M177 Engine - Stage 1 Tune on 91 - Worth it?
Thread Starter
Super Member
Joined: Oct 2005
Posts: 689
Likes: 5
From: Vegas
'21 GLC63, '19 M5
M177 Engine - Stage 1 Tune on 91 - Worth it?
Hi, I'm in a GLC63, which from what I understand has the same power plant that's found in C63, and I'm considering a RENNtech ECU+ Upgrade setup for 91 octane.
When reviewing the dyno graphs for tuned M177 engines, it looks like the power and torque falls on its face after around 5.5K rpms. In stock form, I can already tell that the engine is running out of breath at the top end. Will this be even more evident with a tune? If so, then is the tune really worth it if it makes this issue even more apparent? Looking at the RENNtech dyno graph attached, it seems to add insignificant power up on top, with most power gains had in the middle of the power band. I don't know if that will make the car feel like a rollercoaster with power only appearing in the midrange of every gear. I'm not interested in doing any additional mods to help the engine breath better. So it's a Stage 1 on 91 or nothing at all for me. Lastly, do I need a CPC tune to feel the stage 1 ECU tune do its job?
I appreciate those with Stage 1 tune to chime in, especially those running 91. I'm one of the lucky ones to get ***** gas here on the West coast.
TIA!
When reviewing the dyno graphs for tuned M177 engines, it looks like the power and torque falls on its face after around 5.5K rpms. In stock form, I can already tell that the engine is running out of breath at the top end. Will this be even more evident with a tune? If so, then is the tune really worth it if it makes this issue even more apparent? Looking at the RENNtech dyno graph attached, it seems to add insignificant power up on top, with most power gains had in the middle of the power band. I don't know if that will make the car feel like a rollercoaster with power only appearing in the midrange of every gear. I'm not interested in doing any additional mods to help the engine breath better. So it's a Stage 1 on 91 or nothing at all for me. Lastly, do I need a CPC tune to feel the stage 1 ECU tune do its job?
I appreciate those with Stage 1 tune to chime in, especially those running 91. I'm one of the lucky ones to get ***** gas here on the West coast.
TIA!
Last edited by DirtyVegasMB; Sep 26, 2023 at 10:54 AM.
Junior Member
Joined: Mar 2016
Posts: 21
Likes: 3
2019 C43 AMG Coupé
I’m pretty sure that only the face lifted 63 models require the CPC to be tuned to allow for the benefits of a tune to be felt, the pre-facelift (model years prior to 2019) don’t require it. As for the tune, Renntech is top notch as they have been involved with Mercedes for such a long time, but you will not be getting as much power as some of the other tunes that are available, I think of it more as an “OEM+ upgrade” with their Stage 1, the higher power is brought out in their more expensive power package (R2-R3 if applicable).
Thread Starter
Super Member
Joined: Oct 2005
Posts: 689
Likes: 5
From: Vegas
'21 GLC63, '19 M5
I’m pretty sure that only the face lifted 63 models require the CPC to be tuned to allow for the benefits of a tune to be felt, the pre-facelift (model years prior to 2019) don’t require it. As for the tune, Renntech is top notch as they have been involved with Mercedes for such a long time, but you will not be getting as much power as some of the other tunes that are available, I think of it more as an “OEM+ upgrade” with their Stage 1, the higher power is brought out in their more expensive power package (R2-R3 if applicable).
Thanks for your input! Anyone else?
