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Holset turbo on stock manifold...

33K views 94 replies 15 participants last post by  comtrang 
#1 ·
I'm thinking it might fit.
Asked Vigge about this and he said he wasn't sure, so I figured I would post here. They make a t25 to t3 adapter which is 3/4" thick (saw it on ebay) which would allow the Holset to fit to the stock ex. manifold.I think with the adapter, nick's manifold spacer, and the intake side trimmed down a bit, it might work. Has anybody tried this? I'm thinking about using the HX35w (internal wastegate model). Does anybody have dimensions on this unit?
Watta u guys think?
 
#3 ·
My setup is not going to apply one bit to a 9-3 unfortunately because of differences in the manifold setups.

I was able to do it on the 9000 with the stock mani because of how much room there is on a 9000. I suspect things will be much tighter on a 9-3.
 
#4 ·
I'm not that familiar with the Holsets but I think the turbo options are the HY35 or HX35. I will probably keep internal wastegate if I go with one also. Do you know the flow capacities on these (how much hp they are good for)?
Thanks.
 
#6 ·
They are monsters and spool-up just about as fast as a gt3076 or gt3582 and just keep flowing to like 80# or so of air.

Marko made 600hp no problem on his ng900 or 9-3, not sure on that, but he had 300hp at 3500rpm or something.

I don't think you could get it to fit on a 9-3 stock manifold unless you flip it around and remove the ac and get the dp on belt side to make it fit. You could get a gt35r to fit on the stock manifold if you flip it around like Nordic did on their 10 second car.

I almost did this, but decided I have to have ac in the summer;)

John
 
#8 ·
Those things are monsters and if I do another big turbo application, I will most likely get away from the "superior technology" of the gtbb turbos and go with a nice big Holset.

I also hear the Holset turbos are much more reliable when it comes to compressor surge that can knock a bb turbo out fast. You can also rebuild the Holset and find them used all over the place dirt cheap! They seem to spool up as fast or even faster in some cases and just keep flowing well beyond what a gt35r would do.

The biggest issue is the size and need for a tubular manifold, but if you are going tubular anyway, why not fab one up for the Holset monster?

John
 
#9 ·
Thanks for the info guys.
I am trying to avoid the extra cost of a tubular manifold. If the Holset I choose (if it will fit) has a divided turbine inlet, I will probably take a grinder to it and port it out like you would the air passages to the intake valves in the head when porting (if that makes any sense). Thin out the division a little bit.
I am looking for about 400 bhp,maybe a bit more. What internally wastegated Holset would support this?I am thinking the one with a 52 or 53 mm compressor inducer diameter.
So the Holsets cmpressor sides are measured in this way, what about the turbine sides? Aren't the turbine housings numbered like#12,#14, etc?
 
#10 ·
Yea, I think the #12 is a 12cm2 and the #14 is a 14cm2, its huge! The regular gt3071 .64ar is like 9cm2....!

Do some google searches, there are some companies that make the Holset turbos and the one company was going to make me whatever combination I wanted. You could call them and tell them you're hp goal and the builder will make a recomendation for the size wheels and housings and then he will even set up the actuator for the base boost that you want...

Good Luck,

John
 
#11 ·
I would say look for a something with #12 housing and mostly look for examples from real life, because many delers do not have "that" much experince how the semi turbos work on small discplacement engines like our saabs. I believe to John one US dealer quoted that the Super HX40 with 60/65 #14 wouldnt spool on a 2.3 prior to rev limiter, but in real life even on a 2.0 saab with proper HW it will deliver full boost just after 4000rpms ;) On the 2.0 it will sign up to 7800rpms a good for 600+ bhp.

In Finland I know one car with HX35 (54mm inducer #12) , mounted to orig 9k manifold in a 2.3 9000. This consept delivers 0.5bar boost at 2500rpms.

The Holset internal WG's are not really that good and you may run into problems that you cannot limit the boost low enough.
 
#13 ·
All the above, the housing # is the a/r for them or #12 is 12cm2 and #14 is 14c,2, they offer many wheel combinations. Call them up and see what they recommend and then do some more research and see what guys are using.

Marko would be a good source of info and vigge.

The 60 in and 60out or super 40 is supposed to be the real performer.

Good Luck,

John
 
#17 · (Edited)
Check out the difference in the holset super 40 vs. gt3076 on dsm.
John is there a specific reason why the comparison on dyno is 2nd gear with Holset and 3rd gear with garrett? In terms of spool higher gear is favored. And to be honest that super HX looks relly "wicked" or is just a holset wheel in a different frame?
Pics of one super hx40
http://www.stcf.net/viggen/super_hx40.jpg
and an another one
http://www.stcf.net/viggen/turbo2.jpg
http://www.stcf.net/viggen/turbo3.jpg
http://www.stcf.net/viggen/turbo5.jpg
 
#16 ·
Thanls for the info guys! Seems like the spoolup on these is comparable to Gt series turbos and they are capable of making even more power. I can see i have some research to do. I'm gonna do my best to get one of these on a stock manifold. Do you guys know anything about the oil feed and return line connection sizes? These are only oil fed right? No water cooling jacket?
 
