KW Clubsport on Track

[medphysdave]

I'm guessing there is a lower threshold for which cavitation begins to occur. Would the cylinder valving have anything to do with this, or is it strictly governed by the pressure?

I ask because on the bottom of the R3 canisters it looks to me like it would be easy to add a fill valve .

BUT. You'd think if it were as easy as adding a valve that Nitron would offer it.

[M3SQRD]

Originally Posted by medphysdave

I'm guessing there is a lower threshold for which cavitation begins to occur. Would the cylinder valving have anything to do with this, or is it strictly governed by the pressure?

I ask because on the bottom of the R3 canisters it looks to me like it would be easy to add a fill valve .

BUT. You'd think if it were as easy as adding a valve that Nitron would offer it.

Cavitation is controlled by reservoir pressure. It’s around a 60/40 split that remote reservoirs come with a Schrader valve. I found adjusting reservoir pressures on my Moton 2WR installed on my e46 M3 dedicated-track car to be very useful. Dumping most of the pressure on a wet track day allowed me to make only small adjustments to the rest of the suspension. Only problem with the Moton reservoirs is they’d have to be re-pressurized every ~3 weeks.

I’d be surprised if Nitron installed a one-off Schrader valve.

[medphysdave]

Originally Posted by M3SQRD

Cavitation is controlled by reservoir pressure. It’s around a 60/40 split that remote reservoirs come with a Schrader valve. I found adjusting reservoir pressures on my Moton 2WR installed on my e46 M3 dedicated-track car to be very useful. Dumping most of the pressure on a wet track day allowed me to make only small adjustments to the rest of the suspension. Only problem with the Moton reservoirs is they’d have to be re-pressurized every ~3 weeks.

I’d be surprised if Nitron installed a one-off Schrader valve.

I was thinking to have inertia lab install the valves before they are shipped.

[bipp]

Originally Posted by M3SQRD

1-way dampers are a great starting point and allow you to more simplistically alter suspension setups vs. getting in over your head on 2-way or 3-way dampers. However, 1-way is also limiting because you don’t have independent control over R and C damping. I started with 1-way dampers (five settings) on my ‘92 Civic Si in 1993 and I had outgrown them by 1994 partly because there were just five large adjustments. Unfortunately, there weren’t other options but then it wasn’t long before I had my e36 M3. The R1 is so advanced compared to what I started with and it will take you a lot longer to outgrow their capabilities.

Yes, I’ve been dealing with major issues and no doctor (including Mayo Clinic, Cleveland Clinic and Hopkins) knows what’s causing my issues so they end up doing nothing. I get the same statement - your case is extremely complicated and multi-factorial which reading between the lines means you’re screwed and find someone else because I can’t help you. I definitely miss driving my Moonstone f82 as well as my two e92 M3s and even my wife’s m240ix with MCS 2WR. I’d even enjoy driving our stock g20 330ix or r56 Cooper S!

best of luck with the diagnosis and recovery. modern medicine is truly incredible - I really hope the doctors find something that can help.

Originally Posted by medphysdave

I was thinking to have inertia lab install the valves before they are shipped.

I think we've both been at it prodding Jason for updates on the Nitron development on the F87 forum, but I'm curious about your interest in adjustable valving. for me, I've taken an interest in the MCS setup with that being one of the reasons, but at the same time, am I / are you confident in being able to make changes that really benefit the car? I guess the issue is that while it's another thing to tweak, does it improve anything if the setup was designed around specific pressure?

on another subject though, have you looked into the Intrax 1k4 or Ohlins TTX setups as other options in the high-end 3/4 way market? I believe another forum member on the F8x section (I forget who) spoke highly of 1k2 with ARC. a lot of my future decisions (though likely years into the future, when I need a rebuild or need to step up) are likely going to be motivated by access to vendor support (which Jason has done a great job of), else I would consider Intrax more. I'm definitely interested in your thoughts.

