Dedicated Track - Ohlins R&T or SpecE46 MCS 1W NR Dampers

[OldRanger]

Anyone with experience running Ohlins R&T and the MCS 1-Way dampers?

How about just experience with the MCS 1-Way (SE46) kit?

Car weighs 3,255 w/driver, 2/3 tank fuel and a FAST cooler

Currently: Starting year 3 on Ohlins R&T w/400 front and TCK 700 rear. Front sway is GC set to med-stiff. Vorshlag front camber and rear spherical.

Wants:
1) fresh dampers with springs that are more common for a dedicated track car
2) reduce the front bar stiffness a bit

Needs:
1) learn how to drive the SE46 spring rates (750-850) and dampers on the M3. There's no aero and we're contemplating finding a 330
2) rebuild the Ohlins, and potentially revalve for higher rate.

[S54330Ci]

For track use MCS will be far, far superior to the Ohlins R&T. MCS is a motorsport-level damper which is why in part SPEC E46 chose it. You would need to step up to the Ohlins TTX to get similar capabilities (although I don't think they make the TTX in a 1-way version).

While not an apples-to-apples comparison, I have MCS 2WNR dampers on my 330Ci track car with the full coil-over rear. I am running 2.25" diameter Eibach springs 650lb in the front (5") and 500lb spring in the rear (7"). This is combined with Hotchkis sways front and rear, Ground Control race camber plates and Nitto NT01 tires (255/40R17) on 17x9 wheels (square). You can order the MCS 1WNR in a coil over version.

With the 650lb front spring and the Hotchkis bar I am able to run the bar a bit stiffer to combat roll without having to take away from the compliance of the car if that makes sense. This combination made the car easier to drive with better turn in. The car is very balanced and easy to drive fast.

I originally wanted to go with the SPEC E46 spring rates, however my shop (who races both standard E46 platforms as well as E46 M3 platforms uses the configuration I have with a great deal of competitive success. They indicated if I was to run a R7 tire I they would bump up the spring rates. For reference the SPEC E46 class runs the Toyo R tire with those 750 / 850 spring rates. Many also don't run a rear bar.

I'd definitely recommend the MCS dampers over the Ohlins. You can probably keep your GC front sway bar and camber plates.

[CrookedCommie]

My buddies WRL endurance E46M's run both of these, don't think there's much difference between the two and lap times are comparable. Morehead ran the 4 way Ohlins and their car wasn't really any faster either fwiw.

[OldRanger]

While not an apples-to-apples comparison, I have MCS 2WNR dampers on my 330Ci track car with the full coil-over rear. I am running 2.25" diameter Eibach springs 650lb in the front (5") and 500lb spring in the rear (7"). This is combined with Hotchkis sways front and rear, Ground Control race camber plates and Nitto NT01 tires (255/40R17) on 17x9 wheels (square)...With the 650lb front spring and the Hotchkis bar I am able to run the bar a bit stiffer to combat roll without having to take away from the compliance of the car if that makes sense. This combination made the car easier to drive with better turn in. The car is very balanced and easy to drive fast.

I'm not good at math...did you ever calculate or speculate what a rear 500lb spring on a coil-over would equate to in the OE spring configuration?

I originally wanted to go with the SPEC E46 spring rates, however my shop (who races both standard E46 platforms as well as E46 M3 platforms uses the configuration I have with a great deal of competitive success. They indicated if I was to run a R7 tire I they would bump up the spring rates. For reference the SPEC E46 class runs the Toyo R tire with those 750 / 850 spring rates. Many also don't run a rear bar.

Great point to consider. I have 18x9.5 wheels with RE71RS 265s. I'm not sure if/when we would change wheel and tire to something like a Toyo R tire.

[Estoril]

Look at manufacturer rebuild cycles for both. MCS is every 3-4 years for HPDE, 2 years for race apps. Not inexpensive.

[S54330Ci]

I'm not good at math...did you ever calculate or speculate what a rear 500lb spring on a coil-over would equate to in the OE spring configuration?

Multiply the divorced spring rate by .55 to get equivalent coil over rate. Divide the coil over spring rate by .55 to get the approximate divorced spring rate. Keep in mind the motion rates are different for divorced vs. coil over so there it is not a 1 to 1 equivalent from a handling / performance perspective. Some rounding (up or down) will be required.

