toi

Iphone

Dr. Manhattan

In order to forestall the above-mentioned lack of traction, I'm considering obtaining a differential unit from an SL63 (posi) as a prelude to getting a tune. I have no way of knowing whether the gear ratio is the same as the one in my SL450, or if not, could my gear set be swapped into the AMG diff? I'm not interested in changing my final drive ratio from stock. It blows my mind that I have to scrounge and add posi to a $98k "sporty" two-seater. I sure hope the 550 guys already have it...I can't imagine having that much more power without it.

crconsulting

You’re looking for a diff with a 3.067 gear ratio. The SL63 will have a 2.65 gear ratio. Not only the SL63, but the E63, C63, and CLS63 diff’s are interchangeable with the SL550 (R231). Recently swapped the one in my SL550’s with a LSD out of a low mileage e63. Somewhat easy swap…
I think in your case it may be easier to swap out the carrier to keep the same gear ratio 3.067

The r231 is somewhat prone to understeer which can be exasperated under certain conditions with too much “lock”.
The factory chose the Drexler 2-way clutch type differential with 40% torque transfer under acceleration and 60% under deceleration. Though the exact spec is elusive as that particular carrier isn’t sold separately…



Mercedes HAG215 Drexler/AMG Rear Differential assembly (option 471)

AMG Rectifier

Drexler LSD AMG part number.

billvp218

The 2013-2014 R231 SL63 did not come with an LSD, unless it had the performance package ... I think from 2015 on it was standard since the performance package option was no more (all had it).

I'm not sure if any SL550 had an LSD even as an option, although I'm no expert on them.

I added a Wavetrac LSD to my SL63 - it is part 48.309.185WK. Their chart on the website is a bit dated, so I had to send an email asking, but Wavetrac recommends that one for the SL63 and the E63 and many other Mercedes vehicles and it is apparently a direct swap (I didn't do the install, but there were no issues noted from the shop that did it). You can get them for under $1000 new, and they are designed & manufactured in the USA.

ThatsMyDawg

Hey, just curious about what other cars are around you that your SL400 can basically out perform? Perhaps you mean since performance mods?

I ask this because even though I love my stock SL (and I really do, it is one of my dream cars) there is nothing impressive about it’s performance. I actually think the car under performs based on the price points of the SL and it’s factory hp. When you have a 55, or higher you get solid power, but the 400 should have came minimum with 400 hp at the 100k + price IMO.

Again, I love my car, because the SL is truly a beautiful car, but I am looking the other way when most cars are beside me on the highway ie: Mustang, Charger, Camaro, practically any Subaru, etc. The SL looks better than 100% of them, and out classes them all and it ain’t even close, but out performing them? Not so much.

crconsulting

That is one of the reasons they are tougher to find. But the E63 and CLS63 seem to be more abundant.

It was NOT an option for the sl550.

They do fit, but it requires some modification to the housing. It’s not a major issue, but will add to the installation costs.
I think this is the best course of action for sl400 and SL450 owners though (3.06 final drive ratio). It wouldn’t really make sense $$$ wise to do the factory Drexler LSD swap for an SL450 if you’re not doing it yourself. Quaife is also another readily available mfg’er of torque bias diffs you may want to look at.

billvp218, what did they charge for labor on that Wavetrac installation?

JettaRed

iTrader: (1)

Since the tune, the car scoots quicker than it feels. Several times I have pulled onto the highway and look down to see that I’m in the 3-digits range. I don’t street race and no one ever seems to want to “challenge” me. I dunno. Maybe it’s because I live in The Villages. (J/K).

billvp218

The labor was about $1,000.

JettaRed

iTrader: (1)

Weistec has a turbo upgrade for the SL400/SL450 that will boost HP to 540hp. Now, THAT'S worth pondering!

Mercedes Benz AMG M276 W.3 Turbo Upgrade C43 E43 | Weistec

ThatsMyDawg

I would be completely happy with that power addition, however I wonder what’s the deal with saying it’s non street use only and why it will effect emission testing where states require it? ?

JettaRed

iTrader: (1)

That's standard now for any kind of engine performance mod so that the EPA doesn't come along and fine the companies into bankruptcy.

