Holset turbos

[RB24D]

I need some help I have been building a rb25 and am trying to decide on a turbo I was going to go with gt35r .Untill I started reading about the holsets . I want 600 hp to wheels so I was thinking hx40 or 35/40 hybrid. The issue is getting a oe part number to try to find one I have a source for them and I even called holeset but they cannot tell me wich one I need .So help I need a part number for a hx35 and a hx40 that you guys arte using.

[Cjmartz2k]

Depends. For 600rwhp, you'd need an HX40. HX35 or 35/40 hybrid ain't going to get you there. You'd have to be pushing a HX40 pretty hard to get it there as a matter of fact. The biggest HX40 compressor (there are several) is a 69lb/min compressor, but I think that's at like 2.5-3 bar or something stupid.

Ebay is the best source for these, but if you've got a super secret squirrel place to get them for even cheaper than a few hundy bucks, figure out what cm housing you want and I can show you some places to look. I would reccomend at least a 19cm T4 (about .84 a/r'ish).

*Edit--these are real hp #'s I'm talking about, not dynojet BS. The DSM guys are making like 650awhp on .70 a/r custom ex housings, but that's dynojet. I think they are ballpark 8-10% higher than everything else, but that's JMHO.

[Cjmartz2k]

FYI--here's a great source for Holset info. This is thread is part 5 of a freakin 200 something page monster, but has a good summary at the beggining. I really sat down and read it from the beggining when it was 3 threads long, and have been keeping up since.

http://www.dsmtuners.com/forum....html

Here is a thread devoted specifically to part numbers, which will probably give you the answer to your original question.

http://www.dsmtuners.com/forum....html

[RB24D]

FYI--here's a great source for Holset info. This is thread is part 5 of a freakin 200 something page monster, but has a good summary at the beggining. I really sat down and read it from the beggining when it was 3 threads long, and have been keeping up since.

http://www.dsmtuners.com/forum....html

Here is a thread devoted specifically to part numbers, which will probably give you the answer to your original question.

http://www.dsmtuners.com/forum....html

Thanks! I am pretty new to turbos and I want to get the right one the first time .I was also thinking gt 40r but I heard spooltime for a street car was rediculous. I can get a hx40 for 150 but if it will not get me to my # then I need to figure out somthing else.

[Cjmartz2k]

It'll get you there, it just won't have much room to grow. The DSM guys are hitting easy 10's on them, but they are AWD. I spool my HX40 with a 19cm ex housing to 1 bar right at 4k rpm, and that's with 264 cams and no VCT. That's better than a GT35r spools, with way more top end.

If you want to go really big, you could always go HX52. I saw one go for $150 used on ebay last week. That's a 90lb/min compressor (about 900hp). My buddy has one of his RB25 with a ported/polished big cammed built head and spools it by 4.5k

[MATTs14]

Wow! What kind of power is your buddy making with that turbo?

[Cjmartz2k]

Well, there is no dyno on island, but he stpped turning up the boost around 1.5 bar because he was running out of injector. 740's to be exact

[MATTs14]

So he's making near 7? Thats pretty badass with a 25. My calculation might be wrong but thats what i figured it would be

[BoostFab]

the hx52 is the king (almost) of the HX's my rb30det is marry to one LOL

see my signature for a picture

[Vetal]

How is spool-up of Holsets comparing to ball-bearing Garretts? I'm thinking about some 400-450whp (was thinking about GT30, but maybe there are better turbos?)

[RB24D]

It'll get you there, it just won't have much room to grow. The DSM guys are hitting easy 10's on them, but they are AWD. I spool my HX40 with a 19cm ex housing to 1 bar right at 4k rpm, and that's with 264 cams and no VCT. That's better than a GT35r spools, with way more top end.

If you want to go really big, you could always go HX52. I saw one go for $150 used on ebay last week. That's a 90lb/min compressor (about 900hp). My buddy has one of his RB25 with a ported/polished big cammed built head and spools it by 4.5k

Is there only one hx 52 or several like 35's and 40's? I also thought the 52 was a t2 flange right . Do they come without internal wastegates ? Sorry for all the Q's . My head is fully built and so is the bottom end and I will be using 850 to 1000 cc injectors. I was hoping to get full boost around 3-35k rpm's but 4 would be ok.