[medphysdave]

Originally Posted by bipp

I think we've both been at it prodding Jason for updates on the Nitron development on the F87 forum, but I'm curious about your interest in adjustable valving. for me, I've taken an interest in the MCS setup with that being one of the reasons, but at the same time, am I / are you confident in being able to make changes that really benefit the car? I guess the issue is that while it's another thing to tweak, does it improve anything if the setup was designed around specific pressure?

on another subject though, have you looked into the Intrax 1k4 or Ohlins TTX setups as other options in the high-end 3/4 way market? I believe another forum member on the F8x section (I forget who) spoke highly of 1k2 with ARC. a lot of my future decisions (though likely years into the future, when I need a rebuild or need to step up) are likely going to be motivated by access to vendor support (which Jason has done a great job of), else I would consider Intrax more. I'm definitely interested in your thoughts.

A big reason for going with the Nitrons are that they are being developed on an M2CS by someone that tracks the f series platform and has support from inertia lab. The E-trons are hella expensive compared to just getting a good set of something else. Ogshark will share some good starting points for setup on street and track. The hours that go into tuning a suspension is worth a lot to me. Being able to head out on track with a great starting point means less time I'm spending tuning and more time having fun. Let's assume I put $2k worth of value on that. Now the overall price is significantly improved over buying from someone that gives me an off the shelf setup that needs to be dialed in and/or may be less than ideal for the platform.

The lack of Schrader valve is puzzling to me. This is a huge pro of the MCS that allows slightly better street comfort but being able to run full on track spring rates. I don't see why I couldn't pay to have the valves added and fill to standard pressure for track, but drop it down for street. I've got a specific goal in mind for this car so I'm willing to throw a little extra coin at it to get there. I wasn't willing to give up the electronic suspension on my car. For better or worse.

[bipp]

Originally Posted by medphysdave

A big reason for going with the Nitrons are that they are being developed on an M2CS by someone that tracks the f series platform and has support from inertia lab. The E-trons are hella expensive compared to just getting a good set of something else. Ogshark will share some good starting points for setup on street and track. The hours that go into tuning a suspension is worth a lot to me. Being able to head out on track with a great starting point means less time I'm spending tuning and more time having fun. Let's assume I put $2k worth of value on that. Now the overall price is significantly improved over buying from someone that gives me an off the shelf setup that needs to be dialed in and/or may be less than ideal for the platform.

The lack of Schrader valve is puzzling to me. This is a huge pro of the MCS that allows slightly better street comfort but being able to run full on track spring rates. I don't see why I couldn't pay to have the valves added and fill to standard pressure for track, but drop it down for street. I've got a specific goal in mind for this car so I'm willing to throw a little extra coin at it to get there. I wasn't willing to give up the electronic suspension on my car. For better or worse.

that's definitely a fair take and was my justification at the time for going with the OGSM R1s. besides MCS, a valid criticism is lack of car-specific development - I recall some discussion about PSI (a NorCal based Ohlins R&T/TTX distributor) not really providing input on car setup but rather advising based on what other clients had specced. being able to go out to track without thinking about dialing anything in and just setting it to Jason's recommendation took some stress away from my first events. from speaking with community members running the OGSM non-e R3 kit, it seems like he's put the same attention into those on the E92 platform and one of those kits with 700/100 springs is likely in my future shopping cart. something I am becoming aware of though is the real benefit of having a shop familiar with your hardware - hopefully Nitrons become a bit more popular in my locality, otherwise I'll stay wishing I lived within servicing distance of OGSM.

for what it is worth though - I am yet to ride in a F87 CS to have a baseline comparison but I would be surprised if you even found non-e R1s upsetting to ride in on the street. while I am somewhat irked by the number of interior rattles in a 10 year old (albeit 65k mile) car, I don't think I can criticize the R1's damping for the street on the recommended "3 or 4 clicks from full soft". I def get the "extra coin for a specific goal" approach - it's how I'm planning on rationalizing throwing too much money at an aging car myself. excited to see your build over time! (and always fun to see your x% to coilover budget posts in the Nitron thread)

edit: I am very interested in hearing Track/S's extended feedback on the off-the-shelf R3, especially in comparison to MCS. I think few people have had the opportunity to jump between both on their car.

