Ohlins R&T Spring/Sway Choice

[LSB4Me]

Personally, having owned a new E90 with the EDC (in the past) and now an e46 with Ohlins R&T, I don’t think Ohlins could have made anything better for the road than what was original with the E9x. So, another guess on how they chose spring rates would be they simply offered a replacement “shock” and spring for failed OEM EDC systems and needed to stay close to OEM feel.

I had Ohlins on my ZCP e92. They were infinitely better than EDC.

I haven’t had a better handling, better behaved car than that e92. Some cars do certain things better, but none have been a better total package (admittedly, with all my mods).

[OldRanger]

My question is then why did they go more "flat ride" on e9x?

400/628 e46 vs 342/685 for e9x.

Did they learn something?

Though perhaps it's due to something like e9x front end being more rigid thus requiring less spring idk.

I (1) question whether or not there was a learning curve for Ohlins between the E46 and the E9X, and (2) generally discourage comparisons on spring rates between the two.

1) Based on a brief Google search, I believe Ohlins released the R&T for the E46 in late 2012. I believe the E9X R&T suspension was released at about the same time (early 2013)? Does anyone know if that’s accurate?

2) The M3 aftermarket in 2013 would have been vast, with a wide variety of driver preferences. I would tend to agree with LSB on likely motives and market analysis.

Those Ohlins design teams ended up making a tough choice. Taking a stab at spring rates (which are inextricably linked to ride height) and choosing one spring for the E46 M3 would have been difficult. Choosing only one spring rate for the various E9x drivers in 2013 would have been even more daunting. The newer E9X had a sedan version, and automatic electronic damping control. That would have been seemingly impossible to choose an ideal spring rate for such a multipurpose, adaptable car.

Personally, having owned a new E90 with the EDC (in the past) and now an e46 with Ohlins R&T, I don’t think Ohlins could have made anything better for the road than what was original with the E9x. So, another guess on how they chose spring rates would be they simply offered a replacement “shock” and spring for failed OEM EDC systems and needed to stay close to OEM feel.

[LSB4Me]

My question is then why did they go more "flat ride" on e9x?

400/628 e46 vs 342/685 for e9x.

Did they learn something?

Though perhaps it's due to something like e9x front end being more rigid thus requiring less spring idk.

I was told Ohlins went more “road” on the E9x and more “track” on the e46 due to their perception of intended use.

342 definitely feels better up front. When I change out my diff, I’m going to put the original 628 springs back in the rear as it’s flat ride and I’m a glutton for punishment.

[Tbonem3]

Yes. Ohlins got it right for (mainly) a street car.

400lbs is way too much for street e46 imo.

[Tbonem3]

Lots of data points here but not that much consensus for a mainly street car.

Looking to install mine soon... perhaps Ohlins got it right with the included springs/rates?

My question is then why did they go more "flat ride" on e9x?

400/628 e46 vs 342/685 for e9x.

Did they learn something?

Though perhaps it's due to something like e9x front end being more rigid thus requiring less spring idk.

[OldRanger]

...perhaps Ohlins got it right with the included springs/rates?

Yes. Ohlins got it right for (mainly) a street car.

[freshprince2421]

Lots of data points here but not that much consensus for a mainly street car.

Looking to install mine soon... perhaps Ohlins got it right with the included springs/rates?

[eacmen]

I get it, but how much grip can that unloaded wheel that wants to come off the ground really give you even if it does brush the surface?

Not saying it's not worth trying, but I'd be prepared to make additional adjustments to balance things out. Tire staying on the ground is good, but it may end up with even more understeer.

anyway, sorry, didn't mean to derail.

Good ref here from speed secrets:

https://speedsecrets.com/q-how-can-i-use-the-anti-roll-bar-to-reduce-understeer/

what i'm saying is that with Ohlins and their short travel that it ends up being “the exception and not the rule” category especially with relatively soft springs.

[tnord]

I get it, but how much grip can that unloaded wheel that wants to come off the ground really give you even if it does brush the surface?

Not saying it's not worth trying, but I'd be prepared to make additional adjustments to balance things out. Tire staying on the ground is good, but it may end up with even more understeer.

anyway, sorry, didn't mean to derail.

[eacmen]

maybe I'm remembering things wrong, but if he's already having issues with understeer then stiffening the front bar will make that worse.

maybe stiffen the front and rear bar?

Stiffening front bar typically will make understeer worse, unless your understeer is caused by too much roll and lifting the inside wheel. It's a rule of thumb but not a hard and fast rule.

