Planning the next
AO Silver Member
Join Date: May 2007
Location: United Kingdom
I had some time to spare today and as I shall be doing a similar conversion in the not too distant future ( I hope! ), I did some measurements.
So I lifted the car and removed the wheel, brake caliper, tin guard and disc.
I then fitted a 305mm disc ( Brembo ) and held it in place with some wheel bolts.
With the wheel fully extended ( jack supporting body ) I measured the distance between the wishbone and disc for straight ahead, full lock left and full lock right -
( Measurements over 3.5mm are approximate to 0.25mm, measurements less than 3mm were done with feeler gauges and are pretty accurate )
Fully extended suspension ( body supported by jack ) :
Straight ahead : 4.75mm
Full right lock : 4.25mm
Full left lock : 4.75mm
With the jack under the wishbone and the car lowered to standard ride height ( my car isn't lowered )
Straight ahead : 4mm
Full right : 2.5mm
Full left : 4.25mm
With the jack now lifting the car and compressing the suspension to the equivalent of a 20mm lowering :
Straight ahead : 3.3mm
Full right : 2.95mm
Full left : 3.4mm
With the jack now lifting the car and compressing the suspension to the equivalent of a 30mm lowering :
Straight ahead : 2.9mm
Full right : 2.7mm
Full left : 3.25mm
This incidentally is with a factory original wishbone ( yes, it is almost 18 years old - it has never been changed! And it is still in good nick ).
For fun, I then refitted the tin guard and checked the clearances by eye - I didn't bother measuring. That also looks good.
What is interesting is that I was expecting the clearances to increase as the spring was compressed but the opposite happened. I don't get that.
So, when I fit the 305mm discs, I don't anticipate having a similar problem with the disc touching the wishbone.