Holset Turbos, PART 6

[jm1080]

To the people who know about hx35 turbos:

I was planning on buying an hx35 but am not sure if I should choose an 8 blade or 7 blade. I know the 8 blade flows a bit less than the 7 blade, but I will be running BEP Housing which doesn't really matter. Is the spool the same or is one better than the other? I cant seem to find the info anywhere about it. I read the only difference is the flow, but what about spool speed? Is one better than the other?

Thanks!

 

[dsm-onster]

I've not had a direct comparison between the two. Nor do I know of any one who has compared them one directly after another. But, it seams that the 7blade does spool a little later. Based on comparisons of different setups. This would make sence as less blades will make flow increase but only after the air gets moving. The extra blade give more to grab the air and draw it into the compressor initially. As well the larger number of blades at the exducer increases the slip factor, which encourages higher efficiency. And higher efficiency means that more work is being put toward boost instead of heat. But we really don't know.

And yes, the 8blade hx35 flows 52ish lb/min by 60% efficiency in common ambient conditions. I wouldn't try to ask for more flow to be squeezed through the low trim hx35 turbine wheel and bolton housing.

 

[jm1080]

I've not had a direct comparison between the two. Nor do I know of any one who has compared them one directly after another. But, it seams that the 7blade does spool a little later. Based on comparisons of different setups. This would make sence as less blades will make flow increase but only after the air gets moving. The extra blade give more to grab the air and draw it into the compressor initially. As well the larger number of blades at the exducer increases the slip factor, which encourages higher efficiency. And higher efficiency means that more work is being put toward boost instead of heat. But we really don't know.

And yes, the 8blade hx35 flows 52ish lb/min by 60% efficiency in common ambient conditions. I wouldn't try to ask for more flow to be squeezed through the low trim hx35 turbine wheel and bolton housing.

Thanks for your response dsm-onster

I do want a faster spool, so I think I will try the 8 blade with BEP housing, I would just like to make it to 400awhp and I'll be good

 

[my4ATEurV8]

im just about done with my holset build but im still up in the air on wich fmic to order.
i got my 7 blade Hx35 back from k and s fuel injection. i had them rebuild it for me. im using the stock twinscroll housing.
my question for you guys is where do you guys think it will spool at? i know that spool speed has been talked about befor, but i think mine will be a bit different. this is my setup so far.
1250 injectors.
t3 ss tube style manifold wrapped
264 cams.
magnus billet 2.4 stroker kit with 9.1 compression. im thinking about sending the pistons back for 10.1 compression. the magnus kit should be here tomorow. so i dont think they would have a problem with it if i wanted to swich to a higher compression, seeing that its obviouse that ive never installed them yet.
and a3.5inch turbo back .
these ar by no means all my mods, i only listed the ons that i feel will efect the temper of the turbo! so anyone have any thoughts on spool speed.

p.s. im shooting for the record of hiest hp/torq to the wheels on the stock hx35...

 

[SkylinesSuck]

Hey guys!! I've been lurking on this thread since Part II and wanting to post for a long time. Their are a bunch of us here on Okinawa running Holsets on RB's (Skyline motors), and one guy who's also on this board is putting a HX52 on his Evo I (radix).

Anyways, first question I've got is has anybody experienced any boost creep issues with the factory holset exhaust housings? I would have expected it a lot more with the BEP housings you guys use, but not the OEM housings. I used to creep my 19cm (6 blade HX40) REAL bad until I went to twin 50mm wastegates (RB25)--it was still climbing at 2.0 bar when I got out of it WTF My buddy has a 16cm housing on his HX40 (56mm inducer 6 blade) and can't run less than 1.6 bar with a single 50mm wastegate (RB26).

I've seen some of you guys even using the internal gates on these things and getting away with steady boost all the way down to 20psi which boggles my mind. Could it be because of the extra displacement?

 

[JWoodley]

I've seen some of you guys even using the internal gates on these things and getting away with steady boost all the way down to 20psi which boggles my mind. Could it be because of the extra displacement?

I'm running the internal gate setup from the turbo trader. I'm 99.99% positive it has a 24psi spring in it. I finally got hold 21psi to redline before my stock motor let go. It wouldn't hold anything under that even with my Hallman MBC. Before I go dyno the car I will be switching to an 02 mounted wastegate to better control the boost.

