The Project Pad

dubsmith wrote:Loxx, you will definitely need to have your turbo rebalanced if you change out the turbine wheel. I had my K26/27 i built balanced at majestic turbo in texas. It was about two weeks door to door, and was $95 including shipping. Worth the peace of mind i think. Unless you'd like to see what what happens when the turbine grenades at 80,000rpm...

If the turbine and shaft are zero balanced and the compressor is zero balanced then the only unbalanced thing is the nut. If you want to do it just in case I bet most major cities have a local option (at a cost <$100).

yeah, thats what I was thinking dubsmith. Supposedly the Holsets are all zero balanced, so it shouldn't matter...but it still bothers me in my mind.

I agree with you Ed and I do know that they are zero balanced (it says right in the literature I'm looking at). The nut currently on my turbo doesn't have any material taken off, so I'd say its fine. Still, it bothers me to some extent. However, turbo blowing up when it costs $150 isn't that big a deal. Holsluts stay in their housings when blown up too, so no fear of dieing or anything if it were to blow up
Check out their testing videos of that sort of thing...its awesome. They compare real Holset to a fake, Chinese one.

Still, I'm going to look for a place to do it since I've got plenty of time. It would be interesting to see how out of balance it really is.

Yeah, for <$100 its not a bad idea just sometimes unnecessary.

it seems that with BIG turbos, the need for assembly balancing is much, much less necessary then with smaller turbos which have much lower inertia and a lot more affected by small imbalances. That is why most large turbos aren't balanced as an entire assembly, but its required for smaller ones. *supposedly*

My T3 seems to have not been assembly balanced (compressor bolt not ground); the compressor wheels has marks for zero balancing as does the turbine.

Got quoted $75 by a place in miami to do it. They didn't seem to think it was too important for a zero-balanced, large holset. Two of my other turbo sources didn't seem to think it was going to be necessary either.

loxxrider wrote: Also polished the comp housing last night.

Could you give me a quick run-down on what's involved? Grits/etc. I know it's a pain, but I want to polish the comp housing on my 35R too 8)

Boxing up that headlight today, I didn't forget about it!

Oh nice! I actually did forget about that.

Here's your rundown.

First you need to hit it with 80-grit. I'd suggest flap wheel on a dremel. This is the only way to get the casting marks out.

From that point, you can hit it with another 120 grip flap wheel OR you can do like 160 by hand.

Then, the wetsanding commences. Not much technique to it, you just have to be thorough to get a great finish. The more time you put in, the better it will come out. You can go with as many steps as you want.

Typically I do:

220
320
400
600
800
1000
1500

and then I hit it with the best metal polish evAr! Autosol. Look it up on ebay or somethin. Its seriously the best stuff I've ever used. You have to hit it fast though so a buffing wheel of some sort is required. I use a buffing wheel on a drill for small parts, and a real buffer on big stuff. You can use any polish you want, but autosol works really well for me.

dubsmith wrote:Loxx, you will definitely need to have your turbo rebalanced if you change out the turbine wheel. I had my K26/27 i built balanced at majestic turbo in texas. It was about two weeks door to door, and was $95 including shipping. Worth the peace of mind i think. Unless you'd like to see what what happens when the turbine grenades at 80,000rpm...

Actually, it's not that spectacular. I was in a gen III Supra that broke the shaft. Just some bad noises for about 2 seconds and then it was naturally aspirated. The wheels just rattled around in the housings until they came to a stop.

Hmmm, it was my understanding that the whole rotating assembly was balanced as one. If you swaped out wheels, or even took it apart and reassembled it with one of the wheels out of it's original position, it would be unbalanced.

I can't remember if I shared this on this forum, but at Sema, I was talking to the BW EFR engineer about housings and offerings.. We got on the subject of heavy castings and exhaust housings. He told me that turbo housings are as thick as they are in order to contain turbines and compressors should they come unglued. They are safety factor to keep turbines out of your forehead when they come apart at 150k rpm... Still, I have seen some spectacular pictures of turbines coming through the housings, and through hoods and firewalls. Look at Jimmy Greens thread to learn about his failure when it came through his hood on the old 60-1 HO turbo.

dubsmith wrote:Hmmm, it was my understanding that the whole rotating assembly was balanced as one. If you swaped out wheels, or even took it apart and reassembled it with one of the wheels out of it's original position, it would be unbalanced.

