Performance/Mileage Enhancement

**RonJonCMC** · 08-24-2009, 02:51 PM

Has anyone tried using one of the plug and play enhancement modules? I was thinking of using the Bully Dog or the TS performance MP-8 module on my 08 Sprinter. Both claim to increase HP and MPG. Anyone using one of these? Are there any known negetive side effects to the engine or trans/drivetrain?

**piper1** · 08-24-2009, 04:59 PM

For the Sprinter.....not a good idea. You will find that with the Sprinter when you start to go "off script" and play with things it leads problems eventually.

Remember too,most of these products are designed for a recreational user, so if it does bad things it won't add up to much damage as the vehicle runs lower miles. In a commercial high mileage application (like expediting) anything that pushes the envelope is pushing on it a lot longer and eventually will likely lead to problems. Long and the short of it, when you see stuff advertised in the magazines or on other enthusiasts websites, it likely has never been intended for a high mileage commercial application.

**60MPH** · 08-24-2009, 07:45 PM

The only thing i would ever consider doing would be having the fuel map redone. I have been looking into it for my d-max. I am looking for it to be more efficient on take off and a little better on the top end. Basically they just go in and tinker with the fuel timing and the fuel trim adding longer pulse width "more fuel" at the low end and shorting up the pulse width "less fuel" on the top end. From what i read they are clamming 1-2 mpg on the top end. If this is true then it will pay for it self in no time.

**guido4475** · 08-24-2009, 07:58 PM

I would think things such as a K&N air filter, free-flowing exhaust would help a great deal without really altering the vehicle.

**Turtle** · 08-24-2009, 08:13 PM

K&N air filter, not for a Sprinter, or likely any turbo diesel. The TDI forums and several other places have detailed more than enough experience with what happens with K&N air filters in turbo diesels. It's bad. Really bad. K&N filters allow an inordinate amount of silicon dioxide through the filter which enters the turbocharger. Silicon dioxide, or silica, is a quartz mineral which is the primary constituent of sand, is extraordinarily hard, and is what is used when sandblasting. The Sprinter's turbocharger makes an excellent sandblaster.

**guido4475** · 08-24-2009, 08:21 PM

I appreciate the info.And although I do not doubt your knowledge, wouldnt this be a liability issue ? Is this with any high performance air filter, or just K&N? It seems I go through too many filters on my 7.3, and wanted to go this route, using a re-useable filter.

**piper1** · 08-24-2009, 08:50 PM

Me thinks the high flow filter companies get around the liability with instructions about "cleaning more often under adverse conditions" and other such legal escape language. Also, as you are the one cleaning it, you are therefore responsible for it's performance.

More airflow needs to come by having a bigger filter (more surface area) not just bigger holes to let in more crap.

Bigger exhaust on anything with a DPF is a crap shoot. While you may have gains from free flow, the pressure sensors in the DPF will see this as a pressure drop which signals the ECM that regeneration is needed which...uses fuel, likely more than you saved.

guido, how often are you changing your air filter and what are you basing the change need on (guage, time?)

**Turtle** · 08-24-2009, 09:45 PM

I don't know if it's a liability issue or not, but I wouldn't think it would be since the filters generally work as stated. K&N does have a rather extensive warranty that extends out to the repair of any engine or engine part that is determined to be a direct result of the K&N filter. I don't know if anyone has taken advantage of that or not, but I do know that when you need to replace a Mass Airflow Sensor under warranty, Daimler will not honor the warranty if there is a K&N filter installed. K&N also makes it very clear that the filter needs to be very, very, very properly serviced and oiled up juuuust right or their warranty becomes void.

Several people have had to replace the Mass Airflow Sensor (MAF) in their Sprinter because of the oil and the silica grit that gets accumulated there which renders the MAF dead. I know three personally who were using K&N filters in their Sprinters who had this happen to them. One was still under warranty, which Dailmer did not honor because of the K&N filter. Was the MAF damaged by the filter, or just worn out? Hard to say. But it usually happens within weeks of installing the K&N filter.

It takes a little longer for the turbo to sandblast the turbo vanes and engine, but even at that an oil analysis will quickly tell you what it happening when the results invariably show a dramatic increase in wear metals. It would be hard to definitely pin that on the K&N filter.

With any diesel in general, but with a turbo diesel especially, clean air is critical, and the K&N's simply don't filter the air all that well. They let large volumes of air through that will increase horsepower, but that's really more for gas engines than with turbo diesels that have Mass Airflow Sensors that are tied to air intake temp sensors and turbochargers and intercoolers and EGR valves and ECU's and everything else that scales up or down in response to more or less airflow. So the increased airflow of the K&N (of which there really isn't any) ends up being negated by the signals sent to the computer by the sensors, anyway.

