HX35 Rebuilt and Installed

[jbolt]

Well so far so good (knock on wood, cross your fingers)Oo.



Rebuild was very easy to do. Fortunately all the parts had balance marks on them so I'm 99% sure all is good. It took longer to clean every thing than to rebuild and install. Bolted it up to my 16cm housing and took it for a test drive. I think it is going to be a very nice improvemnet.



Has a wild wistle to it. Sounds like a jet engine spooling up.



The turbo surging is gone, at least the low end surging. Haven't had it over 20psi yet until it gets some breaking time, but boy will it build boost quick.



Now I think I'll need more fuel



The turbo was from a 98. 5 24 valve w/12cm housing and had about 80k on it. I picked it up from a fellow TDR member for $200 and spent $65 on the rebuild kit.



Jay

 

[Philip]

So you going to have it broke in by tomorrow so we can have the full report? All you need to do is drive all night. Then post back tomorrow morning.

 

[formula]

Originally posted by jbolt

Has a wild wistle to it. Sounds like a jet engine spooling up.

Great sound eh



What was involved in the rebuild? Got any pictures?



Sean

 

[jbolt]

Ya know I meant to take pictures but I didn't.



The rebuild is very staright forward. Holset has all the service and repair manuals online for download. They do a great job of walking you through the dissasembly and reassembly of the turbo.



Depending on the age of the turbo they can be balanced differently. One method, used on older turbos I'm told, balances the turbine (hot end & shaft), thrust washer, oil slinger and compressor wheel out of the center section. Each component has a small alignment mark for assembly.



The other method balances the whole assembly in the center section. There are no alignment marks and this would have to be balanced by a shop with the right equipment.



The hardest part to do was removing the snap rings that hold the journal bearings in place. They have a 1mm hole and the inner snap rings are too deep for standard snap ring pliers. I ended up grinding down the tips of an old pair of needle nose pliers.



The most nerve racking part is taking it for the test drive.

 

[Philip]

jbolt a set of hemostats are good to use for snap ring also. They are made of stainless steel. If you need to grind down to a small size. Then they are stronger than a set of neele nose pliers ground down.



They run around $1 here at the flea markets/junk sales. I keep a selection of curved and straight tips in different sizes for jobs like that.

 

[Old Smoky]

I just rebuilt my turbo and jbolt is right, it’s pretty easy. To remove the journal bearing snap rigs I ground down both ends of two nails so that they would fit into my snap ring pliers and into the small holes in the snap rings. It worked very well. I also downloaded the repair manual from Holsets website, it’s a great resource.



The rebuild kit comes with everything needed. Thrust bearing, journal bearings, snap rings, cap screws, seals, gaskets, etc. I got upgraded journal bearings. Theses allow for better lubrication, which I thought was very important running at nearly 3X the stock boost pressure (rpm).



I had the turbo rotor balanced to Holset specs since I used a different compressor wheel. It wasn't too far off, but it is well worth the money as insurance.



Mike

 

[jbolt]

Philip- thanks for the tip. Never would have thought of that.



Mike- What did the balancing cost? I tried grinding some tips for my snap ring pliers too but they are of the cheap variaty and would cross up. So what is your hybrid turbo assembled from?



Jay

 

[R.E. Miller]

Arrrgh, I would like to have the HX-35 singing under my hood too, those WH1-C's are quite shy compared to the new ones.



Russell

 

[Old Smoky]

Jay,

I think the balancing was about $25. I had to send it to a turbo shop to have it done. My turbo is uses a rebuilt H1C center housing with upgraded bearings, a port matched 16cm2 exhaust housing, and a 60mm compressor impeller which is supposedly the largest available for the HX40 or H1E, and housing to match. It doesn’t have the capability of having a silencer ring, so it whistles pretty good. If I remember right everything cost me about $325.



As I understand it, the H1C and HX35 are quite similar. They use the same turbine wheel, but a slightly different compressor wheel. The bearing housing is constructed similarly.



Mike

 

[jbolt]

Hey Mike- FYI the HX35 center section is quite different from the H1C. The HX35 is fatter and the flange that the compressor housing attaches to is cast as part of the center section. I'd bet that the trubine is the same from the looks of the two.



The H1C has a bolt on flange so I'm guesssing you were able to use one from a larger tubo that bolted up? Very clever. How is the performance? Is the larger compressor housing outlet the same size as the H1C?



$25 for the balancing is great. The two local shops to me had a 1 hour shop min of about $90. Keeping my fingers crossed.



Jay

 

[R.E. Miller]

Hey, can one of you guys give me a contact? That sounds like a really cool modification, and not too costly at that.

Thanks,

Russell

 

[MCummings]

Did you leave the Silencer ring in it ?

 

[Old Smoky]

Jay,

Didn't mean to sound like the bearing housings were the same, just not a COMPLETELY different animal. I was told that the turbine wheels are the same, however. I thought I would have to replace the diffuser to match the back face of the new compressor wheel, but they match right up. The outlet flange is the same size as the factory flange, so it matches right up too.



I am happy with it. To be completely honest I thought I would gain more boost. Boost is up a few pounds on the top end (haven't tested it real hard) and cruising pressure is up a little too. Throttle response is better. It seems to produce more boost in lower gears before the governor kicks in. For instance, if I could hit 22psi in 3rd before, now I can get about 26psi. It doesn't have a silencer ring, but is by no means annoying.



Russell,

I bought the hybrid kit and rebuild kit from Mountain West Turbo & Supply (email - -- email address removed --). They are great to work with, and answered my seemingly endless questions. If you want the upgraded bearings you have to specify (extra $25). This kit can be found on ebay. I don’t know if there are any up for auction right now, but they will sell you one if you email them. Everyone who I have talked to that has done this conversion has been happy with the results. From what I have heard I would recommend a PDR turbo if the funds are available. If not, this is good too.



Mike

 

[jbolt]

Originally posted by MCummings

Did you leave the Silencer ring in it ?

Silencer ring? What silencer ring?







Mike- Ok, I got the impression you thought they were almost the same. Nooooo Problem





OK, had a chance to "flog" the turbo today. WOT uphill in forth I maxed out a 28psi. Truck accelerated through 90 mph uphill but as the speed went over 82-83 mph the boost level started to drop even though I was still accelerating. EGTs never got over 1050. On the flats WOT I never saw more than 23psi, 900 EGTs up to 100mph.



At 70-75mph on the flats boost is only 4psi, rpms around 1700. I get no smoke on acceleration when at highway speeds which leads me to believe I'm not pushing enough fuel for the supplied air. My fuel screw is back at the stock position right now.



Acceleration from a stop is much better. Turbo lag is reduced and it will hit 20 psi in a couple of seconds. I get a puff of smoke and then it clears up.



Best of all- No Surging! Oo.



Jay

 

[Old Smoky]

Jay,

Good to hear that it's working well for you.



Mike