Lazz83

Has anyone had a Renntech tune on their C43, C450, C400?

It seems that the tune for the C43 gets flogged on here a lot because it is very expensive and does not give the gains of the other big 3 tuners. I believe the Renntech increase is 41hp and 62lb ft, but they measured the actual HP at the crank of the C43 to be 375hp and 398tq. I think it costs $2240- I have not seen any reviews or real world speed numbers posted on here. My sales guy at MB dealer, told me that if I "Rennteched" my C43, it would have similar or better performance numbers than a stock C63.

I agree when factored to Wheel Horsepower those numbers are not good for the investment.

The question is Since Renntech is affiliated with MB in someway, does it still void your warranty when you get your ECU reprogrammed? I even saw new MB AMG's at this dealer with Renntech kits installed for sale and ready to go?

Im curious because my MB Dealer is also a Renntech Dealer and will do all Renntech installs for you.

Peace & love to you all

Lazz83

I found some more info-

So at the wheels you would get 31hp and 52tq for $2240 plus tax

aggies15

41hp/62tq is not worth $2240, IMO. That's a pretty hefty price tag for such minimal gains. According to MB, ANY modification to your car outside of factory parts will 'void' your warranty, even if it's with RennTech.

Lazz83

That is so bizarre and the dealer sells and installs these parts for Renntech. Did you know that you can get parts for a Mustang from Ford Racing- Like a larger super charger, exhaust, re-map etc and it does not void the warranty.

For the price the Renntech numbers blow, literally. It would give you .2 tenths quicker to 60 and probably the same in the quarter. That does sound like a rip off.

A wise man will notice that Renntech does not start going over 100whp on its C63 tunes, until it swaps out the turbos for higher output models, makes you wonder if it is really safe to push the C43 pumps to over 17psi? Then again the CLS 45, 4 cylinder is pushing 26psi stock.

aggies15

A lot of tuners (EC, AMR, etc.) are pushing 17+psi for their tunes without upgrading the turbos, so we'll have to see how the cars hold up long term. In regards to RennTech and how some dealers sell their product, they usually have an agreement to where RennTech will directly pay (the dealer) for any issues related to the modification if it was discovered that their part was the culprit (this is supposed to make the process more seamless so that you wouldn't have to go back and forth with both RennTech and your dealer). Most ECU tuners/Dinan have their own warranty, it just won't be as convenient if anything goes wrong.

Lazz83

Yes I understand that and know other tuners offer the warranty.

Its always been the thought of people in the know, that increased boost pressure will cut down on the life of the turbo- the higher you push boost the more life is taken off.

With everyone having their cars for only a year or two this has not been a factor yet and some are pushing it quite a bit harder than stock. Turbo problems like that usually don't show up until at least 80k mi though when the Impellar/compressor bearings start to go.

waisoserious

I find that very very very unlikely. Especially with those low numbers. Maybe if you were talking about a EC/AMR/OE full remap with downpipes and exhaust it could be faster (0-100mph) than a stock C63. But even then I would still be skeptical. A stock C63s traps close to 120mph. I havent heard of ANY tuned C43 from any tuner even breaking breaking 120. I think the highest I read was 118.

jonathan358

0-60's are pretty close. It's very plausible that a tuned C43 can beat a 63 because of it's AWD hook up.

threefirs

This. You're 100% correct.. HOWEVER, I believe the average tuned C43 driver will win against the average C63 driver. Takes a lot less skill to get the AWD down the track than it does the RWD 63. I've seen M3's and M4's struggle to break 13.0et but trap 118mph+. They'll run out of road before the C63 has time to catch up.

sean1.8t

17-20psi on these turbo's is not outrageous in the slightest. Hell, if we had a tune for it, I'd put in a water/meth injection kit and run these things at 22-24psi daily, if I could.

Now, that would be getting close to or about the limit of their efficiency, I'm sure. Turbos are meant to spin. And especially with todays design, quality of materials, and oil; hell, they love to spin. Kind of like an internal combustion engine. Uninformed people don't think it's good for a car to rev past like 5krpms, I've actually had a person freak out one time when I keep shifting late (not full throttle) and keeping it in gear or downshifting to slow down. Ignorant non carguy thought I was killing my car. But no, as long as you properly maintain these things and keep them within their range, then they'll last far longer than the rest of the car will.

Bonus, our cars have an after-run pump which circulates coolant through the turbo's for a few minutes after shut down so even if you don't properly cool the car down for the last few minutes of driving, "Zee Gurrmehns" got ya covered