Brakes 'n' Tyres

EdinburghCSL · 23-05-2010, 10:36 PM

Hi Guys and Girls

Trust you have all had a great week end soaking up the sun and exercising your CSL's! The sunshine even reached Scotland and 7 hours standing around at Knockhill resulted in well sunburnt face and arms!

I posted a few weeks ago as a newbie and with a few miles and tankfulls under my belt thought Sunday evening was a good time to get on my laptop!

I went up to the Scottish Motorfair at Knockhill yesterday and was invited by the organiser of the super car demo team to join the various exotica that would have two half hour sessions in front of the watching public. We were instructed to be sensible which all bar a Diablo spinning at the hairpin we adhered to.

This is my second CSL. My first an ultra low mileage minter and my present a higher mileage ( still mint!) but with all the right track toys (Milltecks, 100 cell cats, KW Clubsport, Thorney Stage 2, AP's Recaro Profi's and a nice harness bar and Schroth belts)

I use hand controls so a good brake is vital to any fast road or track use. Having warmed the engine, tyres, and brakes up I started to proceed at pace ( Can't let the CSL reputation down in front of spectators and various exotica can we) and the car on the whole is awesome and quite different to a standard model.

So after a rather long entry to this note I now would really appreciate feedback from you track experts onto my problem which may be linked. Some of you know Knockhill so will have experience of the track and maybe a similar sitiuation at Knockhill or other circuits.

Driving flat out at say 125/130 mph along the main straight and then braking very hard for Duffus Dip initial braking was good but then the brakes pulsated and the car did not continue to decelerate as I would have expected AP's to. I came in rather disillusioned with what I expected to be dream brakes. The car has not been on track or severe driving for a few months and the brakes could be glazed although I would have thought a few laps may have sorted that! I spoke to Mark (Mark CSL) today and he suggested cleaning up the pads. Another track driver suggested that I need to get more compound on the disks. A similar situation happened under very heavy braking into the hairpin.

The first session was rushed and therefore I had no time to check tyre pressures which may have contributed if they were wrong.

My own and hopeful conclusion is that the brakes are fine, that it was the abs coming on and that the Good Year Eagle F1's (lots of tread left) did not have enough traction to decelerate the car that quickly!

Does this scenario ring any bells with anyone? It was only braking on those two corners that caused the problem every other one was Ok, but entry/approach speeds were less.

Initial thoughts are to try and clean up pads, try cup tyres, check pressures..... or even consider braking earlier before the corner ( last resort) Should reasonable road tyres run out of grip braking in a straight line in the dry when not trying to lock them e.g emergency stop?

Should some new rubber be the answer I have read some posts re Toyo 888 v Cup Sports. Quite a mixed opinion. I would like the CSL to be perfect on track for 10 lap sessions at say Oulton and Knockhill yet be safe to use on the road for a blat in the dry which concerns me slightly re cups. I hear the 888's are good for lighter cars and can overheat quickly.

If I were buying some spare wheels do I go for 18" or 19". I see that Thorney sells some 18" wheels for a reasonable price.

If anyone has a spare track day set and wants to clear some garage space please drop me a line. I live in Edinburgh.

Lots of questions there! Feedback on any appreciated.

For those in Scotland or anyone fancying a trip to Knockhill I am going to the Hot Marques (cars over £15k) evening on 1st June. It would be good to meet up.

Jonathan

**shimmy** · 23-05-2010, 11:24 PM

what pads u using?

EdinburghCSL · 23-05-2010, 11:40 PM

Hi

RS29's

**shimmy** · 23-05-2010, 11:58 PM

hard to say, too many variables without looking at the car but road tyres will be slightly worse than cups but not to the degree you are explaining i guess

i would start with checking the geo and most importantly check what settings you have the KWs on. Set up can affect braking quite alot and dont assume the last guy knew what he was doing or the garage that last dealt witht he car

Also make sure the callipers are all working evenly on the front

unless the pads and discs are new there should be some deposits enough to get the brakes working but like you say taking out the pads and giving them a sand down to clear the face might be a good idea (or buy a new set even better and never likely to be wasted)

overall though dont forget stopping from 130mph aint easy and even with the Aps it needs some skill and precision to get the car stopped without fade or lock up.

finally are you runnign with DSC on or M Track on!!!!!!!!!!! take it off if so and see what happens

3wheels3 · 24-05-2010, 02:51 AM

Quote:

Originally Posted by EdinburghCSL

...the brakes are fine, that it was the abs coming on and that the Good Year Eagle F1's (lots of tread left) did not have enough traction to decelerate the car that quickly!...

...safe to use on the road for a blat in the dry which concerns me slightly re cups...

Tyres. Cups. Sorted. Eagle F1's

Great road or wet tyre probably.

Cups nice on road but don't be hero in wet...or dry because if you're getting to 90% with Cups you really should keep it for the track!

**Fasteddie** · 24-05-2010, 08:46 AM

As I undesdtand it whether DSC is on or off it doesn't matter under braking the DSC function is ON.
the pulsing suggests ABS is active is this the case or are you talking about another kind of pulsing?
If it is ABS it could be tyres running out of grip as the wheels stop rotating the abs will release the brake pressure. If it isn't the ABS I find it hard to think it is the tyres. I'm not a brake expert, I thought I knew a bit about this but I know enough to know I don't know!! Sombody on here may know but Shimmy is right try new pads, if that's too much of a waste for you reface them and burnish the discs (look on this site for how to burnish your discs, tehre is nice video somewhere).

