Vendor Model 3 Öhlins DFV Coilovers - Engineered by Redwood Motorsports ™

[tm1v2]

@P3D-R My front dampers are at Redwood's recommended length, which is the same for any ride height. They were preassembled that way, I measured to verify of course. Redwood recommends adjusting ride height only via preload. My understanding - which could be wrong! - is their recommended damper length ensures a minimum height under compression that's about the same as stock suspension (regardless of static ride height so long as you only adjust that via preload). Thus avoiding any increased risk of battery-to-ground/debris contact.

For the divorced rear Redwood has two recommended damper lengths depending on ride height, and the rears were preassembled for the shorter length they say is safe for any height (including lowered). For higher heights like stock height, where I'm at, they say it's safe to extend the rear dampers another 15mm. I attempted to do this and for some reason failed to, the whole damper body kept turning, so the lower section never unthreaded further from the upper gold colored part. I was afraid to clamp the upper section to keep it from rotating, didn't want to risk damaging anything, and it was clear that the shorter length was perfectly safe, so I ended up leaving the rears that way. I therefore should have another 15mm of "safe" rear compression travel to be gained, per Redwood's recommendations, whenever I feel like revisiting this again. Which I will at some point. (I did try calling Redwood for advice when I got hung up on this but it was a Sunday, easter Sunday specifically, and they were closed.)

With all of that said...the only time I've felt it clearly hit the (rear) bump stops so far on the new suspension, was over a big dip where for sure it would have hit them with the stock suspension too at the speed I was traveling. The kind of dip where someone helpfully spray painted "DIP" as a warning to not go so fast and destroy your car or crash your bike on it. It was WAY smoother over that dip than it would've been stock, but I could still tell the bump stops got involved.

I don't think the Model 3 is challenged for travel compared to a low sports car or such. My main comparison point is my old Subaru WRX STI, long gone from my ownership but never forgotten. I'm pretty sure it had more travel and ground clearance than most sporty cars. I don't recall hitting its bump stops as easily, and I would tear up these same roads in it, when opportunity allowed. Maybe I'm remembering it through rose colored glasses though!

 

[tm1v2]

@P3D-R Btw I measured about 395mm hub/wheel center to fender edge at the rear of my October 2021 M3P on stock suspension. That's the height I went with all around, because I neglected to measure the front height before taking it apart.

It's possible I've since settled slightly lower. I checked height post-install by mounting wheels, taking car off lift, and driving reverse+forward a few times in front of the lift with some quick brake applications. That definitely helped it settle but I haven't checked if it's since settled more, I don't really know if I should expect more settlement or not. Need to find where my wife has (mis?)placed our tape measurer...

Visually it still looks about stock M3P height to me - ever so slightly lower than most Model 3s, but not drastically so. For whatever that's worth.

 

[drpheta]

When measuring from the hub to fender are you doing middle of the hub?

My car is set about 362mm from hub center to fender. Ride is nice on the sport springs and sport valving. Didn't think I would do it, not now I'm getting the camber set up for HPDE/track hopefully this summer.

 

[tm1v2]

When measuring from the hub to fender are you doing middle of the hub?

I measured from the middle of my center caps. Eyeballed middle as I wasn't really concerned about matching stock height down-to-the-mm, I just wanted to be close, e.g. +/- 2mm okay.

 

[Occhis]

When I asked Redwood about adjusting ride height, this was the answer from their email:
“You would want to use pre-load up to 20mm higher than stock, beyond that we will add in some free length, depending on how high customers are trying to go.
Above or below 10mm from stock, we suggest adjustable camber and toe arms (both spherical and our FPX low vibration versions work the same).”

 

[tm1v2]

@drpheta What damper settings are you using and liking?


Wife drove the M3P for the first time since the mods. She has a habit of cutting very close to corners in 90° turns. Within a few blocks she brushed onto a curb, thankfully at a crosswalk cutout, and said it happened because the steering responds too quickly now...

(That's one more reason why 18" wheels are right for us!)

 

[drpheta]

@drpheta What damper settings are you using and liking?


Wife drove the M3P for the first time since the mods. She has a habit of cutting very close to corners in 90° turns. Within a few blocks she brushed onto a curb, thankfully at a crosswalk cutout, and said it happened because the steering responds too quickly now...

(That's one more reason why 18" wheels are right for us!)

I believe I'm at 8 clicks up front and 11 clicks in back (from fully open). If/when I hit a road course I'll probably stiffen it to around 15 up front and 19 in back.

 

[tm1v2]

I believe I'm at 8 clicks up front and 11 clicks in back (from fully open). If/when I hit a road course I'll probably stiffen it to around 15 up front and 19 in back.

@drpheta How many clicks is that from full stiff?

Do you actually count from fully open? I thought the correct adjustment procedure was to always tighten to full stiff, then loosen to desired setting. And that's why clicks are usually counted from full stiff, from what I've seen / recall. But I am new to adjustable dampers as mentioned.

