Ride Height Discussion

[cobra]

I am trying to understand my suspension's physical limits for a new shock setup. I currently have Koni yellows.

In front, at 13.5" wheel to fender edge, there is only about 2.25 inches of travel before the shock goes metal-to-metal (attached photo). The bump rubber is about 2 inches tall. This means it almost immediately runs into the bump rubber.

At full compression (metal to metal), the wheel to fender is at 12.0". However, it still looks like there is some gap between the tire and inner fender.


My question is - does anyone have comparison measurements for minimum ride height? I have a feeling these Koni's are reducing my potential bump travel due to the length. But don't want to risk running the tire into the fender.

Also shocking is how much droop travel these have. 4 inches of droop!

[Cronenberged]

I cant remember if the flat ride thread talks about required shock travel, but your height is perfect.

[cobra]

I cant remember if the flat ride thread talks about required shock travel, but your height is perfect.

Based on what I've seen so far, lowering to 13.5" already is quite a compromise. Stock ride height is 14.375" in front. By going to 13.5, we are giving up .875" of travel, almost 30% of the available! If no other measures are taken, such as shortened bump stops or shortened shocks, the ride is guaranteed to be worse. I notice this with my Koni/Dinan setup. Small bump/roughness compliance is good, but as soon as I hit a more substantial bump I can feel the shock bottoming out. Not a great feeling.

As lame as it looks I am thinking of raising the front back up to 13.75 or 14.0 as to not give up performance. This totally ignores the whole roll center migration issue, I'm just looking at travel.

[maupineda]

^^100%

i left my Z4M at stock ride height and tuned my setup to have 50:50 ratio between bump and droop.

[K-Dawg]

Konis are stock replacement dampers, so that makes sense. People say you gain some additional bump travel with Ground Control or Turner caster/camber plates.

Dinan springs put your car at 13.5" in the front?

[cobra]

Konis are stock replacement dampers, so that makes sense. People say you gain some additional bump travel with Ground Control or Turner caster/camber plates.

Dinan springs put your car at 13.5" in the front?

That makes sense with the camber plates. If the top mount is thinner then it will have more room up there. Based on my quick measurements (bottoming out the shock and rotating the wheel side-to-side, I only have about 1/2" additional bump travel before the tire risks hitting the inner fender. With the wheel turned it's even less, depending on the angle of turning. Of course that depends on your wheel size/offset, alignment, and tire size.

Dinan springs put my car at 13.75" on the front left side and 13.5" on the front right side.

[Tbonem3]

Stock ride height is only relevant at that specific spring rate of 143lbs/in.

Throw in a 400lb and see how much compression you get at that height.

[cobra]

Stock ride height is only relevant at that specific spring rate of 143lbs/in.

Throw in a 400lb and see how much compression you get at that height.

That is definitely going to factor in. The measurements I was taking were independent of spring rate. I bet you could still bottom it out with a 400lb/in spring going over a bump almost as easily as the stock spring but more energy will have been absorbed (stored?) by the time it got there.

The Dinan springs IMO are a little sketchy because they are quite a bit lower than stock but only 20% stiffer.

[jet_dogg]

Stock ride height is only relevant at that specific spring rate of 143lbs/in.

Throw in a 400lb and see how much compression you get at that height.

I hear you get even more travel if you lift the car from stock height.

[wahsm]

I hear you get even more travel if you lift the car from stock height.

lol

[cobra]

I hear you get even more travel if you lift the car from stock height.

Time for a Rally E46

[cobra]

Continuing this thread with a question.

Does anyone know the minimum compressed height on the E46 M3 before the tire interferes with something during normal driving conditions?

This is with Koni yellows at 13.5" ride height and the stock bump stop installed. As you can see it is touching already. As I mentioned earlier, without the bump stop in there it can go up further, to 12" until the shock goes metal-to-metal. I confirmed that these Koni's are physically almost identical to the stock Sachs shocks in terms of body length.

But it seems like the wheel might have more space in there to get some more bump travel.

I saw mention of someone measuring minimum height at 11" metal-to-metal but not a lot of info on this subject.

[Obioban]

That’s not a Koni bump stop 🤔

[cobra]

That’s not a Koni bump stop 🤔

No it's an OEM bump stop. When I bought the Konis they didn't have any so I reused the stockers.