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1989 Detroit Diesel 8.2 liter V-8 tuning

March 30, 2011, 12:31:58 pm

Can the old diesel be tuned? Right now we average between 7.8 and 8.9 miles per gallon.
Who, if it can be done, would be the best to take it to. Approximate increase in MPG? Cost?
I know the newer diesels are electronically controlled but is this old turbo-charged model capable of adjustments?

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #1 – March 30, 2011, 12:49:32 pm

Norm,
There's approx. 139,000 BTU's of energy for each gallon of diesel fuel.  Think of this now as 15,400 BTU's per mile traveled @ an average 9 MPG.  Now consider the variants of each mile traveled such as the speed (engine RPM's) grades (gears), winds, weight of fuel & other stuff carried, etc.  Now I think you can begin to see that MPG is a moving target.  If you have a stiff wind head-on you will burn more fuel (BTU's) to get the rig to travel that mile...maybe 20% more fuel (BTU's).
 
The components of a diesel engine that burn the fuel completely (so as to get every single BTU available in that gallon of fuel) is what needs to be fine tuned by that elusive competent diesel technician.  So, turbo gate valve is one item, injector fuel pressure, etc.  the "etc" to be provided by others that know a lot more than I do.
 
What I mean to say is that more than likely, the best thing you can do to squeeze more miles per gallon is to improve your driving habits...drive slower, think of using the brakes less (translates to anticipate coming to a stop & quit using fuel throttle sooner and coast a lot more).  Reason I say this is that your fuel consumption averages seem to be in line with your engine's capabilities.

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #2 – March 30, 2011, 02:35:02 pm

Sure it can be tuned.  But if you are getting  8 to almost 9 mpg with a 8.3, I would say you are in good shape.  But you can do all kinds of things to a diesel as far a power, and also economy.  You want to check out the forum at • Index page.  The guys at Pittsburgh Power are very well known for doing good things with Cummins diesels.  They took a old Cummins Forumla 290 of mine and beefed it up to run side by side, bumper to bumper, on any hill, or red light to redlight, with a Cummins 400 with similiar 80,000 pound load.  And I gained in the mpg field too.  But it all depends on how much money you want to spend, and what exactly you want to accomplish.  And can your transmission and rear end handle it???

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #3 – March 30, 2011, 03:07:04 pm

I drive as if I have an egg between my foot and the foot pedal. I also, once I get up to speed, let up on the pedal and then press down just enough to maintain speed. Getting somewhere in a hurry is not the way to enjoy our travels. We closely monitor coach tire pressures, toad tire pressures, liquids in the tanks, wind direction, take less traveled routes, closely monitor engine temperature, (cold weather is kinda detrimental to MPG) and finally, try to avoid heavy stop and go traffic.

I posted this subject because I do not have anyone else's 8.3 data to compare to. The Detroit Diesel "Fuelsipper" has kind of become in the minority as far as info is concerned.

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #4 – March 30, 2011, 03:08:25 pm

Is it an 8.3 series 50 or an 8.2L. Big difference.

Might watn to speak to these guys:
http://www.expertdiesel.com/82_detroit.htm

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #5 – March 30, 2011, 03:19:32 pm

Boy, was I wrong. Thanks, Dave. It is an 8.2T Detroit with an Allison 4-speed transmission.
Turbocharged V8.

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #6 – March 30, 2011, 03:53:32 pm

Oh my, the dreaded DD Fuel Pincher.  Dave sent you the right place.
http://www.expertdiesel.com/82_detroit.htm

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #7 – March 30, 2011, 04:06:33 pm

I thought so - I really think that those 8.2L Detroits are decent engines that suffer from bad press. Get them to the right people and they can make them right as rain. They may not be fire breathers, but they get their job done when treated right.

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #8 – March 30, 2011, 05:05:44 pm

If you are driving something with an 8.2 in and getting that kind of mileage, I wouldn't mess with it

There is no margin at all for fooling with those motors IMHO

Probably the only thing worse is the Cummins triple nickel in my 1980 ftxred38

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #9 – March 30, 2011, 05:48:08 pm

Well I guess I could share my thoughts here. I have probably defended the GM line of diesels as much as anybody. I have a 5.7L in an olds sedan (yes the hated olds diesel) I have a 6.2L in a suburban and the 8.2L in my coach. My findings with all three of the engines is this: If a repair shop tells you what junk they are they have no idea how to work on them. I have found that all three are good engines if treated right and only taken to competent GM diesel mechanics. I have had no trouble with the 8.2l I have three others in trucks a flat bed GMC, a GMC dump and a Ford tractor. All are the 230hp turbo and do there jobs well. My coach is also running a 230 and I can get 10mpg a 60mph. The KEY to a GM diesel is maintenance. Keep the filters clean and don't overheat it. I agree that expertdiesel is the place to go. good luck!

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #10 – March 30, 2011, 06:31:16 pm

Really, they are not bad engines.  But there are areas you need to watch closely.  Expecially the turbo.

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Re: 1989 Detroit Diesel 8.3 tuning

Reply #11 – March 30, 2011, 10:37:46 pm

The attitude that Mr Holder displays about his GM diesels is a good one and his kind of thinking is why I bought that Triple Nickel powered Foretravel IN SPITE of the fact that NOBODY has anything good to say about that engine, and..... so far, so good!

But I sure won't be pushing my luck looking for much more power out if it.

I agree, keep it maintained and it will probably be fine

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