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8.2 DD V8 plus resonator ??

February 19, 2013, 12:25:43 pm

All the discussions regarding adding resonators, plus improvements in power and MPG has got me wondering if it would be worth it to put a resonator on our '89 Detroit Diesel turbo-charged V8 with the 4" exhaust. Possibly the Aero AT4040Xl? Or would a 5050 be better?

The reasons for considering this? HP is on the low side, "git-up-and-go" is a little low, MPG is around 8.5 towing a 1996 two wheel drive Tracker convertible with standard shift, and finally, any possible improvement in MPG at current fuel prices will definitely improve payback and allow us to travel a bit more.

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Re: 8.2 DD V8 plus resonator ??

Reply #1 – February 19, 2013, 12:44:23 pm

All the little things like exhaust, clean air cleaner, tire air pressure, proper front end alignment and perhaps the most important factor, speed can add up to a significant increase in mileage. Stock exhaust can be restrictive so how about input from owners that have made the change to the less restrictive mufflers/resonators?

Pierce

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Re: 8.2 DD V8 plus resonator ??

Reply #2 – February 19, 2013, 12:52:45 pm

The answer really starts with your current muffler.  Many Foretravels came with a well-larger than required (measured in CFM at a certain restriction) by the engine manufacturer.

If yours well exceeds the flow rate of your engine, you will gain little by going to an even freer-flowing system.

Of course, if your present muffler is a restriction, then you WILL gain by going to a freer-flowing system.

No "one answer fits all".

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Re: 8.2 DD V8 plus resonator ??

Reply #3 – February 19, 2013, 01:22:07 pm

Diesels are basically air compressors, where air in and air out are very important. 

But with your Detroit Diesel 8.2, you want to be very careful.  The DD 8.2 is notorious for blowing head gaskets, especially the turbo charged version. Anything that increases cylinder pressure will increase the probability of blowing a head gasket. It is an inherent design problem. There are four bolts around each cylinder and they do not provide the clamping pressure necessary. DD did an interim fix of upgrading the size and strength of the head bolts but it was not sufficient to correct the basic problem.  So as long as it is running well -  leave it alone!!!

You will find lots of info at 8.2 Detroit Diesel - Diesel Forum - TheDieselStop.com.

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Re: 8.2 DD V8 plus resonator ??

Reply #4 – February 19, 2013, 02:36:46 pm

WOW, thanks Pat.

Engine runs great now and don't need it to blow so guess I will leave it alone.

I plan on driving with tail winds, max inflation on tires, front end was aligned at FOT, not exceed 56MPH, pedal pressure as if a rotten, thin walled duck egg between accelerator pedal and foot, and drive downhill wherever possible! Air cleaner gets serviced or changed every spring. Storage compartments are never full. Waste water tanks are always emptied.
Years ago, when I was driving 180 miles from school to home I would get up to speed, then let up on pedal and then slowly push it down just enough to retain speed. (back then we had carburators) Didn't use speed control (DIDN'T HAVE ONE). Smooth even starts and coast to a stop minimizing brake usage wherever possible.

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Re: 8.2 DD V8 plus resonator ??

Reply #5 – February 19, 2013, 11:11:06 pm

Nitehawk,
 You are not going to blow your engine by reducing back pressure. I run a 5" open exhaust on my 8.2 and a K&N air filter. My engine has over 300k miles and purrs along beautifully. The better airflow through the engine the better it will run; to a point of course.

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Re: 8.2 DD V8 plus resonator ??

Reply #6 – February 20, 2013, 02:20:08 pm

Blowing a engine and blowing a head gasket are two different things.  I'm just saying that one wants to be careful with what they do when building up that particular engine. 

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Reply #7 – February 20, 2013, 04:00:21 pm

Makes me kinda wonder what happens as the muffler interior deteriorates and backpressure becomes less. Do I then plan on the engine going to hell?

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