[RB24D]

the hx52 is the king (almost) of the HX's my rb30det is marry to one LOL

see my signature for a picture

Boost fab can you e mail me with the hx52 number from your turbo [email protected] how about the hx40 pro the 6 blade impeller one if you please.

[480sx]

How is spool-up of Holsets comparing to ball-bearing Garretts? I'm thinking about some 400-450whp (was thinking about GT30, but maybe there are better turbos?)

Its within 100-300 rpms, its not a big difference at all. The bigger difference is on the smaller turbos, such as the GT28R. The S series borg warner will spool just as fast if not faster a large framed (t4) because of a lighter more efficient compressor wheel.

[Cjmartz2k]

Yeah, he's guessing around 700'ish at the motor. I think that figure will go up rapidly with more boost though. His problem is right now he needs more clutch too. He's slipping a new'ish twin plate.

As for spool, these things outspool comparbly sized GT series BB turbo's by a good bit. That's impossible according to some of the namebrand nutswingers on some other forums. The fact that something is BB makes a couple hundred RPM difference over wet float--it's wheel design that matters most all sizes being equal. Holsets and Borg-Warner's have great wheel designs. I'd compare the HX35 to a GT30r and the HX40 to a GT35r. Each of the holsets will outspool the respective GT series, and in the case of the HX40, make a lot better on the top end. Probably the HX35 too, but I'm not to familiar with what the GT30 is capable of. HX35's have made more tha 500awhp on 4G63's and are full boogy by less than 3500rpm on a 2 liter. O yeah, and they cost about $1k less

I've only ever seen one kind of HX52, with a 16cm housing. They have all been volvo's. I think they are a special one off thing, and they are ballpark the size of a GT40r-GT42r--and o, did I mention they are about a grand cheaper? They are there own unique flange--a bit bigger than T4 I believe, but not T6 size. No way are they T2 though. Do they even make flanges that small? I can't remember off the top of my head if 52's have an internal gate, but you wouldn't want to use it anyways.

If you are wanting spool around 3-3.5k on a 600rwhp turbo, buy a V8.

Dude looking at a GT30r, I'd look at a 7 blade HX35, or do the HX35/40 hybrid. All of the spool with more top end. O, and lets not forget, $1k cheaper

These turbo's do kick *** for performance, but my biggest thing as you guys may have noticed is the price. They go new for under $500 shipped on ebay, and a couple hundered for used. They are super beefy, but if you do need to rebuild, cheap OEM rebuild kits are on ebay too. No down side really, other than a bit of a loack of info on them. They were never designed to be used on performance gasoline engine. It's gotta make you wonder about how hard some of the "namebrand" companies are trying.

[SullivanRacing06]

hx35w are mighty cheap (ie price) but can pack a hell of punch!

[Vetal]

So, journal-bearing Holset will spool like ball-bearing Garrett, but will have better top-end, costs 1/2 of Garrett, and is rebuildable?Looks like a free dinner to me... And a bit hard to believe. Why would anone want expensive Garrett/HKS/xxx then if Holsets are so good?

Not trying to bash you. I'm searching for a new turbo and would be glad to have it for cheap, but it looks too good to be true

[Cjmartz2k]

So, journal-bearing Holset will spool like ball-bearing Garrett, but will have better top-end, costs 1/2 of Garrett, and is rebuildable?Looks like a free dinner to me... And a bit hard to believe. Why would anone want expensive Garrett/HKS/xxx then if Holsets are so good?

Not trying to bash you. I'm searching for a new turbo and would be glad to have it for cheap, but it looks too good to be true

No, they spool BETTER than BB Garetts. HKS is just rebadged ****. And they aren't half the price, they are 1/3 for new ones, and like 1/5 for used ones. Yes, they are rebuildable for cheap. I'm not offended in the least BTW. People want namebrand crap because that's what they know and have been told on the internet. Don't get my wrong, the other stuff works too. It's just expensive. Let me get some info from the DSM guys real quick...........

