Clutch, suspension and downpipe upgrade

Been a while since my last update, and the reason is that I’ve mainly been waiting for parts…

About a month or so back, I was out driving and noticed that when pulling in 4th and 5th gear, the engine revs increased, but the speed did not. I was hoping that I could get away with the engine upgrades without changing the clutch, but it seems it wasn’t so. I decided to upgrade the clutch instead of just getting a new standard piece. After some research, I opted for the 240mm FX100 clutch designed by ClutchMasters as well as a new 240mm lightweight single mass flywheel to match. Upgrading to a larger sized flywheel holds a lot more torque than the original 224mm dual-mass one in addition to the added gripping power og the new clutch. Installation went flawlessly without major hassles, but I’ll tell you, lifting the gearbox in place when alone is not a straight forward job… I laid on my side under the car while guiding the gearbox with my hands and operating the jack with my feets 🙂

While the car was already on the jack stands and the driveline was disconnected, I decided to get new front suspension control arms and upgrade to polyurethane bushing as the original bushings were worn out. I got a complete set of front control arms and a complete set of bushings for street use (although I got an upgraded (track) piece for the lower-front control arm on both sides). The tricky part installing these were to get the original rubber bushings out of the control arms. I don’t have a hydraulic press which ment getting the hammer and angle grinder out. After some struggling, the original bushings came out without damaging the control arms and the polyurethane bushings were installed using the supplied grease. I also had to replace the rear passenger side control arm as it had some damage and was somewhat bent… I also painted the inside of the wheel wells with an anti-rust/corrosion solution and washed all the parts that had to come off.

I also upgraded the exhaust downpipe as I only had done the first 30cm or so when upgrading the turbo. I decided to go for a 3in pipe all the way back to the 2.5in Simens sports exhaust. In addition to this, I fitted a flex-joint so the exhaust can move without damaging the turbo as well as a v-band joint for easy removal in the future. I also fitted a third lambda-connector in case I want to install a wide-band air-fuel gauge in the future.

Brake upgrade

As the Audi A4 B6 standard car is not known for its awesome brakes, I figured it was time for a brake upgrade.

I spent some considerable time researching brake upgrades for the car and after a while landed on a set up that wouldn’t cost a years pay (read big brake upgrade) while still providing a big improvement in braking performance. I managed to track down a set of callipers and brackets from an 2006 A4 B7 2.0T avant witch had the 320mm front disks. These are bolt on replacement callipers for the A4 B6 which fits the project perfectly. In addition to the callipers, I bought a set of yellow-stuff brake pads and slotted 321mm ventilated disks produced by EBC. Since then, I’ve heard that people have had bad experiences with the yellow-stuff brake pads but I decided to give them a try and see how they behave. I also bought a new set of Bosch rubber brake lines to compliment the new callipers.

As of tonight, I replaced the right side brakes before i got hungry and decided to get some food. The brakes fitted perfectly and bolted on without issues.

I’ll update after I’ve done a test-run with both sided replaced.

Update: Finished replacing and bleeding the front brakes and took it for a test run. Unfortunately, it was snowing, so I couldn’t do any hard brake tests, but I drove it for a good half an hour to get the protective film off the disks and pads. It seems to work pretty well and I defiantly noticed an improvement over the standard disks and pads. I took it out for a ride a few days later and noticed that the brakes has reduced performance when cold – this was expected though, and shouldn’t be a problem.

All in all, very happy with the upgrade. Time to make a plan for replacing the rear as well. I’ll write down the part numbers in case someone would like to do the same upgrade.

Calipers: 4F0615123 (left) and 4F0615124 (right)
Disks: EBC USR1423
Pads: EBC DP41495R (EBC yellowstuff)

Link to the shop –

Project update 2018-01

After fixing the misfire issues, I decided to protect the coils a bit by creating a rudimentary heat-shield over the turbo and exhaust manifold. I modified the original heat-shield to fit alongside the PCV modifications which turned out ok. I’ll post some pics of the engine bay as I’ve completed the upgrades I intended to do this time around 🙂

Misfires fixed!

After many hours of head-banging I finally solved the misfire issues! I had previously compiled a list of possible issue that I used as a checklist for eliminating possible faults one by one. 

Now, lets review the list of suspects from an earlier post:

  • Bad coilpacks
  • Bad gas (water etc.)
  • Bad spark plugs
  • Bad MAF
  • Vacuum leak
  • Low fuel pressure
  • Bad crank position sensor
  • Bad O2 sensor
  • And several others.

From just about every post and article I read on the internet, coils and plugs were on, or near, the top of the list of usual suspects. I had previously upgraded coils and plugs when I tuned the engine to stage one back in november 2016, so I figured they were OK. I did fix a few vacuum leaks thinking it was it, but the problem was still there.

I then went on and replaced the following items:

  • Spark plugs
  • MAF
  • Crank position sensor
  • O2 sensor
  • Fuel filter
  • MAP sensor
  • PCV valve
  • PCV check valve (pancake valve)
  • Misc. check valves

As it is a 15-year old engine, most of these parts needed replacement anyway, so I figured this was a golden opportunity to get it done. Unfortunately it did not resolve the misfire issues and I was running out of ideas.

As a stroke of luck, I got a hold of four coils from my brothers 2001 VW Passat before he sent it to the scrappers. I threw them in there to see if it made any difference – and voilà – the engine purred like a kitten!

Lots of work, lots of parts changed and the issue was what everyone said it would be… Lesson learned, listen to the majority and change the obvious culprit first.

Turbo Inlet Pipe v2.0

As I am afraid of water entering the inlet system, I decided to rebuild the turbo inlet pipe. I had initially though of going this route, but as space is tight, I mean really tight, I didn’t do this the first time around.

Since the 90degree pipes I already had didn’t have a sharp enough bend, I had to improvise and create a sharper bend by cutting the 3in pipe in a 45degree angle and weld the two parts together. I suspect this might not be the best solution as air have to pass through the sharp bend just before the turbo, but it’ll have to do for now. I also had to reroute the crankcase ventilation system in order to fit the PVC pressure release valve (which I’m replacing because I suspect it being bad).I reused some of the original piping and rubber bends to route the system close to its original path. This turned out pretty good and actually looks quite nice! 

I’m currently waiting for a 3in to 2.75in silicone reduction hose to fit the original mass airflow meter to the 3in intake pipe so I cannot test it quite yet, but it will be nice to hear how it sounds. The previous turbo inlet pipe (first version behind the fog-light) was a bit longer than the original one which resulted in the dump valve being almost inaudible from inside the car.

Since the air inlet is now very close to the exhaust, heat might become an issue. I decided to modify my old heat shield (created from an old computer case) and placed it in between the turbo and the air filter.  

I’m attaching some pictures from the build, but remember – I’m not the best welder… Still learning though 🙂