[TripleU]

I recently went to a track day and one of the drivers who showed up had a dedicated track car that he drives for Global Time Attack Limited class. His car had JRZ Motorsport Dampers on his car, so I was talking to him asking him how he liked it, because I was interested in getting JRZ or MCS coilovers for my car.

He told me that to be honest that he didn't think the JRZs were worth it and that I was better off saving my money with cheaper coilovers, and that I should talk to his suspension tuner, who not only re-valves high end coilovers such as JRZ, Penske, Moton, but also makes his own custom coilovers that are cheaper but have very good valving. The company is Shaftworks USA, and the guy highly suggested Shaftworks, and so did my local shop who does all of my track servicing. I looked Shaftworks up and he has had some E9X customers, but no one on E9X Bimmerpost has seemed to mention him.

I just wanted to get a second opinion on here whether I should get cheaper shocks with very good valving and springs, or should I just spend the money on higher end coilovers like JRZ or MCS.

[sibanez]

Posted this in another thread, but very relevant.

If you are looking for a true upgrade that is cost effective, I'd suggesting calling up Chris at Red Shift Motorsports: https://store.redshiftmotorsports.com/

He starts with BC Coilover bodies, guts them and rebuilds them custom for the application using very high-end parts. They are used by some of the fastest cars at TT and SCCA solo - I ran a set on my 128i and was amazed. I've driven cars with Motons and Penskes in the past and these are right up there.

Standard BC coilovers aren't awful, but I wouldn't call them an upgrade on these cars, either. The factory suspension is light years ahead of what's on most street cars.

RedShifts are around $1800 with Swift Springs. Even with 400/700 springs on my 128i, the car felt like a stock M2 on the street due to the excellent valving.

The single adjustable are the sweet spot. They've earned lots of trophies at Nationals for both SCCA autocross and TT. Also has excellent support, he'll answer any question you have and even do a revalve if you aren't happy.

[FaRKle!]

Anybody making claims about "better valving" and doing custom builds should be able to show you their damper curves and explain what makes them better, what level of damping they're aiming for across the shaft velocity range, and why they recommend the spring rates they do. If they don't have a suspension model with motion ratios and proper weights (including what just the sprung mass is) to calculate ride frequencies and damping ratios I wouldn't have confidence.

Otherwise you're having someone tell you, "Just give me your money and trust me you'll like it."

One thing I wonder about shaftworks, is if you're actually intended to change the damping from their recommended setting or not. I'm not a huge fan of "1-way" damping where you're locked into whatever compression/rebound ratio they've provided. Of course if they don't really intend for you to change that from the "optimal setting" they give, then it doesn't really matter.

[sibanez]

Originally Posted by FaRKle!

Anybody making claims about "better valving" and doing custom builds should be able to show you their damper curves and explain what makes them better, what level of damping they're aiming for across the shaft velocity range, and why they recommend the spring rates they do. If they don't have a suspension model with motion ratios and proper weights (including what just the sprung mass is) to calculate ride frequencies and damping ratios I wouldn't have confidence.

Otherwise you're having someone tell you, "Just give me your money and trust me you'll like it."

They offer dyno curves for each set they build and explain in great detail why they are set up the way they are. When he built the set for my 128i, he researched the weight distribution of the car and what the suspension issues were from the factory.

Chris is a real-deal racer and real-deal racers use his stuff (Andy Hollis the main tire reviewer for Grassrootsmotorsports.com swears by them). Tons of trophies belong to these, and plenty more will come.

[TripleU]

Originally Posted by FaRKle!

Anybody making claims about "better valving" and doing custom builds should be able to show you their damper curves and explain what makes them better, what level of damping they're aiming for across the shaft velocity range, and why they recommend the spring rates they do. If they don't have a suspension model with motion ratios and proper weights (including what just the sprung mass is) to calculate ride frequencies and damping ratios I wouldn't have confidence.

Otherwise you're having someone tell you, "Just give me your money and trust me you'll like it."

One thing I wonder about shaftworks, is if you're actually intended to change the damping from their recommended setting or not. I'm not a huge fan of "1-way" damping where you're locked into whatever compression/rebound ratio they've provided. Of course if they don't really intend for you to change that from the "optimal setting" they give, then it doesn't really matter.

Good point. He does provide dyno charts and will suggest springs and damper settings for me, but I should look further and ask him these other questions such as weight and reasoning for his valving.

[FaRKle!]

I'm not saying one vendor does or doesn't do the things I recommended. It was rather meant to be a guide of good things for consumers to ask outfits like this (custom builds).

For any custom build the consumer should feel like they understand the design process, design priorities, and in a sense feel like they took part in the design by agreeing to aspects of the custom build, and understanding what would change if x-design aspect changed by a bit (spring rate up/down, damping up/down, ect.). I think that custom builders need to be able to educate their customers.

[FreeDarko]

Originally Posted by sibanez

Posted this in another thread, but very relevant.

If you are looking for a true upgrade that is cost effective, I'd suggesting calling up Chris at Red Shift Motorsports: https://store.redshiftmotorsports.com/

He starts with BC Coilover bodies, guts them and rebuilds them custom for the application using very high-end parts. They are used by some of the fastest cars at TT and SCCA solo - I ran a set on my 128i and was amazed. I've driven cars with Motons and Penskes in the past and these are right up there.

Standard BC coilovers aren't awful, but I wouldn't call them an upgrade on these cars, either. The factory suspension is light years ahead of what's on most street cars.

RedShifts are around $1800 with Swift Springs. Even with 400/700 springs on my 128i, the car felt like a stock M2 on the street due to the excellent valving.

The single adjustable are the sweet spot. They've earned lots of trophies at Nationals for both SCCA autocross and TT. Also has excellent support, he'll answer any question you have and even do a revalve if you aren't happy.

How do these handle harsh winters. From what I remember the damper bodies weren't stainless steel.

[HP Autosport]

Most of us are not likely going to out drive a decent set of coilovers. If you have a dedicated track car and is a pro driver, go for the motorsport style MCS 2Way/3Way/4Way or JRZ's Motorsport line. MCS 1WNR/2WNR, Ohlins R&T, TCKR DA or the KW CS will be find for most.

[sibanez]

Originally Posted by FreeDarko

How do these handle harsh winters. From what I remember the damper bodies weren't stainless steel.

They hold up well if cared for properly. I used BOESHIELD T-9 on mine and they looked as good as new. My friend has a set on a daily driven 330i and uses T9, no issues adjusting them after 36 months.

Oh, and don't put those coilover bags around them. That never ends well on anything I've seen.

[M Fifty]

KW and MPS are Stainless, so the only potential problems are with the lower adjusters if driven somewhere that puts salt on the road during winter.