My review: Koni Yellows / Eibach Springs on a daily driven M3

[cobra]

The way you describe your car on 650lb rear springs sounds exactly like my current ride quality. That said, clicking down the rear dampers (per Tyler’s suggestion) has settled things a bit. Feels like I’m working through it. Maybe I should start messing with rear tire pressure.

1. Do you guys think that adding upper spring pads (I bought a set of 5mm ones) will do anything to change—meaning, improve—ride quality? I don’t think I have anything other than the Ohlins insert that comes with the setup on top.

2. If adding upper pads and/or raising the rear height (I’m at 13” on 18s with 275/35s) won’t give me any relief, I won’t bother going to the shop next week. What say you?

3. If rear spring rate is the cause of my concerns and I am currently on 628lb springs, would going to 575lb or 600lb springs be the sweet spot? If so, I’m happy to approach Ohlins on this for the collective group.

PS: Thanks for the very generous offer re: your 550lb springs, Tbone. If you weren’t happy with the balance though, we should come back to this as a last resort. Same goes for a change to a Koni/Eibach setup. Trying … to be … patient. O_O

Increasing rebound damping to settle down the stiff springs will slow the vibration but increase overall harshness. The best solution is softer springs and less damping.

1.No
2. Shop not needed.
3. I would try his 550 springs and 325 or 350 front springs. It will still be sporty but a bit more streetable.

[LSB4Me]

I have 650lb rear springs and I gotta say they're pretty stiff. I can feel a noticeable lack in "articulation" due to the stiffness and reduced ride quality just from the higher natural frequency (not damper related). On smooth roads it's amazing but bumpy/uneven mountain roads it is right on the edge of what I'd call streetable.

I think it depends on your priorities. I still thing you should aim lower if you want comfort and a less "busy" ride. Somewhere around 500-550.

The way you describe your car on 650lb rear springs sounds exactly like my current ride quality. That said, clicking down the rear dampers (per Tyler’s suggestion) has settled things a bit. Feels like I’m working through it. Maybe I should start messing with rear tire pressure.

1. Do you guys think that adding upper spring pads (I bought a set of 5mm ones) will do anything to change—meaning, improve—ride quality? I don’t think I have anything other than the Ohlins insert that comes with the setup on top.

2. If adding upper pads and/or raising the rear height (I’m at 13” on 18s with 275/35s) won’t give me any relief, I won’t bother going to the shop next week. What say you?

3. If rear spring rate is the cause of my concerns and I am currently on 628lb springs, would going to 575lb or 600lb springs be the sweet spot? If so, I’m happy to approach Ohlins on this for the collective group.

PS: Thanks for the very generous offer re: your 550lb springs, Tbone. If you weren’t happy with the balance though, we should come back to this as a last resort. Same goes for a change to a Koni/Eibach setup. Trying … to be … patient. O_O

[Tbonem3]

I mostly agree. While I love the linear 550lb in the rear, it's not firm enough to keep up with the front, even when I had a "mild" 325lb.

I'm loving the 628lb I just went up to, and I agree 625-650 is top of the range I think for street. That's if you have 300-400lb up front (I found 400lb overkill for street).

If you suggest 550lb for rear for comfortable, but still sporty use, and I agree, I would say you'd need to make it clear that there's another side to the story - that is the front. You'd need to run a 7-8" 250-300lb (325lb was aceptable) spring IMO.

Max, now that I'm no longer using my 550lb springs, I could offer them to you, even isntall them for you, but I wouldn't suggest it unless you're also willing to go down in the front, but that would require camber plates, so that's why I had suggested abondoning the ohlins for something like the GC coilover conversion with koni/bilstein.

Shit, at this point, just get Koni/eibach or billy/eibach aka b12, and be done.

[cobra]

I have 650lb rear springs and I gotta say they're pretty stiff. I can feel a noticeable lack in "articulation" due to the stiffness and reduced ride quality just from the higher natural frequency (not damper related). On smooth roads it's amazing but bumpy/uneven mountain roads it is right on the edge of what I'd call streetable.

I think it depends on your priorities. I still thing you should aim lower if you want comfort and a less "busy" ride. Somewhere around 500-550.