#18 ·
Don't know, it was supposed to be a caparison of the two turbos on the same car, did not notice it was different gears, he said he stopped the run on the holset because he had proven the spool-up part of the test.

John
 
#21 ·
Did a little research...
Apparently there is a turbine housing for the Hx35 or Hx40 called the Bullseye housing, which has a larger wastegate hole and flapper valve so you can keep the internal gate. Anyone familiar with this? Trying to find a place that sells it. Someone on a forum said it's like $170 for one so not too bad.
 
#24 ·
I have been a bit aprehensive about the small WG hole in my HX35, and I will likely have it bored out as much as possible before it goes on my Aero. It looks to me like there is plenty of excess that could be removed.

I'd personally like to avoid a custom manifold myself because other than being able to use an external WG, it does not seem worth the effort to me.
 
#25 ·
Exactly!
Can you post some pics of the internal gate and flapper on the HX35w? I tried to find some but couldn't.
So if I understand the design correctly, it looks like the wastegate only vents exhaust from one of the scrolls, correct? With that bullseye housing it appears as if the divided inlet design is eliminated.
 
#35 ·
Also: I found on some websites where people have the hy35 and it does have an internal wastegate (at least some of them). It is not a divided inlet turbine housing and what people are doing is opening up the flapper hole and keeping the stock flapper valve. They say you can open it up enough to prevent boost creep since the casting hole there is much smaller than the diameter of the flapper valve. This may still be an option. They spool quicker than the HX35 and Hx40 but don't give as much power. I think someone said they are good for 450 bhp but that is plenty for me.If I can get some dimensions on one and it will fit the stock manifold I may go this route.
Anyone have any more info on this turbo?

http://www.motorgeek.com/phpBB2/viewtopic.php?t=17708
 
#36 ·
For 400whp, that might be the perfect turbo, good spool-up and its durable and cheap. Looks easy to get to the waste gate hole and open it up some.

I think this whole boost creap thing is over-rated anyway. I am now trying to get my turbo to make good boost up top and if it climbs a psi or two, I am happy, its not really a big deal and I actually prefer it. The fact that the back pressure and volume of the engine will be causing the boost to drop off in the high rpm anyway, the offset of a couple psi boost creep will not even be noticed in my opinion and even if it was, its not enough to hardly notice or worry about. Its just not enough of a issue to worry about in my opinion.

I have heard the hy series are good for quick spool-up. Keep searching, there is lots of info with the dsm guys and holsets.

John
 
#39 ·
I agree completely. Boost creep can be a major problem, especially if the fueling is not there to support the extra airmass.
Did he port the wastegate hole on that Hx35? Also-that's a divided scroll design hosuing, and I believe the wastegate only allows exhaust to bypass one half of the turbine wheel, not the same as the Hy35w which would allow for better boost control, especially with a ported wastegate hole.
 
#40 ·
I would not call a psi or two a major problem, this is over-rated. That would barely change the a/f mixture and if it was 12.0/1, it might make it 12.2/1.

The boost naturally drops off in the high rpm anyway and with our cars and all the turbos I have run, they still fall off in the high rpm past 5500rpm.

Even if I make 28psi at peak torque, I am down to 24psi by 6500rpm and that is with a turbine that Nick said had a little boost creep.

Unless you had major boost creep, the issue will hardly be noticable. I guess the best bet is to do what you can to avoid it and then see how bad it really is.

My last 3071 I listened to all this boost creep stuff and ported the waste-gate hole and had a hell of time keeping the waste-gate closed under high boost high rpm conditions. I had to run above 15psi for base boost to keep the boost from falling off badly. Nick said this housing had boost creep.

My new 3076wg has no porting to the waste-gate and its a little easier to keep the waste-gate closed, but if I test base boost, it creeps about 2psi, but when running on my full boost setting, the boost still drops off from 28psi to 25psi or so in the high rpm... I wish I had more boost creep;)

John
 
#42 ·
Sounds like you need a stronger wastegate actuator and that the size of the flapper hole is not the problem.
Still, the holsets do have very small wastegate holes, but there is much room for porting so I would def. port it out if I end up going this route.
I need to find dimensions on the hy35 or he351 to see if they will fit. My a/c is removed so there may be just enough clearance, especially if I go to a slim mount fan.
 
#41 ·
This brings us naturally to the topic, is more boost for better or for worse?
Some believe boost = power while others see out what level of boost is enough after which the turbo is incapable of providing more. Forcing wg shut to get the PSI up in many cases does not lead not gain in any other parameters than EGT and back pressure.
 
#43 ·
Without the ac you could probably flip the turbo around and make it fit no problem and have the dp on the passenger side, like Nordic did.

My gt3076 would have fit like a dream flipped around with huge 35r compresor housing .70ar and 4" inlet, but I opted to keep my ac....

If you port the waste-gate hole, that will help some, but I honestly don't feel its a big problem, at least with the turbos I have run so far, I outflow them up top every time and that is why the boost drops off. The Holset may give you enough # flow that you will not outflow it, especially at sea-level and it may become a concern.

You could always revert to external if you had to. Cut a 1" hole in the manifold and run it to external waste-gate and then pin or weld internal waste-gate shut. Keep it as a last resort if you do find its an issue you just can't live with.

John
 
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