CL-Class (W215) 2000-2006: CL 500, CL 600

Renntech Hand Held Tuner CL600 review

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Old Sep 13, 2016 | 05:33 AM
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CL600 Bi Turbo 2003 Renntech, BMW E39 530D SE
Renntech Hand Held Tuner CL600 review

Hi

Thought i'd write this for anyone who is considering buying the Renntech Remap/Handheld Tuner for the CL600 Bi-Turbo.

One word..amazing!

I decided to get the handheld tuner as you can go back to a standard tune as and when required with a flick of a switch which living in the UK can be useful as when it rains 625bhp has no use!

I have been running the map now for about 6months with no issues, only tyre and brake wear. Before though i did fit new coil packs,spark plugs as one coil pack was faulty, new Ignition control unit to be on the safe side and changed all fluids and uprated Bosch charge cooler pump.

There are from what i have seen other maps which are cheaper and some give more power but stuck with Renntech due to their reputation.

Its a very odd sensation as no matter what speed you drive at, it pulls the same wether 0-60mph or 60-150+ just ridiculous!

Only draw back i have found is when driving slow around towns/cities you feel like your "riding" the brakes more than usual as its always wanting to go if that makes sense. But then if you do drive around town, you can always go back to the standard tune. Once plugged in the map takes about 2-3mins to upload the file.

Hope that helps as i always think its good to give something back to the community, and as always keep it sideways!

Last edited by bennybelmont; Sep 13, 2016 at 05:36 AM.
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Old Sep 13, 2016 | 07:33 AM
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Interesting, thank you for sharing. I just got an ECU and TCU tune from Kleemann and am enjoying it so far. My review is to come. I did not do all of your prep, I kind of just threw it on there. For me, the car drives very similar to how it did before, unless I put my boot in it. Has the upgraded pump shown any benefit?
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Old Sep 13, 2016 | 07:54 AM
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CL600 Bi Turbo 2003 Renntech, BMW E39 530D SE
I was looking at the Kleeman one too i just like the idea of having standard and tuned. Yeah i only did prep work as one of the coil packs was broke anyway so thought, do the rest whilst i'm at it. Has the TCU upgrade any difference? I can get that as an extra upgrade too but quite happy with the gearbox as it is for now.
Only difference i've found is it pulls strong right up to the red line where as before with the old pump (which was dead) just didnt feel to pull as strong like the power tethered off. I think though the pump some recommend the Johnson one but i just like the plug and play of the Bosch.
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Old Sep 13, 2016 | 08:21 AM
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2018 C300
Originally Posted by bennybelmont
I was looking at the Kleeman one too i just like the idea of having standard and tuned. Yeah i only did prep work as one of the coil packs was broke anyway so thought, do the rest whilst i'm at it. Has the TCU upgrade any difference? I can get that as an extra upgrade too but quite happy with the gearbox as it is for now.
Only difference i've found is it pulls strong right up to the red line where as before with the old pump (which was dead) just didnt feel to pull as strong like the power tethered off. I think though the pump some recommend the Johnson one but i just like the plug and play of the Bosch.
Fair enough. I was worried about running into the factory engineered torque limits, so having the TCU tuned removed them. They say it now shifts very much like an AMG but mostly I've noticed that it kicks down easier and quicker, holds gears a little longer, and when coasting down, it downshifts and keeps in gear, so if you get back on the gas it has a quicker response. If it's shifting quicker, I can't tell, it was pretty quick before. Also, I think the redline was extended 250rpm, but I'm not sure if that's in the TCU or ECU.
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Old Sep 15, 2016 | 02:47 PM
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03 CL600
Hmm good review. Im most likely going to get the renntech HHT for my cl600 because it is much more convenient for me to just plug and play vs removing the ECU and shipping it. I also like the fact that you can switch off the tune as you feel. Thanks for the review.
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Old Sep 17, 2016 | 12:59 PM
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When I had my CL600, I shipped the ECU and TCU off to Renntech. The handheld tuner was not an option. On mine, I gained 125 rwhp with just the tune. Totally transformed the car.
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Old Sep 18, 2016 | 04:09 AM
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Originally Posted by bennybelmont
Only draw back i have found is when driving slow around towns/cities you feel like your "riding" the brakes more than usual as its always wanting to go if that makes sense. But then if you do drive around town, you can always go back to the standard tune. Once .......
That's interesting. Is the idle speed any higher?

One thing I'm very aware of in my Eurocharged tuned car is that it DOESN'T creep like other automatics do, especially in reverse, and it needs a surprising amount of revs to pull away slowly.
Its like the torque convertor is slipping, or there's a brake being applied within the transmission.

I didn't think a tune would affect this sort of thing, but maybe yours does?

Cheers, Nick
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Old Sep 18, 2016 | 01:52 PM
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Are you sure your car isn't starting off in second, Nick? I know mine does in comfort mode, but in sport it takes off like a normal car. In reverse, it does take more effort than most cars, but not overly so. I've noted no tendency to have to ride the brakes, but I did also have the TCU tuned as well.
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Old Sep 19, 2016 | 12:55 AM
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Mercedes do not have the same idle creep that other cars do. Volvo also don't have it
Regardless of that I always Leave mine in sport it feels sluggish in C
On some years it was called S and W for winter mode as it would start the transmission in second
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Old Sep 19, 2016 | 04:26 PM
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CL600 Bi Turbo 2003 Renntech, BMW E39 530D SE
Originally Posted by Welwynnick
That's interesting. Is the idle speed any higher?

One thing I'm very aware of in my Eurocharged tuned car is that it DOESN'T creep like other automatics do, especially in reverse, and it needs a surprising amount of revs to pull away slowly.
Its like the torque convertor is slipping, or there's a brake being applied within the transmission.

I didn't think a tune would affect this sort of thing, but maybe yours does?

Cheers, Nick
Hi

Idle speed is the same, just seems to have more low down grunt. Even with standard exhaust too it sounds more throaty at idle when on the tune, unless its just in my head? Either way good fun!
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