It's like the guy who swore up and down he could modify his Sprinter with a "warm air intake" which would give him more power and better fuel mileage, not realizing that the warmer air gets compensated for by the air intake temp sensor and the MAF and the intercooler. Or those Sprinter owners who will idle when it's really, really hot and will pop the hood to keep the engine cool (like you would or any gasser), when in reality the temperature control system of the Sprinter will just compensate for that, too, and will operate at the temp it's supposed to, hood popped or not.

Basically, if you have a turbo diesel that employs a MAF, stay away from any oiled "performance" air filter. The stock air filters will outflow any performance filter, anyway.

Do some searches over at TDIClub for more information and horror stories. It is a little harder doing a search for K&N because of the "&" so you have to get creative with the use if quotes and stuff, but here's a couple that will give you an idea.

Thoughts on K&N Air Filter - TDIClub Forums

K&N Air Filter for new 2009 TDI? - TDIClub Forums

K & N Air Filter - TDIClub Forums

It's a topic over there that really and truly has been beaten to death, perhaps hundreds of threads, all saying essentially the same thing, so finding a bunch of K&N Filter threads won't be a problem.

Best "recap" from the site:
-No appreciable power improvement (dino tested)
-Less filtering capability
-Causes MAF failure
-Many have reported bad seal with the airbox. (Bad seal=driving with no filter...

)

Best signature line:
Friends don't let friends buy K&N Air Filters

**aileron** · 08-24-2009, 10:14 PM

Originally Posted by guido4475

I appreciate the info.And although I do not doubt your knowledge, wouldnt this be a liability issue ? Is this with any high performance air filter, or just K&N? It seems I go through too many filters on my 7.3, and wanted to go this route, using a re-useable filter.

Guido,
Why do you go through lots of filters? On my sprinter I have an indicator on the filter box that tells me when I need to change it. It never moved (I tested it and it works) so I change my filters every 60k, but they would go longer than that.

**OntarioVanMan** · 08-25-2009, 12:40 AM

Originally Posted by aileron

Guido,
Why do you go through lots of filters? On my sprinter I have an indicator on the filter box that tells me when I need to change it. It never moved (I tested it and it works) so I change my filters every 60k, but they would go longer than that.

My tech told me to never believe that little gauge on the filter box..it is a cheap toy..*L*..always do a visual check and keep it clean as possible especially vacuuming the sand and gravel from the bottom of box...

I don't understand all this tinkering folks try to do...what are you looking for? The Mercedes diesel and all the computer and sensors are all finely tuned and programmed for pretty much peak performance anyhow.....At 431,000 miles and never been twinked or altered and getting 23-27 mpg...and never been on a hook...what more could one ask for? Stick to the list....

**guido4475** · 08-25-2009, 04:19 PM

Here's the deal. I bought the van from Ryder with 180,000 miles on it, the restiction gauge was not really showing any kind of restriction at all, but the filter was black, and full of dirt,(which makes me wonder about their maintenance program) so I changed it.Alot better performance, and pulling power, as well as mileage. I used Purolator filters from Autozone.But not soon after (A little over 5,000 miles) the air restiction gauge on the side of the air filter box is showing 75% restriction.I have blown it out, etc, and the gauge will go back to that reading after a reset.I am thinking of trying Fram filters the next time.My fuel mileage has dropped through all of this. I did take the whole air tube sysem off and inspect for any foreign material, but did not find any. Real clean.Any thoughts?

**aileron** · 08-25-2009, 04:30 PM

Dont know what to tell you, but 5k is an awfully short time for an air filter to clog up. You sure that the gauge is working properly?

**guido4475** · 08-25-2009, 04:37 PM

That's what I am wondering..It always worked well in my big truck.I once had the air filter in my big truck clog up at 25,000 miles to the point where it sucked the air tubes closed going to the turbo. I usually changed them every 30,000 miles, so after that, I went to changing them every 20,000 to be on the safe side.

**piper1** · 08-25-2009, 05:23 PM

If your mileage and pulling power change then the filter is indeed clogging, switching brands may not help.

Have a really good look at the air intake piping BEFORE the filter and see where the air is coming from, something may be off or mislocated and sucking in a bunch of crud.

If you can remove the restriction gage, clean it off and try seeing how hard you need to suck on it to make it lock in the red zone, it should take a fairly deep breath and pull your cheeks in.

I also HIGHLY RECOMMEND doing this in a location you are 100% sure you are alone, otherwise you will never hear the end of it.

**guido4475** · 08-25-2009, 05:31 PM

Yes, I took everything off, before and after the air filter box, and it is fine.I just may of been in some really bad, dirty area, maybe.And thanks for the tip on sucking on the restiction gauge.I'll have my girlfreind do that, lol.no comment.