[tnord]

maybe I'm remembering things wrong, but if he's already having issues with understeer then stiffening the front bar will make that worse.

maybe stiffen the front and rear bar?

[eacmen]

I'm curious: is it possible to install the 3DM spacer on the bottom of the strut without removing the three nuts from the top the strut tower? I'd like to add the spacer, but I don't want to have to deal with all the alignment variables to sort out after I do it.

My car is basically stock up front in terms of weight on the suspension. I have the Ohlins RT front 400# springs. I had a reputable shop/dealer install them. They set the ride height at 13.25 - 13.5 inches. I have the Ground Control front sway at nearly full soft. The link bracket is about 1cm from the end of the bar.

Here's the issue: mid-turn I have some understeer and I speculate it's because the inside wheel is getting too light. Here's what I found when looking at relative bump/droop: the Ohlins RT 400# spring supporting a car with stock weight on the front 'axle' at 13.25-13-5 ride height only has about 1” of droop travel. This equates to only 27% of the total travel, and based on opinions here, is not an optimal amount of droop for traction mid turn.

Droop should be more like 1.5 inches (40%) right?

So my experience with the GC front bar and Ohlins was that the general rule of thumb for front sway adjustment didn't apply. If the front sway is too soft you will induce too much roll in the front and lifting the inside tire too much. I forget how much front sway but I think it's between 1.5 and 2 inches from the end on each side seemed to be the sweet spot. Try to stiffen front sway to see how it feels, can't hurt and it's free!

[Obioban]

I’m curious: is it possible to install the 3DM spacer on the bottom of the strut without removing the three nuts from the top the strut tower? I’d like to add the spacer, but I don’t want to have to deal with all the alignment variables to sort out after I do it.

My car is basically stock up front in terms of weight on the suspension. I have the Ohlins RT front 400# springs. I had a reputable shop/dealer install them. They set the ride height at 13.25 - 13.5 inches. I have the Ground Control front sway at nearly full soft. The link bracket is about 1cm from the end of the bar.

Here’s the issue: mid-turn I have some understeer and I speculate it’s because the inside wheel is getting too light. Here’s what I found when looking at relative bump/droop: the Ohlins RT 400# spring supporting a car with stock weight on the front ‘axle’ at 13.25-13-5 ride height only has about 1” of droop travel. This equates to only 27% of the total travel, and based on opinions here, is not an optimal amount of droop for traction mid turn.

Droop should be more like 1.5 inches (40%) right?

Yes, you can add it just from below. Doing so without any other changes will raise your ride height.


Agreed that doesn’t sound like enough droop travel.

[OldRanger]

I’m curious: is it possible to install the 3DM spacer on the bottom of the strut without removing the three nuts from the top the strut tower? I’d like to add the spacer, but I don’t want to have to deal with all the alignment variables to sort out after I do it.

My car is basically stock up front in terms of weight on the suspension. I have the Ohlins RT front 400# springs with a Vorshlag camber plate. I had a reputable shop/dealer install them. They set the ride height at 13.25 - 13.5 inches. I have the Ground Control front sway at nearly full soft. The link bracket is about 1cm from the end of the bar.

Here’s the issue: mid-turn I have some understeer and I speculate it’s because the inside wheel is getting too light. Here’s what I found when looking at relative bump/droop: the Ohlins RT 400# spring supporting a car with stock weight on the front ‘axle’ at 13.25-13-5 ride height only has about 1” of droop travel. This equates to only 27% of the total travel, and based on opinions here, is not an optimal amount of droop for traction mid turn.

Droop should be more like 1.5 inches (40%) right?

[mrgizmo04]

I'm not 100% sure, but I *think* I want to make it clear to those reading this thread, that, "optimizations" being discussed in this thread to lower all rates to have the ride be less jarring over imperfection on LA roads and wherever else, apply to "straight" line driving. Running 300-350 front and 450-500 rear springs with beefed up front bar will make the car VERY understeery in twisties/track/autox. I would also note that, Ohlins, due to their SUPER limited front damper travel, are not ideal to optimize for poor roads where you may actually need to run softer springs but need more travel (the lower in lbs you go, the more inches you need to absorb enough energy to rebound). Also, front end busyness goes up significantly even with 300 front springs, given you are > 2x stock rates, while rears at 600 are still within the progressive stock range, -ish.

There is a lot of Frankenstein-ing going on.

That said, Swift and Hyperco make a lot of springs in a lot of rates and lengths. I don't know what everyone is after, but there are choices. You'd probably feel more comfortable dropping the front rates below 300 at appropriate length/ride height to help with poor roads.

Sent from my SM-S911U1 using Tapatalk