[medphysdave]

Take my money......take my money....


This thread is almost a year old. Might as well wait for the thread anniversary for a big update.

[M3SQRD]

Originally Posted by bipp

wake up babe og shark just posted !

Always exciting to read a new long OG Shark (or M3SQRD) post. Understandably, certain things can't be shared - but exciting to read the priorities that went into speccing the Nitron kits.

Been beating a dead horse with this one - but looking forward to having my car back, making the most out of fiddling with the R1, and moving to the R3 down the line. Sounds vain, but I'm also excited to see what sort of street driving improvements an R3 setup offers. I'm also wondering re: whether now that I have Hotchkis F/R bars and roll center correction, a less sprung setup might offer equivalent track performance while affording more dailyability - or if the more roll resistance the better, and to still go with the same spring rates. Guess that's a decision for the future, but always fun to window shop.

I think jumping to R3 as well as figuring out sway bar settings might be a bit of a hurdle to overcome as well, but I'm excited to figure out where I'm going with dialing in the car in the future (or, that OGSM has great suggested settings that obviate the need for adjustment :P).

I think this thread has definitely passed just elecTRON talk - would be great if you made a thread somewhere to encompass all OGSM discussion across F8x/G8x/E9x platforms, as well as maybe for general centralized suspension chatter.

If you have the tube inner & outer wall diameters (or OD and wall thickness), the tube straight length, and the length of the cantilevered tube ends, it’s easy to calculate the equivalent axial stiffness of the anti-sway bar (ASB). Now, with spring and ASB motion ratios, you can calculate what the total wheel rate is for the main spring + ASB or calculate the equivalent combined main spring rate at the damper (coilover rear) by adding the main spring rate and the transformed ASB rate at the damper location.

I would not opt for the conventional or et R1 ogsm spec if your main concerns are the effective ASB axial rates. Jason probably has a spread sheet to look at setups with aftermarket main springs + stock ASB or aftermarket main springs + aftermarket ASB. Basically, don’t worry about your aftermarket ASBs. It’s always best to buy once, cry once. Also, you’ll not outgrow the conventional or eT R3 ogsm spec dampers for many, many years and for a 3-way it’s not really that you’ve outgrown them, it’s that you’ve mastered them.

[bipp]

Originally Posted by medphysdave

Take my money......take my money....


This thread is almost a year old. Might as well wait for the thread anniversary for a big update.

Definitely a testament to something that we've gone on for a 11 page thread on a vendor's offering - bit different than weekly vendor self-bumps.

Testament to what? Not sure. Maybe our faith in OGSM, our boredom, the mystique of Jason's now-explained vanishing, who knows?

[bipp]

Originally Posted by M3SQRD

If you have the tube inner & outer wall diameters (or OD and wall thickness), the tube straight length, and the length of the cantilevered tube ends, it’s easy to calculate the equivalent axial stiffness of the anti-sway bar (ASB). Now, with spring and ASB motion ratios, you can calculate what the total wheel rate is for the main spring + ASB or calculate the equivalent combined main spring rate at the damper (coilover rear) by adding the main spring rate and the transformed ASB rate at the damper location.

I would not opt for the conventional or et R1 ogsm spec if your main concerns are the effective ASB axial rates. Jason probably has a spread sheet to look at setups with aftermarket main springs + stock ASB or aftermarket main springs + aftermarket ASB. Basically, don’t worry about your aftermarket ASBs. It’s always best to buy once, cry once. Also, you’ll not outgrow the conventional or eT R3 ogsm spec dampers for many, many years and for a 3-way it’s not really that you’ve outgrown them, it’s that you’ve mastered them.

Thanks! I'll definitely need to do the math, but this is what Bimmerworld had to say, as a reference:

Front 4 way adjustable- 295 lbs/in, 335 lbs/in, 380 lbs/in, 435 lbs/in
Stiffness over stock: +52%, +73%, +96%, +124%

Rear 3 way adjustable - 175 lbs/in, 195 lbs/in, 215 lbs/in
Stiffness over stock: +56%, +74%, +92%

I'm already on the OGSM conventional R1 on my E92 - apologies if my yapping throughout the thread left any confusion. I don't think I'll outgrow my R1 any time soon - more constrained on how often I can get to the track than anything, and I fully plan on getting the full use out of them. With the DCT bill in mind, I don't think I'm in a responsible place to upgrade anytime soon - maybe try to get another season or two on the OGSM R1 before I succumb to temptation and get the R3s so I can see shiny reservoirs when I put my bag in the trunk to continue growth.