To answer your question 500lb / .55 = 909lb

My rates of 650 / 500 work fantastic on the track but would not be my first choice if it was a 50/50 street / track car.

Great point to consider. I have 18x9.5 wheels with RE71RS 265s. I'm not sure if/when we would change wheel and tire to something like a Toyo R tire.

Then I would use softer spring rates than what SE46 specifies. If you are happy with your current 400 / 700 split then I would not change it.

[S54330Ci]

Look at manufacturer rebuild cycles for both. MCS is every 3-4 years for HPDE, 2 years for race apps. Not inexpensive.

Using Ohlins R&T on a track car (driven at 9/10th) will wear faster and perform worse than MCS. Here is what MCS recommends for service intervals:

Street : 25,000 miles
Street/HPDE: 15-20,000 miles
Sprint: 150 hours
Sprint/Enduro: 125 hours
Endurance Race: 75 hours
None of the above: Every 5 years

15-20,000 HPDE miles is a lot. Probably closer to 8-10 years than 3-4 years. Keep in mind that motorsport usage increases wear as drivers are pounding the suspension over curbs and driving the car at 9 or 10/10ths. Not something your average HPDE driver is going to do.

[OldRanger]

Using Ohlins R&T on a track car (driven at 9/10th) will wear faster and perform worse than MCS. Here is what MCS recommends for service intervals:

Street : 25,000 miles
Street/HPDE: 15-20,000 miles
Sprint: 150 hours
Sprint/Enduro: 125 hours
Endurance Race: 75 hours
None of the above: Every 5 years

15-20,000 HPDE miles is a lot. Probably closer to 8-10 years than 3-4 years. Keep in mind that motorsport usage increases wear as drivers are pounding the suspension over curbs and driving the car at 9 or 10/10ths. Not something your average HPDE driver is going to do.

I will go check what Ohlins recommends for R&T maintenance intervals: I drive at what I would consider 8/10ths (of my ability)...equating to 1:25s on Summit Main and Ben drives at 9/10ths equating to 2:09's at VIR. This is in an A group setting with passing. Btw - I think he was on track with you last July at Summit, but black M3's are rather common...so I'm sure you wouldn't remember.. He is not afriad to use curbs, I'm a bit more conservative. Maybe 50-60 hours o ftrack time (?). All this to say, the car works hard.

I'm entereing into year three on the Ohlins R&T, we're at 12,000 miles mixed. I detected some clunking last weekend with weight shifts (like turn 5 Summit Main), and with the help of a professional I am rather sure it is not the wheel bearing or other susmpesion components. It is likely the damper. I'm digging in this week.

[bigjae46]

FYI...I use a Vorshlag non-M camber plate and get a lot more negative camber with my TC Klines. I had to change the caster setting to max negative and you still lose a little bit of caster. Probably would work the same with the MCS.

[S54330Ci]

I drive at what I would consider 8/10ths (of my ability)...

Not at all intending to disparage your (or anyone's) driving abilities, but honestly, your 8/10ths is probably the equivalent to a pro driver's 5/10ths. This is why MCS service intervals are what they are for motorsports use.

[OldRanger]

The Ohlins Road and Track owner's manual indicates the Recommended Service Intervals:
Racing: Every 15 hours of operation. Maximum 30 hours
Regular Street Use: 60,000km (37k miles)

So, that is quite different than MCS.

I don't have an actual number of track hours, but I estimate it's in excess of 30 hours over two seasons (I understand my DE 30+ hours isn't equivalent to racing 30 hours)

[S54330Ci]

The Ohlins Road and Track owner's manual indicates the Recommended Service Intervals:
Racing: Every 15 hours of operation. Maximum 30 hours
Regular Street Use: 60,000km (37k miles)

So, that is quite different than MCS.

I don't have an actual number of track hours, but I estimate it's in excess of 30 hours over two seasons (I understand my DE 30+ hours isn't equivalent to racing 30 hours)

Probably why you are hearing clunking noises . . .

[OldRanger]

I’m going to try 650 front, 750 rear. I have another few sessions on the RE71RS. Then I may try a different tire with more grip.