Welcome to Uncle Joe's World.

billvp218

I'm not knowledgeable about the process, but Wavetrac did say that the final gear ratio isn't changed - that you transfer your ring and pinion over during the installation.

crconsulting

Correct. You’re just swapping your existing ring gear on the new Wavetrac (or Quaife) carrier. That’s why I mentioned it’s probably the best course of action for SL400/450 owners.
There really isn’t a LSD assembly from the factory or AMG with the proper gear ratio they need.
Just make sure you take it to a reputable shop that will either properly install or outsource the ring and Wavetrac carrier install. They’ll need to check backlash and pinion depth (gear pattern) and adjust if necessary.
If they don’t set it properly, or have the correct tools (you need to spread the differential housing to preload it in order to simulate installed environment), you might experience diff noise or have gear wear issues down the road : (

And btw $1000, is very reasonable for that amount of labor. 👍

JettaRed

iTrader: (1)

From what I have been able to determine, you need to send your stock turbos to Weistec for modification. You should also get their tune. Lastly, it's recommended to install a water/meth kit for optimal performance. All together (minus labor) you are close to $7500 (retail) to get 540hp. You could shop around and probably bring that down a bit. I know Vivid Racing resells the turbo upgrade for $3000 versus $3300. And Snow Performance has a water/meth injection kit for about $600 versus $1500. The Weistec tune is still about $2400 (with handheld flasher). So maybe around $6000 to get close to SL63 hp.

I'm just concerned about the transmission and drivetrain.

Wolfman

Except you won't get anywhere close to an SL63. That is just the better SL all around if performance is the focus. Besides the engine, the car has a better AMG-tuned ABC suspension, most likely the aforementioned LSD, better forged wheels, plus better looking front fascia, seats, center console etc.
The SL450 is a great convertible with a nice balanced ride but it isn't a performance car and rather than spending too much money on performance upgrades it may make sense to switch models at that point.

JettaRed

iTrader: (1)

I know. I wasn't suggesting the mod would make it into an SL63, just that for between $6000 and $7500 you could get some respectable performance out of that little V6. I like sleepers. An AMG car is rather obvious.

Dr. Manhattan

Well, folks...a lot of good info to unpack here regarding differentials. Thanks so much for the out-pouring. Actually, I have to agree that for my 450 the most sensible/desirable route would be to put a WaveTrack in my housing. I've been to their site and searched for my car's application...to no avail. However, as some of you have made me aware, the AMG diff (in posi form) is also used in other, far more numerous applications than the paltry few SL63s out there. WooHoo! I don't know about whatever mods to the housing it takes to get WaveTrack's unit in there, but the pinion depth shouldn't need to be touched...resetting the backlash should be all that's required. I'm not too worried about understeer. Pounding the tight twisties in the north Georgia mountains has revealed a car that's currently amazingly neutral...though I can't turn off all the nannies like you can in the 63. Back in the late '60s-early '70s, the rap on Corvettes was if you wanted a Corvette that handled, you went with a small block. That was the magic of my first Corvette ('70 LT-1)...it had the handling of a small block with the power of a big block. The 450 is a bit like that...handling-wise. Obviously, it's no 911 or Corvette as sports cars go, but I'm very pleasantly surprised by how well it really does handle. I wouldn't mind more brakes (AMG?), but that's a subject for a different thread.

Regarding whether or not I choose to get a tune for my 450...I couldn't care less if my car is emissions-legal. However, I do care very much that it should remain emissions-compliant at part-throttle. If any tuner can't promise me that, then I won't do it at all. Weistec (as well as others) want(s) the removal of the cats for that level of power, and that just is not happening on my car. That LT-1 Corvette that I owned had to be one of the worst emitters ever produced. It's aggressive solid-lifter cam and Holley toilet would barely allow it to idle at 900 rpm. If you stood behind that car while it was idling, you'd start coughing and your eyes would start to burn. I won a few bets from people on how long they could stand there an take it before staggering away coughing. That was the start of my acceptance of emission regs. Thankfully, the tech eventually caught up with the regs and we all ended up with cars that not only were far cleaner, but ran better as well. My SL450 does run quite well right now. It's just as fast as my current C4 Grand Sport, and though it's 400-500 lbs heavier, it gets better fuel economy too. So, to those who suggest the SL450 isn't a "sports car", while I admit that may be true, I'm pretty sure it fits the traditional definition more closely than the SL550.



Seriously. Seriously? This forum has plenty of older members...members old enough to realize that the whole EPA/emissions deal has been with us for decades. It did not start in 2020.

crconsulting

As billvp218 mentioned, the correct Wavetrac part number for the HAG215 in the r231’s is 48.309.185WK
Call them to confirm…
The modification is, you need to grind a little off the inside the housing for clearance. If you talk to them, they’ll explain the process.