Given the cost diff between R1 and R3, maybe I should've ponied up an extra 4 grand last year and gone straight for them, but at the time I would've had no idea what to do with a 3 way setup. So for that matter, I'm grateful to have picked up a fair bit of knowledge, and find the time to read the books you suggested in the KW thread (on the F80/2 board) before I move up to the R3.

[medphysdave]

The ARB are now an interesting subject. I added the CSR front bar and kept the stock rear. With suck suspension I really like the change on road and track. The stock suspension eats curbs pretty well in my opinion and didn't upset the car. An instructor was with me and he also commented with surprise. I was able to take an aggressive line.

With a suspension that can control body roll. Is it better to go back to the stock bar? Will the stiffer front bar inhibit things? Even more concerning is the rear bar. It's expensive to swap. I'm thinking about leaving that one stock.

[bipp]

Originally Posted by medphysdave

The ARB are now an interesting subject. I added the CSR front bar and kept the stock rear. With suck suspension I really like the change on road and track. The stock suspension eats curbs pretty well in my opinion and didn't upset the car. An instructor was with me and he also commented with surprise. I was able to take an aggressive line.

With a suspension that can control body roll. Is it better to go back to the stock bar? Will the stiffer front bar inhibit things? Even more concerning is the rear bar. It's expensive to swap. I'm thinking about leaving that one stock.

Quote from Jason via email:

Ok so on sways – I very much like them as a finisher. If you are already in that area yes I would get them. I usually default to Hotchkis here. Don’t use them a band aid but as a fine tuner. With builds that see a fair amount of track time I do include them. I will say we do not often adjust them once happy with the setup but like having that option when we need it.

I made a big jump to square 275 200tw, sways, monoball rear lower camber arm bearing, solid subframe raising bushings in the rear (the latter not a F8x concern). My shop set up with middle setting rear sway and one of the middle two settings front sway (escapes me at the moment, and car is still in the shop so I can't check). However, between all of this, I noticed a ton of initial front turn in - the car is a ton more playful and I like the balance very much personally, though I need more time to get used to it and fine tune. In shorter corners, it's brilliant; in longer corners (T8 at Thunderhill) I definitely have to build up the confidence to get accustomed to the extra turn in.

Would I have spent the money for the rear sway install if I wasn't doing other stuff back there? Probably not, but I don't regret it and I certainly won't be paying labor to remove it in the future.

[medphysdave]

Originally Posted by bipp

I made a big jump to square 275 200tw, sways, monoball rear lower camber arm bearing, solid subframe raising bushings in the rear (the latter not a F8x concern). My shop set up with middle setting rear sway and one of the middle two settings front sway (escapes me at the moment, and car is still in the shop so I can't check). However, between all of this, I noticed a ton of initial front turn in - the car is a ton more playful and I like the balance very much personally, though I need more time to get used to it and fine tune. In shorter corners, it's brilliant; in longer corners (T8 at Thunderhill) I definitely have to build up the confidence to get accustomed to the extra turn in.

Would I have spent the money for the rear sway install if I wasn't doing other stuff back there? Probably not, but I don't regret it and I certainly won't be paying labor to remove it in the future.

I'm putting in a diff brace so I'll get the chance to add one to the rear. The front bar made the car feel really planted when hitting a series of corners where weight shifted quickly from one side to the other.

[M3SQRD]

Originally Posted by medphysdave

The ARB are now an interesting subject. I added the CSR front bar and kept the stock rear. With suck suspension I really like the change on road and track. The stock suspension eats curbs pretty well in my opinion and didn't upset the car. An instructor was with me and he also commented with surprise. I was able to take an aggressive line.

With a suspension that can control body roll. Is it better to go back to the stock bar? Will the stiffer front bar inhibit things? Even more concerning is the rear bar. It's expensive to swap. I'm thinking about leaving that one stock.

