Making a Holset bolt on cheap & easy

[imagine-02]

This is for the cheap guys out there that want to run an HX35 or HX40 with their stock manifold, stock Holset twin scroll housing, and stock Holset internal wastegate.
This isn't an ideal setup to really utilize these turbos to their full potential, but it could be a great stepping stone.

What I'm doing is designing a transition/adapter flange from the Mitsu style to twin scroll T3. I think there's something out there similar to this already, but I'm designing this so it fits HX35's and 40's into a DSM engine bay without needing to remove or modify stuff around it (AC fan might still have to go though).

This is what my first rough version looks like. I'm sure it will change A LOT.

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[JusMX141]

Plan on fabbing a 2"-thick spacer so the housing clears the block while you're at it. The problem isn't the fitment of the housing to the manifold as much as the housing to the block itself.

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Nice design, however.

 

[imagine-02]

Thanks for the info and pictures. That helps a lot since my engine isn't assembled right now. Confirmed my idea on how to use the bolts for mounting too (not represented in my design above).
I think I can make some adjustments in the design to make it work.

 

[JusMX141]

If you can somehow angle the adapter to pitch the base of the housing away from the block a little, that would be a welcome addition.

 

[imagine-02]

Exactly what I was thinking.
I really gotta throw the head on my block so I can mock stuff up.

 

[WES_393]

I like the idea. Going faster for cheaper is what Holset's are about anyways. However, there are a few other bumps in the road besides manifold and housing being compatible. Like Justin showed, standard Holset housings have issues clearing the block. In the first picture Justin showed you can see that an adapter is already in use. Second issue is performance. The standard Holset housings are only worth their weight when a full twin-scroll setup is used.

However, the biggest issue I see with any Holset setup is the downpipe. Mitsu cursed us with this funny thing we call an O2 housing. For many, having a custom housing or even an "O2 eliminator" fabricated isn't very cost effective. So not shooting down the idea, I think it's on the right track. But what the Holset users could really benefit from is:

1) A cheap and reliable T3 manifold, preferably cast and designed to angle the turbo away from the block. Think FP race manifold with a T3 flange, possibly with TS and EWG options. Maybe even a modified FP mani with your T3 flange welded on...

2) A cheap, universal, possibly flexible V-band downpipe adapter. Something that could bridge the gap between turbo and downpipe regardless of manifold or turbine housing. It seems like a tall order, but really isn't a crazy idea.

If you brought those two things to the table, you would have Holset users lining up at your door. If your just trying to get yours bolted up, then disregard my rambling. But that's exactly how I see a Holset (or any T3/v-band turbo) being anywhere close to bolt-on.

 

[imagine-02]

Thanks for the input. Very good points & ideas. I would love to design a manifold like that eventually. I know of some foundries around where I live, so I might have to talk to them about it someday.
As long as people are using a smaller Holset housing like my 12cm, spool should be pretty good.
An o2 housing that works with our downpipes is on my list of things to design and fab. I'll try making it somewhat universal, but that does seem like a tall order indeed.

 

[richard33]

Thanks for the input. Very good points & ideas. I would love to design a manifold like that eventually. I know of some foundries around where I live, so I might have to talk to them about it someday.
As long as people are using a smaller Holset housing like my 12cm, spool should be pretty good.
An o2 housing that works with our downpipes is on my list of things to design and fab. I'll try making it somewhat universal, but that does seem like a tall order indeed.

I don't know about the spool. When I have an open T3 manifold connected to the stock 12cm twinscroll hx35 backhousing i wasn't seeing full boost till past 5k on a 2.0 with bc272s.

 

[imagine-02]

I don't know about the spool. When I have an open T3 manifold connected to the stock 12cm twinscroll hx35 backhousing i wasn't seeing full boost till past 5k on a 2.0 with bc272s.

I was going by the Holset FAQ thread on here.
"The stock hx35 12cm^2 twinscroll turbine housing is a t3 flange housing. This mated to a NON-divided runner manifold has produced a 132mph trap speed with a full weight 1g AWD. This is about 600whp. So the flow is there with the stock housing if you use a non-divided manifold. The spool speed of the 7blade hx35 is similar to the 8blade hx35 with 20+ psi by 3500rpms in the bolton housing and by 4000rpms with the stock housing with a non-divided manifold."