[M3SQRD]

bipp medphysdave

BimmerWorld does develop MCS dampers on f series cars (f82 primarily) just like OG Shark develops Nitron on f series cars (f87 primarily). All f series cars use the same damping (MCS f series dampers can be used on e9x M as well). MCS has extremely wide range of damping, probably wider than Nitron.

Reservoir pressure can be used to improve street ride quality (now running 85 psi on my wife’s m240ix with 500/800 lbf/in rates, ride quality is amazing and so is its performance) and provide another setup variable for on track. It can help deal with a bumpy brake zone by reducing gas pressure and getting the piston rod to compress with less force or improve cornering by providing more support without having to increase main spring rate. I’ve been adjusting gas pressure on track since 2004 with measurable increase in performance (lap time) at different tracks. There is no single pressure the dampers are designed to use. Obviously, you want to run a min pressure to prevent cavitation from occurring on track.

Intrax are excellent dampers but their 4-ways is setup like JRZ Motorsport 4-ways - R, LSC, HSC, and adjustment to raise-lower overall C curve instead of the typical LSR, HSR, LSC and HSC. I prefer the latter. No pressure adjustment on Intrax.

MCS customer service and after-sales support is the best in the business. Also, BimmerWorld track support/setup is just as good. They can provide a solid baseline for a large number of tracks (tinkering types) or a baseline that works well on many different tracks (set and forget types). I’ve been in the paddock with James making major changes to car setup.

I was surprised to hear Track/S’s comments on how the Nitron R3 is much harsher than the MCS 3WR with similar spring rates. MCS ride quality is phenomenal but I expected the R3 to have similar compliance. Not surprised to hear KW Competition are very harsh. You can’t describe how well the MCS absorb bumps and it’s only after someone has tried them do they understand.

[Track/S]

Originally Posted by M3SQRD

bipp medphysdave

BimmerWorld does develop MCS dampers on f series cars (f82 primarily) just like OG Shark develops Nitron on f series cars (f87 primarily). All f series cars use the same damping (MCS f series dampers can be used on e9x M as well). MCS has extremely wide range of damping, probably wider than Nitron.

Reservoir pressure can be used to improve street ride quality (now running 85 psi on my wife’s m240ix with 500/800 lbf/in rates, ride quality is amazing and so is its performance) and provide another setup variable for on track. It can help deal with a bumpy brake zone by reducing gas pressure and getting the piston rod to compress with less force or improve cornering by providing more support without having to increase main spring rate. I’ve been adjusting gas pressure on track since 2004 with measurable increase in performance (lap time) at different tracks. There is no single pressure the dampers are designed to use. Obviously, you want to run a min pressure to prevent cavitation from occurring on track.

Intrax are excellent dampers but their 4-ways is setup like JRZ Motorsport 4-ways - R, LSC, HSC, and adjustment to raise-lower overall C curve instead of the typical LSR, HSR, LSC and HSC. I prefer the latter. No pressure adjustment on Intrax.

MCS customer service and after-sales support is the best in the business. Also, BimmerWorld track support/setup is just as good. They can provide a solid baseline for a large number of tracks (tinkering types) or a baseline that works well on many different tracks (set and forget types). I’ve been in the paddock with James making major changes to car setup.

I was surprised to hear Track/S’s comments on how the Nitron R3 is much harsher than the MCS 3WR with similar spring rates. MCS ride quality is phenomenal but I expected the R3 to have similar compliance. Not surprised to hear KW Competition are very harsh. You can’t describe how well the MCS absorb bumps and it’s only after someone has tried them do they understand.