I agree 100% with Jason’s comment about ARBs being a finisher or fine tuner to dial in the balance you’re looking for. Also, adjusting the sway bar position is an easier way to add or remove roll stiffness to alter the balance at different tracks. The BW GTmore used ARBs to extract that last few % of performance. Adding a stiffer rear bar will do more good than putting the front bar back to stock. If you’re doing something else that allows you to install a rear bar then definitely do it. Rear bar is an expensive upgrade. If cost is a factor, save a little here and there and then do the upgrade down the road. You can still dial the car in and maybe you’re missing that last 2-3% of lap time and “perfect” balance.

[bipp]

Originally Posted by M3SQRD

I agree 100% with Jason’s comment about ARBs being a finisher or fine tuner to dial in the balance you’re looking for. Also, adjusting the sway bar position is an easier way to add or remove roll stiffness to alter the balance at different tracks. The BW GTmore used ARBs to extract that last few % of performance. Adding a stiffer rear bar will do more good than putting the front bar back to stock. If you’re doing something else that allows you to install a rear bar then definitely do it. Rear bar is an expensive upgrade. If cost is a factor, save a little here and there and then do the upgrade down the road. You can still dial the car in and maybe you’re missing that last 2-3% of lap time and “perfect” balance.

I guess a question is like - would you find bars advantageous at the same spring rate, or would you lower spring rate to reach the same end goal as bars?

i.e. say you're at 700/1000 - after adding bars, would you go down to 600/900? or is it an exercise in "the most roll stiffness while being liveable on the street"?

[M3SQRD]

Originally Posted by bipp

Thanks! I'll definitely need to do the math, but this is what Bimmerworld had to say, as a reference:

Front 4 way adjustable- 295 lbs/in, 335 lbs/in, 380 lbs/in, 435 lbs/in
Stiffness over stock: +52%, +73%, +96%, +124%

Rear 3 way adjustable - 175 lbs/in, 195 lbs/in, 215 lbs/in
Stiffness over stock: +56%, +74%, +92%

I'm already on the OGSM conventional R1 on my E92 - apologies if my yapping throughout the thread left any confusion. I don't think I'll outgrow my R1 any time soon - more constrained on how often I can get to the track than anything, and I fully plan on getting the full use out of them. With the DCT bill in mind, I don't think I'm in a responsible place to upgrade anytime soon - maybe try to get another season or two on the OGSM R1 before I succumb to temptation and get the R3s so I can see shiny reservoirs when I put my bag in the trunk to continue growth.

Given the cost diff between R1 and R3, maybe I should've ponied up an extra 4 grand last year and gone straight for them, but at the time I would've had no idea what to do with a 3 way setup. So for that matter, I'm grateful to have picked up a fair bit of knowledge, and find the time to read the books you suggested in the KW thread (on the F80/2 board) before I move up to the R3.

You need to look at roll stiffness (main spring rates + ASB axial spring stiffness) and heave/bounce stiffness (main spring rates only) separately. I personally have never lowered spring rates when adding ASBs (ASB stiffness ranges may be influenced by main spring rates if multiple bars are available). On my e46 M3, I swapped to GC race ASBs which were softer than the UUC ASBs I was using because we had upped the main front and rear spring rates by 50%. However, we ended up maximizing the ASB stiffnesses (which were still softer than the UUC mid-high rates). The GC ASBs were still ~45-50% stiffer than stock and, coupled with the stiffer main springs, made the car’s balance great. The UUC ASBs front and rear stiffness, in particular the rear, were just too much even for the original setup with the softer main springs. The GC front ASB really helped with maintaining what little camber curve there was on the e46 M3 without having to run even higher main spring rates.

For the e9x M, the front ASB equivalent axial wheel rate is 0.96^2 = 0.92 x front ASB axial rate which is the same for the front main spring wheel rate. The rear ASB equivalent axial wheel rate is 0.84^2 = 0.71 x rear ASB axial rate and the rear main spring coilover equivalent wheel rate is 0.82^2 = 0.67 x rear coilover spring rate. What are your current front and rear main spring rates?

