Thursday 26 March 2015

Brake Bias & ABS Pump Removal

We've had a lot of problems with a soft brake pedal which is apparently a common problem on the TT. We changed the brake master cylinder, as the bleed nipples has snapped off, and re-pressure bled the system - still the same..
We cycled the ABS pump using vagcom - still the same..

So we decided to totally remove the ABS system as it was disabled anyway to accommodate the race Haldex unit (fights the ABS as it keeps driving the rear wheels) and fit a brake bias valve so we could control our front rear bias.

So the front brakes get 100% of the brake pressure and the valve can divert a percentage to the rear.

Slight improvement but still more travel than there should be (it used to be rock hard). So the only thing left is the brake servo, apparently these can get damaged if you press the brake pedal to the floor whilst bleeding which I must confess I did once. Another job on the list :)

Update: Whilst cheking the brake boost NRV we found a split hose:

Wednesday 25 March 2015

More Front Camber

Whist racing last year it became apparent that we were a little down on front end camber. Looking at some of the faster cars in the corners they had significantly more negative camber:

There's a really good post on TT Suspension here:  TT Suspension
On the stock Audi TT you can get a max of -1 degree of negative camber so some work was needed to get some more. There are various solutions, you can fit adjustable top mounts at around £400 and get a further 1 degree, or fit new modified wishbones for around the same price and get a little more. The thing is we don’t know how much we need yet so we wanted a more cost effective solution. 

Some people cut and shut the wishbones but I didn’t like the sound of that, another solution was to modify the ball joints. Then looking around at the various ball joints available I noticed that the Mk2 Audi TT ball joints were spaced further from the bolt holes and could with a little fettling do the trick!

One of the holes is offset on the MK2 version so we re-drilled it to fit..

 All fitted and we now have -1.7 degrees which is much closer to our -2 degree goal. We also had to reset the tracking and it was all out with the new spacing, so we set it with a little toe out (2' each side) to help the turn in.

All ready for the first race at Donigton with the 750MC


Zircotec Heat Management

We also wanted to reduce the engine bay temperatures as occasionally we would boil the clutch fluid with the radiant heat! So we opted to get the manifold ceramic coated and sent it off to Zircotec for the full treatment!

We were lucky enough to take a look behind the scenes to see how this process was done while we were there..

Here's our manifold Ceramic coated, you can just see the top of it in white:

 Apparently this special Ceramic coating can reduce radiant heat by up to 33%

New Turbo and Water Meth

After our end of year strip down we discovered that our Turbo Dynamics Turbo had died, not only had the bearings gone (after two seasons) but the case had cracked too!

Talking with the guys at Badger 5 they recommended we talked with BBT (Beach Buggy Turbos) who have been pioneering the hybrid turbo upgrades for a number of years.  So for 2015 we have decided to go with a BBT turbo with uprated baring and a race optimised turbine wheel etc.

Turbo Features:
BBT Ported K04-0023 Turbine housing
BBT K04 compressor housing
TFSI turbine 44.5mm/50mm
BBT designed 7+7 2283 compressor wheel with ETT
BBT uprated thrust beating/collar
BBT improved O-ring sealed backplated
Step gapped rear seal
BBT uprate 15Psi actuator

Whist we were at it we also removed our trusty hi-flow manifold (that had survived a whole seasons racing with 1000 degree EGTs!) from Badger 5 and sent it back to them for the Gen2 flow splitter upgrade. 

Towards the end of last year we fitted a Water Methanol injection system from Devils Own that not only help the engine run with more consistent power but also lowered the EGT’s to a more acceptable level.