 

[drpheta]

@drpheta How many clicks is that from full stiff?

Do you actually count from fully open? I thought the correct adjustment procedure was to always tighten to full stiff, then loosen to desired setting. And that's why clicks are usually counted from full stiff, from what I've seen / recall. But I am new to adjustable dampers as mentioned.

It's 32 clicks total adjustment. That's 24 front and 21 rear from full closed.

Yes, you typically adjust from fully closed, but you can count either way as long as it's consistent. I turned the knobs both ways and counted the clicks to be sure my adjustments were correct. It was just easier/faster to count from fully open with that range.

I remember RW recommending stiffer settings, but I settled on the softer side of things for the rougher New England roads.

Maybe my track setup will end up being even tighter, but we will see.

 

[Motion122]

@drpheta How many clicks is that from full stiff?

Do you actually count from fully open? I thought the correct adjustment procedure was to always tighten to full stiff, then loosen to desired setting. And that's why clicks are usually counted from full stiff, from what I've seen / recall. But I am new to adjustable dampers as mentioned.

You can count it the other way as long as you know where you end up that is all it really matters. Someone else's setting isn't necessarily the best for you, but may provide you with a good reference.

 

[P3D-R]

You can count it the other way as long as you know where you end up that is all it really matters. Someone else's setting isn't necessarily the best for you, but may provide you with a good reference.

This is assuming that all dampers have the same number of detents. Counting from full close or full stiff and backwards will ensure you have symmetrical settings on left and right.

 

[P3D-R]

@P3D-R My front dampers are at Redwood's recommended length, which is the same for any ride height. They were preassembled that way, I measured to verify of course. Redwood recommends adjusting ride height only via preload. My understanding - which could be wrong! - is their recommended damper length ensures a minimum height under compression that's about the same as stock suspension (regardless of static ride height so long as you only adjust that via preload). Thus avoiding any increased risk of battery-to-ground/debris contact.

For the divorced rear Redwood has two recommended damper lengths depending on ride height, and the rears were preassembled for the shorter length they say is safe for any height (including lowered). For higher heights like stock height, where I'm at, they say it's safe to extend the rear dampers another 15mm. I attempted to do this and for some reason failed to, the whole damper body kept turning, so the lower section never unthreaded further from the upper gold colored part. I was afraid to clamp the upper section to keep it from rotating, didn't want to risk damaging anything, and it was clear that the shorter length was perfectly safe, so I ended up leaving the rears that way. I therefore should have another 15mm of "safe" rear compression travel to be gained, per Redwood's recommendations, whenever I feel like revisiting this again. Which I will at some point. (I did try calling Redwood for advice when I got hung up on this but it was a Sunday, easter Sunday specifically, and they were closed.)

With all of that said...the only time I've felt it clearly hit the (rear) bump stops so far on the new suspension, was over a big dip where for sure it would have hit them with the stock suspension too at the speed I was traveling. The kind of dip where someone helpfully spray painted "DIP" as a warning to not go so fast and destroy your car or crash your bike on it. It was WAY smoother over that dip than it would've been stock, but I could still tell the bump stops got involved.

I don't think the Model 3 is challenged for travel compared to a low sports car or such. My main comparison point is my old Subaru WRX STI, long gone from my ownership but never forgotten. I'm pretty sure it had more travel and ground clearance than most sporty cars. I don't recall hitting its bump stops as easily, and I would tear up these same roads in it, when opportunity allowed. Maybe I'm remembering it through rose colored glasses though!

Adjusting height at preload is mostly necessary when lowering. When raising the car you can do it from the bracket rather than adding additional preload. That will keep your piston in an optimal position as well and prevent you from topping out the shock. Either way works but there's already a lot of preload on the spring. Since you're going back to OEM height you can definitely lengthen the shock to achieve that and not add additional preload. They should probably indicate a max amount of preload as well. That way you can ensure you have good compression stroke in the spring relative to the available compression stroke on the shock. I could be wrong but that's what makes sense to me. I was probably the one who first did the shorter rear damper length because the original damper length was a bit too short for my ride height and I was engaging the bumpstop prematurely. I believe they redid the calculations after my results and it was determined that they had more room to shorten up the damper length.

 

[Motion122]

This is assuming that all dampers have the same number of detents. Counting from full close or full stiff and backwards will ensure you have symmetrical settings on left and right.

Someone at QC better get all their fingers out and count! lol

 

[tm1v2]

@P3D-R Did you mean they had a bit more room to lengthen (not shorten) the damper length?

I changed my fronts and rears to 16 clicks from full stiff this evening. Only did two short drives around town, but early impression is this might be close to a Goldilocks setting for me, if I had a daily driving commute.

I'll probably leave them at 16 clicks for a bit to see how I like it with more varied driving. Then I might try stiffening and softening the rear relative to the front.

 

[Motion122]

Shorten rear damper for more up travel before engaging the bump stop.

