Edwin, you should use some care here......if you have an unbalanced or poorly balanced assembly then you're asking for the rarely heard but always entertaining.......
BOOM..RATTLE...CLANK....GRIND....

I'd REALLY hate to see you push high speed metal into the intake manifold...and it has and can happen, even to a truck with an IC too...

pb...

edit: BTW, if you are running a gated 12cm you should set the opening to roughly 20 - 23psi. By the time it actually gets to the "fully open" state you'll already be into the high 20's for boost pressure...depending on your fueling...and that pressure is at/beyond the map for the turbo you're using.

pb..

 

What does the term MAP mean? According to what I've read elsewhere the stock H1C gets up to 25 PSI max boost. I also have heard that 35 PSI boost isn't unreasonable.

However my basic desire is to get more boost earlier which the 12 cm WG housing provides. I've also been told that the WH1C is a much better choice because the H1C had surge problems.

I plan to assemble the WH1C compressor wheel on my H1C shaft and then spin the assembly with air to see how bad it vibrates. If it seems OK then I'll assemble the whole thing and run it on the truck. I understand that an unbalanced wheel can cause premature bearing failure but hopefully I'll detect that before major damage happens. The wheels are balanced now so I don't see any major problem simply switching it to a different shaft. I could be wrong but I'll know that before I put the unit on the truck. If push comes to shove I can just put the 12cm WG housing on the H1C and get better performance until I get the funds to buy a better turbo.

Thanks for your advise.

Edwin

 

MAP=Manifold Absolute Pressure. The MAP width of a turbo is the gamut of psi readings that a particular turbo is designed to operate efficiently in. Outside the mapwidth, the turbo begins super heating the air as it compresses it, leading to very high egt. I think the Pastor is saying that our little early h1c's begin to loose efficiency above 25psi or so---they'll spin that fast if you push them there, but you'll pay the price with unnecessarily hot air at the intake of the engine which pretty much defeats the purpose of adding more air. As for swapping and balancing turbo parts...that's outta my league. I do know that those little pinwheels spin in excess of 100,000 rpm under full boost...
g

 

I was looking to run it probably at the max of 25 PSI which seems to be where it is set to open now but I need a better gauge to hook up to see where it's at. It seems to me that the WG should be fully open with 25 PSI at the diaphram. Is that correct?

The RPM numbers I've heard are up to 140,000 but this is a learning experience for me and I have a backup to put things back the way they are if it vibrates to badly. It seems to me that the wheels are balanced of themselves so it doesn't matter what shaft they are on IMHO. The balance also gets more critical the further it is from the center of rotation so the shaft plays very little part in the scheme of things.

Time will tell. I may go spin the thing as it is and see how badly the melted turbine wheel does. Just for fun. Besides I like to hear the sound.

Edwin

 

The H1c was ballanced as a unit from the factory where the hx35 and I think the wh1c were ballanced piece by piece. I think the wh1c compressor wheel is 56mm in dia and the H1C is 54mm. The shaft diameters could be different.

 

Edwin, you won't get it spinning fast enough with compressed air to check for wobble.
Shaft dias should be the same for the H1Cs.
I think the wheels on the H1C and WH1C are the same.
I'm running a W housing on an H turbo and it seems fine. I easilt get over 30 psi...and that maxes my guage...I need to get a bigger one I guess...duh.
Jay

 

As DJ said, the WH1C's are balanced as an assembly.

If you spin it with compressed air you MUST have oil pressure to the turbo or you will destroy the bearings. And wear safety glasses.

You may get lucky and the H1C has the same size wheel as the WH1C, then you can just swap housings. According to HTT the 1 ton trucks have a bigger wheel than the 3/4 tons.

On my truck with a WH1C the EGT was not positively influenced by high boost pressure (over 30 PSI). You will have to see how your truck responds. Leave the wastegate alone until you see how it runs. If it's too hot, try increasing the boost to see if it helps, hurts, or is innefective. I would limit boost to 35 psi to make sure you don't blow the turbo by overspeeding.

 

Just for fun, I spun the toasted turbine wheel with compressed air today. It got up to several thoudsand RPM's I think. It was screaming pretty good but nowhere near as fast as it could. Curiously it didn't vibrate at all. I wasn't worried about the bearings since they still had some oil on them.

I think the WH1C compressor wheel is larger than the H1C but the turbine wheels are the same. If the compressor wheels are the same then I can just change housings on my turbo but I think I will need to change the compressor wheel. That's the only reason I was worried about balance but if the wheels are balanced separately then it should be no problem. Got to gather a few more parts before I attempt the change over though. Stay tuned...

I welcome all of your advise. I feel like I'm halfway to being a turbo mechanic from the education I've gotten here. I also found the manual on the Holset site in .pdf format.


Edwin

 

for what it's worth, i ran a definitely unbalanced wheel (it had 1mm cut off the backside) for almost a week with no problems. other than the pucker factor. as soon as i found out that was a bad idea, i ordered a 60mm wheel from htt and put it on myself. no balancing or anything. been running it for a while with absolutely no problems. i was told by htt that the failure rate was NOT higher doing it this way. anyway, these things sure sound cool when you run em on air, huh? i've been working on getting a gas turbine engine together for a bit and have had some fun.

dave

 

That was MY thoughts. Glad to have some confirmation. Since the wheels are balanced independently the shaft has very little effect on balance.

Edwin

 

Edwin,
I put a pic of the new setup in my photo gallery. Don't laugh at the blue color...I'm not sure I like it either...may take some getting used to.
I can't give any performance info yet....I blew the pipe out of one of the hose clamps on my first run....the dog really didn't like that!!


I'll take it for another run later on today and let you know.
Jay

 

OK, I didn't laugh.

I was thinking if I grind off the flange on the WH1C compressor housing then I can use a 2.5 inch to 2 inch reducer boot to mate up to my current crossover pipe. Hopefully I won't have to much of an issue with the restriction. I'm wondering where you got the parts to do your hookup.

Let me know when you start cranking the fuel up.

Edwin

 

Edwin,
I used a 2 1/2 inch end on the compressor side without grinding off the flange....it WILL fit over...I used some dishwashing liquid soap as a lubricant and it slid right on.
Then clamp BEHIND the flange...and behind the flange on the crossover end as well.

My fuel is cranked up pretty good right now....ran fine on the way to work this am...but I didn't put my foot into it....didn't want to risk blowing a clamp off in the dark and rain.....
I'll give it a good test tonight on the ride home.

I bought all my hose adapters, clamps and tubing thru road race engineering.

Jay

 

Your crossover is a lot bigger than mine. here's a pic of mine currently so I was wondering how you came by yours.

 

Yep...that's the stock set-up...mine looked like that sunday morning

It was fabbed from 3 inch intake tube from Road Race

Jay