Holset Turbos, PART 7

[dsm-onster]

It's the last post in the results thread. Just wanted to say that his car is probably the heaviest dsm with 130+ mph trap. AWD and convertible! And he mentioed "full weight"; so no weight savings. The results thread has some real pigs making some real nice trap speeds. Also this was on street radials.

. . . I'm trying to get the discussion in here because someone started asking questions in the results thread

. . .Ormaybe he can start a thread in the dragstrip forum???

 

[GST95]

Might be picking up a 7 blade HX40. Few questions, anyone have any experience using the 16 cm housing and an open manifold and can tell me what spool times are. I seen someone said they had the 18 cm housing with an open manifold and was getting 20 psi by 5k rpm and JESUS thats slow.

Anyone ever consider taking the 12 cm turbine housing from the HX35 and having it machined to fit the HX40 turbine?

Yes it was slow. This was on a 135k mile 6 bolt with hks272s. It was probably closer to 25psi@5100rpm though. It was like a light switch around that rpm though which is why it was hard for me to give a definite spool rpm. It would hit so hard in 3rd that it felt like it would break the tires loose just a little (might have been clutch slipping). It was too laggy for me, so i switched the housing and manifold.

With the WH1C and 12cm housing and the same manifold i was seeing 25psi@3700-3800rpm. It was a little more linear, but still very much like a light switch. There are a few guys working on twin scroll 12cm setups, but i dont know of any that are finished. Im very interested in their results though.

I saw in the results thread, a guy with a built 2.0 had a 17 cm^2 divided T4 housing and he saw 30 psi, full boost, by 4200. Is this accurate or a typo because that spool seems pretty damned fast for a T4 housing. I have this housing on my HX40 and was going to go with a .70 A/R but if this factory housing can have this turbo spooled up that quick, I may just use it. Any input on this housing is appreciated.

When i switched to the TS manifold and 17cm housing, i also changed pistons and rods. Its still stock bore and i didnt hone it when i put them in. Ive read elsewhere that changing only the compression shouldnt affect spool much at all, but does increase power pre-spool. Some people have different opinions though. Anyways, its not a typo. 30psi right around 4200rpm. Its an awesome street setup. It is a much more linear setup partly due to the higher compression and partly due to the twin scroll. Im very happy with it.

Also, with the Holset housings the inlet doesnt change the rest of the housing. A T3 inlet 16cm housing is the same size as a T4 inlet 16cm internally as far as i can tell. It doesnt seem to matter if its T3 inlet or T4 inlet, the rest of the housing is the same.

 

[my4ATEurV8]

still working on mine. should be done by mid june. magnus 2.4L 9:1 smim k272 cams v3 punishment t3 twinscroll manifold with twin 38mm gates and a 7blade hx35 with stock t3 divided housing.
the only thing i still need for my setup is the punishment manifold, wast gates, cams and suspension. no idea what my spool will be like but i sure i wont be disappointed.

 

[rampridersrider]

Yes it was slow. This was on a 135k mile 6 bolt with hks272s. It was probably closer to 25psi@5100rpm though. It was like a light switch around that rpm though which is why it was hard for me to give a definite spool rpm. It would hit so hard in 3rd that it felt like it would break the tires loose just a little (might have been clutch slipping). It was too laggy for me, so i switched the housing and manifold.

With the WH1C and 12cm housing and the same manifold i was seeing 25psi@3700-3800rpm. It was a little more linear, but still very much like a light switch. There are a few guys working on twin scroll 12cm setups, but i dont know of any that are finished. Im very interested in their results though.



When i switched to the TS manifold and 17cm housing, i also changed pistons and rods. Its still stock bore and i didnt hone it when i put them in. Ive read elsewhere that changing only the compression shouldnt affect spool much at all, but does increase power pre-spool. Some people have different opinions though. Anyways, its not a typo. 30psi right around 4200rpm. Its an awesome street setup. It is a much more linear setup partly due to the higher compression and partly due to the twin scroll. Im very happy with it.

Also, with the Holset housings the inlet doesnt change the rest of the housing. A T3 inlet 16cm housing is the same size as a T4 inlet 16cm internally as far as i can tell. It doesnt seem to matter if its T3 inlet or T4 inlet, the rest of the housing is the same.

Thanks for the input. Its always appreciated. Quick question though. I seen some pics of your old setup with the 18cm housing and you have the exact manifold I'm using (XSPower, Junk but it works) and it looks like you have a half inch manifold to head spacer in there also. Were you having turbine to block clearance issues? I have the 12cm housing on right now and I have a good 3/4 of an inch of space between the turbine housing and the block without a spacer. Let me know as I'm gonna put the HX40/16cm turbo on this weekend and I'll be real dissapointed if I have to get a spacer and all new studs and blah blah blah.

 

[GST95]

Thanks for the input. Its always appreciated. Quick question though. I seen some pics of your old setup with the 18cm housing and you have the exact manifold I'm using (XSPower, Junk but it works) and it looks like you have a half inch manifold to head spacer in there also. Were you having turbine to block clearance issues? I have the 12cm housing on right now and I have a good 3/4 of an inch of space between the turbine housing and the block without a spacer. Let me know as I'm gonna put the HX40/16cm turbo on this weekend and I'll be real dissapointed if I have to get a spacer and all new studs and blah blah blah.

