Hello all!

I just bought a 2014 C250 for my wife. I drive it on occasion and think it drives pretty good. It's pretty underwhelming in the power department. I've read a lot about the JB + Tuner but that seems to add just a bit more low end grunt. Problem seems to be that the turbo cannot maintain boost pressure at higher RPM falling to some 11psi down from 16psi by redline. Sucks because the car feels decent before 4500rpm then it falls off a cliff. Are their any turbo options for this car?

I've been modifying turbo cars for some time now doing all the work myself. However this my 1st experience with a direct injection turbo motor. On most other turbo cars I've dealt with you can just add a boost controller or flash for more boost and add more fuel with more fuel pressure and pick up some good power. The turbo on the C250 seems to be maxed out from the factory and then you get that pesky overboost code when you increase boost too much with the Jb + mod. Is it possible to use the turbo from the A45? Seems like that would be a nice mod. Any flashes that can bypass the overboost situation? Is the overboost limp mode triggered by the knock sensor detecting knock? Just trying to gain an understanding of this setup.

Also any flashes that help the tranny shift quicker? Seems you lose about a full second with each shift because they are so slow, and yes this is in sport mode after resetting the TCU. You can feel the car reduce the throttle, retard timing, shift, then feed back full throttle/timing with each gear shift. If trans was able to shift with more speed and at full throttle you would probably drop a full second off the 0-60 and 1/4 mile times without even having to add horsepower.

the A45 has a complete different engine so i doubt that

How different are the engines? Heads could be similar. They are both using a Borg Warner turbo. Depends on how the bolt patterns are on the turbine housing. The A45 turbo appears to be a top mount with the turbo sitting on top of the exhaust manifold rather than hanging from it like the C250. The turbo on the C250 looks alot like the turbos Volkwagen use on their Passat and other 1.8-2.0t turbo cars.

Ive been patiently waiting and praying for a tcu upgrade, but dont see anyone developing or enough interest in increasing power in these cars unfortunately. We are also at a standstill too because there is not real tune for these cars, just piggyback systems.

TCU? all you need xentry dev. for that

The transmission programming holds this car back a lot. Even if the manual shift mode actually shifted when you wanted it to, it would be a great improvement. I mean, if you're WOT and push the shifter to up shift to the next gear before power falls off a cliff and it doesn't do it, and will up/down shift automatically no matter what you do, whats the purpose? If you could at least short shift to keep the car in the powerband it would perform much better. There is really no good reason to rev this car beyond 5000rpm, the power just drops after that. A CVT would be an improvement at this point!

Unfortunately it seems like most of the people with the C250 don't care much about performance just cosmetic upgrades. The chassis has great potential. I guess all the performance oriented guys have the AMG. This could be a nice little sleeper with a decent turbo and tune. Maybe the injectors from the A45 too. Does anyone know what Borg Warner turbo is on the car? I looked at the turbine housing and the outlet is a 3 bolt to the down pipe from what I could see. I believe the Audi/VW use a similar configuration.