Performance Upgrade

[Deezelweazel]

It is interesting how much Mercedes stressed out proper fuel supply and filtration.
Since the original system just has a mechanical pre fuel pump, I did add an electric aftermarket fuel pump, which provides fuel under all circumstances to the
(modified) pre-fuel pump. Fuel supply ist extremely important due to the sensivity of the high pressure fuel pump.

A special arrangement of the electric fuel supply pump makes sure the fuel supply is guaranteed under all circumstances. Remember, fuel pumps are good in pushing— not pulling, as in the oe application.

Last topic for today is fuel filtration.
Since Common rail injectors are very, very sensitive to dirt contamination, I did install a pre filter, making sure the dirt particle size is not bigger than 3 micron. The OE Filter is not bad, but only filters down to 5 micron according to the specs of the major manufacturers. Good Injectors aren’t cheap and additional filtration is a good and cheap insurance. The pre-filter also takes care of water.

Water is a problem. Not because you might have in the system causing corrosion. No, because of cavitation. Its micro explosions destroy injector tips when boiling. And more than 100C are reached with ease in the combustion chamber.

Detail information? Do your own homework and research, when going this way.
By the way, the shifting setpoints for the transmission are the same on W5J400 and W5A580. What does this tell you?
Right, Mercedes engineers don‘t know how to do their homework and they don‘t have the magic shade tree shed tools you do have…
It does not help to go on Sprinter web pages, Adrian… (Sorry, I couldn‘t resist to tease the copy cat.)

[Adrian D]

Originally Posted by Deezelweazel

It does not help to go on Sprinter web pages, Adrian… (Sorry, I couldn‘t resist to tease the copy cat.)

Transmission tuning is not just shift points. And as for calling me a copy cat, whatever floats your boat.

[Deezelweazel]

Just trying to heat your jets, Adrian
I know, that you love to gather knowledge…
Problem is that that I do work now for a Company with three letters and do have access to research and development- which I can use for my own enjoyment, but strictly not externals.

[Deezelweazel]

Drive Wheel Torque = (Flywheel Trq x Gear Ratio x Final Drive x Efficiency)/ Tire rolling radius

So what happens if you run bigger tires?

[JoeTe]

I tuned wg with hibryd turbo, c30 injectors… 285cv in dyno.

[JeanLuke]

Originally Posted by Deezelweazel

Drive Wheel Torque = (Flywheel Trq x Gear Ratio x Final Drive x Efficiency)/ Tire rolling radius

So what happens if you run bigger tires?

Your formula is for driving wheel force, not torque. The equation is effectively the axle torque (calculated from flywheel torque and drive ratio) divided by a lever arm length. Newton.metres divided by metres gives an answer in Newtons - a force. It is high-school level physics.

To answer your question, bigger tyres means less motive force and consequently acceleration. The alternative way to look at it is bigger tyres means more torque is required to produce the same motive force OR at the limit of tyre grip (maximum force) more torque can be applied to the axle. It is this "more torque" that can result in broken axles with larger tyres.

[Deezelweazel]

Ouuww, wasn‘t finished here.
It should be named:
How to calculate drive shift rpm…
Because gearing and tire size determine the rpm range in which your engine makes the highest average force.- and that Rpm range is where you want to increase power.
As far as I remember the drive force curve of each gear represents engine torquemultiplied by the transmission ratios…
The highest average power curve represents the combined torque curvesof each gear.
That‘s what your afterwhen choosing you shift RPM….
High school level, huh…?