Summary provided by wiseman, Dsm-onster:HX35:

The 8blade hx35 has a 56mm compressor inducer. This is found on 1995-1998 cummins manual pickups. The compressor flows 52 lb/min according to the compressor map. The bolton BEP housing (0.55 a/r) is enough to push the limit of the compressor. There's several 500whp 8blade hx35 cars out there with the bolt on housing. It reaches 20+psi by 3500rpms in 3rd with 272 cams. Smaller cams would equal a faster spool speed in most cases.

The 7blade hx35 has a 56mm compressor inducer. This is found on the 1999-2002 cummins manual pickups. The compressor flows 60lb/min according to the compressor map and logged results from a member here. The bolton BEP housing with the hx35 turbine wheel do not SEAM to have enough flow to really reach the potential of 60lb/min. But many have logged over 50lb/min so far and seen 500whp. 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.

HY35:

The hy35 has a smaller turbine wheel than the hx35. And, it has a turbine housing connection that does not allow for a bolton housing to be used. It does not have a divided housing so any t3 manifold can be used effectively with this turbo. It has the same compressor as the 7blade hx35. We don't know if te hy35 turbine wheel and housing is enough to reache the 60lb/min potential of the 56mm 7blade compressor. Some one try it out already!!! It should at least be a faster spooling viable option to the full t3/t4 50-trim.

H1C/WH1C:

In 1994, there was the Wh1c which has pretty much the identical compressor as the hx35 but with a Vband compressor cover. The turbine wheel is the same. It will bolt into the BEP bolton hx35 turbine housing. It has 4 bolts at the housing instead of 6. So you will need to buy 2 more bolts and use 6 washers cut to make a flat side. Honestly, I just used bolts that were cut a little short and the bolt head was wide enough to pull the chra to the turbine housing. No sealing issues. Since the Wh1c is for all practical purposes an 8blade hx35 the spool and flow is the same too.

I have the big h1c. It comes on the INTERCOOLED 1991-1993 cummins pickups. It has the webbing for MWE but no groove cut like the hx35/wh1c has. This turbo I term the big h1c because it has a 54mm compressor inducer and same exducer than the 8blade hx35/Wh1c. The other h1c is the small h1c found on the NON-intercooled cummins pickups. This has a 50mm inducer but only 7blades and has no webbing for MWE. Less blades helps flow, but so does a larger inducer diameter. The most whp ever recorded on a gas 4cylinder with the small h1c was done on a KA24 nissan: 411whp. Since the big h1c has a 4mm larger inducer and the same turbine wheel as the hx35, it is safe to say that it flows enough for between 411whp and 500whp. The diesel sources state that it flows SLIGHTLY less than the early hx35. So 4lb/min less than the 8blade hx35 puts the flow of the big h1c at 48-49lb/min right where a 50-trim or 20g is. The small bep housing is all that's needed to get the most from the compressor and the spool speed is 20+psi by 3500rpms.

HX35-40 hybrid:

Keeping the long tradition of the marriage of sportcompact and hybrid turbos, there is the hx35 turbine and the hx40 compressor. It is strongly recommended to use the large bep turbine housing or the stock hx35 turbine housing with an non-divided t3 manifold for this turbo. The small bep housing around a t31 size hx35 turbine wheel is probably not enough to merit any of the hx40 compressor wheel upgrades. 20+ psi by 4000rpms can be seen in the hx35/40 with the hx35 12cm^2 turbine housing with a non-divided t3 manifold. With the large bep housing, spool times are to be determined. But likely similar.

HX40:

The 8blade hx40 has a 58mm inducer and flows about the same as a 60-1 (around 60lb/min) with ALOT better high boost efficiency and spool speed. It is the most common hx40 out there. The small bep housing with the hx40 turbine wheel is plenty to reach the full potential of the 60lb/min 8blade hx40 compressor. 20+ psi by 4100rpms with 272s.

