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2007 3.2 VR6 Roadster
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Many thanks to cas5259 for this excellent write up! This was originally posted at ~ https://www.audizine.com/ -

Went with the Bilstein kit to replace my aging magride. I didn't want something too stiff for a car that only runs a few track days a year and I'll never adjust coilovers. Tire Rack had the B12 kit on a closeout sale so I jumped on it. This job isn't that difficult, it took about 1-1.5 hours per corner. The B12 kit contains their B8 struts/shocks and matched Eibach springs.

If you need any additional information, feel free to refer to the workshop manuals -

FAQ - Audi TT (8J) Workshop Manuals & Self Study Programs
Section 5 - Brakes, Suspension and Wheels
https://www.ttforum.co.uk/forum/viewtop ... &t=1833829

Due to the number of excellent photos, this write up has been split into two posts; the first one is for the Front shocks, the second post is for the Rear Shocks and how to sort out the Mag Ride Delete coding.

TOOLS -

• Spring compressor
• Spindle spreader socket
• Triple square sockets, 17mm and 22mm strut socket.
• 21mm strut socket or pass through socket if you want to take apart the stock struts.
• VCDS is a must if you want to get rid of errors. I'll address mag ride deletion at the end.

PARTS -

• Front strut mount and bearing: 8J0412331 (2), 6N0412249C (2)
• Front dust boot: 6N0413175A (2)
• Spindle bolt: N90954802 (2)
• Spindle nut: N10106402 (2)
• Rear shock mount: 3C0513353C (2)
• Rear dust boot: 8E0512137E (2)
• Rear shock bolt: N91066201 (2)
• Rear upper spring isolator: 1K0512149B (2)
• Rear lower spring isolator: 1K0512297D (2)
• Lower control arm bolt: N10628601(2)
• Lower control arm nut: N10106402 (2)
• Beer: 6

FRONT SHOCKS

Bilstein-01.JPG

Starting with the front driver side. Unbolt the level sensor from the lower control arm. Tuck it out of the way to avoid damage.

Bilstein-02.JPG

Remove sway bar link nut. A triple square bit fits into the bolt to hold it while you undo the nut. I used a pass through wrench.

Bilstein-03.JPG

Bilstein-03a.JPG

Remove spindle bolt. 18mm nut and triple square.

Bilstein-04.JPG

Disconnect the mag ride wire on the bottom of the strut and insert the spindle spreader into the hub. Turn it 90deg so it opens the hub up.

Bilstein-05.JPG

Bilstein-05a.JPG

Leave the spreader in place while you push the hub down. This may take some force. I had to jump on one of them to get it loose. Penetrating oil may help.

Bilstein-06.JPG

Bilstein-06a.JPG

Now that the strut is free from the hub. Remove the 3 bolts on the strut mount. They are under this cover.

How to: Plenum Removal

https://www.ttforum.co.uk/forum/viewtop ... &t=1979747

Bilstein-07.JPG

Remove the strut assembly. This will require some moving of the hub and general fidgeting to get it out.

Bilstein-08.JPG

Assemble the new strut/boot/spring/bearing/mount. Read about spring compressor safety - there's a lot of force involved here so be careful. There's no bump stop, the B8 struts use an internal bump stop.

Bilstein-09.JPG

Torque the top nut. 22mm strut socket and 7mm allen. Torque spec is in the Bilstein manual.
Make sure the spring is rotated to be against the spring stop while removing the spring compressors.

Bilstein-10.JPG

Bilstein-10a.JPG

Install the new strut assembly the same way you took it out. The arrows on top of the strut mount must face outwards.

Bilstein-11.JPG

Install the top bolts hand tight. Then work the hub over the strut body until its fully seated. I jacked up the hub a bit to make sure it was in all the way. Remove the spindle spreader.

Bilstein-12.JPG

Torque top bolts. Reinstall the sway bar link and spindle bolt/nut.

Bilstein-13.JPG

Secure mag ride connector out of the way.

Bilstein-14.JPG

Secure the level sensor back in place. Done! There is no need to torque the bolts at ride height because you are not touching any bushings in the front. The passenger side is the same except there is less room by the sway bar link nut. You'll see.

Bilstein-15.JPG

Onto the rears!
 

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REAR SHOCKS

Disconnect level sensor from lower control arm. 2 torx bolts and remove the wheel liner.

Bilstein-16.JPG

Remove lower control arm bolt and push the control arm down out of the way.

