Diesel Tuners

[Bob_Vaughn]

I received an email and video from Trailer Life about Bully Dog GT tuners for diesel engines. It all sounds good but I have been warned that the warranty would be voided if I use a tuner. Now I wonder if this is true. If so then I guess I will have to wait until my warranty is up. It is 699 bucks and I wonder if there is enough of a fuel economy savings to ever break even?

[AH64ID]

Based on OEM timing profiles, for emissions, you can increase the power even on the newest of engines and make more power at a lower EGT. They are close to tapped out, especially at upper rpms but at low/mid rpms a fair amount of additional power can be made. Mid range is where we want power anyhow.

[TXiceman]

The purpose of the turbo on the diesel is to stuff more air in the cylinder which means you can stuff more fuel into the cylinder and get more power. Doing all of this will increase the EGT to the point if unchecked, the engine will reach melt down.

The newer engines have pretty well been maxed out with the manufacturers tuning and emissions controls. The old 7.3L Ford and the 5.9L Cummins had some room for tuning and could take the extra pressures and fuel.

Ken

[wilber1]

Turtle n Peeps wrote:

GoPackGo wrote:
"On a diesel engine the turbo is on there to just keep EGT and emissions in check."This is the first time I have ever seen a statement like this. Turbos have been used on diesels since forever to boost HP - John Deere tractors, semi's, etc. Long before there were any emissions standards at all.

In fact, possibly the coolest diesel car in existance - the Audi R18 Le Mans racer, gets approx 500 HP from a 3.7L turbo V-6. I doubt that the turbo is on there for emissions reasons.

I'm really not trying to be argumentative as I assume there's a little more to your statement. I'd really like to know what you mean.

Tim

You missed the EGT part Tim. Let me try to explain:

I can add a lot of fuel to a diesel to make a lot of power. Past a certain point the combustion chamber and everything in it will get too hot and fail. Pistons melt, rings get red hot and head gaskets burn.

The turbo is there to prevent that and it adds air to clean up emissions. The more boost you add the cooler the EGT will become because you are adding air to cool things off.

Here is a discussion about turbo boost on diesels. It does a better job of explaining it.

My point is, there is a big difference between a turbo on a gasoline engine and a diesel engine.

While it is true excess boost can cool exhaust gasses and a diesel doesn't need the precise mixture control of a gas engine, both need more fuel to make more power and more fuel doesn't burn without more air.

[Bamaman11]

If you'd post your year, brand and model of your tow truck, you'll get a very good answer.

I have one of the last 7.3 PowerStrokes made, and I have a tuner with a 60 tow mode and an 80 hp econo mode. My truck's low mileage and it's an incredible performer. It was worth the cost in my situation.

But the new model diesels probably don't have any need for more power than they have.

[rxr]

A turbo is on most diesels to help the pressure in the cylinder. There are naturally aspirated (non turbo) diesels out there but they are limited by how much air they can pull in. The only things a turbo does is that it helps increase the pressure in the cylinder which then allows more fuel because there is more air (via the pressure from the turbo) so naturally more fuel is needed to maintain the proper ratios. This is true for gas and diesel engines. Gas engines usually run well at lower pressures (non Turbo/naturally aspirated) because they have an ignition source (spark plugs) where diesels (a more stable fuel with a different flash point) use pressure / heat / timed fuel injection to go "bang".

EGR (Exhaust Gas recycling) was introduces on diesels in the mid 2000's as a way of filling some of the space in the cylinder space with inert gas (does not burn/no air) to maintain pressure. Because some of the space is used there is less room for the fuel/air mixture. Now the engine uses less fuel/air per stroke. Less air because of the EGR means the fuel air mixture takes less fuel) this also helps keeps the cylinder temps down as it burns a little less fuel per stroke. Lower cylinder temps help keep the engine from producing some of the emission problems that form with high cylinder temps, specifically NOX. This introduces another concern.

Now many feel that feeding an engine (specifically diesels) being fed it's own exhaust is not just inert gas but also soot etc. as a diesel is not know to burn cleanly - simply put - there is soot in the exhaust.

Take the Emissions off and increase pressure (also fuel) with no EGR you are now feeding an engine clean air and ,some say, making each power stroke have a full fuel/air mixture makes engine run better/as designed etc. (this is part of why Cummins went from a 5.9 to the 6.7 but that is a totally different discussion) Now there is the possibility of raising or exceeding the safe limits of EGTs (Exhaust Ga Temp) which can be a very bad thing.

I am not going to get into why a turbo charged engine has an intercooler but in general cool in the combustion chamber does not cool an engine.

Tuners on the engine gives the tuner or owner control of many parameters of how an engine runs so it is often recommended that if you change the stock parameters you get gauges of some type to monitor you engine to help prevent some obviously expensive problems.

I hope the OP will take a some time to do some more research.

good luck

[Turtle_n_Peeps]

GoPackGo wrote:
"On a diesel engine the turbo is on there to just keep EGT and emissions in check."This is the first time I have ever seen a statement like this. Turbos have been used on diesels since forever to boost HP - John Deere tractors, semi's, etc. Long before there were any emissions standards at all.

In fact, possibly the coolest diesel car in existance - the Audi R18 Le Mans racer, gets approx 500 HP from a 3.7L turbo V-6. I doubt that the turbo is on there for emissions reasons.

I'm really not trying to be argumentative as I assume there's a little more to your statement. I'd really like to know what you mean.

Tim

You missed the EGT part Tim. Let me try to explain:

I can add a lot of fuel to a diesel to make a lot of power. Past a certain point the combustion chamber and everything in it will get too hot and fail. Pistons melt, rings get red hot and head gaskets burn.

The turbo is there to prevent that and it adds air to clean up emissions. The more boost you add the cooler the EGT will become because you are adding air to cool things off.

