My 93 is an everyday driver. Would like alittle more pep and power, but am worried about mileage.
I've done a bit of searching and am wondering if I would do better with a 16cm2 exhaust housing or try to find a WH1C? I do occasionally pull a 30' gooseneck with tractor or D5 Cat or such.
Again, not looking for 300 hp/800lb tq, as if I need to pull something that big, I will just climb into my Peterbuilt with 3406 Cat.

Thanks
Virgil

 

You can do some adjustments to the AFC spring and turn the cone to a deeper setting if it is in the minimum setting. I think the sticky has info on this.

You can turn the full fuel screw in a turn or two. If MPG suffers, you can always turn it back to where it was. It shouldnt affect MPGs if your injectors are up to par (need to remove them and test on a stand for that- the Nutcracker method only picks out REALLY bad sticks, and if they arent all evenly bad).

As for the turbo, I'd pass on the WH1C and go for either an HX35, or get a impellar housing/ wheel upgrade from HTT, GIllette Diesel, et al. The 16cm housing may or may not be worth the money since you have an 18 already. I towed with a PDR HX35 and a 18 and did just fine to a point (no intercooler, so no matter what turbo I ran, 28-30psi was about all the boost I'd be able to use towing).

Daniel

 

Mileage is completely controlled by your right foot.

Do you have a stick or an auto? Do you drive mostly in town or out on the highway?

 

Thanks for the replies.
I drive mostly on the highway, truck has a NV4500 and 3.42 (GM rearend) gears

 

You would do fine with a 16 cm housing, but it won't make a huge difference. A WH1C or HX-35 with a 12 cm housing will make it into a totally different truck.

 

Thanks again for the replies. I guess I need to read "Cummins Turbos for Dummies" as I have dealt with mostly GM stuff. Truck is a 350 2wd. I don't understand enough about 60 mm compressor wheels, etc.
Will turn the fuel up a bit, and go to a piston type lift pump.
One other ? my turbo has no play, so would I be able to bolt on a 12cm2 housing from an HX35 to keep from changing the whole thing? I understand it will help with throttle response, but will it hurt when towing? I see I can get a new 16cm2 housing for about $150 so that may be the way I go. So many options.....

 

No real need for the piston pump just yet.

You can put a 12 cm housing on your H1C, but you will get a compressor surge at low RPM and high boost. I'd recommend swapping on the whole turbo, or getting a compressor upgrade like the HTT Stage III at the same time as the 12 cm housing.

On an intercooled truck with stock injectors and a 5 speed, the 12 cm housing can't be beat. It really makes it a whole different truck. You can't get enough fuel through the stock injectors for the 12 cm to be restrictive.

 

I guess that would explain why my pyro never goes above 1000. I think I saw it hit 1100 once before the intercooler swap. Wonder how much difference that fuel screw mod will make? Hmm...

 

Guess I will keep a lookout for a reasonably priced WH1C or HX35.

Thanks,
Virgil

 

If your turbo has no slack, I'd keep the cartridge (center part with the wheels on it, good bearings in the center), and just go for a bigger impellar side and smaller hot side, as you need to. Or, you can cut your own MWE slots to prevent surge with the 12cm housing, stock cold side. HTT stage 3 or 4 kit- $250-300. 12cm housing- free (ok, pay shipping), no more than $50. You'll have a better turbo than an HX35 or WH1C.

You have a pyro and boost gauge, right?

DP

 

Issopro Pyro and boost are on order. How do I go about the MWE slots? Also, after I get a base with the pyro and boost, then I will probably go to 4" exhaust.
Thanks

 

Go with the 4" exhaust anyway. Keep hanging around here, and you'll be glad you did.

I have never attempted the MWE slots, but Greenleaf has cut a few, and it looks quite easy. I looked on my new (to me) turbo, and it has a slit in the housing, going around the radius of the opening, about 1/4-3/8 inch inside from the edge of the plane of the turbine blades. This allows air to escape when surge conditions come on. Rather than fluttering, barking, (whatever you want to call it), the air just goes out the slot and back into the intake hose.

DP

 

12cm housing- free (ok, pay shipping), no more than $50

Where can you find these elusive 12cm housings?