We all learn the hard way about buy once, cry once. Even if you’re not going to outgrow the R1 in 1 or 2 or 3…seasons, you don’t really outgrow the R3, instead you continue to learn how to extract more performance from them. As long as you have someone, like Jason, that can give you a solid conservative baseline, or a baseline you can get back to after creating a monstrosity of a setup with some crazy 3-way settings, setup then you should have the confidence to try out different setups while learning what does/doesn’t work. I can’t think of one setup with ASBs, from a ‘92 Civic Si to an ap1/ap2 s2000s to an e36 through a f8x, that would’ve been better without the ASBs. Also, it’s pretty simple to find out how the car will react without a single or both ASBs installed.

[M3SQRD]

Originally Posted by bipp

I guess a question is like - would you find bars advantageous at the same spring rate, or would you lower spring rate to reach the same end goal as bars?

i.e. say you're at 700/1000 - after adding bars, would you go down to 600/900? or is it an exercise in "the most roll stiffness while being liveable on the street"?

The answer is usually yes for an adjustable ASB. There’s enough adjustment to find settings that help finalize the balance, not looking to completely change the balance. BW GTmore build was running 1100/1100 lbf/in (coilover) with aero and GTmore ASBs. The ASBs help extract that last 2-5% out of your setup. I was planning on adding bars to my 700/1100 (divorced) when I converted to a rear coilover with either 700/600 (equivalent to my current divorced setup if I used a 110 N/mm rear spring) or try 800/700. So I’d add bars even if I went stiffer to fine tune the balance.

[medphysdave]

Anyone driven a well sorted Tractive setup? It will be interesting to see how the Nitrons will compare. Nitrons quoted valve speed is similar to Tractive at 6ms.

I always wondered why the Porsche PASM had aftermarket tuning support, but BMW EDC doesn't.

External controllers that modify damping response in relationship to G-force is interesting.

I think the BMW system does monitor compression but it's an external sensor that would be independent of the damper electronics so the car would still receive the information regardless of what was controlling the damping.

Looping back to Tractive. Users seem to report being able to run significantly higher spring rates comfortably. The R3 spring rates are quoted with the softest rates that provide comfort and don't sacrafice much performance as far as lap times. At some point I don't think there is a way to overcome a stiff spring and still be street enjoyable.

Please Nitron make an app for the FAL that lets me set GPS triggers. I believe I watched something that suggests they are doing this. Time will tell

[M3SQRD]

Originally Posted by medphysdave

Anyone driven a well sorted Tractive setup? It will be interesting to see how the Nitrons will compare. Nitrons quoted valve speed is similar to Tractive at 6ms.

I have experience with TracTive (TT) race semi-active dampers (equivalent to eT R3) with their standalone ACE controller. It performed well but I still preferred the MCS 3WR. Both had similar spring rates. TT race did do a better job of isolating bumps in one section of the track. To be fair, extra time was given to the TT to set LSC and HSC. Delta lap times were within the repeatability of lap times.

I always wondered why the Porsche PASM had aftermarket tuning support, but BMW EDC doesn't.

The TPC DSC Sport controller is superior to the PASM controller that pretty much all P cars with TT setups run the DSC Sport controller. They were developing a DSC Sport controller for the f8x and then abruptly stopped development. The Nitron DCU should perform better than the edc plug-n-play setup.

External controllers that modify damping response in relationship to G-force is interesting.

EDC uses accelerators to control low-speed damping.

I think the BMW system does monitor compression but it's an external sensor that would be independent of the damper electronics so the car would still receive the information regardless of what was controlling the damping.

BMW EDC uses inputs from multiple sensors. Internally, there’s only the Dynamic Damping Adjustment (DDA) valve. The accelerometers are mounted externally.

Looping back to Tractive. Users seem to report being able to run significantly higher spring rates comfortably. The R3 spring rates are quoted with the softest rates that provide comfort and don't sacrafice much performance as far as lap times. At some point I don't think there is a way to overcome a stiff spring and still be street enjoyable.

