Hey everyone! I figured it was time for me to make a build thread for my 2013 ML550.

I'm quite a ways in already but here's some pics with a short story up to where I am at now.

To keep a long story and a quick journey short I purchased the car completely stock about a year and a half ago(I have an issue keeping things stock lol). Not too long after, I pulled that massive muffler off the back and had the car tuned. It was fast, but not fast enough.

Fast forward a short while later, and I pulled the trigger on a transmission tune, and a WMI/ASV kit from Weistec along with a retune, along with air some DIY air filter spaces, air filters, and colder plugs. Also, I had replaced the torn cloth intakes with 3in silicon tubes from Amazon that I cut to fit. Wow, it was quick!

But, I still wanted more. Fast forward again, and I purchased valvetronic mufflers, then after that a while later again, I started experimenting. Come to find out, E20 Runs really well without a tune and the car felt a bit better with it. On top of adding some 3D printed air intake tubes to work with some cone filters, added in an ethanol sensor, added 3D printed a pod to fit in the dash for my guages, then got retuned with TunedMercedes on E40, and split the cooling system. That really brought the car to a whole new level right there.

At that point, my fuel pump I assumed was getting weak, or just was not keeping up, so I swapped it out for a new pump(come to find out the ML63 and the ML550 have the exact same part numbers) and with some magic, my ML550 is flowing at ML63 specs.

Currently where I sit, the pump is not keeping up at WOT in the mid/high RPM range, so more experimenting to come! In the mail is a Radium fuel surge tank, then hopefully I can get other parts ordered here soon like the lines and fittings, an AEM Stealth pump, some wiring, and a fuel pressure regulator.

 

Cool build, but honest question:
What is the benefit of pulling in hot air from the engine compartment rather than cold air ramming into the front of the car?
Are you seeing a fuel pressure drop at WOT at mid/upper rpm's on gauges?

 

Pretty sick sleeper, what are the power numbers?

 

Pulling hot air in itself there is no real benefit. However, the hot air is mitigated with some cooling mods along with the higher airflow allowed through the cone filters vs a panel filter. Splitting he water cooler onto its own circuit, removing the rear weather seal across the engine bay, the methanol injection also cools down IAT's quite a bit. Also, because I had split the cooling system, I was able to remove the coolant switchover valve and the mounting plate for it leaving a hole in between the 2 intake tubes to allow colder air to flow in over the motor. The intake tubes from the front also draw in cold air to the filters.

I do have turbo blankets and I also plan on wrapping the bridge pipes and exhaust manifold to keep temps down, but I'll do that when the turbos are out at some point. I should see an increase in turbo spool efficiency doing that though probably not enough to matter.

I do see a massive drop in fuel pressure, but I am suspecting a HPFP is finally wearing out(128k miles on the motor now). I originally thought it was the in-tank pump so I changed it out. Oh well, at least I know the in-tank pump is good now

 

Thanks! I've never taken it on a dyno, but on my previous tune HPT was telling me about 750tq(crank I assume) and based on nerd math and 1/4 mile times 545(ish)hp. The current tune is far more aggressive now and feels significantly faster. If I had to guess, somewhere between 6 and 700 still but maybe the high end of 600. and maybe high 700's tq? The power delivery is far more smooth as well. But next time I get to the track, I should be at around a 1.8sec 60ft and an 11.9sec 1/4 mile. on the previous tune, those were the numbers I was told to expect from the previous tuner and I ended up doing a 2.0 60ft and a 12.7 1/4 mile, but the current tuner also fixed quite a few things that looked pretty generic and copy paste while retuning for E40 at the same time.