xtdoc777

Has anyone done a Renntech ECU software upgrade on their SL?

Comments or advice?

Sungkyo

Probably not. Don’t think it’s that kinda crowd. 😀 I did the whole R2 package my old 16 GTS and did some before and after highway runs with a friend and there was a noticeable difference in power. You might want to avoid the blow off valves as it was straight Fast and Furious sounding and laughably loud! If you end up doing it please chime in and let us know about your results.

vbrisebo

I am planning on doing it next year but I did install the Renntech EVM and just posted it at the top-level

blink2814

Did you get pricing for the ECU upgrade? I know the retail price is $3280, but out the door installed did they give you a price? I wish RaceChip had something for the SL55 but they only show one for the SL63, I had it on my 8 series and was fairly easy to install or remove.

xtdoc777

I called renntech and they quoted $735 labor to install.

They also told me that it was not a traditional ECU upgrade/flash. They have not yet be able to crack the copy protection of the Mercedes ECU so the upgrade was actually a separate computer that hooks up in between sensors in the car to trick the ECU into giving you more turbo boost and power. Should work but I not sure if I like the idea of a spider of extra wires hooked up in the engine compartment.

CharlestheCat

This is just my personal opinion, so don’t roast me, but unless you are taking this car to a drag strip I don’t know why you would mess with a tune. And this comes from someone who back in the day had a heavily modified Mustang.

xtdoc777

After considering it and speaking with Renntech on the phone, I decided against tuning my 2023 SL55. But if someone pulls the trigger I would love to hear about it.

blink2814

Why would I want to do it? Because honestly for being a $145k vehicle I feel it is a little underwhelming. At that sticker price I definitely think the horsepower number should start with a 5.

CharlestheCat

Gotcha. That’s why I got the 63. Also I wanted the AMG aero package, which I don’t think was available on the 55. That said, MB does notoriously underrate the HP on the M177 cars. Check out Renntech’s testing. I wouldn’t be surprised if the 55 is actually over 500 HP at the crank.