Bilstein-17.JPG

Pull out the spring. No need to compress it, there's plenty of room to take it out.

Bilstein-18.JPG

Bilstein-19.JPG

Remove shock bolt. These are in tight.
My big impact was almost defeated. Here is the importance of using new hardware.

Bilstein-20.JPG

Bilstein-20a.JPG

Disconnect the mag ride wire on the top of the shock and remove the 2 upper shock mount bolts. Now the shock is free.

Bilstein-21.JPG

Assemble the new shock/boot/bumpstop/mount. The bumpstop included with the kit is different than the stock one. I wedged the first part of it inside the boot to hold it in place like stock.

Bilstein-22.JPG

Bilstein-23.JPG

Torque the top nut. 17mm strut socket and 5mm allen. Torque spec is in the Bilstein manual.

Bilstein-24.JPG

Old vs. new shock.

Bilstein-25.JPG

Install shock. Torque the top bolts. Leave the big lower one hand tight. It will be torqued later. Install the spring isolators on the new spring. The one with the nub on it goes on bottom. Make sure the spring is rotated against the stop.

Bilstein-26.JPG

Insert spring into control arm.

Bilstein-27.JPG

Install the control arm bolt hand tight.

Bilstein-28.JPG

Put on the wheel and lower the car. Drive it a few feet back and forth. This will settle the suspension a bit. Measure ride height from center of the hub to the fender.

Raise the car back up, remove the wheel, and jack up the hub to the ride height measured above. Torque the control arm and shock bolts. Not much space for the torque wrench on the shock bolt due to the spring being in the way, a short socket does the trick.

It is important to torque anything with a bushing at ride height, otherwise the bushings are stressed at ride height. Google for more info.

Bilstein-13.JPG

Secure the mag ride connector out of the way.Secure the level sensor back in place.
Done! The other side is exactly the same.

Bilstein-29.JPG

Ride height didn't change much for me, but you still should get your alignment checked. Here are the specs I like - just a touch of toe in the rear for heavy braking stability.

• Front Toe: 0° 00'
• Front Camber: 1° 40'
• Rear Toe: 0° 02'
• Rear Camber 1° 00'

The springs will settle after a few weeks or months, so go back and get your alignment checked again at some point. The only decent place near me charges freakin' $200 for a "specialty" alignment because I provide my own specs. May as well go back and get it checked within 6 weeks for free. Those bastards are doing the same amount of work but for double the money.

Bilstein-30.JPG

Bilstein-31.JPG

Bilstein-32.JPG

The car feels great! I had a bad front left strut so it clunked a bit. That is gone, the ride feels tighter - somewhere between normal and sport mode. Harsh bumps are smoother. It is definitely better damped. My guess is the stock springs are a compromise between the normal and sport modes, so they are not matched to either setting. All in cost was about $1000 between the kit, hardware, and alignment extortion.

Mag Ride Coding

As for the mag ride delete, I removed 64 from the instrument coding to get rid of the dash error for now. There are no errors showing, but I can't use sport mode for the steering weight or turn off traction control. There are a few posts about removing the mag ride controller from the CAN gateway, but when you do that, you get a headlight error. All 4 level sensors on the control arms input into the mag ride controller. The headlight leveling system uses the left side level sensors, so when you remove that controller, you get the headlight error that can't be removed.

KW and iSweep kits trick the controller into thinking the shocks are still there. Some data logging before the install showed 1-4A going through the mag shocks under spirited driving. These modules see some decent current, with users saying they get hot. The questionable reliability of these expensive delete kits is why I stayed away. I'm assuming they get real hot and then fail internally.

To me, it seems like spoofing the level sensors is the real solution. Then you can remove the mag ride controller from the CAN gateway and recode ABS. Sport mode and turning off traction control should work. I'm going to play around with an Arduino CAN hat. If I can find the addresses of the mag ride and headlight controllers, then I can code something that looks for the level request from the mag ride controller and sends back nominal data to the headlight controller. This could be connected anywhere there are powertrain CAN hi/lo wires. CAN is a standard communication protocol, so the only thing that might be proprietary is how the level data is formatted in the data portion of the CAN frame.

Bilstein-33.JPG

Took a road trip last weekend and that gave some time for the new mounts to settle a bit. The front dropped about 1/4"-1/8" and the rear dropped back to stock height. You can safely assume this kit will not lower the ride height on a TTS, which has a factory lowered suspension to begin with. I think this setup is perfect for my needs.
 

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