[Tbonem3]

Raising the car wouldn't compress the spring, nor would lowering. Only adding weight to the car would compress the spring, or slowing down rebound will keep the spring compressed a little longer as it returns to full travel after going over a bump.

I just installed rear Ohlins springs on my car (because I wanted to go up to 628lb), and I used the stock upper pad for comfort reasons. I found that it fits very well, with no concern of slipping out. It will deform the rubber and take a seat. I'm using the bottom adjuter perch as intended with the rubber donut underneath and the plastic seat between spring and metal perch.

I even contemplated buying the thicker non-M 7.5mm upper pads, but didn't bother sicne I already had the 5mm stock ones. They turned out to perfectly isolate the spring. I had previously gone up in spring rate to 600lb, but with the GC kit, it's spring on metal and a hard nylon top cone, so it was NVH city (for a street car). That really turned me off ever deviating from my tried and true Eibach rear spring, notwithstanding its fairly low rate of 550lb, that I would run with rubber, until I gave these Ohlins a try.

[repoman89]

Thanks, Tyler! This was sage advice. I clicked up on the damper and am having a happier week. Would raising the rear (effectively compressing the spring, as I understand it) lower the spring rate, much like loading weight in the trunk?

Regarding spring perches (upper pads), I’m told that the Ohlins kit comes with its own—very thin—pads. I presume that my installer went with these, rather than any of the OE variants.

Question for those in the know: Can I run OE upper spring pads with on rear Ohlins springs? I bought a pair of 5mm ones, just in case. The plan is to raise the rear slightly on Monday and/or install the upper spring pads, then reassess.

Yes, you can run the OE pads. The spring diameter is a little wide at the top for them but it doesn’t matter. The Ohlins pads are kind of useless, I’m only using them between the adjuster plastic perch and spring at the bottom.

Raising the rear doesn’t compress the spring because weight on the spring is very nearly the same, and spring displacement depends on the force on it (F=kx). It just raises the car leaving spring compression almost unchanged.

[LSB4Me]

More weight effectively loweres spring rate which is like slowing (stiffer) rebound. You could try a couple of more clicks towards full.

Bouncy means not enough rebound control. I just find it hard to believe that a stout damper like ohlins needs that much rebound adjustment to control the 628lb springs that come with the kit. I think the full track kit comes with stiffer rear springs, so would the dampers then need to be adjusted towards maximum? Dubious, but maybe. I'm actually installing ohlins rear springs now (mcs dampers).

I wonder if the installer forgot the rubber pads (upper & lower) that go under the upper/lower rear spring perches which is contributing to your harshness. I'm contemplating running a factory rubber upper pad (5mm m3 or even 7.5mm non M) to combat that further.

Thanks, Tyler! This was sage advice. I clicked up on the damper and am having a happier week. Would raising the rear (effectively compressing the spring, as I understand it) lower the spring rate, much like loading weight in the trunk?

Regarding spring perches (upper pads), I’m told that the Ohlins kit comes with its own—very thin—pads. I presume that my installer went with these, rather than any of the OE variants.

Question for those in the know: Can I run OE upper spring pads with on rear Ohlins springs? I bought a pair of 5mm ones, just in case. The plan is to raise the rear slightly on Monday and/or install the upper spring pads, then reassess.

[cobra]

By jittery, I mean bouncy and busy. They are simply too active and too eager to react. I have a two phase plan. First, I intend to back off the rear shocks by one click each time I drive to the office (10 miles one way with a perfect variety of road surfaces and speeds). Second, I will have the rear springs looked at for preload issues. If the rear spring has been adjusted (wound more tightly) to yield a lower ride height, I will have the spring returned to full extension.

My rear ride height is 13" and the initial installer told me this was "max height". Didn't seem right at the time. Doesn't seem right now. Maybe phase 3 is switching to a softer spring in the rear?! Idk. It shouldn't be this hard.

As I said above, I am strongly considering making a switch to Konis+Eibachs or Dinans . . . unless you experts counsel otherwise. It would be a bummer to lose my racecar stance, but it's not my racecar.

I was doing some research and stumbled on this conversion kit: https://groundcontrolstore.com/colle...w-e46-m3-01-up

If I were you, I would consider running Koni Sport or Bilstein B12 shocks with this kit, and 300F/500R spring rates. If you don't like it you can tweak spring rates easily rather than being locked into the ride height and rates set by Dinan or Eibach.

