metalica_23

Considering buying an '06/'07 SL600. Looked on Renntech's site and $6,500 for 100+ HP seems like great bang for the buck.

Given that I'd like to upgrade, what mods would people do to increase the overall performance/look/sound of the SL600. (i.e. increased power, increased stopping power, exhuast note, tint, wheels etc.) BTW, Seems cheaper than trying to mod an equally priced SL55, or maybe not?

Also, not sure if there are big differences between Renntech, Kleeman, etc.? I noticed that Renntech and Kleeman have roughly the same price for roughly the same upgrade.

I'd love to hear any and all thoughts (all the way from choice of year/model SL, to which mods, to which tuner...)

Thanks!

metalica_23

BTW, (more just curious) what affect people have seen on gas mileage from upgrading the ECU, etc.

StephenK

I took a ride to the coast, about 150+ miles averaged 21.7 mpg.

I have the RENNTECH Upgrade/Downgrade or the politically correct answer is MOD......

leloz

Gas mileage all depends on how much to keep your foot on the gas and boost. I am getting around 14 mpg in the city with the Stage I upgrade. It was done by the previous owner and makes the car so much fun.

I had a 2004 SL55 that I sold for my current SL600, the SL600 is much more refined and luxurious IMO.

derrick_lui

so stephen,

why does ur car still have the renntech "downgrade"?
what really happened?

metalica_23

Thanks for the replies on the gas mileage. I probably should have left that out. It was more a curiosity. I'm really interested to hear people's opinions on which mods provide most bang for the buck, and which mods really enhance the cars appearance. The SL I happen to be looking at has 20" black rims to match the car, which I really like. I'm also interested to hear anyone's opinion on Renntech vs. Kleeman vs. Brabus etc. etc. Is it all really just the same?

derrick_lui

apart from Stephen's posts regarding Renntech, it seems that a lot of members who did the Renntech ECU and TCU mod were very satisfied. It will get you do the high 11's for quarter mile according to other members. Do a search for Renntech ECU and yu will find a lot of stuff on it.

JackStraw

I thought your question on gas mileage was a good one (especially since I asked the same question a couple of years ago before I had my 600 modded by Renntech!). I wish I could answer the question, but I have yet to be on a long roadtrip since the mod was completed. On a good long highway trip before the mod, I got 22.5 mpg. In the city, my mileage is abysmal, somewhere around 10 mpg. It feels like my mileage has not changed noticeably since the upgrade. I do agree that gas mileage will vary depending on your driving style.

I am very pleased with the Renntech upgrade. It feels like a different car. It's the way the car should have come from the factory. And its all software. It is a relatively simple process to get the ECU and TCU out and send it to Florida, though I must admit being a little nervous while doing it. Turnaround was lightning fast. I thought it was worth the money, but others may disagree since less expensive alternatives exist.

I haven't done any exterior mods, but beauty is in the eye of the beholder. You don't have to have the same shop do the exterior mods.

I like those new wheels that come on the SL63.

IngenereAMG

We do allot of 600s and SL55s, and they are both very very tunable.

I thing that the 55 is more of a better balanced sports car, but we are able to turn the 600 into torque monsters.

Whichever car you pick, I know that you will enjoy it.

We usually outperform the big guys and can save you some money in the process. PM me or email me directly through our web site if you have any other questions.

JackStraw

Just got back from a 300 mile road trip, mostly highway. I got close to 22 mpg. No significant difference in highway gas mileage before and after the Renntech upgrade.

theoallen

Not to hijack this thread, but does anyone have experience with the Kleemann Stage 2 mod? I'm about to pull the trigger on that along with their Limited Slip Diff.

Thanks,
Ted

derrick_lui

How was it? Did you experience what Stephen did with the "downgrade" or was the car stronger?

JackStraw

I highly recommend the Renntech upgrade.

metalica_23

I'm 99% sure I'll be adding the renntech stage 1 in the next few weeks. I'm going to try and get the car dyno'd this week, so I'll have before and afters...

armadillo

Great! Please post the dyno numbers, very interested in the result of the before and after, please try to use the same dyno for both.

metalica_23

Step 1 is scheduled for Friday. So, we'll see. I'd definitely go to the same place, as I want the only (major) variable in my equation to be the ECU/TCU upgrade.

