AMG SL 65 - LSD & Suspension

[digitist]

Lately while trying to figure out how to correctly tune my cars to my particular driving style I've been going through some of the more popular tunes to try and get a handle on how different garages tune. I've only found one tune for this particular car, the SL 65. Which I didn't like. Seems that no one even talks about it much, what with the likes of the SLR and SLS rolling around.

I adore this car, when I first bought it I tuned it only to specs of its Black Edition counterpart. Which I somehow nailed in weight, torque and HP.

Now that I've upgraded it faaaar too much and learning more about tuning I've decided to use this thread to both share and store my findings with other folks. In hopes that maybe they can learn from my mistakes or I can learn from their advice.

Parts
Tires: R3 - though I should probably have S2, I'm usually riding these with the bad tunes I've had before, so I'll leave em on for now.

Suffice it to say this beauty has been completely outfitted with everything except a wing and any turbo charging. For one, putting a wing on this car is just, well wrong. Also I can't make myself upgrade the turbo to any of the tuned kits. The SL65 comes as a V12 BiTurbo. Arguably one of the best twin turbos ever made.

This gives us the following specs:

851HP/54000RPM
871FT/4900RPM

At 1531KG Power/Weight is 1.77

[In case you are wondering:]
@ Low TurboKit: 940HP/5400, 1003FT/3400RPM
@ Mid TurboKit: 996HP/5400, 1049FT/4900RPM
@ High TurboKit: 978HP/6400, 971FT/4900RPM

I keep her with the stock turbo because I've always assumed that replacing that with one large kit would kill the BiTurbo, which currently has absolutely no noticeable lag. Though these numbers are super impressive.

LSD TUNE

I started with Motor City Tunes guide on LSD tuning and the initial settings found here.

If you haven't seen it it yet, its an excellent source of general suspension and LSD tunings to get you started, all to be fine tuned later.

Starting with IT: 10, AS: 25, BS: 15. I took the AMG around Grand Valley Speedway and within 10 laps had the following:

IT: 13
AS: 17
BS: 10


I worked back and forth, adjusting first by fives and then by smaller amounts. I must say I am thoroughly impressed with how much better the car handles even now. I had slight inside tire spin on the corner exits and a seriously pushy beast which liked to spin out on hard corners.

Suspension
Initial Setup is as follows, following MCT's advice on FR drivetrains.

RH -10 -10
SR 12.5 10
DE 7 5
DC 5 4
AB 3 5

CA 2.5 2.0
TA -.25 .20

These are excellent starting points I too would advise anyone on as both a quick FR setup or an initial point to start tuning.

After a few hours of fine tuning I get these. Feel free to try them.

RH -12 -8
SR 10.2 9.0
DE 5 3
DC 4 2
AB 2 4

CA 1.5 2.0
TA -.3 .15

Brakes @ 3 - 8
LSD @ 15, 10, 10.

Seems to work nicely, any feedback appreciated.

 

[Poppins]

I cant handle having any car with the AS on the LSD set so low, acts like the car has an open differential and only spins one tire for a couple seconds before it locks the other one in.

Other then that it is actually really close to what mine's at.

Although after remembering many many races ago when I first tuned my Buick Special I remember it always span only the OUTSIDE tire around corners which dumbfounds me. Maybe it was set too high (I usually set it at max)

 

[digitist]

I should play around with the LSD more, but you are exactly right... it is almost open being so low.

I found that it just pushed far too much when I hammered it down on corner exit, and I couldn't really get the tires to spin, so what the hell... I'll just leave it low if it gets me out of a corner faster.
Or is that only an illusion of the LSD, am I now exiting the corner just smoother not faster?

If the IT was set way up to make the differential basically locked then I suppose it would have the same affect of the AS being all the way up.
Also, with different tires I'd probably find I'd need the AS jacked way up too, it's pretty grippy with the R3's on it.

I'm going to experiment more with it I think once I'm happy with the suspension. Which is working out fairly well now. The other tunes I've seen for it just make it feel like a boat, which it most certainly is not.

 

[Poppins]

if its set low it helps with corner exits but i like to just burn both tires and try keep er straight makes it fun

 

[digitist]

Hah! Awesome.

I've messed with it a bit more but haven't come to anything definite yet. At least now I'm happy with it not being setup like the one other I've found for it which isn't very good. Not at least according to how I drive.

 

[Poppins]

Try lowering the EXT and Raising the COMP , guy in TVR thread showed me whats up with suspension if you read it you'll see his equation.