Contemplating Z4c Upgrades

[BGR]

Hi all,

Just picked up an 07 Z4 Coupe with all options except Nav and Sport Seats (grr...). This is my 6th BMW, and behind the e39 M5 I had probably the most special. This will be a weekend/track car for me, but is actually in great shape. It has 85k miles and I am the third owner (paid $17k from a reputable local dealer that includes lifetime powertrain warranty on used vehicles).

The front bumper has scuffs through the paint on the very bottom from what looks like bumping a tall curb (no cracks), and the center console aluminum trim looks like a baby yeti had its way with it (any suggestions on where to get a replacement are welcome).

I was concerned about the EPS going in, but can overlook the numbness and slow ratio because it is precise and the sum of the car makes it a joy to drive. I am trying to decide if I want to put money into this or just drive it as-is until I find the perfect e9x M3 for me. I have a set of Breyton wheels off of my 135i with extreme perf summer tires that I plan to get spacers for and mount up.

Anyway, I'm considering the following upgrades, in no particular order. Input on "bang for the buck" would be appreciated.

1. M Sport seats (looks like $800-$1,500 depending on condition)
2. New steering wheel (not sure what would fit this car, but I find the current wheel too thin and plastic for me)
3. LSD ($2,500 for a Turner unit in 3.64 ratio, slightly above stock ratio)
4. Sport Koni adjustable suspension ($1,500 installed)
5. Front camber plates
6. CDV delete

Again, not sure how much I want to throw at this car if I am only keeping it for less than a year, but after driving for a few hundred miles it definitely puts a smile on my face. I feel like with the upgrades I'm thinking about I may just keep it.

[E86Z]

Mines very similar to yours, no nav but with sports seats. I'm obviously biased but I'd say mod this car a bit and enjoy it. The torq is such a blast. Congratulations on the purchase

[pungo]

Nice car...I had the same car but w/ nav and sport seats...

If I had kept it, I would have done a LSD and suspension upgrade.

I wouldn't do expensive mods if you're not going to keep it for a year.

[BGR]

Well, I just spent $2k on upgrades, so we shall see

[Vanne]

Lol the Nav is shit anyways, but the sport seats are nice.. Congrats mate. Beaut of a car. Enjoy the ride and show us some more pics matey :-)
Congrats again, one heck of a nice ride. What did you get for 2k?

[BGR]

-M steering wheel
-Koni shocks/H&R springs
-Wheel spacers for the Breyton wheels
-4 new wheel roundels
-ZHP shift knob
-SS brake lines
-Hawk front pads
-New OEM floor mats
-aFe air filter

[Finnegan]

Originally Posted by BGR

-M steering wheel
-Koni shocks/H&R springs
-Wheel spacers for the Breyton wheels
-4 new wheel roundels
-ZHP shift knob
-SS brake lines
-Hawk front pads
-New OEM floor mats
-aFe air filter

Not sure I'd do more than this given the ownership horizon. It's a good list. Maybe bushings, FCABS, etc.

[BGR]

Originally Posted by Finnegan

Not sure I'd do more than this given the ownership horizon. It's a good list. Maybe bushings, FCABS, etc.

Yeah. The steering wheel and ZHP knob I can always easily remove and resell if needed. Same with LSD if I go that route, and even the suspension isn't that hard of an install. The thing about bushings though is they are usually so hard to install and uninstall and might not be something the next owner would potentially want.

Or who knows, after I install these parts I may never want to sell the car.

[Efthreeoh]

Congrats on the car. I'm not sure why you'd keep the car just for a year and do anything to it, but we have freedom of choice. If I were keeping the car, I'd upgrade to the M Sport seats and the LSD as I think they'd make the most impression on the butt-dyno (i.e. make the car feel better to drive).

As far as bang for the buck, CDV is almost free, stainless steel brake lines - hydraulic hoses already have steel reinforcement in them, it's just inside the rubber; so a waste of money IMO. Koni suspension if you are going to track it.

Good luck with it.

[BGR]

Seats are on the list, but not easily had. Trust me I want them though.

[Efthreeoh]

I hope you find a set. When I got my car (just a few months ago) I was worried about fitting in the M Sports, but to my surprise they are more roomy but better fitting than the sport seats in my E90. I think the M-Sport seats are one of the best things about the Z4 Coupe.

[m3griff]

Originally Posted by BGR

-M steering wheel
-Koni shocks/H&R springs
-Wheel spacers for the Breyton wheels
-4 new wheel roundels
-ZHP shift knob
-SS brake lines
-Hawk front pads
-New OEM floor mats
-aFe air filter

06 Si roadster here. Great list. I've done most of this. My comments:

- M steering wheel. Phenomenal upgrade - feels much better than stock. As you say - you can remove later.

- I did TC Kline coil overs. Love the lowered look and the handling.
- did spacers on my style 108 wheels - really helps the looks.
- consider putting clear reflectors on the front fenders - really resent the look.
- updated to drilled rotors and better pads - and painted calipers a gunmetal finish. Subtle and clean look.
- Al pedals add some sparkle to dark interior.

Jeff

[BGR]

Koni was having a 25% off sale so I got the whole set for $550ish. Hard to beat that value, even though full coilovers would be nice.

On another note, I love this version of the N52 (I had the exact motor in my e90 330i). Last night when I was driving home with the cruise set at 70 the mpg readout was showing 36.5mpg. Obviously the computers are 10-15% optimistic, but still that is great.

[pokeybritches]

I have a 3.64 in my 3.0i. It's a great ratio - good compromise among acceleration, top speed, gear changing, engine wear, and gas mileage.

I'd look at moving to linear springs since you plan to track the car. They will make it more predictable, and offset some of the numbness in the steering. For a track car, the last thing you want is both a lack of feel and predictability, especially since the Z4 has a short wheelsbase that loves to rotate. They can be taken off and sold when you sell the car.

I'd consider the Recaro Profi over M seats. Again, these can be parted out when you sell the car.

[BGR]

I thought about aftermarket seats, but honestly they are more expensive than OEM when you include mounting brackets.

The linear springs are a good idea, but can't be had as easily on a non-coilover setup. I will see how the Konis/HR setup goes this season, and if I decide to keep the car could see upgrading next year.

[Twixboy]

Hey nice ride. $17k seems like a great deal for the coupe. When I replied to your post on the other forum I was thinking it was a roadster for some reason, even though you specifically said coupe in your thread title!

[NickyC]

A lot of the money you are spending could be used to buy an ///M after selling your car. Just a thought.

[BGR]

Originally Posted by NickyC

A lot of the money you are spending could be used to buy an ///M after selling your car. Just a thought.

True. While an ///M was certainly in the cards cost-wise, NONE were local. I also like the N52, and being somewhat of a sleeper and walking ///M cars while on the track once I'm done will be fun.

[BGR]

From what I've read, the 3.0si coupe comes standard with a 3.46 open diff. Can anyone confirm this ratio?

When looking at a limited-slip unit, I'm tending towards a 4.10 ratio. This would be an increase of about 20%, which is fairly aggressive. Anyone have experience with this? My other option (if I don't want to spend another $1,000 on in-between gearing) would be to go with a 3.64 ratio, which is only 5%. Obviously the traction part will help immensely but acceleration won't be greatly increased.

[chickdr]

Only M's have a ltd slip diff.

[BGR]

Originally Posted by chickdr

Only M's have a ltd slip diff.

Yup.

[BGR]

Got the wheel spacers and Breyton wheels installed today.