Yeah, i believe its the same manifold. It was given to me by a friend, so im not 100% sure its the XSPower. On mine the angle it placed the turbo at gave way too much compressor cover clearance which reduced the exhaust housing to block clearance and also points the exhaust more towards the engine as well. I had to use a 1/2" spacer with the 18cm housing. It fit fine without it with the 12cm housing. I didnt check the 16cm housing though. I can check that this weekend on a spare engine if you dont have your car apart. Im not sure if you will have to use a spacer for block clearance, but you might want to use one to make it easier to make a smoothly flowing downpipe. A friend of mine had some 3/8" spacers made. I can check if he has any left if you want.

 

[rampridersrider]

Yeah, i believe its the same manifold. It was given to me by a friend, so im not 100% sure its the XSPower. On mine the angle it placed the turbo at gave way too much compressor cover clearance which reduced the exhaust housing to block clearance and also points the exhaust more towards the engine as well. I had to use a 1/2" spacer with the 18cm housing. It fit fine without it with the 12cm housing. I didnt check the 16cm housing though. I can check that this weekend on a spare engine if you dont have your car apart. Im not sure if you will have to use a spacer for block clearance, but you might want to use one to make it easier to make a smoothly flowing downpipe. A friend of mine had some 3/8" spacers made. I can check if he has any left if you want.

Yah ask him if he does. I'm hoping the 16cm housing will clear though. I'd hate to have to pull all the studs outta the head and install longer ones, though, I will if I have to. Lol. It would be awesome if I could just pull the HX35 and replace it with the HX40. Haha, wishful thinking probably though.

 

[GST95]

Changing the studs would be the easy part of the swap. The hx40 exhaust outlet is bigger, so you will have some exhaust work to do if nothing else.

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[rampridersrider]

Changing the studs would be the easy part of the swap. The hx40 exhaust outlet is bigger, so you will have some exhaust work to do if nothing else.

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Well #### my life. I was looking at those flanges and wondering if they were the same size or not. Looks like I may have some more work on my hands.

Well I guess I'm looking for a 12-14cm HX35 housing. Anybody got either one laying around? Lol.


Anybody know how much it usually costs to have a housing turned to accept a bigger wheel?

 

[JusMX141]

Well I guess I'm looking for a 12-14cm HX35 housing. Anybody got either one laying around? Lol.

I probably have more than anyone else on this site. All of mine are 12cm divided, with a wastegate flapper.

Anybody know how much it usually costs to have a housing turned to accept a bigger wheel?

Varies by the amount of work required; although there are limitations. You can't machine a factory HX35 housing to accept a HX40 turbine, for example.

 

[rampridersrider]

I probably have more than anyone else on this site. All of mine are 12cm divided, with a wastegate flapper.


Varies by the amount of work required; although there are limitations. You can't machine a factory HX35 housing to accept a HX40 turbine, for example.

Soooooo what your saying is that I can't have a 12cm housing machined to fit on to a HX40 turbine? If thats the case then why? Its only going from a 60mm wheel to a 65mm wheel.

So there is no possible way to have a 12cm housing put on the HX40?

 

[JusMX141]

Soooooo what your saying is that I can't have a 12cm housing machined to fit on to a HX40 turbine? If thats the case then why? Its only going from a 60mm wheel to a 65mm wheel.

So there is no possible way to have a 12cm housing put on the HX40?

I don't know if it's possible or not, but the twin-scroll design isn't as easy to open up as a standard single-scroll housing is. Just going 5mm bigger may completely grind the divider out of the turbine radius of the housing.

It's not as simple as a T3 Bullseye housing where the HX35 and HX40 housings are based on the same casting and machined differently- the factory Holset housings are two completely different housings.

 

[rampridersrider]

Thankyou for your input. I'm gonna take them both to the shop and see if it can be done.





Edit: After tons of researching I've found only one person that has done this on the Cummins forums. Its not a very popular setup obviously since nearly all diesel guys are concerned about high EGT's so they usually stick with the 16cm housing it comes with. But that at least tells me its possible. This combo should make for a kick ass turbo IMO. Great spool up and still a ####ton of topend power which is something I think the bolt on .55 mitsu housing lacks. Hopefully all goes well and this works.

 

[abaum565]

If you spend some more time on diesel forums you will find more people that have done this. I had a 12cm^2 hx35 housing I was going to have machined, but after researching much more on here (re read the beginning holset threads) I found that the 12cm^2 housing will be to small for the hx40. Divided a/r housings are a whole different animal when it comes to what you think might work. There seems to be varied conversions from cm^2 to a/r. All I can tell you from researching is that the small 12cm on a 40 will probably be too small. I picked up a t3 16cm^2 housing for my hx40 and will not even think about machining the 12cm^2 to fit the 40.

 

[rampridersrider]

We'll see what happens

 

[turbotalon1g]

Since we are on the subject of exh. housings, the only 2 options for a HX35 are BEP T3 .70A/R and a huge stock housing?