Here is a discussion about turbo boost on diesels. It does a better job of explaining it.

My point is, there is a big difference between a turbo on a gasoline engine and a diesel engine.

[Hank85713]

The best place to ask a question like this is on the site for the particular vehicle you have. Tuners do help, but it all depends on what you are wanting it for. I run a hypertek economiser, its a 1 tune that is added and thats it. It does seem to help on my diesel ford. I added a mikes/sct tune to my rv and it definitely helps. I am not looking for milage increases although both seem to have given one. The diesel is much more responsive with and without towing milage went up maybe 1 mpg but overall performance is so much better. We run 80mph non tow and around 19 mpg (2350 rpm), for the rv I got 9+ at 70 crossing nebraska this summer. got 8+ in colorado mountains. so yes it did help and it improved the manners of the v10 significantly.

So go to your site of choice, explain what you have, what you want and then ask them to give you the pros-cons of a particular tuner. BD and some of the others have some downsides, most are recommending other brands with live tune. Just remember many are against tuners, improved air intake systems etc, yet trailer life and motorhome magazines have positive reviews on these installs.

[wilber1]

GoPackGo wrote:
"On a diesel engine the turbo is on there to just keep EGT and emissions in check."

This is the first time I have ever seen a statement like this. Turbos have been used on diesels since forever to boost HP - John Deere tractors, semi's, etc. Long before there were any emissions standards at all.

In fact, possibly the coolest diesel car in existance - the Audi R18 Le Mans racer, gets approx 500 HP from a 3.7L turbo V-6. I doubt that the turbo is on there for emissions reasons.

I'm really not trying to be argumentative as I assume there's a little more to your statement. I'd really like to know what you mean.

Tim

More boost will reduce EGT if you don't add more fuel but they are there so you can add more fuel and make more power.

[NHIrish]

To answer the question;

Void warranty; Yes
Save money...No.

[dspencer]

I'm not a big tuner fan however one thing you can count on is that your warranty will be voided. I'm in the car business and have been for over 23 years.

[GoPackGo]

Sorry - double post.

[GoPackGo]

"On a diesel engine the turbo is on there to just keep EGT and emissions in check."

This is the first time I have ever seen a statement like this. Turbos have been used on diesels since forever to boost HP - John Deere tractors, semi's, etc. Long before there were any emissions standards at all.

In fact, possibly the coolest diesel car in existance - the Audi R18 Le Mans racer, gets approx 500 HP from a 3.7L turbo V-6. I doubt that the turbo is on there for emissions reasons.

I'm really not trying to be argumentative as I assume there's a little more to your statement. I'd really like to know what you mean.

Tim

[Turtle_n_Peeps]

Bob Vaughn wrote:
I received an email and video from Trailer Life about Bully Dog GT tuners for diesel engines. It all sounds good but I have been warned that the warranty would be voided if I use a tuner. Now I wonder if this is true. If so then I guess I will have to wait until my warranty is up. It is 699 bucks and I wonder if there is enough of a fuel economy savings to ever break even?

#1. Yes, your warranty will be toast with a tuner.

Now, if you put a tuner on your truck and your radio or window motor goes out does that mean the dealer won't fix these things? No, not at all. What if your engine, tranny or rear end blows up? More than likely yes. All OEM's want a computer snapshot sent to them before any major work is done on their dime. IOW's if you blow your motor and want it fixed on the OEM's dime the dealer will have to send in all computer records before they can proceed to fix it.

And before anybody starts; no you can't hide a tuner from the OEM. Not going to work no matter how many times anybody says it on here.



Lets talk about fuel savings. A tuner adjusts just a few "major" things on a diesel engine. (there are more but these are the big 3)
#1. Boost pressure.
#2. Injection timing.
#3. Fuel setting.

#1. Boost pressure on a diesel engine does nothing by itself to raise power levels. IOW's if I raised my boost pressure from 30 lbs to 40 lbs I would gain nothing. On a diesel engine the turbo is on there to just keep EGT and emissions in check.

#2. When injection timing is played with you can pick up a few HP because the engine will become more efficient. This is where the tuner picks up a little mileage. Not much, but a little. Problem is NOX will go sky high if you jack up the timing rate. Same way with the gasoline engines of the 70's. Anybody remember the BB they would put in a vacuum advance lines to limit NOX? It also used a lot more fuel and killed a lot of power but it did lower NOX significantly.

#3. The big one. Fuel. Any tuner that adds more than a few HP adds fuel. No way around that no matter what people say. With a diesel engine the more fuel you add the more power you will make.
The problem is if you add more fuel your mileage will go down "if" you use that HP.
If you have a diesel engine that will use X amount of fuel at 200HP it will use 2x's X at 400HP at WOT.

Now, to answer your question. Will you get better fuel economy with a tuner? The answer is a solid maybe. It just depends on how you drive your truck while towing.

If you drive your truck with a light foot with a tuner you will see better economy than with a stock setting. Remember the injection timing and how it makes the engine more efficient? This is where the mileage savings is coming from.

If you drive your truck more aggressively you will see a drop in mileage. Remember how the tuner makes more power? Yep, with more fuel; and this is where the drop in economy will occur.

So there you have it. It just depends.

[BenK]

Propane injection and H2O/MeOH injection

Begets better MPG, more complete combustion of diesel, lowers EGTs...

More 'Boy Racer' stuff than tuners...

[ib516]

Yes, you would be putting your warranty in jeopardy if you tune your truck.

No. It is very unlikely you would see enough of a fuel economy increase to pay for the tuner.

Yes, they add serious power that amkes the truck much more fun to drive. I ran tuners or chips on my previous diesels, and really enjoyed the experience. I had no issues and huge power increases, but no fuel economy increases.