 

[95tzlgst]

im just about done with my holset build but im still up in the air on wich fmic to order.
i got my 7 blade Hx35 back from k and s fuel injection. i had them rebuild it for me. im using the stock twinscroll housing.
my question for you guys is where do you guys think it will spool at? i know that spool speed has been talked about befor, but i think mine will be a bit different. this is my setup so far.
1250 injectors.
t3 ss tube style manifold wrapped
264 cams.
magnus billet 2.4 stroker kit with 9.1 compression. im thinking about sending the pistons back for 10.1 compression. the magnus kit should be here tomorow. so i dont think they would have a problem with it if i wanted to swich to a higher compression, seeing that its obviouse that ive never installed them yet.
and a3.5inch turbo back .
these ar by no means all my mods, i only listed the ons that i feel will efect the temper of the turbo! so anyone have any thoughts on spool speed.

p.s. im shooting for the record of hiest hp/torq to the wheels on the stock hx35...

Best of luck to you as I am going for the same goals, but I will be on a 2.3L and 272's. Are you running a twin scroll manifold or standard t3?

 

[my4ATEurV8]

im actualy going to do both! ive already got the t3 open style header. now im trrying to find a good deal on a twin scroll manifold. this might sound dumb but i am going to gather a few t3 manifolds and do a tuned dyno run for each of them just to see how dramatic the differences will be.


any ideas on my spool speed. its going to be fast, but how fast.

 

[DraginX]

Ok guys, I've read through this entire post and I'm more confused than when I started out... Currently I'm looking at a hx35 7 blade, and an hx40 8 blade, I'll be using the stock housing for whatever one I get as I'll be getting a custom manifold made. Both supposedly flow around 60lbs/min. So am I right in saying that both should make simular power? But since the hx40 is an 8 blade it would spool a bit quicker? Or is the hx40 still going to make more power at lower boost levels? Sorry if this has been answered but with all the searching and reading through hundreds of posts my brain has turned to mush... Thanks in advance.

 

[DraginX]

I also found this page while searching it has a tonne of part numbers for holset turbos that aren't posted here.
http://www.turbomaster.info/eng/downloads/catalog_holset.pdf

 

[DraginX]

The supposedly hx35 I am looking at is off an automatic 01 dodge ram, the only part numbers I can find is 3593085, AA2600, 3592470 and the wastegate actuator says 3592428. It was the only number I could match up with anything saying it was a hx35. Can anyone confirm that this is actually a hx35 and not a hy35 or something simular?
I'm curious as when I look at the first post in this thread it says the hx35's come from standards of that year, did they also come on the automatics?

 

[jking29]

Is the turbine housing bolt on or v band? The hx35 is bolt on and the hy35 is v band. Also, the hx35 has a twin scroll turbine housing and the hy35 is a undivided t3. Also the hx40 should make more power at the same psi due to the higher flowing turbine wheel than the hx35. However the hx35 should have the edge on spool time.

 

[DraginX]

Is the turbine housing bolt on or v band? The hx35 is bolt on and the hy35 is v band. Also, the hx35 has a twin scroll turbine housing and the hy35 is a undivided t3. Also the hx40 should make more power at the same psi due to the higher flowing turbine wheel than the hx35. However the hx35 should have the edge on spool time.

Ok so it takes a 5 bolt flange(which isn't there) is that what your talking about? So it's safe to say it is a hx35?

 

[donniekak]

Ok so it takes a 5 bolt flange(which isn't there) is that what your talking about? So it's safe to say it is a hx35?

No, the hx35 has bolts and a 2 piece ring that secures the chra to the turbine housing. The hy has a v-band that holds them together, like a mitsu turbo.

 

[DraginX]

No, the hx35 has bolts and a 2 piece ring that secures the chra to the turbine housing. The hy has a v-band that holds them together, like a mitsu turbo.

Awe gotcha, I'm pretty sure it's an hy35 and not an hx35. Thanks for the info guys!