Not much harsher, i said they were harsher than the mcs, I need to test it well, I will do it when the rear silencer arrives, I just remembered that nitron r3 makes rear shock absorbers with different lengths for f82 and f87, the f82 version does not work for f87.

[M3SQRD]

Originally Posted by Track/S

Not much harsher, i said they were harsher than the mcs, I need to test it well, I will do it when the rear silencer arrives, I just remembered that nitron r3 makes rear shock absorbers with different lengths for f82 and f87, the f82 version does not work for f87.

Understood. I know it was based on limited street testing but still surprised to hear the R3 was harsher than the MCS. MCS 2/3/4WR has an awesome blow-off valve and that could be the difference between them. It’s the harsher street ride quality that determines whether a damper will tolerable on the street. Look forward to your update on street ride quality as well as on track performance.

[medphysdave]

Originally Posted by M3SQRD

Understood. I know it was based on limited street testing but still surprised to hear the R3 was harsher than the MCS. MCS 2/3/4WR has an awesome blow-off valve and that could be the difference between them. It’s the harsher street ride quality that determines whether a damper will tolerable on the street. Look forward to your update on street ride quality as well as on track performance.

I thought the Nitrons also had a high speed blowoff? This feature seems to be a common thread for dampers running track spring rates but still maintain street drivability. Or considered reasonably comfortable on the street.

[medphysdave]

This could be more meaningful to some. I try to make sense of everything but don't know enough about this other brands to come to any conclusions. There's very little info out there on Nitron construction and parts.

[M3SQRD]

Originally Posted by medphysdave

I thought the Nitrons also had a high speed blowoff? This feature seems to be a common thread for dampers running track spring rates but still maintain street drivability. Or considered reasonably comfortable on the street.

I didn’t say Nitron doesn’t have a HS blow-off valve. I said MCS may have a superior HS blow-off valve in the remote reservoir. Not all HS blow-off valves are the same. You can increase the area/shape to get more HS blow-off and, therefore, a more compliant ride over large bumps/curbs.

[bipp]

Originally Posted by M3SQRD

bipp medphysdave

BimmerWorld does develop MCS dampers on f series cars (f82 primarily) just like OG Shark develops Nitron on f series cars (f87 primarily). All f series cars use the same damping (MCS f series dampers can be used on e9x M as well). MCS has extremely wide range of damping, probably wider than Nitron.

Reservoir pressure can be used to improve street ride quality (now running 85 psi on my wife’s m240ix with 500/800 lbf/in rates, ride quality is amazing and so is its performance) and provide another setup variable for on track. It can help deal with a bumpy brake zone by reducing gas pressure and getting the piston rod to compress with less force or improve cornering by providing more support without having to increase main spring rate. I’ve been adjusting gas pressure on track since 2004 with measurable increase in performance (lap time) at different tracks. There is no single pressure the dampers are designed to use. Obviously, you want to run a min pressure to prevent cavitation from occurring on track.

Intrax are excellent dampers but their 4-ways is setup like JRZ Motorsport 4-ways - R, LSC, HSC, and adjustment to raise-lower overall C curve instead of the typical LSR, HSR, LSC and HSC. I prefer the latter. No pressure adjustment on Intrax.

MCS customer service and after-sales support is the best in the business. Also, BimmerWorld track support/setup is just as good. They can provide a solid baseline for a large number of tracks (tinkering types) or a baseline that works well on many different tracks (set and forget types). I’ve been in the paddock with James making major changes to car setup.

