Zen and the Art of E46 M3 Ownership

[Bimma360]

Got the front end suspension stuff all done this past weekend. Put the old rotors and wheels on (no calipers), and dropped it back on the ground immediately after installing the CABs.



When thinking about my suspension set up before I went shopping, Iike I mentioned before, my goal was to achieve the CSL feel as much as possible. I used the FCM Ride Harmony spreadsheet to make the best effort in doing so. I wanted more street oriented coilover kit, as my assumption is that the CSL suspension also leaned a good bit towards being street friendly. While my intent was to use the CSL sway bars front and rear, realizing that the front spring rates of the PSS10's were going to be stiffer than stock I ended up going with a smaller front bar. Funny enough, the Bimmerworld bar fits that bill really well. It's less than a mm smaller than the CSL bar and it's also hollow, with some adjustability to boot.

PSS10 Spring Rates: 250# F / 450# R (under some compression)
Front Sway - 30mm hollow - Bimmerworld
Rear Sway - 22.5mm CSL
CSL Kingpins

I realize that the springs are progressive and that the rates here are an estimate. The front bar wall thickness is an estimate as well. For now this is where I am at. If the want/need is there, custom linear springs would make all of this a certainty.



Moving on, I stripped the calipers and sent them to Renewed Finishes here in PA to get powder coated black. Looks like someone took a rattle can to em at some point.



Now just waiting for all the brake stuff, and the front end will be done done. In the meantime, I'll focus on the O2 wiring and carbon airbox install.

[bavarian3]

Got the front end suspension stuff all done this past weekend. Put the old rotors and wheels on (no calipers), and dropped it back on the ground immediately after installing the CABs.

So good.

[Bimma360]

So good.

Love new parts! haha

[Bimma360]

Got some pics from Renewed Finished. The calipers are all done. Also the exterior bit of the pistons got cerikoted.










In the meantime, I got all the O2 wiring stuff taken care of and the airbox installed. Euro headers, Euro section 1, and carbon airbox are all done! Will need to get a tune by the time I get the rear end done and back on the road.

[Bimma360]

Now I just need the calipers back. I decided on running 7.5mm spacers up front. This pushes the face of the wheel within 1.5mm of where the CSL fronts sit, and adds +4.5mm to the scrub radius vs the CSL. Fingers crossed the new scrub radius is minor in effect.

[Bry5on]

Your scrub radius will be vastly better than most folks on this forum, and your steering feel will thank you. I expect you'll be fine - I'd personally cap my offset limits at ~et40 which is roughly where you're at.

Also, I think that airbox is designed specifically to not need a tune - what makes you think that you need one? I'd leave it as is.

If you're up for getting the springs measured - it would be great to have real numbers for those and not just guesstimates from a few shops. As you're looking to dial the suspension in, keep in mind that your FRC couple will be relative to ride height. If you target CSL ride height, 70.5% is pretty good. I run stock M3 ride height and prefer ~69% even with square tires. If you want lower than CSL, you may want to push it a bit above CSL FRC. This is driven mostly by changes to front suspension geometry as small ride height changes make pretty big roll center changes. Not so much in the rear.

If you're an NVH hawk like I am, the CSL front sway bar bushings should work fine with that bimmerworld 30.2mm front sway bar. I did this with my old hotchkis bar when I ran that. I'm on a cabrio front bar/CSL rear bar now.

Beautiful car and hardware

[Bimma360]

Your scrub radius will be vastly better than most folks on this forum, and your steering feel will thank you. I expect you'll be fine - I'd personally cap my offset limits at ~et40 which is roughly where you're at.

Also, I think that airbox is designed specifically to not need a tune - what makes you think that you need one? I'd leave it as is.

If you're up for getting the springs measured - it would be great to have real numbers for those and not just guesstimates from a few shops. As you're looking to dial the suspension in, keep in mind that your FRC couple will be relative to ride height. If you target CSL ride height, 70.5% is pretty good. I run stock M3 ride height and prefer ~69% even with square tires. If you want lower than CSL, you may want to push it a bit above CSL FRC. This is driven mostly by changes to front suspension geometry as small ride height changes make pretty big roll center changes. Not so much in the rear.

If you're an NVH hawk like I am, the CSL front sway bar bushings should work fine with that bimmerworld 30.2mm front sway bar. I did this with my old hotchkis bar when I ran that. I'm on a cabrio front bar/CSL rear bar now.

Beautiful car and hardware

Thank you for the insight. It is super helpful!

On the tune: B/c I have euro headers and euro cats, you mentioned before that I would need to convert over to the stock euro tune. I know I should be fine with that, but a part of me figures that maybe there is something to gain from taking it a step further. I was hoping that an HTE tune might yield a bit more power (I don't care about power but if possible to inch a little closer to CSL territory I'll take it), and perhaps a slightly better dynamic. For sure I am open to input here, and something I can take into account.

Unfortunately with the springs, since the fronts are already on the car I don't think I am going to get them measured. At least not at the moment. My thinking is to see how the car behaves on the road once it's all set up. If I ever did want to be a bit OCD about it, I might just have custom springs made. And then I can have the Bilstein's measured. To be honest, I suspect that I will be pleased with the setup as is though. Might be something for the future if I want to tinker.

As far as ride height, good call on the FRC. The CSL ride height is supposedly 607mm/602mm F/R +-10mm. That's as low as I want to go. I am inclined to leave the height as pre-set from Bilstein, which I measured just now as 604mm(FR) and 611mm(FL). The rear still needs to be installed, and I am sure it will settle further, and then there is also corner balancing. But overall, it's kind of on point for me out of the box.