A lot of people are very happy with the H1C and a 16 cm housing. Ball bearings you don't need. I have a wastegated 12 cm housing on my truck, I love how quickly it spools up. Wastegated housings allow you to run a smaller exhaust housing for better spoolup while not overspeeding the turbo at high RPM and load.

Not really. There are directions on porting the exhaust manifold and turbine housing floating around somewhere, though.

 

So wannadiesel, do you suggest a wastegated turbo then? Do I need it with the 16cm? Would it allow me to run more boost safely?

 

The wastegate is in the turbine housing, so you can't run it with a 16 cm housing. Your choices for wastegated housings are 12 cm and 14 cm. 14 cm is really expensive, 12 cm you can find for under $100 used. If you go through with your manual trans conversion a small housing on the H1C is a bad idea because the turbo surges at low RPM and heavy load. It's not a problem on automatics because they don't load the engine as hard at low RPM. I had to replace my H1C to cure this problem on my truck.

I'm making 30 psi with stock injectors, max EGT so far is 1,000.

The 16 cm housing is adequate for what you're doing and is the simplest solution, I drive in traffic all the time and prefer the very fast spoolup of the 12 cm housing.

 

Understood, thanks. I see that you state the silencer ring on your mods. I heard the new ones having the silencer rigns, do the first gens have them too?

 

'89-'93 trucks don't have silencer rings. My turbo is off a '94. I had to change turbos to one that was designed to work with a 12 cm housing to cure the surging I mentioned earlier.

 

Ahhhhhh ok.

 

With the fuel mods you are planning, the H1C with a 16 will eventually give out, mine started chirping and barking, and all the noises. If you buy a 16 housing, it wont go to waste, you can use it on another turbo or sell it. I would eventually plan on an HX 40 or a custom PDR or one like I have.

 

HX40 Hmmm ok. Why does it give out? You say about the fuel, does so much fuel put too much of a load on the axial bearing shaft? Or does the extra fuel create it to be too hot for the turbine?

 

We blow 'em up by spinning them too fast or by barking them. Barking is when you get off the gas real fast at high boost, the turbo makes a bark sound. When barking the turbo is slowed down very quickly, and over time the shaft will snap. I would not recommend an HX-40 because it is more prone to damage from barking than a stock turbo. A hybrid like Frostie has is a less expensive and more robust fix. His turbo is a stock turbo with the compressor side of an HX-40 grafted. This allows the turbo to spin slower for a given amount of airflow, which is easier on the turbo.

 

I am assuming "grafting" is labor intensive? At what point does it make more sense to just go buy a new turbo that is wastegated? By your definition wannadiesel, wouldnt a wastegate prevent barking?

If I cant afford a new or custom turbo right now, can I still get a 16cm housing and would it be last for a while? I am not doing any drag racing or truck pulls, just an occasional 16ft camper. I only use the power when I need it. Now I am a little cautious about changing the turbo.

Also, my truck starts quick, meaning it usually doesnt crank over one cycle and it fires to life. Will any of these mods change that? I love the Cummins for its dependiblity, will the mods above change that to a certian extent?

 

HTT sells a bolt-on kit that makes the H1C into a hybrid. Wastegated or not is a seperate issue. The wastegate allows a small housing for quick spoolup while not overspeeding the turbo at high RPM and load. Barking and overspeeding are different things. When you jump off the gas and there's 30 psi in the manifold, that air has to go somewhere. The engine doesn't need it anymore, so the air flows back out the compressor, making a bark noise and slowing the turbo very quickly. Before I changed my intake duct, barking the turbo would blow the stock duct off the BHAF.

The H1C with a 16 cm housing will be fine for now, you'll have to decide when it's time to upgrade based on the EGT and your budget.

It'll still start right up. Nothing you've mentioned doing to the truck will affect its dependability or driveability in a negative way. Other than you will burn out the stock automatic eventually...

 

Well the stock tranny said good night last week, so now its time for the NV4500. Hence the reason I finally get to beef the old Dodge up. Isnt there something called a blow off valve?

 

Yeah, nobody seems to use those on diesels though, they're unneccessary because there's no throttle plate. Barking is easily avoided, just roll off the gas instead of jumping off it. It's just that in the heat of competition it's easy to forget when trying to shift quickly.

 

I see the light at the end of the tunnel now, whew that was close.

 

Learning curve's a little steep at first, isn't it?