I was surprised to hear Track/S’s comments on how the Nitron R3 is much harsher than the MCS 3WR with similar spring rates. MCS ride quality is phenomenal but I expected the R3 to have similar compliance. Not surprised to hear KW Competition are very harsh. You can’t describe how well the MCS absorb bumps and it’s only after someone has tried them do they understand.

sorry for any confusion - when I said "besides MCS" in my post earlier, I meant that I did know that MCS similarly invests time into platform-specific develop as Jason did for the OGSM Nitron kits. my interest in MCS definitely strongly exists - it seems that most locals go with either MCS or Ohlins and my local shop has likely had far more experience setting up MCS than Nitron. in any case, I'm definitely getting ahead of myself by shopping for a replacement set of coilovers that I won't be acquiring until a few years ahead, but I guess that's just part of the hobby...

additionally, interesting to hear about your familiarity with the folks over at BW - lends a lot of credence to your preference here!

Track/S - eagerly waiting for your R3 updates once everything has been sorted out

[M3SQRD]

Originally Posted by bipp

sorry for any confusion - when I said "besides MCS" in my post earlier, I meant that I did know that MCS similarly invests time into platform-specific develop as Jason did for the OGSM Nitron kits. my interest in MCS definitely strongly exists - it seems that most locals go with either MCS or Ohlins and my local shop has likely had far more experience setting up MCS than Nitron. in any case, I'm definitely getting ahead of myself by shopping for a replacement set of coilovers that I won't be acquiring until a few years ahead, but I guess that's just part of the hobby...

additionally, interesting to hear about your familiarity with the folks over at BW - lends a lot of credence to your preference here!

Track/S - eagerly waiting for your R3 updates once everything has been sorted out

No worries. Just a little confusion. It’s never too early to research race dampers and compare pros/cons between available options. The f8x has a large selection of race dampers to choose from! I had looked into getting a set of R3s (between Moton being purchased by AST and MCS releasing their first dampers) for one of my e92 M3s before Nitron USA existed and Inertia Labs was known but I was concerned about servicing/revalving issues with no USA support.

An important key to race suspension setup is based on what your local race shop is experienced in setting up. You want a solid initial setup that you can then adjust as you gain first hand experience with adjusting your dampers and accumulate knowledge on suspension setup. If your local shop is experienced with setting up MCS then MCS may be a better choice for you. However, if they are a very experienced shop then they should be able to figure out, albeit with patience, how to setup different dampers IF they’re willing to spend the necessary time ($$$). Advantage of using MCS is they can help you remotely solve setup issues based on your input/description of the issues.

I’ve been working with BimmerWorld since 2002 when they were a small team and worked with them to develop their BW/Moton/GC ASB e46 M3 complete suspension setup. Swapping spring rates in the paddock was fun! My e46 M3 went from a new ‘03.5 e46 M3 to a dedicated-track car in < one year. Worked with BW in 2009 on developing parts for my ‘09 e92 M3 when little was available for this gen and then my ‘12 e92 M3. Next, they helped with building my ‘16 f82. Finally, I was the first to use MCS 2WR on my wife’s ‘18 f22 x-drive m240ix - standard MCS F series dampers fit perfectly with the x-drive suspension. The entire time I’ve primarily worked directly with James except for the f82 and f22. I’ve watched BW grow from a small low funded pro race team, where James drove their transporter back to Dublin, VA after races when needed, to a well funded factory pro race team and everything in between (e.g., e36 M3 Bergsteiger Pile’s Peak MCS 3-damper suspension setups monster). It’s been a great ride with them!

I’m also waiting to hear from Track/S on how the R3 perform relative to the 3WR.

[bipp]

Originally Posted by M3SQRD

No worries. Just a little confusion. It’s never too early to research race dampers and compare pros/cons between available options. The f8x has a large selection of race dampers to choose from! I had looked into getting a set of R3s (between Moton being purchased by AST and MCS releasing their first dampers) for one of my e92 M3s before Nitron USA existed and Inertia Labs was known but I was concerned about servicing/revalving issues with no USA support.

An important key to race suspension setup is based on what your local race shop is experienced in setting up. You want a solid initial setup that you can then adjust as you gain first hand experience with adjusting your dampers and accumulate knowledge on suspension setup. If your local shop is experienced with setting up MCS then MCS may be a better choice for you. However, if they are a very experienced shop then they should be able to figure out, albeit with patience, how to setup different dampers IF they’re willing to spend the necessary time ($$$). Advantage of using MCS is they can help you remotely solve setup issues based on your input/description of the issues.