The Touring line comes with rate options. I know one is identical to stock spring rates and I’m not sure what the second option is. Touring line uses stock upper mounts. The Track and race lines come with custom spring rates and camber plates + machined rear upper mounts. Spring rates should vary based on your goal. No comment regarding actual rates.

Please Nitron make an app for the FAL that lets me set GPS triggers. I believe I watched something that suggests they are doing this. Time will tell

C8 vette has a feature where it memorizes where you’ve used the lift kit before and automatically starts to lift the car once it’s close to the spot.

[bipp]

Originally Posted by M3SQRD

You need to look at roll stiffness (main spring rates + ASB axial spring stiffness) and heave/bounce stiffness (main spring rates only) separately. I personally have never lowered spring rates when adding ASBs (ASB stiffness ranges may be influenced by main spring rates if multiple bars are available). On my e46 M3, I swapped to GC race ASBs which were softer than the UUC ASBs I was using because we had upped the main front and rear spring rates by 50%. However, we ended up maximizing the ASB stiffnesses (which were still softer than the UUC mid-high rates). The GC ASBs were still ~45-50% stiffer than stock and, coupled with the stiffer main springs, made the car’s balance great. The UUC ASBs front and rear stiffness, in particular the rear, were just too much even for the original setup with the softer main springs. The GC front ASB really helped with maintaining what little camber curve there was on the e46 M3 without having to run even higher main spring rates.

For the e9x M, the front ASB equivalent axial wheel rate is 0.96^2 = 0.92 x front ASB axial rate which is the same for the front main spring wheel rate. The rear ASB equivalent axial wheel rate is 0.84^2 = 0.71 x rear ASB axial rate and the rear main spring coilover equivalent wheel rate is 0.82^2 = 0.67 x rear coilover spring rate. What are your current front and rear main spring rates?

We all learn the hard way about buy once, cry once. Even if you’re not going to outgrow the R1 in 1 or 2 or 3…seasons, you don’t really outgrow the R3, instead you continue to learn how to extract more performance from them. As long as you have someone, like Jason, that can give you a solid conservative baseline, or a baseline you can get back to after creating a monstrosity of a setup with some crazy 3-way settings, setup then you should have the confidence to try out different setups while learning what does/doesn’t work. I can’t think of one setup with ASBs, from a ‘92 Civic Si to an ap1/ap2 s2000s to an e36 through a f8x, that would’ve been better without the ASBs. Also, it’s pretty simple to find out how the car will react without a single or both ASBs installed.

Interesting to hear. Thanks for sharing info about wheel rate calculations. I'm at the standard 700/800.

That's definitely a good point about the R3s. Perhaps it makes sense to make the jump sooner than later - drop the money now, get a bit more out of selling the R1s, and have a setup in perpetuity to fine tune over time. Maybe next year - wondering if it's worth directly upgrading to not have to find a buyer, but then I'd be out of a car for a while.

As always, thanks for providing perspective from your knowledge and experience!

[M3SQRD]

Originally Posted by bipp

Interesting to hear. Thanks for sharing info about wheel rate calculations. I'm at the standard 700/800.

That's definitely a good point about the R3s. Perhaps it makes sense to make the jump sooner than later - drop the money now, get a bit more out of selling the R1s, and have a setup in perpetuity to fine tune over time. Maybe next year - wondering if it's worth directly upgrading to not have to find a buyer, but then I'd be out of a car for a while.

As always, thanks for providing perspective from your knowledge and experience!

If it wasn’t for your DCT issue, I’d say go for the ogsm R3 now. However, you’ve said there’s very limited time for track events this year so waiting until next year won’t really set you back much. Plus if there is time here and there to squeeze in a track day/event, the R1 will still give you valuable seat time that should be useful for your eventual switch to the R3.

This thread may have come across as me not always willing to be helpful but I always try to be helpful where I can. You’re welcome

[medphysdave]

Originally Posted by M3SQRD

C8 vette has a feature where it memorizes where you’ve used the lift kit before and automatically starts to lift the car once it’s close to the spot.

