Author Topic: Diesel Exhaust:  (Read 4647 times)

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McRat

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Diesel Exhaust:
« on: April 08, 2011, 11:12:39 AM »
 :evil:

I'm sure many of you are tired by now of being bombarded by Stinky Diesel Talk (stinky in more than one way).

But here's something to consider.

We are routed straight back at about 16" off the ground, rear exit with a 4" tube.

When in the LSR staging lanes, there were a lot of complaints, especially when cold, that the air behind our truck was obnoxious/unbreathable.  But unlike many other engines, ours makes more power hot than it does cold, nor will it make much heat at idle.  We have to keep it running in lanes.

In Sled Pulling, and some other forms of diesel competition, straight back exhaust is forbidden, but not because it smells nasty and chokes you.  

A major area of concern is "spitting the wheel".  It is normal for many diesel builds to overspeed the turbocharger.  Why?  There really aren't too many turbos designed to make 50+ PSI of boost within the factory map or shaft RPM.  I monitor the shaft RPM with the help of Garrett, and I stay under the RPM limit, but that is not really typical.

When you overspeed, you can break the main shaft, and the turbine wheel can exit at very high speeds out the exhaust.  These wheels can be nearly the size of your fist and be 1800 deg F.  They have caused injuries in the past.  So they make them run "cross-bolts" in the exhaust (Casper has these), and make us run the exhaust straight up, or aimed away from the crowds.

For the diesel entries, it might actually be safer and more "racer-friendly" to require (or just permit) upward facing exhaust, be it in the hood, or in the bed, which are the normal locations for racing.

Just a thought.  I certainly don't want to change my truck, I like it the way it is, but it might be more logical to outlaw my style of exhaust.
« Last Edit: April 08, 2011, 11:26:38 AM by McRat »

Offline glc311

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Re: Diesel Exhaust:
« Reply #1 on: April 08, 2011, 12:13:04 PM »
I was on Diesel Submarines when I was in the Navy. I LOVE Diesel smoke! It brings back lots of great memories.

McRat

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Re: Diesel Exhaust:
« Reply #2 on: April 08, 2011, 12:20:43 PM »
I was on Diesel Submarines when I was in the Navy. I LOVE Diesel smoke! It brings back lots of great memories.

Not everyone in staging shares your enthusiasm.   :-D 

When we were at a Diesel Drag event that was shared with Junior Dragsters, they actually had the tower make us shut off our engines while in lanes.  It was very difficult to stage with a cold engine.  Couldn't build boost.  At least the LSR folk have never done more than a neighborly "man, that is NASTY" and they understand (I think) when we tell them it takes 20 minutes or more to get up to temp.


Offline Morpheus

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Re: Diesel Exhaust:
« Reply #3 on: April 08, 2011, 08:21:25 PM »
 :?  Why couldn't you have a slip-on 90* elbow and upright stack while in staging area & warmups?

                                                              morpheus

Offline BudJ63

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Re: Diesel Exhaust:
« Reply #4 on: April 08, 2011, 08:37:06 PM »
:?  Why couldn't you have a slip-on 90* elbow and upright stack while in staging area & warmups?

                                                              morpheus

I was thinking the same thing.

McRat

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Re: Diesel Exhaust:
« Reply #5 on: April 08, 2011, 08:40:09 PM »
:?  Why couldn't you have a slip-on 90* elbow and upright stack while in staging area & warmups?

                                                              morpheus

That's a good idea. :cheers:

It does keep us from lowering the tailgate to check the water tank, but that is seldom necessary.

« Last Edit: April 08, 2011, 08:42:28 PM by McRat »

McRat

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Re: Diesel Exhaust:
« Reply #6 on: April 08, 2011, 08:47:56 PM »
Come to think of it, I think I have some 5" high temp hose for dyno stuff.  Make a couple clips so it can be removed without gloves or tools, and just remember to have someone remove it on the start line.

Offline Stainless1

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Re: Diesel Exhaust:
« Reply #7 on: April 08, 2011, 09:58:28 PM »
Don't have to run a diesel to pitch a turbine wheel, but even at 400 MPH the really big ones only travel a hundred yards or so
Stainless
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McRat

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Re: Diesel Exhaust:
« Reply #8 on: April 08, 2011, 11:32:21 PM »
Don't have to run a diesel to pitch a turbine wheel, but even at 400 MPH the really big ones only travel a hundred yards or so

True, you can overspeed a turbo on a gas engine if you can figure out how to run 4 bar+.  But overspeeding is normal in the diesel world. 

Life begins at 50.

PSI that is. :-P

Offline kiwi belly tank

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Re: Diesel Exhaust:
« Reply #9 on: April 08, 2011, 11:45:39 PM »
My business is diesel repair & a few minutes of breathing exhaust fumes from a diesel will give me a killer headache so I'm not happy around a blubbering one either.
You might want to shove a couple of good block heaters in the thing & plug em in to a generator (not diesel) in the back of your support truck. Your race truck & the nabours will appreciate it.
  Sid.

Offline RichFox

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Re: Diesel Exhaust:
« Reply #10 on: April 09, 2011, 12:23:55 AM »
For what it's worth i had the art of turbine tossing pretty well perfected in the late 70s. Using a 270 or 302 GMC gas engine and 2 Corvair turbos we got pretty good at it. Till the junkyards around here ran out of Corvair turbos.

Offline Nortonist 592

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Re: Diesel Exhaust:
« Reply #11 on: April 09, 2011, 03:14:04 AM »
Don't have to run a diesel to pitch a turbine wheel, but even at 400 MPH the really big ones only travel a hundred yards or so

Which is fine if you are standing 101 yards or so away. 
Get off the stove Grandad.  You're too old to be riding the range.