No need for Catalytic?
Former Vendor
Joined: Mar 2004
Posts: 4,362
Likes: 3
From: Hendersonville, NC
No harm done, no offense taken, we will move on 
That is a valid argument. I did not agree that the variable vane design played a roll in requiring backpressure, but by that token that would apply for any turbocharger, and makes sense.
The engine that is in my truck now is running about 34 lbs of boost with a straight pipe- no cat, no muffler. This will jump to about 38 or 39 when the water injection is on. So far, it hasn't had any problems, however the engine only has about 7000 miles on it, so it is too early to tell. Time will tell how durable the bearings and components are in these, I suppose. As far as bearings go, I do believe that we have an advantage on our side, with solid free-float bearings instead of the old babbit design in the Holsets on the Cummins (I don't know if the new Cummins uses them or not.)
IMO you are right about removal of the cat possibly causing durability issues, I just simply do not believe it has any effect on the EBPS or any other computer-controlled function.
Originally Posted by Customz
A turbo with too little backpressure will:
Spool up faster, push more volume at slightly higher velocities and rotate faster than designed. This is excellent for horsepower/torque numbers but bad news for bearings and rotating assembies in your turbo.
Spool up faster, push more volume at slightly higher velocities and rotate faster than designed. This is excellent for horsepower/torque numbers but bad news for bearings and rotating assembies in your turbo.
The engine that is in my truck now is running about 34 lbs of boost with a straight pipe- no cat, no muffler. This will jump to about 38 or 39 when the water injection is on. So far, it hasn't had any problems, however the engine only has about 7000 miles on it, so it is too early to tell. Time will tell how durable the bearings and components are in these, I suppose. As far as bearings go, I do believe that we have an advantage on our side, with solid free-float bearings instead of the old babbit design in the Holsets on the Cummins (I don't know if the new Cummins uses them or not.)
IMO you are right about removal of the cat possibly causing durability issues, I just simply do not believe it has any effect on the EBPS or any other computer-controlled function.
Mountain Pass
Joined: Jan 2004
Posts: 110
Likes: 0
From: Oregon
Originally Posted by Customz
A turbo with too little backpressure will:
Spool up faster, push more volume at slightly higher velocities and rotate faster than designed. This is excellent for horsepower/torque numbers but bad news for bearings and rotating assembies in your turbo.
Spool up faster, push more volume at slightly higher velocities and rotate faster than designed. This is excellent for horsepower/torque numbers but bad news for bearings and rotating assembies in your turbo.
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