P-car crew that use Tractive seem to think it's amazing (Rennlist). But maybe everyone thinks there suspension is amazing when they drop 10k+ on it? I'm your you'll hear me say my R3s are magic

[M3SQRD]

Originally Posted by medphysdave

P-car crew that use Tractive seem to think it's amazing (Rennlist). But maybe everyone thinks there suspension is amazing when they drop 10k+ on it? I'm your you'll hear me say my R3s are magic [/COLOR]

The TracTive Track or Race line combined with the DSC Sport is an excellent street and track suspension setup. If DSC Sport had completed the f2x, f3x and f8x, I think TracTive would have been a popular dual-purpose setup. A local guy had purchased a TracTive f8x suspension and TPC had started on the development of the DSC Sport. Once they were done designing a controller, TPC (Turbo Performance Center) was supposed to build a f8x turbo kit. Something went wrong because things shutdown quickly.

The eT R3 with the DCU would be similar in cost and performance to the TracTive Race with DSC Sport. At $10k, a price of +/- $1-2k becomes pretty insignificant It would have been interesting to see which setup ended up being top dog. Tractive and DSC Sport would’ve had a ~6 year f8x head start.

[medphysdave]

I'm still having a tough time believing that a standalone suspension controller isn't somehow limiting other electronic safety features related to stability control? How is the BMW EDC feeding information to and from other systems? A standalone may be a superior suspension control option, but is it at the expense of safety when not at the track?

Good run down here:

https://www.m3post.com/forums/showthread.php?t=2002116

Interesting comments:

Good stuff. I did ask how their EDC kit would compare to different settings on an ACE kit, and they told me, "The ACE is a programable system based solely off an accelerometer. The factory system takes all kinds of data from various sensors across the car. It is not possible to determine exactly what the BMW system does, but it is more advanced than the ACE unit."

Yeah TracTive engineer told me that as well. They say the BMW EDC is even more advanced than PASM. One limitation I can see with EDC + TracTive is that you're stuck with whatever settings BMW has put into EDC. You won't be able to customize it.

Tractive Touring seems like it is more akin to the eR1 and the Motorsport line is more like an eR3 with manually adjustable HS/LS compression. The question then becomes? If a suspension can mimic HS/LS compression characteristics by quickly changing the rebound damping. Wouldn't true HS/LS compression just allow the Tractive damper to not need to work as hard? Soooo confused!

We offer dedicated motorsport suspension systems that have been proven to win races. We provide four different ways of damper adjustments, two of which feature low- and high-speed compression adjustments and two of which feature our Active Controlled Electronics (ACE or R-ACE).

After reading more I question if the motorsport line is Truly 4-way. I think I understand the system. Like a 1-way adjustable that adjusts both compression and rebound with each click. The Tractive valve is so quick that it essentially acts as an independent Rebound, HS, and LS adjustment since these events are occurring at different times. Direction of shock travel can only be one direction in any one moment. I have to believe that over extreme instances where shock travel would exceed or change more quickly than 6ms - 10ms there would be competition between HS, LS, and rebound. Just because the valve operates this quickly doesn't mean the fluid travels and the shock responds this quickly. Someone with a fluid dynamics background can chime in with shock response latency due to fluid movement.

The eTron R3 with DCU will eliminate the competitive need for Rebound, LS, and HS. It will be able to act as a LS/HS rebound adjustment. My guess is it will be able to "hold" a shock position and help further control the pitch and roll.

[M3SQRD]

medphysdave

Here’s a couple of threads discussing EDC from a chassis vehicle engineer that develops edc and fixed suspensions:

EDC vs. other manufacturer EDC-like setups
https://f80.bimmerpost.com/forums/sh...65&postcount=1

ZCP EDC dampers vs. Base EDC dampers
https://f80.bimmerpost.com/forums/sh...63&postcount=1

Converting to CS EDC
https://f80.bimmerpost.com/forums/sh...&highlight=EDC

[m4shifter]

I have been refreshing this page almost every day for the last 2 weeks hoping there will be some updates

[medphysdave]

Originally Posted by m4shifter

I have been refreshing this page almost every day for the last 2 weeks hoping there will be some updates

The electronic revolution is up on us. Waiting to see if the Nitron DCU is better than running the eTrons with factory EDC. Mainly does the cost of the DCU gain enough comfort and performance to be worth it.