550 aftermarket springs and shocks

Dave- I do not know anybody who revalves the Mannesmann-Sachs shocks for the 575M. Does not mean there is not anybody, just means I have not heard of them.

FBB- The 26s are Parachute Adams. Very common on the San Juan. That combination also works well on the Big Horn near the dam.

Philip- I put the HGTC alignment specs in the VIN vs Assembly Number thread. This time around, it has the shock length between the threaded collar and upper spacer in addition to height from the flanblocks. More useful if running non-OEM wheels and tires. Forgot you had the HGTC bar instead of the FHP bar.

 

Oops, I was referring to Bilsteins on the 550, forgot pma1010 was talking about the 575.

 

I have sent Rob an email regarding re-valving the MS shocks. I'll let you know the outcome. Philip

 

Philip- These guys say they do Sachs racing shocks and there is another one in the UK.

Shock Repairs and Rebuilds

I actually do not think you are undershocked, but what do I know? What shock ECU are you running? That makes a huge difference.

 

Thanks Terry. Rob S's delta vee email address bounced so if anyone has an email for him, please PM or post.

I do have the uprated shock ECU which I sourced from Eurospares (IIRC) along with the ARB.

It should "wobble" if grossly under shocked, not damping the spring's natural oscillations. Don't see that. But it is also "not stiff". On my old Miata I had Tokico adjustable shocks. Went from Lincoln to close to board stiff through the range of adjustments.

"Sport" setting does little. I am not sure I can tell a difference versus "non-sport". Is there a way to test?

 

I've never been able to discern any difference in the sport setting which is one of the reasons I used the sport switch to select FHP steering in my selectable steering mod.

In the 355 there was a noticeable difference between sport and normal.

 

Well, at least it is not me being clueless!

 

Philip-Delta Vee url. The contact script on the bottom is hard to see, but it is there on one of the pages. Plus a phone number.

Delta Vee Motorsports ? Race Engineering ? Ferrari Bilstein Shock Absorbers, Dampers ? Moton AST ? Rebuild Services

 

Thanks Terry. Take 2 on Rob S via your link. Be cool if there was just an update that could be made to the shock ECU where the base setting was the current sport and a new setting could be programmed that was quite a bit firmer than the current sport.

Philip

 

Rob indicates the MS shocks have a crimp at the top to inhibit disassembly. Not an easily serviced item today. He also indicates they have about the same range of adjustment as the Bilsteens on the 550.

I seem to recall earlier in this thread we concluded the shocks would be set full hard if we pulled the switch. Sounds like that's a next step as a "look see".

Philip

 

Philip- That would not be that hard to do since 0 amps to the actuator is full hard and 1.8 amps is full soft. Eric355 has had good luck with TCUs and is currently copying an HGTC TCU I sent him, but from what I remember, he was unable to fiddle with shock absorber ECUs. Might be worthwhile asking him. There were also Group 4 and Group 5 algorithms for the shock actuators.

Note there is a curve for the shock actuators that is speed related, much like the hydraulic steering ECU. That curve could also be modified to bring in stiffer settings at lower speeds if someone could get into the software.

 

Terry, thanks. As I said, I'll pull the switch. If it has 0 volts and I can feel little difference then there's no point to revising the programming in the shock ECU and i'll be at a decision point (do nothing, spend some money etc). If it is material change from pulling the switch, then its either a bypass switch (assuming it doesn't trigger a fault on the display) or revised programming and if the later, I'll reach out to Eric (or anyone else that wants to take this on).

What were Group 4 or Group 5 algorithms?

Carl, I do think the system is quite clever. I have not read enough to understand all its inputs and processes, but empirically, it does firm up at speed when subject to lateral load (say on an on-ramp) and the car handles well in higher speed turns (80 - 100mph) on the track.

Separately, I tend to leave the ASR switched on and do so at the track too. You could feel it operating during higher speed turns where an inside wheel was on a curb and the throttle was all the way down. Assume it cuts spark or changes throttle position.

Philip

 

Philip- Everything except for changing the programming will usually set the suspension lamp. Group 4 and 5 were FIA racing classes when the 575M was being built.

I think with 0 amps, she will ride like a truck.

 

If true, and this means "as hard as a board" this is perfect. We know the shocks have the range of adjustment and then it's a question of programming.

 

Pulled switch. Looks like a relay (bulky, lots of prongs). Triggered warning light. May be slightly firmer but not like a board. Comes down to springs.

 

Reserecting an old thread.

I pulled off the hgtc-spec springs from my car and have gone for a firmer set up. Not too hard - it does not crash over our pot holed roads in the Midwest - but noticably firmer and more akin to my taste. SSS are going to re-powercoat the springs I have removed (400f, 250r) which are close to the hgtc specs as you can read in this thread.

I need to connect w/Ken on the thicker rear bar and of I go this way I'll sell the hgtc bar with the springs. PM me if anyone is interested in them.

Philip

 

Sorry to bump an old thread here, but could you point me to the Moton setup you're using? Part number would be great...and the Eibach springs you're using as well if not too much trouble.

My complaints with my car are identical to what you have described. I love my 550 but I miss the handling of my 355, but I think if I can resolve this floating front end on acceleration and body roll in corners I would be much more satisfied.

 

I recently had both the front inner and outer tie rods replaced on my 99 550 along with all the bushings on the front control arms. The effect after was a significant improvement in the feel and accuracy of the steering inputs along with a much improved feeling over imperfect surfaces. I thought about the Moton’s at one point but I’m glad I decided not to, the car when properly refreshed has a perfect balance.

 

What's the mileage on your car?

Mine is at about 22,500mi right now...I supposed age could have deteriorated them. I'll have the suspension gone through this summer to see if there's anything that could be replaced I suppose.

 

20k miles.

 

I'm currently swapping to MSO coilovers on my car. Waiting on them to be manufactured and will post up more info once they come in.

 

There is a MSA Damper, but not aware of any MSO. Factory in Italy was shut down for COVID-19 and supposedly reopening this week.