Tyler's 2011.5 Jerez Black E90 Slicktop Daily

[Tbonem3]

Thank you Ejaz!

[0-60motorsports]

Thank you Ejaz!

My pleasure T! Always an admirer of your attention to detail.

[kaiv]

Not usually a fan of Jerez but this is absolutely gorgeous and perfectly executed!

[Tbonem3]

Thanks Kevin! Once I install the ohlins, drop the rear a 1/4", dial in a little more camber, and then polish/coat the car again, I think it's gonna be perfect!

[0-60motorsports]

Thanks Kevin! Once I install the ohlins, drop the rear a 1/4", dial in a little more camber, and then polish/coat the car again, I think it's gonna be perfect!

That'll look really good.

[Tbonem3]

Some small updates before I post about my suspension changes, to keep things chronological.

New OEM wipers for the upcoming rainy season



New air filter. Cleaned the dust/pebble out of the housing.



And now most importantly, at very little cost luckily, I was able to replace the worn CIC button. You can't buy this from BMW, and buying a whole new controller is $$$.

Aliexpress to the rescue!



Oh and I got lucky and found a like new set of Factory BMW Black Chrome grilles. I thought I grew out of blacking out things after going with a factory look on my E46, but since I'm modding my E90 in a particular way, and because I love this black chrome on my X7, I wanted to give it a try on the E90. These parts are NLA, though I did see ECS listing them for $6xx recently. I got these for $200. The differenc between these and typical gloss black (like from IND) is significant. Not cheap at all. Goes well with my not cheap E88s I think.

[Tbonem3]

Alright, my favorite type of modding! Chassis!

The Bilstein B8s have been great. The swift springs have been pretty good - I just feel like they needed the front rate to be closer to 3xxlb not low 200s as the front would dive a bit too much. The 1" drop looks great, but you're on the bumpstops too much. I tried to alleviate that by reducing the stack above the spring for more travel. That is, cut mounts up front and Monroe (dinan copies) RSMs. I was pretty happy, but this was always a temporary solution until I got Ohlins or MCS.

I actually had bought the ohlins off a local back in summer of 2023! But with moving, no garage and a new baby, I just couldn't get to it.

I went with Ohlins due to their popularity for E46 and E90 as well as their known quality. Price was a bit cheaper back then, I paid $2500. Also, I could re-use the new front mounts that I had cut down. I wanted to use them becuase I planned to use Dinan fixed camber plates which add 6mm of material to the stack. So 10mm of cut mount minus 6mm of dinan plate = still about 4mm of "free lowering" And the rear RSMs have similar. I really want to avoid solid bushings on this car, esp up front. I haven't found that many camber plates options and they all seem pretty hardcore, so sticking with stock mounts was key. GC street is the only viable option for me, but they're $700, so I hope to acheive my goals with just stock mounts.

I was also, at first, impressed with Ohlin's spring rate choice of 343 (60N) & 685 (120N). I felt that they got the E46 wrong with 400/628 (I think it should be 343/628 or 400/685).

After installation, however, with my type of driving, I still don't think 343/685 is enough, so I'll be looking to go up to 400/784, but I'll touch on that later...




So first I disassembled the Bilstein fronts, as I knew I needed to modify the mounts before installing the ohlins.



You take out the bearing to expose the backside of the 3 studs - you have to pop them out



Gotta have a big vice!

Then pop them into the Dinan plates. I used some sockets to create pockets for the studs to go into so that I could press them flush, actually, beyond flush.






Doesn't take long at all if you have a good method.

Now to install...



Ohlins asks you to preload the spring by 6mm, then height adjustment is done with the strut body, where the hub clasps it. Only bad part, the adjustment knob is on the bottom. Everyone has theirs up top for adjustment in the engine bay




Very nice parts, easy to work with for adjustment. I set the damping knob about in the middle for now.

On to the rear...



Comparison of Swift 672 (12kg) versus Ohlins 120N (685lb). Not too different. Ohlins is shorter to allow for adjustment perch.




At least the rear's adjustment knobs are up top, but that area is covered by liners doh! I have no problem leaving liners out, but some have made nice holes in them for access. Maybe I'll get around to that.



Ohlins is great at making sure NVH is limited. They provide rubber and plastic sheets/seats. Having said that, the sheet was barely 1/16" (prob just 1mm) and the footprint (OD minus ID) was pretty small, like 3/8". So next time I'm in there, I'll replace with my own 1/8" thick rubber sheet, and I'll make a larger footprint.

Still, on the first drive, it was almost as quiet and soft as stock. Just slightly harsher - maybe I can mitigate it further.

more coming...

[Tbonem3]

So I drove the car a few times and noticed that I could still get too close to bottoming out for my comfort on hgh speed, big dips. Ostensibly, spring rates at this level do seem appropriate, but then remember that the E90 is a good 350lbs heavier than my E46. Then it's easier to understand how much spring the E9x can take. I've been reading and it seems like track e9x guys are running often 500-600/900-1000 or thereabouts.

So my decision is to go up 10 newtons to 400lb in the front and 784 rear from 343/685. Ohlins says you can go up to 30% increase without revalving the dampers. I'll be doing about 15%.

First step was to reach out to Barry for Ohlins springs. Unfortunately, the perfect sized Ohlins for me were out of stock. He was able to sell me the equivalent swift (65mm) for same price - cool!

Now, for the front, custom rates usually mean the need to switch to camber plates and coilover size perch like 60mm/2.5", BUT there is a little trick we can try. Member LSB4Me, as I understand it, took the 343lb e9x ohlins spring and made it fit his E46 ohlins kit. The e9x front spring is 6mm smaller in OD than the E46, whcih isn't much, just 1/8" on each side to account for when it comes to fitting the rubber pad. I think he said he had to trim his pad. Now, I'm going the other way - I'll be putting the slightly bigger E46 spring on the E90 front mount. It seems like it'll work, just eyeballing it, but I won't know until I get my hands on a set.

Another member here has expressed interest in swapping with me (as I waxed poetic about 343lb front springs on E46). So once I have the E46 springs in hand, I'll measure and take pics and see if we can't make this work.

Worst case, I'll have to sell the cut mounts and dinan plates, and get the GC street plates with 2.5" and then get the corresponding swift spring (~7", 65mm, 7N/mm). Might not lose too much money going this route, but I'd really be happy to make the e46 springs work and stay on OE mounts.

The rear swifts came super fast (thanks Barry - 3DM)



Also pictured are Whiteline subframe bushings - I'll detail that next time



Here's the current stack. I mentioned earlier that it was nice that Ohlins provides cushioning, but I still found it inadequate.



So here's what I've done. I took that little, thin top rubber donut and put it down below, under the plastic seat for a little extra cushion there. Then, up top, I made my own bigger, thicker pad for where the spring perch sits against the body.



The spring is a bit shorter than ohlins, but there's plenty of adjustment. There was an even shorter option still, but both Barry and I thought twice about having so much of the perch's threads above the spring. So just a little weight loss here

Took it for another romp, and WOW so much better. Felt sharper and more responsive all around, which I was not expecting (flat ride?). And of course, as expected, I was not squating all the way down after a dip. It's firmer, but not harsher! Even trying to compress the car as much as possible, there's still no rubbing or bottoming out! The front still does dive a little much, so I still want 400lb.

Now that it's stiffer, I felt comfortable lowering the rear to my desired look which is tires *just* tucked. I'm really really loving the car. Now, I want some more power and noise!

[0-60motorsports]

That looks beautiful