The 7 and 6 blade hx40 is called the super40 and has the 60mm compressor inducer. This compressor flows around 69lb/min. You can get this wheel in billet style (think HTA). The non-billet wheel spools as fast as the 8blade hx40 in the bolton bep housing and has done 653whp at 40psi per the holset results only thread. Billet should spool even faster. The t3 .70 a/r BEP housing slows spool about 400rpms. But reports show a significant gain in flow per psi. So expect more power at lower boost with that turbine housing.

H1E/WH1E:

The Wh1e is like it's little brother the Wh1c. It mirrors the hx40 8blade in every way except that it has a v-band compressor cover and a 4bolt chra-turbinehousing pattern. It will consequently bolt into the hx40 bep bolton turbine housing and this is plenty of flow to max out its 60lb/min compressor.

The h1e is like it's little brother the h1c. There are different size compressors. . . BUT there are also different size turbine wheels too. Check measurements before buying this turbo if you plan on running a BEP turbine housing. There are lower flowing compressors than the 58mm 8blade that are out there. So this turbo may not flow any more than an hx35 if get the wrong one. You need at least a 58mm compressor inducer for this to be a worthwhile turbo vs the proven hx35 or 8blade hx40.

HX52:

This is a big sucker. It is commonly found on the Volvo Semis and usually has a billet compressor wheel. It flows 88lb/min. There is no bolt on housing for it. If you want a bolton housing for this turbo, then you don't want this turbo. In fact if you want a t3 flange turbine housing for this turbo, then you don't want this turbo. You DO want this turbo if you're looking at a gt4294r or gt4202r. The turbine inlet is slightly different than a t4 bolt pattern. You can still get the t4 manifold to work just fine by enlarging the bolt holes.

Misc.:

* Holset's don't spool slow. They spool faster than their garrett or mitsubishi counterparts. Diesel exhaust is cold and slow moving.

* The holset turbine wheel is a work of art. It has been shown to flow very well in a very small turbine housing. For example the hx40 turbine wheel in the small .55 ar bep bolton housing flows as much as a garrett gt35r turbine wheel in a larger .63 ar garrett t3 turbine housing. The hx40 with this configuration spools about 500rpms faster! You can upgrade to the .70 a/r BEP t3 turbine housing and have the same or slightly faster spool speed as the above gt35r with ALOT more flow per psi and consequently more horsepower per psi. This makes for VERY good pumpgas numbers.

* Holset patented map width enhancement. They do not have extended tip technology, but there compressors show more efficiency than their garrett or mitsubishi counterpart.

* They have superback technology witch leads to VERY, VERY durable compressors. The are designed to be overworked and underpaid.

* There are discrepancies all over the web concerning the compressor maps. Take what you hear/read with a grain of salt and a shot of tequila, and the worm.

* The holset is fine with stock 4g63 oil pressure from the oil filter housing. If you have no b shafts, you'll need a restrictor. The drain line is a garret bolt pattern. The feed line is different for different turbos.

----- Follow the links I posted earlier and see. Or search on this board. I've posted up some videos of mine, and then hit ebay for prices.

[DriftingisLame]

Hey Cjmartz2k,

Hate to thread jack, but I just purchased an HX35 for my rb20 (its still in the mail)... I had a couple of questions.

I'm trying to get an oil feed line on the way, What did you use for the holset side? I was planning on getting a banjo to -4 AN on the motor side, then what sort of fitting goes into the turbo? Links are greatly appreciated!

Also, to run an external gate, did you weld a plate that completely blocks off the passage to the internal wastegate flap? or did you just tack weld the flap shut and call it good?

If you'd like to e-mail me, to keep this thread on track, I'd understand.

