Taking a 2014 Z4 from street car to track car

[wmandra]

I'll be updating this thread as time goes on with any new changes to my 2014 Z4 as I still have some other plans for the future with the car. I originally bought the car new in 2013 and mine was one of the first LCI models to be produced in March of that year. After a great European Delivery trip to Germany (and a bunch of other countries) and a visit to the BMW Performance Center in SC, it wasn't long before I had the Z4 out on the race track

Here's a pic of the car a few months after re-delivery in the US:



The first order of business with getting the Z4 track ready was a major suspension upgrade. Luckily the E89 suspension shares many parts with other BMW models

Up front, E9x M3 control arms and M3 tension arms were fitted along with Rogue Engineering spherical tension arm bushings. We had to make a bracket to attach the headlight vertical aim sensor on the right side, but other than that everything was a direct bolt-on.







This had the desired effect of significantly stiffening up the front end and providing more feedback through the steering wheel.

To reduce body roll both front and rear sway bars were replaced with H&R pieces with the rear being adjustable. New adjustable endlinks from Turner were also installed.

In the rear, a set of E46 adjustable camber arms with spherical end links from Turner Motorsport were installed.



The final touch to the suspension was to install a set of JRZ RS-Pro dampers along with Swift Springs and Vorshlag camber plates. The JRZ dampers have a remote reservoir and separate compression and rebound adjustments. Up front a set of 784# springs were used along with a helper, and in the rear a 560# main spring along with a 220# assist spring was used. The rear was also converted to a full coilover by inverting the damper and fitting E46 upper shock mounts from Turner Motorsport.

Swift Springs:


Assembled rear JRZ damper:


Inverted rear coilover:


Remote reservoirs up front:

[BMWZ4RIDER]

Keep us posted.

[wmandra]

Next up, a BMS oil catch can was installed. At the time they didn't offer a kit for the N20, so I had to make up my own connections.

You can see the braided hoses and AN fittings used in this pic.

The catch can is installed just below the front support bracket behind the right side headlight.

The exhaust was also modified with an Evolution Racewerks catless downpipe which was ordered with additional bungs for a 3rd O2 sensor and EGT sensor along with a high temperature thermal coating.


Behind the downpipe, a SuperSprint front pipe and X-pipe was installed and mated up to a pair of Magnaflow race mufflers and CF dual exhaust tips.

[wmandra]

The rear brakes were replaced with the larger components found in the 35is in order to retain parking brake functionality, but these will probably be changed in the future.

Up front, a 358mm 8 piston BBK from Rolloface Performance was installed.



Rear pads are Hawk DTC-30 compound and front pads are Pagid RS-14s.

The rear OEM brake hoses were also replaced with a custom set of stainless steel hoses from Rogue Engineering:


All 4 corners were fitted with Rogue Engineering high strength pro-grade wheel studs and lugs


To keep the front brakes cool, E9x carbon fiber backing plates from Bimmerworld were fitted behind the rotors and brake ducts were custom molded into the front lower grille.



The front ducts are connected to the backing plates via 3" hoses routed through the wheel wells. To fit the ducting, the OEM horns were removed and relocated into the center grill and behind wire mesh to protect the radiator.

[wmandra]

Both factory seats were replaced with fixed back OMP race seats.

Test fitting and positioning drivers side:


The seats were mounted to the factory bolt locations with custom brackets made from MT Fabrication:


The passenger side seat bracket also includes a mount for the fire extinguisher:


To install the 6 point Schroth harnesses, MT Fabrication also built a custom harness bar.

Only a small bit of plastic had to be removed from behind the speaker and the top cover plastic fits back into place.

Both seats and harness bar in:


In the future, the rest of the interior will be gutted and a full cage fitted but this setup works fine for now.

[unixphone]

look fantastic.... would you also include the cost?

[wmandra]

Getting good data when on the track is important for ensuring the car is running as it should and improving driver performance. An AIM MXL data logging dash was fitted to the steering column.



The dash takes inputs from factory sensors over CAN-bus in addition to analog inputs from several other sensors.

One very important sensor to install was the oil pressure sensor:


Other sensor inputs include boost, AFR and EGT via gauges installed in the console. The signal for these gauges is also routed and wired into the AIM.


The AIM display was also modified so that the buttons to control it could be remoted to the steering wheel.


A carbon fiber button plate from Rogue Engineering was fitted behind a Driven Steering wheel along with an NRG quick release hub.


