I was selling my modded SL55 to get an SL65 and just got done taking one for a test drive and I have to say I'm extremely disappointed. I was expecting more, but honestly the throttle response and shifting on the SL65 was so sluggish that I felt my SL55 was much quicker and more exciting to drive. I actually pulled into a gas station in the middle of the test drive to do the ECU reset to try and fix it but it didn't help any. I left not wanting an SL65 at all and felt it was inferior to what I already had. I also missed the little suede piece on the front of the gear shift. Everyone that has went from an SL55 to 65 has been very impressed but I walked away from the drive feeling let down. Was there something wrong with the SL65 I drove or is the SL65 that much different in power delivery? I'm completely confused.

 

The two cars are totally different in power delivery. Maybe it was the intercooler pump that was not working. I loved my 65 and it railed. 0-40 MPH, the car just spins the tires when you gas it, so maybe turn the esp off next time you drive one. The SL65 has a great motor, but it you love your SL55, keep it.

 

There might be a problem with the SL65 that you drove.

I went from a slighly modded (ECU) SL55 to a SL65 and the difference was night and day.

At first The 65 was a monster and kept trying to lite up the rear tires every time I rolled on the power plus the brakes were significantly better then my SL55! I always felt the SL55 brakes were very weak in the twisties for such a heavy car...

Then I started having problems with the intercooler pump being intermittent and for weeks the car was fast but not a monster.

I had repeated trouble convincing the dealer that the car was severly down on power because the car still had around 450-500 hp without the IC pump and to a novice MB tech (not very many have actually driven or even been in a 65) the car was very fast and they all kept saying that nothing was wrong!

Finally a somewhat experianced MB tech verified the IC pump was defective and changed the pump. The ECU computer took a while to relearn my driving style and the car is now almost as fast as before the IC pump drama.

It might be that your SL55 being heavily modded is already closer to the 65 in power but I doubt it. The torque in the 65 is amazing and almost uncontrolable, the car definately needs more tire in the rear like the Viper but unfortunately they wont fit. I just got larger 295x30x19s that should help just a little.

I live in Malibu and there are 10 AMAZING canyon roads all within 5 minutes. I have a lot of professional high speed driving experiance and in my opinion there is very little difference when pushing very hard through the twisties between the SL55 and SL65 even though the 65 weighs about 150lbs more. The biggest problem is trying to keept the 65 going in a straight line when you roll on the power even at speed! And again the 65 brakes are absolutely fantastic! (the SL55 030 brakes are SL65 I think)

Also I noticed (and it might be the 19 inch tires) but the suspension definately is much firmer (almost to firm)on the SL65.

JMHO

 

Drive another and tell that guy to get his I/C pump fixed.

 

My SL55 has ECU, pulley, and upgraded cooling. Everyone that has driven it says the responsiveness on my car is insane, and this is from other AMG owners. It could just be I'm used to mine being so explosive when I touch the gas that other cars feel tame. 451 rwhp 560 torque on a dynodynamics machine, not a dynojet which would read even higher.

I don't know, I just kept flooring the gas in the 65 wondering where the go fast was. It didn't seem to pull hard on the highway and I was equally unimpressed at the stop lights. It was an 06 SL65 with the same options as mine and 11k miles.

 

I'm surprised. My E is over 470 RWHP and the only SL65 I ever rode in would absolutely destroy it. Of course, it was a Renntech car. I'm thinking it was a wounded example. Keep looking, and good luck.

 

The SL65 when running correctly should explode with raw power!

604 HP aint no joke and 740 lbs of torque is insane for any car! The SL65 feels similar to my 1966 427 Cobra or my 2001 Viper. Obviously the Cobra was much smaller and lighter but the SL65 likes to fish tail when you jump on it like the Cobra or Viper (until the TC takes over)

The wife when the car starts to slide sideways under accelleration is constantly saying "what wrong with the car why does it keep doing that?"

I say "yes dear I just hate when that happens!" :-) Then I jump on it again!

 

Perhaps he was feeling a bit of turbo lag in the 65.

When we tune the 55K cars, we get the SC to come on around 1100-1400 rpm, which gives the cars the feeling of instant power.

Or it just might be a shot IC pump on that 65!

 

I didn't think the 65s really suffered that much from turbo lag. Whatever it was it left me wanting. It's sad because the 65 was going to be a reward to myself for something, but now I don't really want it and I'm not really interested in anything else.

 

How about upgrading to VR700?

 

+1. Definitely something is wrong with the one you drove.

 

You all could very well be right. It didn't make sense that it was so sluggish. Unfortunatly there isn't another around that I could try out to be sure.

 

There is one in Fort Worth for sale, HLmotorcars.com. The 65 just has to be driven differently then the 55 to get the power out of it. Also, when it's over 90 outside the 65 feels really slow but once one masters the throttle application on this car (it took me a few days to figure it out) this can be overcome. It's not a punch and go car like the 55 is. Half throttle is alot faster then WOT on a non-modified 65 when driving around town. On the highway WOT is fine but at lower speeds it does not work well at all.

 

either you were spinning the tires the whole time, or a bad IC pump..... any of the 65's are crazy at any speed.....

 

what about sl63?

 

sl600 feels slower when hot.i have new intercooler pump.

 

My SL65 would yank the paint off my SL55 something is wrong with the one you drove.

 

I had EXACTLY the same experience. I decided to either buy a newer SL55
or an older SL65. I found the SL65 big and heavy feeling, even when I flattened it the acceleration felt tame, maybe because it was so quiet!
After the sales guy drove my SL55 with me in as well. even he admitted
the SL55 felt more lively and exciting, so I bought a new SL63. Great car.:

 

Looks like the OP ended up with an SL65 after all.

 

Yes, a different one that ran better about 2 months later. The one I test drove was definately ill. The new one put my modded SL55 to shame.

 

Congrats and I knew the previous car had some issue, IC pump issue on any AMG car such as supercharged V8s and V12TTs mean power loss and sluggishness, car drives in limp mode and is way underpowered and unresponsive. How do you like your SL65 from the stoplights and from a roll? Tuning the ECU anytime soon?

 

Looks like you are wrong again. The OP tried another car and was wowed by the power and now has a 65. All this is amazing considering your claim to have owned a CL65....

-Rob

 

Does the new intercooler pump make a difference?

 

Big time, bad IC Pump= down on power and car drives sluggishly/limp mode, one big thing about FI cars (especially the Mecedes M113 5.4 V8 SC and M275 5.5L and 6.0L V12TT) is that cooling is quite essential. Adequate cooling won't be achieved if there is a bad IC pump. Cars with a bad IC pump and got a new one is now a completely different animal according to owners experiences.

 

What is the cost of replacing IC pump (labor included) on the V12?

I am curious to hear endri's response since we have the same car.