blueSL

Almost had a major accident yesterday after I under-estimated how long it would take to pass a truck (on an undivided road) and pull in safely in the face of another truck coming the other way.

Turned out the SL55 seemingly took forever to get past the truck even though I had preselected 3rd gear, and the turn in to get back in lane was pretty soggy. Only just made it.

Haven't been using the SL55 much recently and this heart-stopping moment convinced me the 996 TT is MUCH quicker in a straight line, MUCH more nimble to turn in and, on the roads I drive, a MUCH safer car.

regor60

or maybe, just maybe mind you, you made a bad decision ?

BoBcanada

its all about the driver.

DFW01E55

I've had a 996TT and a 55 and I disagree. As a matter of fact, with the ASP pulley my CL55 is significantly faster in a straight line.

Your IC pump okay? That's a very common problem and drops your performance down to econo-box range.

Or maybe, just maybe mind you, regor is right.

SoS SWATxV2

Yup true. That or you just suck at whatever JK.

I/C Pump okay?

Vic55

When is the last time your 5 year old car saw the doctor? I mean, how long have you had it and is this an isolated incident or maybe as DFW said your IC is going bad? Any other times you have complained??

I had a stage III 996TT pushing 560hp and my E55, modded as well, pulled better.

xraes

Sorry, have owned both and I disagree.

IngenereAMG

The SL55 is no slouch, even compared to the Turbo Porcky. But this sounds like either a poor choice or an IC pump issue that would make the car down on power.

blueSL

Certainly accept my judgement was off, but it was calibrated based on my experience of the 996 TT.

Stock, the 996 TT is the quicker car, it has a higher power to weight ratio so that providing you are in the correct gear, this will translate to better performance.

My SL55 has just been in the shop, no sign of any problems, it's just not as quick, as sure-footed and as nimble as the 911. How could 493bhp/1955kg be faster than 420bhp/1530kg?

If you think otherwise, you're trying to re-write the laws of physics.

Fast55

Without specifically looking for an IC pump problem, it's easily missed. No, the Sl is not a 996 in the corners, but unless your judgement is failing, the car didn't move as fast as it once did, else you would have had enough time to safely pass no? Being an '03, I would definitely do some data logging and/or dyno the car to be sure. If you're still not happy, do a pulley/ECU and cooling upgrade and you will certainly enjoy the car more.

WSH

Had various new 996TTS/997TT and SL55/65 (at times simultaneously)....disagree w/your conclusions....all great cars in their day, but all somewhat dated tech today...but would argue, overall, new SL55 is just as safe as any new 997TT in active safety....suspect 997TT's rigid coupe body/roof struc may offer superior passive safety vs any retractable hardtop (even when closed)....and SL65 does have traction issues on wet/bumpy roads that may compromise its active safety vs 997TT....

997TT has turbo lag/tq issues (have always had greater confidence in 55/65 tq/gearbox speeds than in 997TT's turbo lag in solving daily traffic "jigsaw puzzles" on busy urban freeways); gear selec error risk w/manual; chassis damping issues on bumpy roads; and high-speed stability weaknesses, esp on bumpy, hilly freeways, as well as cross-wind stability issues....not convinced its steering is necessarily more precise/well-damped vs SL at speed on imperfect public roads....agree, PCCB offers markedly better pedal feel than SL's...but found SL braking superior to PCCB in rain/wet conds...

Fantasm

So if you know this (whether your car is having an issue or not), then why are you trying to drive it against the laws of physics?

Goyard

The SL55 is quicker than your Porsche in a straight line.

You need to get that IC Pump checked asap!

JackStraw

I am sure that blueSL would notice a performance decrement in his SL that was due to a malfunction. He has had his SL55 almost since the launch and is as knowledgeable about the vehicle as anyone on this board.

This whole intercooler issue has arisen only in the last year or so and my guess is that it is being perpetuated by people who want to sell new intercoolers.

Don't cut it so close next time blueSL.

whoover

It's not the intercooler. It's the intercooler coolant pump, and it's a very common failure on MB supercharged engines. If the pump on a 2003 is original, it's due to fail. Lack of coolant recirculation means the intercooler doesn't cool. When intake air temperature rises, the ECU turn off the supercharger. It's not about a better intercooler via modding. It's about the one you have not switching on.

DFW01E55

Nice of you to come to Blue's defense Jack, but as whoover points out, this is not about intercoolers.

It's the intercooler pump and it's been malfunctioning since MB put them in the 55k cars.

Also, please notice that Blue said, "seemingly took forever to get past the truck" --- that's just not normal with a 55K engine. Hence the easy diagnosis of intercooler pump.

Fantasm

The intercooler pump issue is a documented and proven issue, with dealership warranty replacements and only recently has the Johnson pump movement started... and even so they are usually purchased from random ebay sellers, not any particular vendor, so your statement is false and unfounded.

Not to mention that the Johnson IC pump is actually a true upgrade with a higher volume capacity for recirculation and is less than $100!
Even if you arn't seeing issues, I would still do this upgrade right away! Can't beat lower IATs and stronger butt-dyno feeling for all under $100... especially with the cost of normal upgrades for MBZ.

EXECMALIBU

Whats the story on the Johnson IC pump and where can I get one?

JackStraw

I know we are talking about the intercooler pump, sorry if I confused everyone with the shorthand. My view on this issue has been shaped by the discussion on these boards of inadequacy of the intercooler pumps on the V12 which leads to my cynicism.

That being said, If the change in performance is as great as is being stated here, then I am sure that blueSL would have said "something is wrong with my SL55" rather than "SL55 is no sports car".

Exodus

Yeah... do you have any friends? Ask one of them to drive your SL55 while you pilot the 996TT and see who comes out on top.

JackStraw

$100 is a lot more palatable than the $3,500 that Renntech is charging for its upgraded pumps for the 55 and 600.

ndabunka

Sounds like you "thought" the TT would have "made it" easily. This, in fact may have been your second error. Consider for a moment that you mis-judged the speed of the oncoming traffic (i.e. the oncoming truck was potentially speeding excessively). You made an error in judgement and lived to regret it. If you still don't think that is the case, you can give me the 55. Just IM me to let me know where to pick it up!

MSL01

Do what I did - sell the SL55 and buy an SL65. Then Renntech the ECU/TCU and you'll have a car that'll pass anything, anytime while giving you a touch of whiplash . That's what I did and I'm not in anyone's rear view mirror anymore.

Fantasm

I haven't found any videos of an SL65 where the exhaust note has made me think "damn thats a monster"

Can you post some full WOT takeoffs and drivebys MSL01?

Hazy1

The problem is that the IC pump typically degrades the performance slowly over time when it starts to fail (via ECU detuning when IAT's rise too high). I wasn't fully aware of the problem that mine had until the supercharger shut off during several back to back high speed runs. At that point, you could out-accellerate the car with nearly anything and there is no questioning that something is dramatically wrong. Prior to that, the car just felt a little sluggish, but not slow by any means.