Review: 3DM Öhlins R&T kit + TMS camber plates + Syncro Design Works tension arms

[IamFODI]

Thanks for the props, guys. Just trying to put out something as honest, thoughtful, and useful as I can.

[hansbrix]

Great review. I'm glad you took the time to write this up. I have an E60 M5 and I've been thinking about a custom setup also. It is essentially the same suspension design, but a bit heavier of a car. New stock struts/shocks are stupidly expensive, and it's approaching the price of one of these high end setups, KW and Bilstein have setups, but sometimes I'm a glutton for punishment. Did you do any theoretical calculations or simulation? Seems like you also have some background in vehicle dynamics too. I also have my own alignment machine, corner weighting scales, road force balancer, and tire machine.

[IamFODI]

Great review. I'm glad you took the time to write this up. I have an E60 M5 and I've been thinking about a custom setup also. It is essentially the same suspension design, but a bit heavier of a car. New stock struts/shocks are stupidly expensive, and it's approaching the price of one of these high end setups, KW and Bilstein have setups, but sometimes I'm a glutton for punishment. Did you do any theoretical calculations or simulation? Seems like you also have some background in vehicle dynamics too. I also have my own alignment machine, corner weighting scales, road force balancer, and tire machine.

Thanks!

Man, I wish I had an actual background in vehicle dynamics. This is just a hobby for me, and not even one I've gotten that deep into.

When you say theoretical calculations, does that include plugging stuff into suspension calculator spreadsheets? 🤣 I did some of that mainly to try to assess ride frequencies and front/rear roll couples to see how feasible flat ride would be. As I mentioned in the second post, I ended up abandoning that effort, mainly because I couldn't imagine I had the juice to see it through when none of the real experts had even tried. Didn't do anything more sophisticated than that, let alone simulations.

[hansbrix]

Well that was along time ago and I neither had the time or money to do have a decent car. Time has since passed and I have some toys and tools now, it's a hobby for me too. But even back 20 years ago there were standalone programs where you could model the kinematics. I'm sure there are ex Fomula SAE nerds that have done a bunch of modeling. I also did quite a bit of chassis and ride development after college in an earlier life and I was impressed by your ability to articulate the subtleties of ride and handling trade offs. For obvisous reasons it seems only engineers tend to understand and can discuss these topics, it's a bit usually to see this level of intelligent discussion on forums.

I was catching up on more posts since I haven't been on the site for a while. I see you have your vibrations stuff sorted out. 6-7 lbs of force variation is pretty good, the default limit on the machine is set at 26 lbs if I recall correctly, but you can change that and the read out will tell you the exact force regardless. If it's really bad you can get a new tire under warranty, but that's tricky. I'm also in the NE so not very far away so if you needed to do an audit on your wheel/tire combo I could do it. I have a Hunter Road Force Touch.

[hansbrix]

spreadsheets are definitely valid. The fact that you even tried/did to calculate the ride frequencies and roll centers are impressive. The roll gradient is pretty important, but all this can be alot of theoretical tedium, where did you pick up how to do this stuff from? I used to use ADAMS and Matlab to crunch this stuff but you have to set up the model in program first, not hard, but tedious, a bit of a buzz kill too.

[IamFODI]

Well that was along time ago and I neither had the time or money to do have a decent car. Time has since passed and I have some toys and tools now, it's a hobby for me too. But even back 20 years ago there were standalone programs where you could model the kinematics. I'm sure there are ex Fomula SAE nerds that have done a bunch of modeling.

Absolutely. I didn't have and didn't find enough data to make a reasonable go of it (bump stops, lengths, etc.), but I'm sure people have done it and would be interested to see the results.

I also did quite a bit of chassis and ride development after college in an earlier life and I was impressed by your ability to articulate the subtleties of ride and handling trade offs. For obvisous reasons it seems only engineers tend to understand and can discuss these topics, it's a bit usually to see this level of intelligent discussion on forums.

🍻

I was catching up on more posts since I haven't been on the site for a while. I see you have your vibrations stuff sorted out. 6-7 lbs of force variation is pretty good, the default limit on the machine is set at 26 lbs if I recall correctly, but you can change that and the read out will tell you the exact force regardless. If it's really bad you can get a new tire under warranty, but that's tricky. I'm also in the NE so not very far away so if you needed to do an audit on your wheel/tire combo I could do it. I have a Hunter Road Force Touch.

Cool. Will send a PM.

spreadsheets are definitely valid. The fact that you even tried/did to calculate the ride frequencies and roll centers are impressive. The roll gradient is pretty important, but all this can be alot of theoretical tedium, where did you pick up how to do this stuff from? I used to use ADAMS and Matlab to crunch this stuff but you have to set up the model in program first, not hard, but tedious, a bit of a buzz kill too.

Slight correction: Roll couples, not roll centers.

Couldn't assume the roll couple numbers I generated were accurate because I didn't have ARB motion ratios. However, I thought that if I used the same ARB motion ratios for every setup I wanted to compare, I could still use the calculated roll couples to get very rough estimates of how handling balance might change.

Here's the main spreadsheet I used. Took a fair bit of editing,

For stock spring rates, I used 160 lbs/ft front and 550 or 600 lbs/ft rear. Saw those online in various places. For spring motion ratios, I used 0.96 front and 0.57 rear per this thread.