[Tbonem3]

More weight effectively loweres spring rate which is like slowing (stiffer) rebound. You could try a couple of more clicks towards full.

Bouncy means not enough rebound control. I just find it hard to believe that a stout damper like ohlins needs that much rebound adjustment to control the 628lb springs that come with the kit. I think the full track kit comes with stiffer rear springs, so would the dampers then need to be adjusted towards maximum? Dubious, but maybe. I'm actually installing ohlins rear springs now (mcs dampers).

I wonder if the installer forgot the rubber pads (upper & lower) that go under the upper/lower rear spring perches which is contributing to your harshness. I'm contemplating running a factory rubber upper pad (5mm m3 or even 7.5mm non M) to combat that further.

[LSB4Me]

LSB4Me there's a lot of ways to screw up the Ohlins setup, and most people are more likely to get it wrong than right.

You may also not be feeling what you think you're feeling. IMO, as long as you're fighting pitch, you're unlikely to have the ride quality you want. I definitely would not go softer on the rear springs.

Spot on—I am sure something wasn’t done correctly during my initial install. I’m getting there. Lengthening the rear shock gave me compression stroke that I was missing and got me off the bump stops.

I have honed in on 12-15 clicks from full stiff. Anything stiffer rides harsh and the rear end pogos over bumps. Anything softer and the rear feels loose and won’t settle down.

New clue today: With more weight in the rear (half tank of gas plus 30lbs in the trunk), the car rode better at the same damper setting than it does without the weight. It felt more controlled and compliant. Without the weight, it was bouncy again.

[LSB4Me]

Something is wrong. 13” is not the “max height” in the rear. It should be able to ride like a truck if you wanted it to. Mine sits at 13.3 and the adjuster has like an inch worth of extension left. Are you using factory rubber spring pads on top? Can you post a picture of the rear spring and adjuster assembly on the car?

This is very encouraging. Thanks, Repoman.

I will get a photo of my rear adjuster tomorrow but, based on this, I suspect there are still threads remaining to raise the rear. Pretty sure the rubber pads are in place. I wanted to keep everything rubber and OEM … for comfort. Hah.

Would you happen to have a photo of your adjuster (or know how many exposed threads you have above the silver locking collars) for your 13.3” ride height?

[cdnabroad]

So I had the Koni / Eibach combo for a few years. I think my overall impression was that the stance looked awesome, that said I did notice, as others have mentioned some bouncy on desceding roads in corners. Now for reference I am in San Francisco so that factored into it as well. In the end I ended up swithing out the Eibach's for DINAN springs and feel that the ride is much better for me anyway. Now I think the cornering on flat roads is not as true, but its not that far off and compensated for by the handling on uneven roads, especially downhill.

2c

[repoman89]

By jittery, I mean bouncy and busy. They are simply too active and too eager to react. I have a two phase plan. First, I intend to back off the rear shocks by one click each time I drive to the office (10 miles one way with a perfect variety of road surfaces and speeds). Second, I will have the rear springs looked at for preload issues. If the rear spring has been adjusted (wound more tightly) to yield a lower ride height, I will have the spring returned to full extension.

My rear ride height is 13" and the initial installer told me this was "max height". Didn't seem right at the time. Doesn't seem right now. Maybe phase 3 is switching to a softer spring in the rear?! Idk. It shouldn't be this hard.

As I said above, I am strongly considering making a switch to Konis+Eibachs or Dinans . . . unless you experts counsel otherwise. It would be a bummer to lose my racecar stance, but it's not my racecar.

Something is wrong. 13” is not the “max height” in the rear. It should be able to ride like a truck if you wanted it to. Mine sits at 13.3 and the adjuster has like an inch worth of extension left. Are you using factory rubber spring pads on top? Can you post a picture of the rear spring and adjuster assembly on the car?

[SQ13]

Don’t you need to do the opposite by increasing the spring rate in the rear, assuming you’re aiming for flat ride.

[K-Dawg]

LSB4Me there's a lot of ways to screw up the Ohlins setup, and most people are more likely to get it wrong than right.

You may also not be feeling what you think you're feeling. IMO, as long as you're fighting pitch, you're unlikely to have the ride quality you want. I definitely would not go softer on the rear springs.