Engine/Transmission (1994 - 1998) Holset WH1C

[ALehman]

I know on my 94' that i have a holset WH1C turbo. What is different from this and a HX35. Is it better or worse. I would like to get some info.

 

[JPittinger]

I've been told they are very similar, especially when you compare the performance curves. I called the guys at htturbo with the same question and recommend you do the same; good guys to talk to and I got straight answers. Our trucks don't make as much boost pressure because of less fuel from the 160 pump. I don't think there is any advantage to switching a stock WH1C with a stock HX-35. I almost learned this the hard way.

 

[Howard Durand]

I also have the WH1C turbo which has been modified with the Banks exhaust housing that was included with their Power Pak kit.



With the Banks plate, boost seldom exceeded 20# but the truck handled my 7000# trailer quite well and egt's were not too much of a problem. It didn't come off the line real fast but picked up when the governor began fueling.



My first experiment with changing plates was to try the TST #5. It started a little slow but produced great acceleration which continued throughout the throttle range and boost would peg my 30# gauge. The problem with that was towing. I had to keep a sharp eye on the egt. It came up fast and was hard to avoid under some situations.



Today I installed a #10 and the test drive shows good acceleration from a dead stop up to between 70 and 75 mph where it begins to de-fuel. Boost is much less, max at about 25# but egt is much slower to rise.

The proof will be in how it tows.



Getting back to the issue of this thread, I think the WH1C is more than adequate for the unmodified 160 pump and it can produce plenty of boost with adequate fueling.

 

[DRAG DIESEL]

Our trucks don't make as much boost pressure because of less fuel from the 160 pump.

:-laf I guess your right, i hate my 160 pump, it only lets my big single make about 65psi at WOT. :-laf

 

[ndurbin]

I could hit 32 lbs. with my #10 plate before the 370s. I've been a lil afraid to see how much it well go to with the 370s since i still have the stock head gasket.



Nathan

 

[ALehman]

why did they change to a hx35 for 95 and only run the wh1c for one year

 

[JPittinger]

:-laf I guess your right, i hate my 160 pump, it only lets my big single make about 65psi at WOT. :-laf

How many parts on your 160 are stock besides the nameplate?

 

[Jff24Gordn]

why did they change to a hx35 for 95 and only run the wh1c for one year

Only trucks made before Jan 1 94. That was the emmissions hit that forced cummins to give us the P pump and a cat. The early 94's had the WH1C, i dont theink they had a cat, too.

 

[JKouzez]

my 95 has a wh1c i also thought about switching to a pdr 35, e gaskamp hit 48 psi with his whc1 after installing delivery valves it scared him so its gated down to 40.

 

[ALehman]

i dont theink they had a cat, too.

Thats true mine came without a cat

 

[ndurbin]

mine was built Sept. 1993 and it never had one. not that it would have stuck around long if it did have one.



Nathan

 

[edmeyers]

i hit 36 psi every day or almost every day and i can get 38psi mine has the wh1c and it is most likely well past it's effective range at those levels but oh well =)