Some are some are not.

Thats just nutty!

dubsmith, some turbos are balanced with entire rotating assembly as one. Others (such as most if not all Holsets) are zero balanced meaning that the turbine wheel and shaft are balanced and then the comp wheel is balanced and then they are put together just like that. That means, I'm good to go as far as putting this new turbine shaft and wheel in. However, if you have a turbine wheel that scratched the housing or anything like that, then its not balanced as it came from the factory. Then re-balancing would be required.

As I posted above, check out the Holset failure videos. Its really cool and shows the work they put into safety in the event of a failure. (skip to two minutes for the good stuff)


Link to video

Holy Crap! That is scaaary!!!

Man, those failures are nasty!

But it makes my toes curl when they start bringing in the images of the school bus with kids.
Like a turbo on a school bus will be seeing anything approaching the test stresses. Come on...

Tried doing some pulls with a few cars tonight...it didn't end well though. I popped a damned coupler off in third gear racing a 310whp gti. Hit full boost in second and we were neck and neck since he had some serious jump on me due to his spool. Then I shifted hard into third and expected to pull him, but I got 5psi instead of 21. Damned coupler had hair spray on it and still came off lol. Can't wait to get my hargetts on.

Also raced the e30 on 8psi (same turbo), but we didn't really have enough room (or willingness to get a ticket) to really turn them out. Seemed to be pulling it pretty good though. That thing is fast on only 8psi partly because of displacement and partly because it weighs 1k pounds less than my car.

Anyway, worst case even if I was just neck and neck with a 3k lb gti making 310whp, I think that puts me somewhere in the low-mid 3's at the moment. I'm sure there will be a rematch after I whip out the ghetto bead roller and more hair spray lol.

i was going to guess 340 when you first set it at 21 psi. far from rod breaking area. come on turn it up. : )

I'm very tempted to...probably soon

When I went to go fix my blown off pipe, I also took the filter off of the H1C. Noticed some oil inside the inlet. Not good. Looks like a rebuild is in order. Now the question is...what to do...I can get an HX40 super and put it on with the same turbine housing. Then all I'd have to do is weld the comp housing up to the charge pipe like my current one is. Of course I could just rebuild the H1C too.

ORRRR I could get an adapter flange for the HX52. That would cost me a bit of money though since it needs a rebuild too and I'd have to weld the comp housing and make a new downpipe. I think thats a negative, but the thought did cross my mind I'd be most concerned with the wastegate's ability to keep the boost down and it would be pointless because it would spool so slow and make like no power at low boost.

I think a rebuild kit for the H1C is the best idea

Ya, rebuilding the H1C sounds like the best idea. But im very curious about the HX40super... Would would you get it from Goldfarb? How much? And do those have billet wheels? It would be awesome if it will bolt up to the H1C turbine housing as well.

Part of why i am asking is because i am having a hell of a time finding a new wheel for my WH1C because its odd size. And with the recent purchase of the Scats im sure i can handle an HX40

yeah, as long as you get an hx40 with a 60mm wheel and its billet then its an hx40 super ( i think). What size is the wheel on your wh1c? Shouldn't be that hard to find. You can definitely use an hx40 if you have rods. Its an awesome turbo.

Its a 56mm 8 Blade. HTT said it would take 12 weeks-6 months to get it them in... Seems kinda ridiculous to me. Im starting to think sell the rebuild kit for the WH1C (which also works for a H1c ) and just get an HX40... Unless Brant at Goldfarb or HTT gets back to me soon

Mine has the 56mm as well.

If you want to sell the rebuild kit, lets talk

Well, let me talk to Goldfarb tomorrow or the next day and then ill get back to you

You can not put a hx35 or h1c ect housing on a hx40, with out reprofiling the housing which is very spendy, and I'd a hx40 has a 60mm wheel its a super 40 regardless off the billet wheel, the billet wheel is 7 blade which flows the same as a non billet 6 blade, the billet only spools faster, oh and holsets are picky on there oiling, they need a restricter do to our high oil psi, also -10 is not big enough for the re turn, if you measure a -10 to the drian hole on th turbo its way smaller, I know some dsm guys that blow holsets left and right till they put on a restricter and bigger drain line, but its just some food for thought, also I would get. Away from h1 series turbos, from wat I understand they have a less efficient turbine wheel then the hx series, atleast the dsm guys claim they do