I’ve been working with BimmerWorld since 2002 when they were a small team and worked with them to develop their BW/Moton/GC ASB e46 M3 complete suspension setup. Swapping spring rates in the paddock was fun! My e46 M3 went from a new ‘03.5 e46 M3 to a dedicated-track car in < one year. Worked with BW in 2009 on developing parts for my ‘09 e92 M3 when little was available for this gen and then my ‘12 e92 M3. Next, they helped with building my ‘16 f82. Finally, I was the first to use MCS 2WR on my wife’s ‘18 f22 x-drive m240ix - standard MCS F series dampers fit perfectly with the x-drive suspension. The entire time I’ve primarily worked directly with James except for the f82 and f22. I’ve watched BW grow from a small low funded pro race team, where James drove their transporter back to Dublin, VA after races when needed, to a well funded factory pro race team and everything in between (e.g., e36 M3 Bergsteiger Pile’s Peak MCS 3-damper suspension setups monster). It’s been a great ride with them!

I’m also waiting to hear from Track/S on how the R3 perform relative to the 3WR.

beautiful e46!

definitely agree - down the line, a lot of my choices for the E92 will be motivated by my shop's familiarity. I'd like to peddle myself as knowledgeable, but absolutely not as much as people who've worked on dozens or more of these cars. can't believe this started off as a discussion about spring rates but ended in me seriously (and very preemptively) making future decisions about 3W setups...

[M3SQRD]

Originally Posted by bipp

beautiful e46!

definitely agree - down the line, a lot of my choices for the E92 will be motivated by my shop's familiarity. I'd like to peddle myself as knowledgeable, but absolutely not as much as people who've worked on dozens or more of these cars. can't believe this started off as a discussion about spring rates but ended in me seriously (and very preemptively) making future decisions about 3W setups...

Thanks!

Your shops experience with a specific damper manufacturer is one of the primary criteria for damper selection. When properly setup, all high-end dampers will be within tenths of a second of one another. The key is properly setup.

It’s never too early to research high-end dampers especially when there are several available options to choose from. Nitron R3 and MCS 3WR are great options and I’m definitely biased towards MCS. I’m unaware of a single person that I’ve helped select MCS dampers that wasn’t surprised by their performance and compliance.

[Track/S]

Today I was able to test the m3 with Nitron R3 on a winding road and I definitely prefer MCS, it absorbs the bumps better.

And definitely a harsher spring rate at the rear does not work, the rear is too harsh and that makes it lose traction...

[M3SQRD]

Originally Posted by Track/S

Today I was able to test the m3 with Nitron R3 on a winding road and I definitely prefer MCS, it absorbs the bumps better.

And definitely a harsher spring rate at the rear does not work, the rear is too harsh and that makes it lose traction...

Nice background. Are they old blast furnaces or kilns?

What are the spring rates (again)? Rear coilover setup, correct? These were purchased directly from Nitron/Nitron distributer?

In the US, OGSM (OG Shark Motorsport) and IL (Inertial Labs, Nitron US distributer and damper service center) have refined the R3 3-way R, LSC and HSC damping and the R1 1-way coupled R-C damping as well as spring rate options. From what I’ve seen they’ve improved street ride quality and on-track performance. I don’t have specifics for the R3 spring rates but I’ve seen two different rear divorced setup. One was F/R 700/800 lbf/in (divorced rear) and F/R 685/914 lbf/in (divorced rear). Converting these to rear damper setups you get 700/400 lbf/in (rear coilover) and 685/457 lbf/in (rear coilover). Very different rear spring rates compared to rates used on all other high-end damper options. My e92 M3 MCS 2WR setup uses 600/1000 lbf/in (divorced rear or 600/500 lbf/in rear coilover) and my JRZ RS1 setup uses 400/685 lbf/in (divorced rear or 400/353 lbf/in rear coilover). My e92 M3s have a nice balance with minimal understeer (purposely setup this way). I can’t imagine driving a 700/400 lbf/in (rear coilover) setup compared to the balance of my two e92 M3 600/500 lbf/in (rear coilover) and 400/353 lbf/in (rear coilover) setups. However, they’ve been track tuned so, unless they’re using very stiff rear anti-sway bars, I can’t rectify the significantly different rear spring rates?