 

[SkylinesSuck]

Interesting info. I just measured my HX52 which is NOT a xxx996 part number, and the compressor wheel is 64.5mm inducer, and 98mm exducer. Another guy here ordered one (both from goldfarb) and his is the same size. That's a little smaller than the first one we got from goldfarb which IS the xxx996 part number, and it was 67mm inducer/98mm exducer. All of them are 16cm ex housings though.

I guess they aren't all the same size. I wonder how it'll affect performance.

 

[dsm-onster]

Still a half centemeter larger than the hx40 inducer . So anywhere in the middle of 67lb/min to 87lb/min. I'd say about 80lb/min capable or about 800whp with a well-built setup. This is based on the trend in compressor flow based on the maps as you go up in inducer size.

 

[SkylinesSuck]

Hmm, 7lb/min is a pretty big difference though. Are there different maps out there from what you've seen for the HX52's? Also, another interesting tidbit, a buddy over here just put a HX55 on his BMW. The exhaust side was huge as expected (22cm housing on a 3.6L), but the compressor is the same size as my "small" HX52. I wonder if the xxx996 part numbered HX52 is a "super" HX52 similar to the super HX40 only bigger. I've heard it mentioned that the HX52 was just a HX50/55 hybrid with a 16cm housing, making it similar to a HX35/40 hybrid, which would make it about perfect for big hp gasoline engines.

I've also got a copy of an email from a guy in Norway or something that deals a lot in holset gasoline applications. A friend of mine from another board got a hold of him when they saw his results with a twin HY35'd RB26 making over 1000rwhp here. He suggested turbos for him on his RB30 and said

Hi

I have here some suggestions what we have used between 700-900hp.

1. HX52 with 16cm2 turbine housing. Good with OEM cams and manifold inducer diameter 36mm. up to 800hp ( very agressive from low RPM)
2. HX50 with 19cm2 turbine houisng. Good with tuned cams and manifold inducer diameter 36mm. up to 900hp ( For big boys smile.gif) Very good spool up ( 3liter)
3. HX55 with 22cm2 turbine housing. Good for drag race.

If You deside to stay 700-800 hp my suggestion is nr 1. but if You deside to modify cams etc. You need number 2.

I can post up the rest of his emails if you guys want, but I found it very interesting that he suggested the HX50 as making more HP than the HX52.

 

[WIDSM]

This isn't a question directly towards Holset but any large turbo. I was at a shop today to have new intercooler pipes made for my car, and the guy that does all the fab work who seems fairly knowledgeable,was saying that when you run a large turbo all the weight adds stress to the chra because of how far it extends plus that weight. He rambled on about adding a support bracket to my turbo, I didn't want to call him out say how many people have been doing it and are fine though.

So my question is, is there any truth to what he said does it add extra stress on you chra and shaft? Is there anything to be worried about?

 

[gstryyder]

sounds like a stupid comment to me...

 

[dsm-onster]

That would cause a problem with the exhaust manifold not the turbo. Unless the turbo was very poorly built with subpar material.

SkylinesSuck, I don't doubt there are all sorts of different combinations of wheels for the hx5* series turbos. Afterall that is just a frame size. It's like saying t04e or t04b or t3 (or td05 for us MHI guys).

 

[WIDSM]

Ok I didn't think he really knew what he was talking about but I just wanted to reassure myself.

 

[gstryyder]

yeah.. you knew more than the "pro" that is the great thing about knowing your stuff and paying attention/ researching on dsmtuners... it will make you smarter then 90% of the mechanics out there when it comes to dsm's or turbocharging in general. +1 for WIDSM... +0 for the "pro"

 

[Slippi84]

my part number on my hx52 is 359965 but I never really measured the internals. To be honest it's plenty big to do more than you will need unless your going after shep or jake's old car kinda numbers ....in which case it's STIll big enough

 

[SkylinesSuck]

I'm shooting for 10's in a RWD car on stiff arse suspension on 275 nitto DR's. Also, still something with decent enough spool to turn the boost down and at least have fun down a twisty road. Not the fastest guy mind you, but still have fun. I spank purpose built GTR's with my HX40 now down back roads I'm sure this turbo will be enough, but if I can make more hp with less boost, I'd like to. Also nice to have the head room when I get a built motor.