[buddywhite]

Does anyone have any input on the ECU upgrade available by Renntek or the other tuners? Is the 25 HP increase noticeable enough in acceleration or is the extension in redline unusable or a decrease in performance because the torque has topped out? I know the Renntek ECU raises the top speed to above 180. Also under normal service is the upgrade detected by the dealer when you have routine service?

 

[LorinserNik]

Does anyone have any input on the ECU upgrade available by Renntek or the other tuners? Is the 25 HP increase noticeable enough in acceleration or is the extension in redline unusable or a decrease in performance because the torque has topped out? I know the Renntek ECU raises the top speed to above 180. Also under normal service is the upgrade detected by the dealer when you have routine service?

25 HP is noticable with the ECU upgrade by itself but its best if you went with the upgrade kit. The kit consist of a crankshaft pully and an ECU upgrade that will produce 44HP/40lbs of tourque. The kit also will not void your warrante. Call me up so we can set you up with a package deal!
Nik
ImportPower

 

[Renntek]

RE: Renntech ECU

I posted this previously, so I am pasting in just to provide some additional insight and actual experience.

The ECU reflash was done by Renntech (RENNTECH MERCEDES). Their service is a bit pricey (approx $1,500) but is completely supported by MB warranty. That's not a trivial matter, so if you have original or extended warranty coverage it is worth the piece of mind. I had the reflash performed at the same time I installed the Renntech ceramic short tube headers. I had the car dyno'd and the two mods delivered exactly as Renntech claimed, +20 and +18 hp respectively. Again, short headers bolt on to existing downtubes and factory cats, so no issues with warranty.

The performance gains were really nice, but only a slight change in the exhaust note. So I had a performance shop put the car on the lift and thats when I discovered the resonator (two pipes in - two pipes out). Also discovered what appear to be secondary cats. Best we can tell these are to assure all MBs will meet or exceed California emission specs. In researching all of this, I came across the Supersprint (Supersprint North America : Performance Exhaust Systems) products while browsing the BenzWorld SLS forum.

Quick phone call helped identify the right parts. Manufactured in Italy from 314 stainless and takes 3-4 ARO to arrive (Approx $700). The gains I am hoping for are sportier exhaust note and less restrictive flow. I'm leaving the factory mufflers so the sound doesn't get too noisy. No real hard numbers on any performance gain, maybe 5 hp.

So from stock 382hp (at the crank) to approx 425hp/420lb-ft and better sound, I think its worth it.

 

[Renntek]

Renntech ECU and MB Warranty Service

This is from a previous post. It was my real world experience with "ESC Inoperative" error I was intermittently getting.

Update:
I finally took my E550C to MB for diagnostics. Service Rep was very appreciative I mentioned the Renntech ECU mod right away. They worked with Renntech to re-flash the ECU and add latest MB upgrades. Provided me with a loaner MB for the four days it took to ship and get ECU back. No charge, covered by both MB & Renntech warranty! Been driving in my typical fashion now for 2 weeks. No issues.