Matts2015c300

I have read all (of those I could find) the posts on BMS tuning for the c class but no one has talked about how it changes the feel in daily driving around town and spirited driving on the highway. I plan on doing a basic install (no brown wire) if I go with the BMS tune. Can those of you currently using it on your c300's please comment on:
1. Daily driving around town
2. Spirited highway driving
3. Overall feel of the power gains.

Thanks in advance guys!

-Matt

stealth.pilot

You may be better off replying to someone else's post on this tune so they get a notification.

bartola

1. Daily driving around town
There is some noticeable difference, but it seems to fade after a while.

2. Spirited highway driving
With racing fuel it is very nice and noticeable (100 octane)

3. Overall feel of the power gains.
My point of reference is the ChipTunning I have on My CLA, very reliable and always feels like the powered increased, the engine light did come on once. easy as BMS to install.
I expected the same, but I am not getting that same boos.

Also, I got the pedal commander (awesome) but can't have both - BMS was no help on the phone and updates are a pain.

stealth.pilot

Did you do the hard to reach connector? They say with simple install you get +15hp, and with the more difficult install you get +40hp. The latter I would imagine is more noticeable?

I'm talking to my MB dealer on Monday about the Kleeman tune for the C300. Hopefully more robust than BMS.

bartola

no, just the two recommended. Honestly, I am just waiting to order the c450 coupe and be done with trying to squeeze more out of the engine, it has good power already.

stealth.pilot

Fair enough. Although Ford is getting 280hp out of its 2.0T (and that's not the ST version).

I don't have a big need to tune this either. It's my wife's car and she's happy with the power output. I have a 550hp coupe and 560hp sedan for myself.

all-black

the bms stage 1 and 2 maps do quite a bit for the car, overall its a pretty easy install even the quote hard to reach lower plug can be accessed pretty easy once you know where to look and have a few tool. i run the car with a blend of e85 and 91 and the car drives great, much more low end and the top end, the top end i still think the boost should be raised a lil more to keep the hp and tq climbing... I've checked the tune and done lots of logs to make sure the afrs are good. everything seems to be spot on. one thing to note about these cars is that they are in closed loop fuel trims under wot and normal driving, only time it goes into open loop is when you let off and the injectors turn off. This is pretty helpful because the eco will always compensate. bang for the buck this is a great addition to the car and makes it feel like the way it should have come from the factory

BlackjackM

Do you have any pics or a write up of how to reach the lower plug? I asked BMS for it several times and they don't have anything.

all-black

i actually sent a bunch of pics to terry on how i did it. if you have an email i will try and find my pics and send them to you

TopGun32

finally another fellow member that knows how to mod his car.. trying the maps, adding better fuel and log it.

I wish we had more owners willing to do this on the 4 and 6 cyl engines. Most people on this board talk about the negatives about the car.

I have been modding AMG's for 10 years.. the BMS piggy back is by the least expensive and easiest to install and remove.

I plan to ECU flash my C400 car with a OE tune and test running the +3lbs map 1 on the BMS Piggy Back.

This is what is currently being done with the N54 / N55 engines.

all-black

I've noticed the negativity around.... but with anything you can either pick it apart or enjoy the positives. for a stock car with a very conservative tune the car is quite enjoyable. I have dd high hp car and they both have there place.

Im waiting for bms to release something more aggressive for the car, i know the turbo is small so idk how much the actual turbo can flow. maybe have pure turbos do a new compressor wheel for it. the fuel system seems to keep up just fine so far.

all-black

i do have pics of how i got to lower connector and the others if anyone needs them you can pm me your email...

RemmyZero

There some discussion on the N54 boards on page six of this thread (http://www.n54tech.com/forums/showthread.php?t=28003) about where the brown plug is. I do see they discuss it should add another 10-15whp. I'm quite tempted to get this. 30-40 extra whp could be a lot of fun on this car.

RixC300

It would be nice to have step by step procedure getting to the brown patch. Could someone that has done this show us how you got there. What was removed and any special tools if needed.

bartola

I really don't think it will make a difference unless you have high octane fuel all the time (or someone on this board put's e10 mix).

I have racing fuel down the road, it's expensive, even without BMS - try it out and you will feel a big difference in performance - just fuel in your stock - how safe is that!

Anyway, I have BMS for sale (dirt cheap - first $175 takes it), will post pics tomorrow.

LateC300

PM'd

bartola

SOLD !

Sahaj.c

I ran the bms tune for 2 months, there was a noticeable increase in power, the turbos spooled up faster. In 2 months, I got a check engine light, took it out, went to the dealership, which they determined to be emmision problems, most likely due to bad fuel patches. (filled 91 from superstore). Put the tune back in, and in 4 weeks got another check engine light. This time, the dealership claimed it to be- "agressive driving style", which is odd because 80% i drive in eco mode and stay in lowrevs. The dealership also stated the car should be able to handle an agressive driving style anyways, and did some remapping of the ecu. Im considering putting the tune back in spring, as there is no point to have it during the winter in Canada. Anyone else experience a similar problem?

RixC300

I have about 10 miles of winding road and when I catch it without that one car collecting 10 behind it I can push the car hard. That section of road has given light a few times. The light would always turn off after 24 to 36 hours and before I could get the code read. I purchased a OBDII but haven't been able to get the light to come on since. The first couple times it happened I email Terry because it freaked me out a little. I always got a reply in minutes but without a code he wasn't able to help.

all-black

what code were you throwing? was it for fuel pressure at the rail? Sahara.c ?

all-black

<br/>take the engine cover off





disconnect the ecu connectors<br/>





remove the eco and there will be a lower plastic insert to remove





the map sensor is behind the aluminum bracket with the pig tail plugging into the sensor from right to left





here is a connector that is the same style your looking for. there is a little yellow clip that needs to unlocked so the connector can be removed when pressing the rear tab





if you look from the front of the car through the ac lines with a flashlight you can see the connector. this is where you want to look





this is the view between those lines looking in behind the aluminum bracket ....in this picture you can see the sensor dead center. there is the philips screw and just above it and to the right is the clip that needs to be removed. you can do this with a long pick or screw driver. <br/>

if you guys need more help let me know

RemmyZero

all-black, thanks for posting this! and for bartola, terry at BMS claimed the brown patch would be effective with 93 octane but it doesn't seem like anyone has tried it and reported back.

all-black

I have run it with the lower patch cable since day 1. I run the car with a blend of e85 and 91..... I've also ran it with just 91 without any issues and have done data logs with 91 and the mixed fuels both ways are safe. You def feel more power with the stage 2 map and the blended fuel.

RixC300

Thank you all black! Yes the brown path can be run with 91 plus octane with good results. It's the next stage that green patch that needs e85.

RixC300

Last weekend I was able to get my hands and see where the brown patch connects. The plastic insert busted a few knuckles but I wouldn't have that problem next time.

However, once I got there I was afraid to disconnect it because i wasn't sure I would be able to reconnect it. Is there any tricks to getting them back together as there is no way to hold backup/pressure when you push them together. Did anyone pull that bracket just about it off? Or try going from under the car?

Thanks