Usually (and hopefully), but it will be dictated by your gear pattern and checked anyways. Whoever installs, should use a fixture to spread the housing to specification as I mentioned.
Here’s one DIY solution:
https://mbworld.org/forums/w211-amg/...lsd-setup.html

These heavy cars need as much brake as they can get. Short of going to the dealer, things get a little tougher as far as interchangeably. Unfortunately your options are limited to either the S63/65 (W222), SL63/65 (R231)and some Maybach’s that use the Brembo 6 piston front calipers. They were tough to find not beat to $h!t…

Good luck on your upgrade journey 👍


B06 AMG Brakes-SL550

JettaRed

iTrader: (1)

Well, have you seen such disclaimers before this administration? And it is more than a mere disclaimer. For my Vivid Racing tune, I actually had to print and sign, scan and return a form. You can no longer passively ignore the warning, you must definitively acknowledge it.

I'm not trying to be political, but just making an observation.

billvp218

it's been going on for a while, but recently the EPA decided on a new "interpretation" of the CAA

Dr. Manhattan

So these are the SL63 brakes? I'm surprised they used sliding calipers on the rear...not that there's anything wrong with sliding calipers. The brakes on my Grand Sport all have sliding calipers and they're the firmest, most easily modulated brakes I've ever owned or driven. I wish the performance package brakes on my 450 felt even half as good.

Btw, thanks for posting all the great info. I know it'll help me in the future.

toi

Had a 2006 regular corvette with automatic transmission. Had the 6 liter 400hp lt2 in it.

spent a good chunck of money exhaust,supercharging it widening the rear fenders with bigger tires, aero kits etc. ended being a great looking car and i had my pleasure driving it.
come to sell it , yes all those mods put it in front of the line for buyers but you need that specific person that wants similar to what you have done to the car.

anyways, i did tune my 14 sl550 and performance wise i dont need to shave of 1/10th off seconds modding it further.
just did steering wheel exhaust and diffuser and leave it at that.

without launch control having an lsd on our cars will not make a huge difference by the way.
if you are racing an SL , look for a high stall torque converter and that’ll give you great results.

billvp218

there aren't many SL63 with mods to compare to, but rwd E63 & CLS63 without LSD have more problems with traction than I do (anecdotally), with them at lower power levels

At anything over 40* outside, I can floor it at 45+ mph in gear and it won't spin beyond a little chirp - and I'm at roughly 900hp/tq to the crank. That's on Michelin PS4S, so good tires but definitely street tires.

crconsulting

Yes, those are base AMG SL63 brakes.
The rear caliper design is due to the parking brake going electronic. It’s not my favorite caliper either, but it works on the street. The real upgrade for the rear is the larger rotor.
The rear on the non AMG cars is the same design, just smaller. 320mm vs 360mm. All share the exact same parking brake mechanism. You just bolt them up to the larger caliper. For what it’s worth, that TRW rear caliper design is used on BMW and a whole bunch of other manufacturers

As mentioned, if you’re looking for interchangeability, the AMG Brembo/TRW brake combo is identical on the W222 S class and R231’s. It will be a noticeable upgrade especially if you don’t have the “sport” brakes as the fronts are 340mm vs 360mm(sport) and 390mm for the B06 AMG brakes..



AMG B06 Front and Rear Brakes.

Front AMG 6 piston Brembo Calipers and 2 piece Brembo 390mm Rotor

Rear AMG B06 360mm TRW Brakes

crconsulting

You’re talking about drag racing…
Haha, I think there’s only a handful of drag strips in Germany.
These are road cars designed for the Autobahn more than drag racing. I use the word RACING loosely here, as the SL really is a GT not a race car. Especially the regular SL’s . The SL63 is on the spectrum of what one might consider more of a “road racer”. I get that drag racing is a measure of raw power but would personally never drag an SL. Not saying it’s not doable, but these heavy (muscle) cars put out a $h!t ton of torque and have (relatively) excellent traction. In stock form, engine and trans mounts would be a weak point right off the top.

What you’ll notice with a LSD on the regular SL, is the reduction in traction control intervention when cornering. Also when pushed hard, the car squats more evenly coming out of turns. Best way I can describe it is, launch vs lurch from turn to turn. Much of this will depend on a drivers core perceptual/cognitive experience. Some drivers will feel a difference, some won’t…