cfmistry

So tonight I got to install my Weistec Stage I tune via their Cypher handheld tuner. I've only driven a few miles but here are my impressions so far:

The Cypher handheld tuner is easy to use. You have to download your factory ECU data (takes about 15 min) to the Cypher and then email it to Weistec. They return the tune very quickly, then you upload the tune to the car (again about 15 minutes) with the Cypher again. I wish I had known that a PC is needed to use the Cypher system, but regardless, I got it done.

Weistec claims +91hp and +199ft/lbs torque. I do not doubt it. The car was fast before but is is violent now. I was thrust back into my seat ... I've floored this car so many times and that was never the case. The power gain is most noticeable above 2500rpm, as you would expect from the M278 (or any turbo car for that matter). Of course I wish it made more difference low down but no tune will do that. Thankfully the PedalBox+ I got doesn't keep me in the low RPM range for long.

The car otherwise runs like stock. Idles perfect, no CELs, no issues. Just a massive dose of power when you put your foot down.

More to come as I drive it over the next few days. Definitely a thumbs up to Weistec. I may not be the fastest car at the light, but I can keep up.

vinflouen

These are not off the light cars....they are blow the doors off somone at 120mph cars....

seamus2154

Its 5000 lbs. I wouldnt want to drag any heavy car because they break stuff more than lighter cars. I think your expectations are correct that it will be an animal once your moving. Most turbo cars are. I drive mine like an old man car in town, but on the highway or twisty mountain roads, I'm in sport mode driving it like a German car. Car is always awesome and impressive. But I have never seen anyone in an S550 driving like me. I have owned alot of great cars. This is such a cool balance of comfort and power, that can handle very well, but understanding it is 5000 lbs and a touring car! LOL
Looking forward to more reviews on it. I have never read of anything breaking on a Rentech or Weistec tune on the S550. Guess the trans is pretty strong, that alot of torque.
Good luck

C Swenson

Congratulations cfmistry! I agree with you on all points.
I've had this tune for a year now. No problems whatsoever.
Even passed emissions last month with flying colors.

I had my tune installed by a Cypher Pro dealer who is also a longtime MB mechanic and for the last year my mechanic.
He gave me clear instructions that whenever I "put my foot in it" the transmission was to be in Sport mode and ONLY Sport mode.
And then he did this: to emphasize his point. Point taken.

seamus2154

Thats a really good point. Something one may not thought of. Sport mode starts in 1st gear unlike comfort in second gear. You want that low gearing to launch. Imagine being in a manual car and applying full throttle and popping the clutch in second or third gear...thats alot to ask of your clutch and diff. Too much pressure. Things break. Great point thanks!

Have either of you also upgraded to the turbo blow off valve they recommend and offer. Is it mandatory or optional?? Thoughts?

DABRONX

The amazing part of the Weistic tune is its CA 92 octane safe.

Did you also change teh plugs and install their air filters.


As far as breaking things I had my Renntech tune for many miles and years and I beat on that car from a standstill or a roll with zero issues. Yes, the car should be in Sport as it makes an even bigger difference plus for me it opened my Rennetch mufflers which added to the fun.

Want more low end? Then load the converter before launch and let her rip.

Not slow cars and with tune your probably pretty close to 0-60 in 4 seconds.

seamus2154

Did either of you also install the blow off valve?/ is it needed.? There video on it will have you believe the turbos will get killed without it eventually.

cfmistry

Well... the car has A LOT more power on the highway, no doubt about it. I won't post speeds (seems silly), but let's just say I got to some very high numbers very quickly. Much quicker than before. You fellas are correct that I was trying to have a 5000lb car feel like a 3500lb car - that isn't going to happen.

Weistec told me their air filters "would be a good compliment" and I did not need to change the plugs. So everything else is absolutely stock. But I won't be surprised if I need to change the plugs in a few months.

Overall, a fantastic tune. I didn't expect any less from a company with Weistec. I have read every single thread on the internet that has "Weistec" or "Renntech" + "M278". And you are all correct that there have not been any major issues with a tune on the M278. That being said the engine does have its own issues and as soon as those poke up I'm sure people will point to the tune. I'm OK with that.

0-60 on the low 4s you say? That's pretty great. How accurate are those Dragy things..

C Swenson

Good thing we both have Traffic Sign Assist. Voila! It now has functionality.

C Swenson

No and no, IMHO.

But I did upgrade air filters to BMCs.
And now change oil every 5000 miles.

DABRONX

Who did Weistec install as they insist on going one step up on the plugs? Could be why your not getting hit u want. Renntech in Sport was hard hitting at launch especially if you load converter as there is no launch control.

cfmistry

. One thing I WISH I did with BenzNinja was "start in Sport mode" but I don't recall it being available when I had the computer. That would make my car complete.

Agreed. I can't recall reading more than one post about them, so I assume they are not very common with M278 owners. Perhaps M157 owners get them more often.

I have always changed the oil every 5k miles (since I bought the car at 50k miles). With bore scoring coming more to light in recent years, I don't think ANY vehicle should have a 10k OCI.

I did the tune myself with the Cypher handheld. I specifically asked my Weistec engineer about the plugs (I told him I don't mind doing them) and they said they would not recommend changing them unless I have any issues or the next interval.

I am not one load the converter... seems like a sure-fire way to break something. Don't get me wrong if I floor it from a dead stop it will move quickly.. but I still get the sense there's a lot of weight being pulled. I suppose that's because there is. So in summary... it's fast. Damn fast. But still feels heavy. Wondering I the S63 is like that or feels lighter on its feet?

seamus2154

Totally concur on oil changes. I bought my S with 27K and have always done 4-5K oil changes since, with oil analysis every other change. The M278 does not beat up the oil like some of my other cars. It is still good at 5K and they recommend pushing out the change. I do not - the bore scoring is my only concern with this motor. Quality clean oil, and proper filter my only hope. None of the bore score scenarios I have read about match my use, or maintenance, so hoping for the best. There are many high mileage m278's out there, its not an epidemic.

Tom in Austin

Bore scoring? Can someone elaborate on this a little, don't recall many posts ... are Mercedes engines particularly susceptible for some reason?

brl12

Hi,
I have a Weistec stage 1. What do you mean by "load the converter before launch and let her rip"?

carlosinseattle

That means pressing the accelerator pedal and brake pedal at start, then release the brake pedal. I did this with my 2017 S550 4Matic and the starts were super fast, I actually got a little scared. Just be sure to only do this in Sport mode, you want the car to be in 1st gear, not 2nd gear. I did it both ways and there was a major difference. No tune on my car by the way.

Short video explanation:

brl12

Cool man. I'll try it out. Thank you!