eatmycrackers

just took my car to a dyno shop to get a baseline read. my car has a renntech tune as well, so base is 600hp, with tune should be putting out numbers of ~670 or so. torque numbers are crazy 720 but hp low low low

to my surprise and disappointment, my car topped out at 500hp. i think something is limiting the top end power of the car.

coil packs replaced not long ago those are brand new, as well as spark plugs. curious if anyone has ideas one what may be limiting power.

E55Greasemonkey

Mustang dynos always read low. Try to find a Dynojet. How old is your intercooler pump and are you monitoring your air intake temps?

drlc01

Indeed, bleeding the intercooler (the right way) is key to get the performance you are expecting.

eatmycrackers

thank you both. intercooler pump may be original i haven’t replaced it and i’ve had the car for 5 years.

i’ll need to use a shop that lets me be closer to the testing the one i used was not as helpful

drlc01

Hi Eatmycrackers,

Next week Saturday we have a DIY session with the Mercedes club at Mercedes of Plano, you can do some checking there and do the intercooler bleeding. Not sure if you are member of the North Texas Mercedes Club of America?

eatmycrackers

thank you for the information. unfortunately after living in north texas for many years i’ve moved to the northeast so wrenching on the car is now much more difficult now without my own personal garage :-(

drlc01

ok, your profile still shows Dallas.

Hendrik Koster

You should upgrade your intercooler cooling system to the M279 motors (model years 2014-2019)
Part required are;

1. 279 200 01 85 Expansion tank
2. 279 098 08 91 Coolant pipe
3. 279 098 02 83 64 Molded hose

After you install these and properly bleed the system you'll have visual control of the level of coolant in the system.
Use MBworld S65 search to find installation guidelines

Best HK

earl3

In addition to the great recommendations on checking the IC pump and monitoring IATs, boost leaks can rob substantial amounts of power on these cars. Highly recommend running a boost leak check. I found a massive one at the back of the intake manifold on my 09 SL65 -lower mile car too.

drlc01

Just to check if your intercooler is bled as it should be, if it is done well you should be able to put your hands on the intercoolers after driving a bit and they should feel hand warm.

I did do the upgrade that Hendrik Koster wrote (above) a few years ago on my 2005 SL65. Parts are readily available, the only thing to worry about is the transmission dipstick tube. it is a bit in the way. I put a couple of nuts as spacers on the upper mounting point of the dipstick tube to move it further to the firewall. I also did do the upgrade to to latest IC water pump from Bosch (need to take the front bumper of for that, easy job). This new pump is already an improved model compared to the one that came on my car originally.

After a good bleeding procedure the care runs great and has all available horsepower and the intercoolers are hand warm