TIII Holset HX35 project.

[Tony Hanna]

I've been at this for awhile now, but I've finally got about everything I need gathered up, so I thought I'd start posting pics.
Here are some random ones of parts, and one of the turbo on the car.

[RJ138]

Nice! Did you weld a bracket for the wastegate on the compressor housing? Looks good!

Did you have really bad fitment issues with the compressor housing? With the Hybrids you can usually get away with just grinding down the little ear of the tranny that it hits.

Just curious as I have a Holset waiting to go on.

[Tony Hanna]

I had a friend weld it. He does good work.
I'm using the stock Holset turbine housing, so in addition to grinding the ear off of the trans, I had to run a 3/8" spacer between the turbo and the manifold. You can see it in the picture. Also I had to rework the shifter cable bracket to drop the selector cable, and cut the stud and a little bit of the nut off of the bobble strut. That's all I've run into so far, but it's still a good way from being ready to fire up.

[2.216VTurbo]

Tony, you have GOT to be single, no way any wife would tolerate turbochargers on the furniture Man I washed some 'sort of greasy' parts in the kitchen sink ONCE I thought I had cleaned it all up ...

[Tony Hanna]

Not single, just extremely lucky.
Tiff's really easy going about stuff like that. Plus it doesn't hurt that the chair is from my old place and in rough shape to start with.

[87glhs232]

LOL, I was going to comment about that as well. Figures its an old chair, my guess is she wouldn't have picked that fabric

Nice parts and work you have there!

[Darkwolf]

LOL, I was going to comment about that as well. Figures its an old chair, my guess is she wouldn't have picked that fabric

1983 was a good year . Hurry up man I want to go to the track.

[Tony Hanna]

LOL, I was going to comment about that as well. Figures its an old chair, my guess is she wouldn't have picked that fabric

Nice parts and work you have there!

I don't know... I have the absolute ugliest couch in existance. The pattern is 70's I mean straight out of Fear and Loathing. I was going to haul it to the dump when we got this place, but she was having none of it. "I don't care what it looks like. It's comfortable so it stays!"

1983 was a good year . Hurry up man I want to go to the track.

Me too, but I'm having a hard time finding motivation. It was too hot to mess with it today. Here in a few I'm gonna run the the 24hr parts store (I still can't get over that! We have a freaking 24hr parts store!!) and pick up some bolts and fittings. Hopefully I can get a fair bit accomplished tonight/morning and then sleep when it starts getting hot.

[Tony Hanna]

A little update on the project. I got the divider in the turbine housing cut back and knife edged today. I also drilled a hole through the divider directly opposite the wastegate hole to help the pressure equalize when the wastegate is open. Hopefully that will kill any possible boost creep issues.
I picked up most of the small parts I'll need when I went to the parts store last night, including a fitting for the oil feed line. I'm going to start on that later this evening. I still need to pick up an O2 sensor bung to weld in the downpipe and a new stud for the exhaust manifold. The old one spun out of the manifold and is "trapped" on the old turbine housing by the nut.

Anybody know what size those studs are? I may run by the parts store again tonight and see about picking up a bolt I can cut off and use as a replacement.
Thanks,
Tony

[Tony Hanna]

Well, it's alive! I don't have any real data on when it starts making boost because well... there's no boost gauge in the car yet.
That's tomorrow's project as well as running it by an exhaust shop to get the downpipe John and I made connected to the exhaust. Just by feel, it seems as though it's going to spool pretty late. The assometer says it starts making decent boost by about 5k. That's a little (about 1000 rpm) later than what I was hoping for, but that could be due to any number of things. I'll know more tomorrow.
One thing I can say, with the HX35 and open downpipe, it sounds like a freaking road tractor.

[Will Martin]

Time to advance the cam timing.

[Tony Hanna]

Time to advance the cam timing.

Yeah, I should probably invest in a set of adjustable gears. I may put the timing belt off until I can afford to do it and the gears at the same time.
Another thought that had crossed my mind was to fool with the cal and set it up to pull a bunch of ignition timing between 0" of vac and about 5 psi. That should help it spool a little quicker too. I've got some ideas I want to try, but they'll have to wait until I have the money. At least it's back together and drivable now.

[Tony Hanna]

Another little update on the project.
Got a boost gauge installed so I can see what's going on. Onset of boost (2 psi) happens at about 3,000 RPM, and it climbs to 7 psi by 4,000 and holds 7 through the rest of the RPM range. I'm hoping I can get that up to 10 psi by 4,000 by fooling with wastegate preload and mbc. That'll be enough for now as I'm still running the stock fuel system. Keep in mind it's also still breathing through the stock exhaust system minus the cat.

I'm real tempted to go for a quick blast with the wastegate line unhooked and the preload cranked up to see what the best case for spoolup would be, but I'm not sure if I'm comfortable relying on cutout to save the engine if I don't lift off of the throttle quick enough.
Any thoughts on that?
Thanks,
Tony

[Darkapollo]

Id say let off by 5500 and you should be fine if the cut off fails.
Thats what I was doing when my tona wasnt tuned. Just to make sure there was nothing about to POP on the way to redline.

[Tony Hanna]

Well, I gave it a try. Boost builds slow enough with the big turbine housing that it's pretty easy to control. With the vac. line off the wastegate, it just does make 10 psi a little above 4000 RPM in second gear. I didn't push it any past that because of road conditions.

I'm not really happy or disappointed with the way it acts. It's about what I expected and was told to expect by others. I'm sure it would act much better with a ported head, nice FMIC, a full 3" exhaust, and some tweaks to the cal and timing to improve spoolup. I plan on doing that eventually, but even then, I doubt it will ever be a very street friendly turbo without swapping turbine housings.

From my limited experience so far, my advice to anybody considering using an HX35 on a stock to mild street car is to do yourself a favor and spend the money on a Bullseye turbine housing.

Tony

[Tony Hanna]

I've got it back apart now to try another idea. Since this is a divided tang housing and is obviously too big, I'm going to try blocking off the side of the turbine housing closest to the center section. I've been reading a thread on another board where others have tried this, and the results look promising. This should cause much quicker spoolup at the expense of a little more backpressure. How much backpressure remains to be seen. My main concern is that the internal wastegate might be a little too small for the effectively smaller turbine housing. With that in mind, I think I'm going to try to transplant the larger wastegate puck from the TIII and open the hole to match.
Hopefully I'll have the housing sorted out tonight and the car back together with some results to post by tomorrow evening.

[Tony Hanna]

Well, I didn't get done, but I did manage to get a good start on things.
I got a 3/8" thick blanking slug made and fit up. I just need to get it welded in. Here's a pic of the slug. Everything looks alot rougher and rustier in the pic for some reason (the slug is freshly ground and shiny). It's also kind of hard to tell from the pic, but the slug is on an angle from the side of the flange down to the divider in the middle. Once it's welded, I plan on smoothing everything up for a nice transition into the open side.

[RJ138]

Nice! I'm curious how it will work out.

[2.216VTurbo]

I'm not sure I follow the theory how reduced inlet size is going to help if the total scroll volume stays the same Sure velocity at that point of the inlet will go up, but will it stay higher into the scroll? Or is that the point of the trial?

[Millerman340]

Well it's said that the split scroll is .55 a/r per side (Not by me) , so if you use only 1 side