I got ARB rates from this page from Eibach..

[r4dr]

Great review. I'm glad you took the time to write this up. I have an E60 M5 and I've been thinking about a custom setup also. It is essentially the same suspension design, but a bit heavier of a car. New stock struts/shocks are stupidly expensive, and it's approaching the price of one of these high end setups, KW and Bilstein have setups, but sometimes I'm a glutton for punishment.

Eibach Pro-Kit springs + Bilstein B8s should be right around $1000 right? That would be well short of a full, $$$ setup. Are you DDing this car?

Edit: never mind I just realized Bilstein's catalog for E60 M5 cars is pretty bleak.

[tdott]

I also have my own alignment machine, corner weighting scales, road force balancer, and tire machine.

That's awesome, I would like to add a rf balancer and tire machine to my garage. Already have a 2post lift and don't like taking my wheels anywhere to get done, they also never match the low/high spots from the tire/rim. But i'll need a bigger garage, otherwise i'll loose my 2nd parking spot in the garage.

[hansbrix]

Funny you say that, it's so random, since I actually I have a few Hunter RF balancers, long story. I was going to post one for sale on CL, but been busy. I never thought about posting it up here. I have a transformer setup so it runs on 125V. (they are 220V single phase machines). I also can't stand anyone else touching my car because they always eff stuff up. Rotating the tire on the rim is a major pain and I do see why they don't do that unless you pay them extra. It's almost 2x the work. Where are you? you can come check them out. I have a forklift so I load it for you no prob.

[tdott]

Funny you say that, it's so random, since I actually I have a few Hunter RF balancers, long story. I was going to post one for sale on CL, but been busy. I never thought about posting it up here. I have a transformer setup so it runs on 125V. (they are 220V single phase machines). I also can't stand anyone else touching my car because they always eff stuff up. Rotating the tire on the rim is a major pain and I do see why they don't do that unless you pay them extra. It's almost 2x the work. Where are you? you can come check them out. I have a forklift so I load it for you no prob.

ah 220v wouldn't be a problem for me in the garage, but I won't have the space to put them without losing a parking spot. Then if I wanted a tire machine, I'd have to add an air compressor.

I'm in South FL so pretty far from NE state, otherwise I'd take you up on that.

[hansbrix]

I thought the total power requirement would not support what I could do with a transformer, but I've never had it trip out. The Hunter Road Force balancers need air to operate the load roller also. I run that and the tire machine off a small dewalt/emglo air compressor like what you see at Home Despot, I never have them running at the same time though. Tire machines have a big tank in the column or somewhere else because it uses a dump valve to seat the beads. I chose all my stuff so that I could put it in a trailer if I wanted (and had a trailer and half ton truck for track days). It's a time or money thing. also when I said NE I meant North East or New England not Nebraska, but I guess someone told me NJ is in a mid atlantic state, certainly not New England. I'm clearly not a native.

[hansbrix]

Eibach Pro-Kit springs + Bilstein B8s should be right around $1000 right? That would be well short of a full, $$$ setup. Are you DDing this car?

Edit: never mind I just realized Bilstein's catalog for E60 M5 cars is pretty bleak.

EDC is standard, and Bilstein has a nice setup that allows the continued usage of EDC. I think it is the B16 line. They go for like 3200 and they are always out of stock everywhere. I talked to Bilstein at SEMA a few years ago and they confirmed that they produce these somewhat on demand in Germany. OE shocks are like 2k. So that's why I'm thinking that I should put some of my old knowledge to work and go with ohlins, penskes, or motons. None of them have kits for the E60 M5 but, these are only a few hundred pounds heavier than E92 or F8X M3s. That's not a big deal the car I'm thinking of tracking I would stripping down and that would get it pretty close to M3 weight. I just need to play around with spring rates and have the shocks revalved. If I went with the off the shelf solutions (KW V3 or Bilstein B16s or stayed stock), stripping the car down would affect the chassis dynamics anyways, it would be sprung too stiff and over damped. Therefore I don't see the point of dropping that much money on that setup only to then spend more to respring and valve everything. The M5 is just a the more powerful and fatter sister to the M3 anyways. The suspension design is identical, and that is the harder part of adapting suspension hardware in the first place. That's why I'm glad I stumbled upon this thread. There were a few other threads I have bookmarked on the M3 forum but I can't seem to access them.

[Obioban]

Yeah, the e60 M5 is lighter than the e93 M3, so any kit that is fine for the vert should be fine for you.

[r4dr]

Yeah, the e60 M5 is lighter than the e93 M3, so any kit that is fine for the vert should be fine for you.

Wow, TIL. The E93 is hefty hefty.

[Obioban]

Wow, TIL. The E93 is hefty hefty.

The e60 is also just a much lighter/volume chassis (because it alu, likely) than the e90.

If you take the non M versions, and compare same engine, same trans, same drivetrain, body (so, say, rwd 528i 6mt sedan vs rwd 328i 6mt sedan), the e60 is only ~70 lbs heavier than the e90. BMW had to do a ton of work to get the e9X M3 to be lighter (plastic fenders, CF rood, etc), and they still only ended up ~300 lbs lighter for similarly speced cars (e90 M3 vs e60 M5).

On top of that, the hardtop vert adds a ton of weight to the e9X.