sound like 5-cylinder RBs

[Dose Pipe Sutututu]

18 minutes ago, Lithium said:

The twin scroll turbo manifolds are equal length, which is why a lot of the later Subarus don't sound like 5-cylinder RBs

Interesting nevertheless, hopefully my selection of parts will work.

Car is coming out of fab work this week.

[hypergear]

Why should twin scroll exhaust manifold and housing make slightly better response. It very dependent on the design of the actual exhaust manifold and of course the firing sequence of the engine. Lets take Rb25det with firing sequence of:

1 5 3 6 2 4

Stock twin pulse log manifold consist bank 1 of: CYC 123, and bank 2 of: 456. 

So the split plus ensures the combusted air shoots straight into turbine housing rather then towards the other side. I've seen customers drilling out the center divider of factory exhaust manifold result in lose of response and power. I'm currently using a merged pulse external gate on a factory exhaust manifold, and by doing that I have lose about 300RPM of response, I think it would partly contributed the this problem and the extra volume external gate plumbing has made up.

Same principle apply to a spaghetti manifolds, but I found its not as tangible as the runners are separated that ends up in a collector. So there will be a bit of a differences assume a properly made twin pulse, twin gated exhaust manifold used on the right size twin pulse turbine housing. 

The advantage of twin gates giving extra flow would mean you can use a smaller housing on a turbo that makes the same top end as a big housing while avoiding the lag. 

 

Edited June 4, 2019 by hypergear

[Lithium]

6 hours ago, hypergear said:

Why should twin scroll exhaust manifold and housing make slightly better response.

So the split plus ensures the combusted air shoots straight into turbine housing rather then towards the other side. I've seen customers drilling out the center divider of factory exhaust manifold result in lose of response and power. I'm currently using a merged pulse external gate on a factory exhaust manifold, and by doing that I have lose about 300RPM of response, I think it would partly contributed the this problem and the extra volume external gate plumbing has made up.

The advantage of twin gates giving extra flow would mean you can use a smaller housing on a turbo that makes the same top end as a big housing while avoiding the lag. 

The theory on split pulse is pretty well discussed these days, reduces the collisions between high pressure pulses and keeps them separate until they are meant to drive the turbine.  I suppose you could say that it should reduce turbulence and as such keep velocity up.

In regards to people removing the divider in the stock manifold, I think of that more like a turning vane than a split pulse - without it there is nothing to make the exhaust flow think that it should just head straight to the other cylinders due the shape angles required to head to the turbine.  I am not sure that has so much relevance in the twin scroll/split pulse discussion, aside from the fact that the only reason that is at all a workable design with a straight 6 is that you have alternating pulses on front and rear three so it makes it less likely to cause bizarre lean outs on certain cylinders.

In terms of the twin gate advantage meaning that a smaller housing can flow like a bigger one, I could be missing something or misinterpreting  - so how do you mean?   

At face value it seems like you are saying that having more gate means you will reduce exhaust manifold pressure, but just having a second gate won't increase the turbine's ability to drive the compressor for a given amount of exhaust gas, so there is no reason for it to open more... the only reason the wastegate would flow more is if the turbine needs less exhaust energy to do it's job.   It's pretty easy to tell where more gate is an advantage, you get boost creep as you aren't relieving enough exhaust gas.   If you relieve more exhaust gas then you lose the energy you need to drive the turbine and you don't hit target boost.  

Apologies if I've misunderstood what you said, keen to hear what you mean or where you are coming from with that one.

Edited June 4, 2019 by Lithium

[hypergear]

I was referring to stock rb25det manifold.  

The twin gate setup, I found its dependent on  the types and shape of turbine wheel as well as size of housing used. I will conduct some experiments later in the year and upload results.

 

 

Edited June 5, 2019 by hypergear

[R34NeoLover]

Wow i am enjoying reading all the information on this page, keep up the good work

Edited June 26, 2019 by R34NeoLover

[hypergear]

Further development in R33 21U high flowed turbochargers. Latest model made 342rwkws fItted to an unopened R33 Rb25det engine as a bolton turbo with FMIC, 3 inches metal intake pipe, 3.5 inches turbo back exhaust, fuel system and programmable ecu.

  

 

[WR33KD]

Further development in R33 21U high flowed turbochargers. Latest model made 342rwkws fItted to an unopened R33 Rb25det engine as a bolton turbo with FMIC, 3 inches metal intake pipe, 3.5 inches turbo back exhaust, fuel system and programmable ecu.


  
 

I’m guessing that’s on e85?
Have you done many test with 98ron?

[hypergear]

Yes that is on E85. I don't have result of this version on 98 yet. it would be sitting pretty close to 300rwkws on that car. 

[Jordzz33]

6 hours ago, hypergear said:

Yes that is on E85. I don't have result of this version on 98 yet. it would be sitting pretty close to 300rwkws on that car. 

by the looks of the graph did the boys at G7 Adelaide do the install in tuning ? if so It looks like ill be giving them a visit! Great stuff Tao!

[Komdotkom]

What has changed between the older version of the 21U highflow and this one?

 

[hypergear]

New version has a more free flow turbine wheel.