Ohlins R&T Spring/Sway Choice

[Thoglan]

I am by no means well versed in suspension but I try my best. My current setup is ohlins r&t with stock ohlins springs, stock sways, GC street camber plates, 3DM ohlins strut spacers. Personally, I think they ohlins are beautiful and I don't really have any complaints, but my fear is that I might unknowingly be forgoing additional comfort and performance by not trying out some different spring options.

Without access to corner weighting my car, I can only really guess for what the weight would be. But to be honest, from what I can see from others it seems most people end up at around the 325-375lb/in range anyway. Seems a safe bet to aim for 350 front and run the stock ohlins spring in the rear. If anyone does want to guess weights, my M3 is close to no options with the exceptions being xenon headlights and power seats (which have been replaced with recaro PP ABE's on manual sliders). With regards to spring length, is the stock ohlins spring length of 7" optimal? If I understand correctly, simply slapping in a lower rate spring in the front will throw the front roll couple off and require a stiffer front sway. For the purpose of seeing if the exercise is worth while, is it sufficient that I just remove the rear sway (I recall Ian saying something to this sentiment)?. That way if I'm unimpressed I can quit while I'm ahead only having bought a couple springs, and if I am I can go down the rabbit hole of getting different sways/rear springs etc.

[cobra]

You generally set your springs for a desired ride frequency and don't need to mess with it. If you're within a normal range and feel like its uncomfortable it's very likely the damper itself. That DFV is not known as being the most comfortable.

What are your spring rates and how would you describe the ride in terms of ride quality and handling?

[Thoglan]

You generally set your springs for a desired ride frequency and don't need to mess with it. If you're within a normal range and feel like its uncomfortable it's very likely the damper itself. That DFV is not known as being the most comfortable.

What are your spring rates and how would you describe the ride in terms of ride quality and handling?

I am running the stock ohlins rates, which IIRC are 400F/630R. Would be nice to try out a flat ride set up, but ideally I'd like to do so without jumping in straight away and corner weighting/buying 4 new springs and a new front and rear sway. In essence my question is whether just going with a lower rate front spring and removing the rear sway is a worthwhile exercise in determining whether I want to go down the rabbit hole or not. Obviously this would not be a permanent solution.

My current setup is fairly compliant I would say. Firm, but not uncomfortable unless on really bad roads where it can feel quite 'busy'. Like I said, I don't really have any complaints but given how highly others on here speak about flat ride I wonder if it's worth toying with. If so am I right in thinking 350lb/in 7" springs are a good starting point?

[Slideways]

One thing that did not come up much in the flat ride thread is how the added stress from the larger front bar and grippier tires can cause the chassis mounts of the sway bar to tear away. Reinforcement plates would add cost to the setup.

[Obioban]

Whether your change your springs out or not, you should absolutely corner balance and dial out preload. That kind of of wonkiness just makes the car worse, with no benefit in exchange.

350 lb front springs would get you into flat ride, just. Better to go 350 up front, 700 in the rear. Either way, you want to beef up the front sway and leave the rear sway stock to get a reasonable FRC.

How long of a spring you can use depends if you're trying to get the perch above the front tire. If you want to run wide tires (track) with a reasonable alignment, you'll need a shorter spring. If it's just a street car, get a longer spring as it's much easier to get everything to work right.

The R&Ts are very limited on travel, so I'd set front ride height entirely based on bump/droop (60% bump, IMO), then set a 1/2" stagger (rear 1/2" lower, fender to wheel lip, which isn't a real measure of stagger, but is super easy to measure and sets the car up correctly), then set the rear to be 60% bump using their adjustable shock length feature, then corner balance and eliminate preload :P

Flat ride was the most dramatic change for the better (in all ways-- comfort, civility, drivability) of any suspension change I've ever made. But, you can't really do it as a half measure. And, not corner balancing and/or eliminating preload just makes the car worse than stock, with or without flat ride.

