gel11

Hi guys! I got my first Benz a couple of months ago and I've been looking around since then for upgrades that won't hurt my pockets too much, but at the same time is safe and won't cause any problems to my car, like void the warranty. I've been looking for tunes to increase the power, and looking at my budget, I am torn between the BMS JB+ tune and the TMS tuning box. Can you guys help me out and point out some pros and cons? is it worth installing it in a 2013 C250 sedan? Also will I have any problems with my car? I've been researching around and people have been getting error codes and CEL. I'm fairly new with adding stuff to cars, so I just don't wanna have to go to the dealer and find out that I voided my warranty. Thank you and have a nice day!



Also anyone got info about the Race Chip ones? Any problems on those?

Knightmare69

Do you mean the TMC tuning box? I've got one installed and I'll be doing dyno runs hopefully this weekend to see what differences it makes. I've had it installed for over a week now and no error lights whatsoever. The only Benz related error lights that I've come across have been from the BMS kit where they only adapt timing and fuel where as the TMC adapts inlet manifold, can sensor, boost and throttle sensors.

gel11

Yes its the TMC tuning box. In you opnion w/o the dyno, which feels like it gives more power, the TMX tuning box? or the BMS JB+? also did you adjust the power settings for the TMC tuning box? and do you think its traceable by the dealer? sorry for all these questions, just wanted to make sure before I decide which one to buy. thank you very much for replying.

Knightmare69

I never tried the BMS, I decided not to use BMS based on multiple factors including personal. As for the TMC, I can feel a noticeable increase in off the line tq as well as response time. I have not yet adjusted the preset yet, will do so on the dyno.

The TMC is more expensive but it controls more parameters and has a good track record with multiple platforms.

gel11

ah for sure, thanks for all the help. Please post your dyno results when you can. thanks again!

Knightmare69

So bad news, it's almost sure my session will need to be postponed. The shop has a stranded GTR with no gearbox sitting on the rollers and supposedly the parts are supposed to come in tomorrow but they can't be sure. Hopefully I'll be able to get the car in by next week.

kevink2

If you are talking about the "juice box" I have to disagree, politely as possible. I wish the BMS altered timing and fuel, as that is how you eliminate engine lag when you are starting from a stop.

That is my experience when I developed more initial timing on the Classic Saab 900 turbos. What I did was adopted by vendors in their own way, but still use my method .... basically more static advance with a MSD BTM to slowly retard timing as boost rose.

Based on BMS dyno curves, you can clearly see thay have done nothing but change the boost map, which is what they admitted to me when I called them.

Many people like this for the bang for the buck.

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kevink2

Another horse in this race, but pricey:

The Kleeman Numbers for a C250

250-K1: K-Box. Up to 245 HP and 372 Nm (276 lb-ft) of torque.

250-K2: K1 + a stainless steel exhaust downpipe with sport cat and a hiflow air filter.
Up to 255 HP and 385 Nm (285 lb-ft) of torque.

If these are legit est'd numbers at the flywheel, and hp is peak value, the gains could be +34 hp and +56 ft-lbs.

OEM = 221 hp, 229 ft-lbs

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gel11

ah forsure, thanks for the info! I called there dealer in San diego CA, i think they want around 1600-1700$ for it. Its a little out of my budget. Have you guys heard anything bout the Race Chip brand? Apparently it gives around 259hp and 397nm (293 lb-ft).

Knightmare69

No, thank you for the clarification. That's even worse if all they do is modify the boost curve. Without even the basics like timing and fuel to partner with the new boost no wonder some were getting overboost errors.

kevink2

I'm not sure I read you correctly. I've had technical knowledge of an 83 Saab Turbo (RIP) that had the APC boost controller that had an low basic duty cycle dump of the boost pressure signal to the actuator, and a higher freq dump to achieve higher boost. It's all just pressure & knock sensor controlled.

Also worked on a Mazarati Bi-Turbo, whose APC boost control was identical to the saab, and likely under licence to Saab.

I reverse engineered the Rx7 twin sequential turbos control system. Here there was a map for the MAX boost at each rpm. Aftermarket ecu's would raise this limit map and raise the target boost per rpm. Again, no fuel, no timing.

The only time timing comes in is when a non-turbo knocks and timing is retarded ..... still no fuel variable.

.

Knightmare69

As I understood it, when you raise boost one should at the same time modify the timing and fuel maps to ensure a safe usage of the new boost pressure. Of course this is only speaking from my subaru days when we did a full reflash that modified the parameters across the board.

kevink2

With the 93 Rx7, with speed-density fuel control (no mass meter) , the maps were pig rich near stock boost limits, so when mod'd chips were installed, the extra rich condition was over done. I had lined up a techtom dealer to reduce fuel, but they closed shop. I'm back to the stock ecu, rather than the excessively rich 10:1 mod'd ecu.


BUT, I agree with you that not having timing to modify really hurts when dialing in power, esp at the very low end for those starts from a stop. And, if the fuel mapping is near the lean side, I can see adding more fuel than the ecu would make up via the Mass Meter.

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Amin Skaf

I am excited to see your dyno run, Knightmare! There seems to be quite a few options out there but outside of BMS, noone seems to have provided a dyno chart.

Knightmare69

I am too Amin, only if the shop could get its act together and put my car on there.

kevink2

For the JB, it's $280 and plug and play. I think you can just unplug it when it's inspection time, as I think it just fools the boost controller into thinking the current boost levels are a bit lower that actual, so it gets more boost. I suspect it reads the rpm and trims down the boost increase at higher rpms.

Knightmare says it throws overboost codes, which you would have to see if that is still an issue. I've read many positive reports.

www.burgertuning.com/mercedes_benz_c250


Notice that the peak hp is not changed much at all, and just ignore the +23 hp callout.




.

Knightmare69

Yes, both the JB and the TMC just work by intercepting signals and modifying them, once you disconnect the units your car reverts back to the OEM "tune". I think I asked Kevink2 in another thread about this, I'm not sure how fast it reverts back given that our ECU's are adaptive so not sure if the ECU adapts to the new "tune" in a manner that allows it to linger even after you disconnect the unit.

As for the overboost mentioned, there was a thread about it though I can't seem to find it now which is weird.

gel11

did you get you car dyno'd yet?

Knightmare69

No, I'm still waiting for the shop to clear their space. Also I work outside of the country during the week so the weekend is the only time I have to even attempt to get the car to the dyno. I'll post up as soon as I do.

paleface

Hi knightmare,

Can wait to see the dyno result.
Btw, what octane do you use?

Knightmare69

In Hong Kong I think our standard octane is 93 or 98 Ron. I usually use Esso F1 super unleaded but recently switched over to Shell V-Power to try it out.

AkaSigFreak

I use Mobil or Shell VPower 93 octane but just found a station with 110 octane Race Fuel. It's twice as much as 93 and going to cost $140 US to fill my tank.
Might be fun to run a tank when my tune is installed.

Knightmare69

Sunoco?