Of course, the dyno place I'm going to has nicknamed their dyno "The Heartbreaker" because it typically spits out low results. They have a dyno that better attempts to simulate the car/road dynamic and I've learned it typically produces lower results than a standard inertia dyno.

Anyway, I don't really care if it shows I've gone from 100 to 225 HP or 500 to 625 HP, I'd just like to see what the real effects of the upgrade are. Once I get the results in an electronic format, I'll post them. It'll probably be a few weeks before I get the after results, as the installer is going to need the car for at least 3 days (to allow shipping to RennTech, etc.).

IngenereAMG

One of our clients who has an S600 and our ECU/TCU tuning. His dyno results are 508hp/602lb ft at the wheels. Which is roughly 630/740 at the crank.

We are getting some healthy numbers, great drivability and zero issues.

Here's his reading......

StephenK

As most people on this forum know, I was and am disappointed in my RENNTECH upgrade, they advertised results that just aren't there. The dealer I go to is a Renntech dealer, any issue I am told about I had them look into.

Your ECU/TCU tune, how does it compare to RENNTECH???

With your results, why would anyone use Renntech over yours, I think your price would be consideralbly less than theirs.

I would like to see the other runs from the same car on the dyno too.

IngenereAMG

Renntech is a company with a long history and a solid reputation. When I started Veloce Performance, they were definitely one target for our MB/AMG line.

I firmly believe that we are better. I believe that our software people do a great job, and as I do most of the development driving myself... I don't release a tune until I am happy with the performance envelope. That feeling of being better, is reflected by our client's satisfaction.

Because I come from the customer side, I try to make sure that our clients are well taken care of.... before, during and after the sale. We are small enough where we can care for every car and client.

To answer your question as to why doesn't everyone use us? We don't have a six figure advertising budget, and we are still a new player on the block. But I firmly believe that over the next 5 years we are going to be a serious player. For instance, we just introduced a tune for the US SMART, and we take that car from 71 to 85 hp, which is a significant increase..... and we are the only company to release a tune for the US SMART.

So keep watching, and we would love to help you get the most out of your 600, 65, 55...

kokanee

I'm not sure you can do too much to help the sound on the 600. The turbos seem to restrict the sound. Eliminating the resonators may help. I put the complete SL55 quad tip eisenman exhaust system and while it definitly sounds better (not so much like a muted sewing machine now) it is nowhere close to the SL55 sound. I will be doing the Veloce tune soon. I thought I had paid for it already during his sale but it seems someone deleted my e-mail in the composition stage. Perhaps the wife was trying to tell me something? The exhaust with AMG rear skirt, wheels, quaife LSD is done and the baseline dyno (405 rwhp) is done.

greggafford

Keep us posted. I'm very interested to see what happens here. I have an 04 SL600 that I've been on the fence with the ECU tune for a few months now. It's hard to argue with before and after dyno numbers! Perhaps some sort of group buy would sweeten the pot!

el_do33

For $100K+ for the car and you still have to mod it, it's quite overprice IMO. No doubt that the $$$ is not as much compare to what you pay for the car but in logic sense...it's RIDICULOUS.

metalica_23

Well, you don't have to mod the car (it does have ~500hp stock after all), but people choose to. People spend $50k to add twin turbos to $200k Gallardos. People spend $50k for optional factory rims on Veyrons. Others spend $2-3k to mod ECUs on AMG cars to see a 20hp gain. It's all about personal choice.

My guess is the SL600 is plenty fast enough for 95% of people. For me, I spent $68k on the car and for an extra ~$5k or so, I can add 100+hp. To me, that's worth it. To others, it's overkill.

metalica_23

Interesting, my baseline dyno is tomorrow. Could you post your baseline graph?

The baseline dyno that Renntech sent me shows 445 max! I'm guessing I'll be closer to yours than theirs! Sounds like they started out with a pretty healthy v12!

Anyway, the baseline is just the starting point (and can vary by car, operator, weather, machine, etc.). It doesn't really matter if it's 300, 400, 500, etc. Ultimately, it's about the change from baseline to the tuned dyno!

armadillo

You are so right, this time of year, heat is the major factor, and the dynos vary widely, thank you so much for provide this information.