[medphysdave]

Originally Posted by M3SQRD

Nice background. Are they old blast furnaces or kilns?

What are the spring rates (again)? Rear coilover setup, correct? These were purchased directly from Nitron/Nitron distributer?

In the US, OGSM (OG Shark Motorsport) and IL (Inertial Labs, Nitron US distributer and damper service center) have refined the R3 3-way R, LSC and HSC damping and the R1 1-way coupled R-C damping as well as spring rate options. From what I’ve seen they’ve improved street ride quality and on-track performance. I don’t have specifics for the R3 spring rates but I’ve seen two different rear divorced setup. One was F/R 700/800 lbf/in (divorced rear) and F/R 685/914 lbf/in (divorced rear). Converting these to rear damper setups you get 700/400 lbf/in (rear coilover) and 685/457 lbf/in (rear coilover). Very different rear spring rates compared to rates used on all other high-end damper options. My e92 M3 MCS 2WR setup uses 600/1000 lbf/in (divorced rear or 600/500 lbf/in rear coilover) and my JRZ RS1 setup uses 400/685 lbf/in (divorced rear or 400/353 lbf/in rear coilover). My e92 M3s have a nice balance with minimal understeer (purposely setup this way). I can’t imagine driving a 700/400 lbf/in (rear coilover) setup compared to the balance of my two e92 M3 600/500 lbf/in (rear coilover) and 400/353 lbf/in (rear coilover) setups. However, they’ve been track tuned so, unless they’re using very stiff rear anti-sway bars, I can’t rectify the significantly different rear spring rates?

Higher gas pressure in Nitrons due to lower spring rates?

[Track/S]

140nm front and 150nm rear (full coilover).
Schirmer setup.

[M3SQRD]

Originally Posted by medphysdave

Higher gas pressure in Nitrons due to lower spring rates?

No. The gas pressure force, or an effective compressed preloaded spring in parallel to the main spring, has zero effect on the main spring rate. Also, if it did, it would not have the effect of increasing the 700/800 lbf/in (divorced rear) to be equivalent to 700/1100 lbf/in (divorced rear with 150 psi res pressures front and rear). Or another way to look at it is MCS 2/3WR setups run 700/600 or 800/700 lbf/in rear coilover setups vs. Nitron 700/800 lbf/in (divorced rear). Steady-state handling/balance is not altered by damping because the relative piston velocity is zero so no damping forces exist (ignoring seal drag) and the balance is based solely on spring rates. I know my 700/1100 lbf/in (divorced rear) is well balanced with minimal understeer when 285/305 tires are used.

The setup used on the R3 setup Track/S is using falls more inline with MCS, Moton and Ohlins TTX setups.

[M3SQRD]

Originally Posted by Track/S

140nm front and 150nm rear (full coilover).
Schirmer setup.

So 799/856 lbf/in (rear c/o) spring rates with stock ASBs or aftermarket ASBs? It’s very interesting how the Nitron R3 spring rates fall in line with spring rates used by other high-end dampers whereas OGSM & IL rates (700/400 lbf/in, rear c/o equivalent) are very different. Not doubting Jason’s setup skills and COTA lap times but spring rate comparisons are odd.

Is the harshness dominated by the front or rear or both? Does it feel like the compressive blow-off valve (CBOV) isn’t absorbing large bumps as well as the MCS remote CBOV?