The buttons used are all from Grayhill and provide a nice tactile feedback and signals are all routed via a 10 conductor coiled cable. In addition to the standard buttons, a mode selector switch was also installed to allow the bottom 4 buttons to perform up to 3 different functions each.

Button functions:
Yellow - 2 way radio push to talk
Green - (Mode 1 and 2 - flash to pass), (mode 3 - horn)
Red - (Mode 1 - AIM Menu), (mode 2 and 3 - windshield wash)
Black (Mode 1 - AIM Page), (mode 2 and 3 - windshield wipe)
Blue - (Mode 1 - AIM OK), (mode 2 - ECU MAP0)
Orange - (Mode 1 - AIM View), (mode 2 - ECU MAP1), (mode 3 - Pit Limiter)

To make connecting to the AIM dash easier at the track, an IO Gear wireless USB hub was also installed into the glove box.


Over the winter the DME was also shipped to BR Performance in Belgium for a flash tune. The tune was customized with 2 different MAPs (race and caution) and able to be switched by either the dynamic drive button in the center console or steering wheel buttons in mode 2.

[wmandra]

Originally Posted by unixphone

look fantastic.... would you also include the cost?

honestly, lost track of the cost of this project a long time ago

[wmandra]

To further reduce weight in the car the OEM battery was replaced with a Lithium Ion unit from Antigravity Batteries.



This thing is TINY and only weighs in at 3.5 pounds.



A custom rear diffuser was also fabricated for the car by MT Fabrication:

[wmandra]

Thanks to the guys at Elite Vinyl Design, the Ratchet Head Racing livery was installed onto the Z4.

Here's the original design we were working off of:


Wrapping the roof:


Laying out graphics:



Wrapping sides and trunk:




Wrapping hood and front:

[wmandra]

Some new rubber for the track:



Corner balancing:



Alignment:


And finally, some pics of what the car looks like now

[Innovative AutoConcepts]

well done sir!

[hiltonfa]

Great build thread, thanks for sharing.

[Wozich]

Oh my... Good job!

[nicknaz]

wow, nice pics thank you for sharing!!

If you don't mind me asking about a few details:
- how much fuel was in the car when you weighed it and was there any ballast to account for your weight?
- what are the other cars you compete with in TTB typically?
- what do you think on your prepped TTB Z428 versus prepped TT1/2/3 cars like C6 Z06?

[wmandra]

Originally Posted by nicknaz

wow, nice pics thank you for sharing!!

If you don't mind me asking about a few details:
- how much fuel was in the car when you weighed it and was there any ballast to account for your weight?
- what are the other cars you compete with in TTB typically?
- what do you think on your prepped TTB Z428 versus prepped TT1/2/3 cars like C6 Z06?

There was less than a quarter of a tank of fuel in the car when we weighed it, but it didn't have track wheels and rubber. It did have ballast in the drivers seat to account for my weight fully suited. With zero fuel and me in it on track wheels and tires the car comes in at exactly 3260 pounds (which happens to be my min weight for TTB).

Other cars in TTB in the Northeast include a WRX STI, a Z4 M Coupe and an E36 M3 along with a few others.

Can't really compare my car to a prepped TT123 car other than to say they are definitely faster, but that's not to say I couldn't modify the Z4 further to compete in those classes if I wanted to.

[Bigmouth Studio]

Wonderful.
Will you consider replacing the roof with CF made roof?
Also do you think you can wire the Wifi antenna out the car to the trunk so that you can close the window with better aerodynamic?

[VailM3]

would like to hear that exhaust some time. vid? Great build

[wmandra]

Originally Posted by Bigmouth Studio

Wonderful.
Will you consider replacing the roof with CF made roof?
Also do you think you can wire the Wifi antenna out the car to the trunk so that you can close the window with better aerodynamic?

definitely looking at CF or fiberglass replacements for the roof for the future.

No real need to wire wifi antenna out of the car as its only used in the paddock. Rules prevent running with windows up anyway.

[Hujan]

Car looks great and I'm sure is a blast to drive. Any plans to pick up some lighter wheels?

[wmandra]

Originally Posted by Hujan

Car looks great and I'm sure is a blast to drive. Any plans to pick up some lighter wheels?

not really worth it right now. Car is already really close to minimum weight, and the cost for very lightweight wheels outweighs the benefits. I'd rather spend the money on a lightweight flywheel and clutch.

[nicknaz]

Originally Posted by wmandra

Other cars in TTB in the Northeast include a WRX STI, a Z4 M Coupe and an E36 M3 along with a few others.o.

Any advice on Z4M vs. E36 M3 vs. STi for TTB ?