Vinesh

Brake Setup:
GGR Group N Discs (Manufactured by Lucas)
Mintex 1155 Pads

I have had the above brakes for about 2 months. When braking from 70mph+ the steering wheel vibrates badly.

I first thought it was down to the wheel balance, so I the balancing sorted.

But the vibration is still there.

No trackdays and most of the milage is done on the motorway.

Will GGR exchange the discs?

Is the setup up wrong, ie Lucas and Mintex?

Any help/suggestion appreciated.

Floyd

iTrader: (9)

Read this:

http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

and don't do it again

F

Vinesh

Good info

Miniman

iTrader: (2)

Despite the fact that article says its a myth I think its real. I had a warped disk on a car (not an Impreza) some time ago. Essentially it looked like Figure 2 but only over 1/4 of the disk. So it you laid the disk on a flat surface, 1/4 of the disk was not touching the surface and was a few millimeter off.

If you asked someone with a bicycle who had a wheel that did that (was out of true for a 1/4 of its circumference), they would call it warping. I guess warp is only a word, but its adequate to describe some situations, despite it being called a myth.

It produced a strange feeling where the break pedal biting point, the point at which I started to feel any resistance moved outwards as the disk turned it pushed the pad back out towards the caliper. So on one side of the car the pad engaged before the other side. This only made breaking uneven and didn't actually produce much vibration through the column.

SlowBoy

iTrader: (1)

Could the vibration under braking be due to wheel alignment?

Have you had it checked?

Mungo

There are a couple of other threads currently running on this same topic, so apologies if there's repetition.
What I might be missing from the excellent article, is why am I only feeling the judder when the brakes are hot? If I've got uneven pad deposits on the discs which have then created cementite (iron structure changed) deposits in the disc material, surely that hardness is there in the disc regardless of whether the discs are hot or not?
Any experts out there?

Jerry B

I fitted 17's over Brembo discs and noticed brake judder after having new tyres fitted. Checked balancing - ok. Tyre guys spotted that wheel needed to be mated up onto hub carefully as very slight mis-alignment possible so held in place while nuts done up gradually in opposite order by hand.
This - surprisingly - was the cause. Seems the original fitter may have gunned on the nuts without doing them up gradually, opposing nuts in turn.....worth a try?

Vinesh

Wheel alignment was also checked and corrected by Roger Clark Motorsport.

GGR are willing to send the discs back to Lucus for inspection. They are STi Group n discs, but made by Lucus!

This means I have to buy another pair of discs in order to have my old ones inspected.

My uncle works for Lucus, may be I can ask him what material is used to manufacter the discs.

[Edited by Vinesh - 4/28/2003 6:24:51 PM]

rally colin

try some Prodrive Group N discs from Roger clark you should find them ok with the 1155 pads they are not cheap though we run them with pagid black pads and find them to be very good