e46 M3 suspension setup, or how to not downgrade your car with suspension mods

[Subfra///Me]

Am I off base? I thought the Turner street plates didn't really add significant NVH.

[Subfra///Me]

In my opinion, yes, esp if your car is on the lighter side. BUT, why are you running a hardcore part (camber plates) with stock replacement suspension? It's not really the right combo.

One reason would be to get enough travel for the B12 kit. Another is that I feel being able to adjust camber for the occasional track/autocross day is beneficial. Even for a fairly stock car.

[Tbonem3]

Would using camber plates give the B12 kit enough travel to avoid the bump stop issue? Roads are smooth here.

In my opinion, yes, esp if your car is on the lighter side. BUT, why are you running a hardcore part (camber plates) with stock replacement suspension? It's not really the right combo.

[Subfra///Me]

Would using camber plates give the B12 kit enough travel to avoid the bump stop issue? Roads are smooth here.

[cobra]

I think stock springs are 143lb/in. Eibach pro-kit is 155. But good points!

Yes, my bad.

[Tbonem3]

I think stock springs are 143lb/in. Eibach pro-kit is 155. But good points!

[cobra]

A couple things to consider when trying to maximize bump travel:

1. You may have limited travel due to shock length and top mount height, but your wheel/tire might crash first so it's a good idea to check. The way I did this was remove the spring and bump stops and move the wheel through its travel then turn the wheel side to side a little bit (90-180 degrees at the steering wheel in either direction). From here you can measure and see what the limiting factor is. With my 18x8.5et38 with 245/40 tires, which is pretty conservative and not terribly flush, this was 11.5 inches wheel center to fender. So I would benefit from gaining about 1" of bump travel from the Koni or stock shock.

2. Of course this is complicated because the front springs are so soft, they really rely on the bump stops as an added spring to support when cornering. Careful about adding too much bump travel without also increasing spring rate. It might end up being a terrible handling setup. As Obioban said in the original post, stock springs are 143lbs/in! Dinans are still only 175! When I was running 300's without the support of bump stops, it still felt soft but with so much more linearity and predictability.

Moral of the story is - it very quickly makes sense to go to "coilovers" on this car if you start tweaking things and you want the ideal balance of performance and comfort.

[Tbonem3]

Unless you use eibach pro kit springs which are designed to work with stock style dampers and will keep flat ride like factory. The rest are all junk on this car for stock style spring. You are technically losing travel with lowering springs though.

Don't be pedantic, you know what I'm saying Corey.

[01SG]

The b6 paired with lowering springs rides pleasantly in most all situations. There are certain times the limited travel will be evident, however. There are places I have learned to be careful, but these are few and far between.

I do not feel the need for camber plates. The roads by me are fairly good, and I do not daily it.

[thegenius46m]

Basically, the E46 m3 shouldn't be lowered at stock/stock-like spring rates.

Unless you use eibach pro kit springs which are designed to work with stock style dampers and will keep flat ride like factory. The rest are all junk on this car for stock style spring. You are technically losing travel with lowering springs though.

[Tbonem3]

Basically, the E46 m3 shouldn't be lowered at stock/stock-like spring rates.

[K-Dawg]

Thanks for the info. For some reason I thought I had previously read that the B12 kit really needed the extra travel the camber plates offered in order to keep it off the bumpstops.

I forgot to mention that several people have reported that out of the box, B6 dampers have less (bump) travel than the other twin-tube (stock, Koni, B4, etc.) options available. So between the Eibach lowering springs and B6 reduced bump travel, you would be correct. I have a B12 kit on the bench, but I haven't gotten around to taking measurements of it yet.

According to cobra , the Koni/Dinan combo gets into the bump stops real quick as well.

[Subfra///Me]

Neither B12 (B6/Eibach) nor Koni/Dinan require camber plates. The B6 and Koni dampers are designed for stock height. Eibach and Dinan are lowering springs, so the idea is that both can benefit from camber plates that increase bump travel.

Thanks for the info. For some reason I thought I had previously read that the B12 kit really needed the extra travel the camber plates offered in order to keep it off the bumpstops.

[Bry5on]

Yes, I actually just finished taking measurements of new OE strut mounts, Turner Street, Ground Control Street, and Turner Hybrid mounts. Besides stock, Turner Street is the worst for bump travel (especially with the spacer). Turner Hybrid is the king. I'm putting the information together for a separate post.

Very much looking forward to this, thank you!

[K-Dawg]

Do the Turner Street plates allow enough travel for the B12 kit? I live in the south. Roads are pretty good overall here.

If I recall correctly, Koni/Dinan doesn't even require the use of plates.

Neither B12 (B6/Eibach) nor Koni/Dinan require camber plates. The B6 and Koni dampers are designed for stock height. Eibach and Dinan are lowering springs, so the idea is that both can benefit from camber plates that increase bump travel.