[email protected]

Thank you!-Max

[BoostFab]

HX52:

This is a big sucker. It is commonly found on the Volvo Semis and usually has a billet compressor wheel. It flows 88lb/min. There is no bolt on housing for it. If you want a bolton housing for this turbo, then you don't want this turbo. In fact if you want a t3 flange turbine housing for this turbo, then you don't want this turbo. You DO want this turbo if you're looking at a gt4294r or gt4202r. The turbine inlet is slightly different than a t4 bolt pattern. You can still get the t4 manifold to work just fine by enlarging the bolt holes.

the turbine inlet is a T6 - divided scroll. one big sob. yes, think GT42

[MATTs14]

Hey Cjmartz2k,

Hate to thread jack, but I just purchased an HX35 for my rb20 (its still in the mail)... I had a couple of questions.

I'm trying to get an oil feed line on the way, What did you use for the holset side? I was planning on getting a banjo to -4 AN on the motor side, then what sort of fitting goes into the turbo? Links are greatly appreciated!

Also, to run an external gate, did you weld a plate that completely blocks off the passage to the internal wastegate flap? or did you just tack weld the flap shut and call it good?

If you'd like to e-mail me, to keep this thread on track, I'd understand.

[email protected]

Thank you!-Max

Im definitely wondering the same thing. If you have any info could you please please please post that on here or email me. mattamus240(at)yahoo(dot)com

[RB24D]

Great thread guys let's keep the info flowing on these turbos

[Cjmartz2k]

When I had the HX35/40 hybrid, it was just tac welded shut. I've got a 19cm housing that didn't have an internal gate design from the get go on there now.

I'll ask my shop guy about the oil feed. I can go take a pic of it when I get off work tomorrow morning--mid shift AND we have a exercise going on right now. I'm sitting here wearing chem gear I didn't do the fabbing to get it all on there. I just research the **** out of them and buy parts. My shop guy puts everything on. He's the one with the HX52

I don't mind keeping the discusion going at all. If there is enough interest, maybe we could start a RB Holset thread like the DSM guys did. That thing is a gold mine for info. Somebody already has some limited holset info on NICO, but I think it's in the SR forum. I'm running one, Boostfab has one, and there are 3-4 other guys here on Oki I know are running them on RB's.

[MATTs14]

Ive got an hx35w. Its not bolted on yet but ive got one lol. Also was he saying that the twin scroll was good or bad?

[RB24D]

How is the spool time on a rb25det with hx52 just sourced one for 130 ?? It's the one with the billet wheel and no internal waste gate with t6 ex flange.

[Cjmartz2k]

You just won it on ebay, right? No tag? If so, you beat me by about a day. I would guess spool in the neighborhood of 5k rpm or a little less on a basically stock RB25 with a good split pulse manifold. Obviously cams, intake, VCT, and all that affect it a lot. My buddy is getting 1 bar by a little more than 4.5k, but he's got HUGE cams, custom intake, no VCT, and all kinds of things that factor in. He said cams help spool up, but I thought they would hurt low end? I dunno, he's the expert.

Dual scroll is great as long as you have a split pulse manifold. It seperates the exhaust pulses and spools the turbo quicker. If you have a non-split pulse manifold, you may want to knife edge teh divider for a smoother transition.

[RB24D]

You just won it on ebay, right? No tag? If so, you beat me by about a day. I would guess spool in the neighborhood of 5k rpm or a little less on a basically stock RB25 with a good split pulse manifold. Obviously cams, intake, VCT, and all that affect it a lot. My buddy is getting 1 bar by a little more than 4.5k, but he's got HUGE cams, custom intake, no VCT, and all kinds of things that factor in. He said cams help spool up, but I thought they would hurt low end? I dunno, he's the expert.

Dual scroll is great as long as you have a split pulse manifold. It seperates the exhaust pulses and spools the turbo quicker. If you have a non-split pulse manifold, you may want to knife edge teh divider for a smoother transition.

Not on ebay but have access to a few of them I have stock cams but my head has been match ported and cnc'd stock cams unless I find a cheap set of am and non devided mani. They all have tags

[Cjmartz2k]

Shoot, can you get more?

[RB24D]

yes sir but shipping to japan may be tricky

[Cjmartz2k]

Emailing. I really wish we had PM's on this board.

[BoostFab]

yes sir but shipping to japan may be tricky

us postal will take it, even fedex, but cost alot for international.