Holset (7 blade hx35) turbing housings

[jpmxrider489]

So i recently come to the conclusion that my divided 12cm housing was my restriction. I was only able to flow 45lb/min and after porting the housing, I noticed flowing 47, which is much lower from other peoples reports.

So I have a divided 16cm housing that I plan on installing. Issues I ran into is the 16cm housing has only a 2.5 outlet instead of the 3 my 12cm had. With that being said, I welded my 3 inch vband flange to the outlet. My question is what should I expect from this?
Also, with the 3 inch flange welded on, there is plenty of materical I can take away from the outlet to make it a actual 3 inch outlet. Is this something I should do? Should I also port the divided part of the housing? I know its not reccomended but I saw a very small difference when porting the divided 12.

Like i said, I welded the 3 inch vband to the 2.5 section. I can open it up so it is the same diameter of the vband. Should this help with power, backpressure and overall performance?

 

[Mello]

Opening up the V-Band flange will help when you move closer to maxing out the turbo. I would open it up now to save having to do it later.

 

[jpmxrider489]

Opening up the V-Band flange will help when you move closer to maxing out the turbo. I would open it up now to save having to do it later.

What about opening up the divided section to match the gasket? Everything I read was that these housings should be ported. I was also unaware that there were some housings with 2.5 and 3 inch outlet.

I wish there was a true list that is applicable to our cars that talk about the housings and outlets. I know there is a list of part numbers but would be nice to simplify that. Especially since there are hybrid holsets. Some with gates and some without.

 

[RWD4G63]

Are you using this on a non-divided manifold? The 12cm housing isn't a restriction until 500whp or more.

 

[jpmxrider489]

Are you using this on a non-divided manifold? The 12cm housing isn't a restriction until 500whp or more.

Im am using a divided manifold with the divided 12 housing previously and on average I saw 45-47 lb/min at 33psi. I recently upgraded to the divided 16 and see 47lb/min at 28 psi.

 

[RWD4G63]

Im am using a divided manifold with the divided 12 housing previously and on average I saw 45-47 lb/min at 33psi. I recently upgraded to the divided 16 and see 47lb/min at 28 psi.

Well if you port the turbine housing like your pictures you're going to destroy the twin-scroll effect. Do not remove the center divider.

 

[jpmxrider489]

Well if you port the turbine housing like your pictures you're going to destroy the twin-scroll effect. Do not remove the center divider.

I never said I was removing the center divider. Simply matching it to the gasket. As far as the twin scroll effect, I cant see any more than 45lb/min for airflow. So how the heck are other people getting above 50 for airflow. Even in a bolt on housing. I saw minimum changed results in my 16cm without porting. Im about to port it to see it it helps.

 

[RWD4G63]

What cams do you have? What intake manifold? What intercooler? All these things affect your total mass airflow.

 

[jpmxrider489]

What cams do you have? What intake manifold? What intercooler? All these things affect your total mass airflow.

Hks 272 regrinds, and vrsf intercooler. The intercooler has 2.25 outlets. My jmfab mani I believe is the street version because its smaller. I would have to to through my purchase history. S90 throttle body.

In my opinion these might be minimal factors in why I'm seeing low airflow? I see many people with more airflow.

It was also recommended by a non dsmer to adjust my cam gears a little. I read one post about it regarding this issue but many people run cams on stock gears.

 

[RWD4G63]

Every bend and every restriction adds up in the system. I can tell you right now that 272 regrinds are garbage, people like them because they're cheap, and that is their only redeeming quality. A real cam will make more power and torque.

You should adjust cam gears on the dyno.

As an example of what a 12cm twin-scroll housing can do, here's a good setup:

http://morrisonfabrications.com/tech/mr-peepers-twin-scroll-t3/

 

[jpmxrider489]

Just dynod at 530