TCK makes nice 700 lb rear springs, Eibach makes front springs with abnormally much travel (their "extreme travel" line) if you're trying to get the perch above the front tire.

[repoman89]

Aren’t the stock Ohlins springs 8 inches? Thought that’s what I measured before I put mine in. Based on the spreadsheet I also have a 325lb and 350lb 7.5” spring I want to install in the front right and left side of my car respectively along with stock 630lb rears for now.

[Obioban]

I don't remember what the stock spring length is, but it doesn't get the perch above the tire-- so if you want a wide front tire, stock length won't cut it.

[mrgizmo04]

Stock fronts are 8". 7" - depends, if you try a 400# spring, it does not require as much preload to support that corner's weight and get you to proper ride height so it will not get the perch above tire, if you try 325#, it requires a lot more preload and will get the perch up high and since you have 3dm spacer you should be fine with a soft 325/336 spring. For springs I also looked at Swift/Hyperco brands.

Sent from my SM-G950U using Tapatalk

[cobra]

I still don't understand flat ride, and not trying to bash it I just genuinely want to learn. Are oem's specifically targeting these frequencies because it's good from a performance standpoint, or because it's required to meet other requirements? For example in the m3 they have to account for 4 passengers and a trunk full of luggage. A pickup truck is a worst case example of this- they ride like shit in stock form because they're compromised to meet so many other objectives.

When discussing flat ride I see two things mentioned- that many oems use this ratio, and also that it will settle the front and rear at the same rate due to the wheelbase offset. This will really only be correct at a certain speed over a certain singular event and more or less irrelevant in real world driving conditions.

The only really compelling thing I see about it is with relation to removing the sway bars, otherwise known as grip removers. I see that as a potentially good thing and something most people don't talk about as much, maybe because it's more complex to think about than springs with very obvious rates.

Seems to me that ohlins selected springs to achieve a balanced ride frequency which will be better from a performance standpoint with a single driver. The rates are not particularly high either, but it also comes down to personal preference.

I'm really really curious to ride in obiobans m3 or a similarly set up m3, too bad we live on opposite sides of the country lol.

[Mayan-Viking]

I have had this same question on flat ride for some time. I think it looks great. But I don't know what the supposed benefits are. So I don't know how to find out whether the costs associated with this setup are worth with the benefits. Further insight would be much appreciated.

Edit: I found the answer in another thread. I'd like to ask the question differently because I'm curious and I love to ponder about things that don't let me sleep some times. I am intending to order order Dinan/Koni in the coming days. In real world street only applications where roads are generally very acceptable is going flat ride worth the effort?

Pandora's box...

[LSBNick]

I have Ohlins R&T waiting to go on. Are the GC plates you run the stock spring diameter with 14mm studs?

[Obioban]

I have had this same question on flat ride for some time. I think it looks great. But I don't know what the supposed benefits are. So I don't know how to find out whether the costs associated with this setup are worth with the benefits. Further insight would be much appreciated.

Edit: I found the answer in another thread. I'd like to ask the question differently because I'm curious and I love to ponder about things that don't let me sleep some times. I am intending to order order Dinan/Koni in the coming days. In real world street only applications where roads are generally very acceptable is going flat ride worth the effort?

Pandora's box...

Dinan's springs are flat ride with zero effort.

I think you may think flat ride is something different than it is-- flatride is having higher frequencies in the rear than the front.

[Sid_E46]

Dinan's springs are flat ride with zero effort.

I think you may think flat ride is something different than it is-- flatride is having higher frequencies in the rear than the front.

Is a flat ride necessarily more comfortable on the street?

[Obioban]

Is a flat ride necessarily more comfortable on the street?

I mean, if you used 1000 lb front springs and 2000 lbs rear springs it wouldn't be

Flat ride is generally more comfortable, in comparable setups.

[Sid_E46]

I mean, if you used 1000 lb front springs and 2000 lbs rear springs it wouldn't be

Flat ride is generally more comfortable, in comparable setups.

What would you say is a good street spring rate for a flat ride on TCK DAs?