 

[P3D-R]

@P3D-R Did you mean they had a bit more room to lengthen (not shorten) the damper length?

I changed my fronts and rears to 16 clicks from full stiff this evening. Only did two short drives around town, but early impression is this might be close to a Goldilocks setting for me, if I had a daily driving commute.

I'll probably leave them at 16 clicks for a bit to see how I like it with more varied driving. Then I might try stiffening and softening the rear relative to the front.

Yes you can lengthen the fronts but do not want to shorten them. There are a few reasons for that. One of which is ensuring you bottom out the shock before other components contact critical points on the chassis or the ground. For that reason there's a minimum length that the damper assembly can be, which they have illustrated in their instructions, but increasing the length is not an issue. The same story goes for the rear. If you make the damper too short you can have contact with the body and the ground or tire up in the fender well etc... so to speak. Ideally you'll want the shock length to avoid any of that from happening. This is why we setup adjustable shock lengths without any springs on the car at first to see movement of the tire/sway bar assemblies through the whole sweep and then add in the spring after with helpers if needed to get the heights sorted out.

 

[tm1v2]

Thanks both @P3D-R and @Motion122. I wasn't visualizing correctly what happens to the bump stop vs damper body as it's lengthened or shortened. I realize now I also misunderstood Redwood's "w/ reduced ground clearance" part of the instructions for rear damper free length.

I'm at ~ stock M3P static height (minus a few mm of settlement maybe), but with the rear free length at 630mm (Redwood's "reduced ground clearance" option for lowered cars) instead of 645mm (their default recommendations for any ride height). So right now I probably have more compression travel than stock in the back, right?

Redwood's instructions suggest 645mm rear free length by default for all listed ride heights (360mm-410mm center-to-fender), with 630mm as a "lowered clearance" alternative for cars at 360-380mm height (i.e. lowered cars). I'm around 390mm-395mm ride height. I did try to length the rear dampers to 645mm but as mentioned, couldn't get them to actually unscrew initially and didn't have time to mess around further, so my rears are still at 630mm length as assembled by Redwood.

Is it correct that if 630mm rear damper length avoids any arm-to-chassis or tire-to-chassis contact issues at lower ride heights, then those should also *not* happen even with my higher height? In other words, only the rear damper free length dictates how high up into the chassis the rear wheel can travel, right? The spring height adjuster / ride height is irrelevant there, right? (At least within a reasonable range of heights e.g. 360mm-410mm covered by Redwood's table in their instructions.)

If everything above is correct, then the reason Redwood only lists 630mm "reduced ground clearance" as an option for lowered cars, is because they feel the increased risk of HVB/chassis-to-ground contact is never worthwhile for cars at stock height, not because the risk at 630mm length is actually any different stock vs lowered. Does that seem right?

Yes I'll probably call Redwood about this too, just to make sure. I was already planning to try lengthening the rear damper to 645mm again at some point. I'm asking all these questions to evaluate if I should do that ASAP, or if it's probably okay to wait a while (e.g. wait until I think the car could use an alignment anyways).

 

[tm1v2]

I changed my fronts and rears to 16 clicks from full stiff this evening. Only did two short drives around town, but early impression is this might be close to a Goldilocks setting for me, if I had a daily driving commute.

I'll probably leave them at 16 clicks for a bit to see how I like it with more varied driving. Then I might try stiffening and softening the rear relative to the front.

Switching back to damper settings topic, 16/16 from full stiff is really feeling great. My initial "Goldilocks" assessment still stands so far. Really nice balance of ride vs handling response. 11/11 is more of a sports car feel, still rides perfectly fine to me but it definitely emphasizes very tight chassis/weight control, at the expense of the car following ups-and-downs in the road a lot more than stock. 16/16 honestly seems better for most people's day-to-day driving, the car still responds great, and it really rides well. Think good sport sedan, vs 11/11 feeling more sports car.

(Whereas 22/22 was extra smooth but just felt too soft in the car's responses for my taste. No actual handling issues exposed in my casual driving on 22/22, but it just didn't feel sporty like I want.)

16/16 is also reminding me of the excellent ride vs handling balance I experienced in a car with factory Öhlins DFV. It's been half a year since I drove that car so I'm not making any direct comparisons, but definitely 16/16 feels up there in terms of ride-vs-handling tradeoff. (That car with factory DFV is what led me to buy this Redwood Öhlins kit.)

 

[drpheta]

Now that the roads have been fixed (yay nice weather!) I set the dampers to 17 clicks front and 14 clicks rear (counting from fully closed) and the ride is real flat and nice. Spring rates are default Redwood Sport Performance 8/11k.

I'm tempted to run a firmer setting to see if I like it. I'm also kind of regretting not taking the 10/13k from the start when I had the option.

 

[tm1v2]

@drpheta Go firmer on those dampers before thinking about stiffer springs! 17 up front is daily driver comfort territory. Redwood says 5-10 range is typical for track use and that sounds right to me based on how 11 felt.