Yes,comfirmed for sure its a 60/70 turbine wheel.The first H1C on the 89 Dodge cummins has the same size turbine wheel as the hx35 on an 02 (for example).

 

The hy35 can not damage the engine bearings it can give a stock trans/torque convertor issues with lots of fuel though.A bigger turbo with lots of fuel will do the same damage.

 

so your saying from 1k to 2k will cause more damage on my engine than 2k to 3k?

 

The fact that these trucks can make so much torque at low rpms is why we can only run a limited number of transmissions without causing total destruction. I'd think oil pressure would be lower at the lower rpms too, but I've got a dummy guage on mine so I can't say for sure.

 

That is why I said that I'd rather err on the side of a bigger compressor housing than turbine housing. Since the exhaust housing does the driving, there will be reduced lag with a smaller housing.

Has a lot to do with velocity. Think of it as a blow gun. With the tiny hole in the rubber tip, you can blow larger things. But, screw the tip, you have a lot of air flow, but it is not very well directed and has a reduced effect.

I've driven loaded trucks that had the wrong turbine housing before. Extreme lag, excessive EGTs, lots of smoke and no power. The compressor was the correct size, but the wrong exhaust housing. Once it was corrected, no more problems.

 

I can see why you'd rather err on the side of compressor, but the point is that *neither* is a good setup, and BOTH can cause high EGTs, smokiness, and lag. The only difference between a proper compressor with a huge turbine and a huge compressor with a tight housing is that the latter adds surging as well as lag, smoke, etc. Neither is desirable, imo.

IMO, large compressor singles only belong on engines that have been modified to allow much higher RPM ranges. You can only stuff in X amount of mass flow at 40psi at 2700rpm or so. Even a 62mm compressor is plenty to do this.

Obviously, 40psi at 4000rpm is a LOT more air than 40psi at 2700rpm. Thus, you might be able to take advantage of the 60-70lb/min that a larger single might offer.

But if you aren't running an aftermarket cam with fancy springs and such, you can't rev high enough to need the larger flow of a huge single.

The problem is that you run out of PR capability before you run out of mass flow.

That's why twins work so well when properly executed. The PR limitations are removed and both compressors can be dialed into the sweet spots. A good set of twins can run PRs over 7:1 (all but impossible with a single) and have BOTH compressors be in a very efficient area of the compressor map.

 

the original post was made by someone with a manual trans. In skimming through all the responses I didn't see this issue addressed, if so and this is repeat, sorry. any way I just installed a silver 64 on my 5 speed 12 valve. I do have a cam which helps for sure, but the 24 valve head may make up the difference in his application. I live at 5300' and have no problems at all towing my boat around, and we have some good grades on the way back from the lake. I put it on cruise at 80 and never have to worry about it. Egt's will max at around 1200. sure the stocker was better for towing but as infrequently as I tow I can deal with it. I find myself wondering if I went big enough, If I was this guy and had a sweet deal on a 66 I would jump at it in a heart beat, as driving around a turbo's problem areas is very easy with a manual.

A little info for those who care
cruising egt at 80 700-800 on flat ground at around 5000'
boost is 0-5
in fifth gear I have great power from 1800 rpm
might have good power down lower but try to avoid rolling too much smoke, at 1800 in fifth the smoke is minimal as spoolup is very quick from there.
haven't dynoed yet, hope to at the utah diesel nationals.

 

Larger compressor are sometimes beneficial at higher elevations because they can help to partially offset the reduction in air density. With a tight(ish) housing, they can work pretty well.

The problem is that a turbo set up for good performance in thin air will surge like nuts in thicker air at lower elevations...

 

True, but I think it really depends on the truck, how it is setup, used and so forth. Would also depend on how much difference in the optimal setup, vs. a turbo that it a bit big either way. Not to mention the particular charger chosen.

Doesn't a large compressor with too small of turbine housing cause surging, and not so much of a small comp with a large turbine? I would think that putting a 66/12 together would be the worst setup to try.

My 64/14 works great for me. I didn't get the 12 housing because I was concerned with surging and the higher RPMs I run having 4.10 gears. If I had 3.55 gears, a 12 might make more sense, since I would be cruising at lower RPMs. Lag would be horrible then. I do have some lag, but I've learned how to drive the truck so it is very minimal.

NO EGT issues and haven't found a hill big enough around here or in MO to slow me down yet. Just runs like a raped ape.

Going from a HX40 (60/16) to the 64/14 is the best move I've made yet. Lag is similar, can control the smoke at will and no longer have EGT issues. The 40 was fine empty, couldn't control the EGTs towing at all, let alone I had constant smoke at 20+ boost pulling hills or light accel. This setup can run clean towing heavy.

66 and larger compressors for sure. The 64 still works good if you have enough fuel and intake/exhaust mods. Cam or not. Do have one in the plans, though. F1 or PDR.