A local guy that rebuilds turbos said he could machine a T3 housing for me for a good price, would this be worth looking into?

I am wondering this because of BEP history of not so well performing housings.

 

[Hubbard 0]

Since we are on the subject of exh. housings, the only 2 options for a HX35 are BEP T3 .70A/R and a huge stock housing?

A local guy that rebuilds turbos said he could machine a T3 housing for me for a good price, would this be worth looking into?

I am wondering this because of BEP history of not so well performing housings.

BEP also does a .55 A/R Mitsu Flange housing for the HX35.

 

[dsm-onster]

Its the turbine wheels that havn't worked so well for the bolton bep housing. The old garrett wheels used back in the day need larger housings for the hotside to flow well enough for the larger t4 compressor wheels. That's because most of the folks back then were so scare of a little lag that they would run the tiny t31 turbine wheel (the hx35 turbine wheel is larger and still manages to spool faster in the same turbine housing: see bep 50-trim spool speed vs hx35 spool speed) for something like the t4 60-1 compressor and then bellyache about not seeing the full flow potential and having to run extremely high boost to see good numbers. Yet, the .55 a/r housing has 690whp with the hx40 turbine wheel and several are in the 10s. More than half a dozen are trapping 132-140mph with it. And the .55 a/r housing has done low 11s and 500ish whp with the hx35 on many occasions.

My t31 bep housing 60-1 flowed less at 30psi than my h1c in the bep housing at the same boost. Same setup direct swap showd an increase in hertz throughout the rpm range. And spool speed was worlds apart . . . The new aero tech in more modern turbine wheel designs (holset garret bw) allow smaller volutes to do more vs. 1970s T3 & T4 turbine wheels. The volutes still need to be properly designed though. The term "Bolton" got a bad rap from PTE frankly. Those housings have an inefficient offcenter volute that is TINY. The bep housing has a centered tearshaped volute shaped more like the FP bolton and garrett housings.

If you want a higher flowing turbine housing for a hx35 (if you're looking to take a hx35 turbine wheel and max out a 7blade 60lb/min hx35 compressor), yes the t3 .70 a/r bep housing will flow more. But the .70 a/r housing spools about the same as the stock hx35 12cm^2 hx35 turbine housing and requires about the same amount of customization and parts/costs to use it. And the hx35 turbine wheel and 12cm^2 housing is proven to 132mph with a nearly full weight 1g so far.

The garrett t3 .63 a/r housing may flow more than a .55 a/r housing and spool faster than the .70 a/r housing, but the spool of the .70 a/r housing or the stock 12cm^2 housing isn't that bad at all. Your hx35 will spool as fast as an hx40. And with a 7blade hx35 you'll have the same flow potential as an 8blade hx40. IF you do run a garrett housing small enough to spool as fast as the .55 a/r housing with the hx35 (like the .48 a/r housing), I seriously doubt it will do better than the what the bolton housing has already done on many occasions with the hx35.

So it really comes down to your goal. The bolton housing is good enough to push the 8blade hx35 to the limit which flows as much as an fp3052 (52lb/min). The 60lb/min 7blade hx35, if you want to push that one to the limit, of course needs something larger than a fast spooling .55 a/r housing. And the 12cm^2 hx35 housing flows just as well or better and spools just as fast as the .70 a/r housing.

 

[my4ATEurV8]

im in the middle of buildinga holset set up and i have a couple small questions. the setup is a 2.4L 9:1 compression, k272 cams, smim, t3 divided manifold from punishment and a 7blade hx35 with stock divided housing. would i benefit from swapping in a 6 or 7blade hx40 compressor wheel into my stock compressor housing. what would the changes be like. spool, efficiency? would it be worth it. what would i have to do to make it work?

 

[GST95]

im in the middle of buildinga holset set up and i have a couple small questions. the setup is a 2.4L 9:1 compression, k272 cams, smim, t3 divided manifold from punishment and a 7blade hx35 with stock divided housing. would i benefit from swapping in a 6 or 7blade hx40 compressor wheel into my stock compressor housing. what would the changes be like. spool, efficiency? would it be worth it. what would i have to do to make it work?

The compressor wont fit unless the cover is machined. It will probably be cheaper to find a used hx40 compressor cover than it would be to have somebody machine the it. Externally, the hx40 cover isnt any bigger than the hx35 cover.

 

[my4ATEurV8]

so then just swap the compressor wheel and housing then? would there be any major differences in performance?

 

[hurricanecris24]

I have a question. I can get a holset out of a 2007 dodge cummins for 50 bucks is it worth it?

 

[aero_sallee]

so then just swap the compressor wheel and housing then? would there be any major differences in performance?

I believe the backplate needs to be machined also.

 

[my4ATEurV8]

whats the backplate?

 

[turbotalon1g]

Thanks for the info guys, But I'm currently rocking the .55 bolton housing.

 

[aero_sallee]

whats the backplate?

The plate that is directly behind the compressor wheel, the part that the compressor cover attaches to. If the back of the compressor wheel has a different contour, or a different size exducer it needs machine to match or if it bolts on replaced with one that matches.