God luck and don't forget to let us know what worked, cheers

**shimmy** · 24-05-2010, 10:44 AM

On the CSL, if you turn off DSC the ABS stays on but all other aids turn off.

**glendog74** · 24-05-2010, 11:40 AM

As already said, clean off the brake pads - ditch the Goodyears!

When was the brake fluid last changed/checked?

EdinburghCSL · 24-05-2010, 08:50 PM

Quote:

Originally Posted by shimmy

hard to say, too many variables without looking at the car but road tyres will be slightly worse than cups but not to the degree you are explaining i guess

i would start with checking the geo and most importantly check what settings you have the KWs on. Set up can affect braking quite alot and dont assume the last guy knew what he was doing or the garage that last dealt witht he car

Also make sure the callipers are all working evenly on the front

unless the pads and discs are new there should be some deposits enough to get the brakes working but like you say taking out the pads and giving them a sand down to clear the face might be a good idea (or buy a new set even better and never likely to be wasted)

overall though dont forget stopping from 130mph aint easy and even with the Aps it needs some skill and precision to get the car stopped without fade or lock up.

finally are you runnign with DSC on or M Track on!!!!!!!!!!! take it off if so and see what happens

Hi

Running with DSC off as with M Track mode car bogged down coming out of the hairpin.

Think fluids would have been done 6 months ago.

Feel that with more track mileage hopefully I will find the point of braking pre ABS operating.

I would have hoped that 12 track laps should have deglazed pads

Got cups costed at £1273 today. Not sure if that is good or bad.

J

**shimmy** · 24-05-2010, 08:57 PM

These days £1150 seems to be about the best you will get unless you have got a special friend in tyres

generally the m3 has very good brakes and stops very well and with APs it dies it TWICE .

Either your not used to the car yet or you have a fault with the pads or callipers.

23-05-2010, 10:36 PM	#1
EdinburghCSL Wonky 'L' after Washing Join Date: May 2010 Location: Edinburgh Posts: 15 Casino cash: $545	Brakes 'n' Tyres Hi Guys and Girls Trust you have all had a great week end soaking up the sun and exercising your CSL's! The sunshine even reached Scotland and 7 hours standing around at Knockhill resulted in well sunburnt face and arms! I posted a few weeks ago as a newbie and with a few miles and tankfulls under my belt thought Sunday evening was a good time to get on my laptop! I went up to the Scottish Motorfair at Knockhill yesterday and was invited by the organiser of the super car demo team to join the various exotica that would have two half hour sessions in front of the watching public. We were instructed to be sensible which all bar a Diablo spinning at the hairpin we adhered to. This is my second CSL. My first an ultra low mileage minter and my present a higher mileage ( still mint!) but with all the right track toys (Milltecks, 100 cell cats, KW Clubsport, Thorney Stage 2, AP's Recaro Profi's and a nice harness bar and Schroth belts) I use hand controls so a good brake is vital to any fast road or track use. Having warmed the engine, tyres, and brakes up I started to proceed at pace ( Can't let the CSL reputation down in front of spectators and various exotica can we) and the car on the whole is awesome and quite different to a standard model. So after a rather long entry to this note I now would really appreciate feedback from you track experts onto my problem which may be linked. Some of you know Knockhill so will have experience of the track and maybe a similar sitiuation at Knockhill or other circuits. Driving flat out at say 125/130 mph along the main straight and then braking very hard for Duffus Dip initial braking was good but then the brakes pulsated and the car did not continue to decelerate as I would have expected AP's to. I came in rather disillusioned with what I expected to be dream brakes. The car has not been on track or severe driving for a few months and the brakes could be glazed although I would have thought a few laps may have sorted that! I spoke to Mark (Mark CSL) today and he suggested cleaning up the pads. Another track driver suggested that I need to get more compound on the disks. A similar situation happened under very heavy braking into the hairpin. The first session was rushed and therefore I had no time to check tyre pressures which may have contributed if they were wrong. My own and hopeful conclusion is that the brakes are fine, that it was the abs coming on and that the Good Year Eagle F1's (lots of tread left) did not have enough traction to decelerate the car that quickly! Does this scenario ring any bells with anyone? It was only braking on those two corners that caused the problem every other one was Ok, but entry/approach speeds were less. Initial thoughts are to try and clean up pads, try cup tyres, check pressures..... or even consider braking earlier before the corner ( last resort) Should reasonable road tyres run out of grip braking in a straight line in the dry when not trying to lock them e.g emergency stop? Should some new rubber be the answer I have read some posts re Toyo 888 v Cup Sports. Quite a mixed opinion. I would like the CSL to be perfect on track for 10 lap sessions at say Oulton and Knockhill yet be safe to use on the road for a blat in the dry which concerns me slightly re cups. I hear the 888's are good for lighter cars and can overheat quickly. If I were buying some spare wheels do I go for 18" or 19". I see that Thorney sells some 18" wheels for a reasonable price. If anyone has a spare track day set and wants to clear some garage space please drop me a line. I live in Edinburgh. Lots of questions there! Feedback on any appreciated. For those in Scotland or anyone fancying a trip to Knockhill I am going to the Hot Marques (cars over £15k) evening on 1st June. It would be good to meet up. Jonathan

23-05-2010, 11:24 PM	#2
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	what pads u using? __________________ .

23-05-2010, 11:40 PM	#3
EdinburghCSL Wonky 'L' after Washing Join Date: May 2010 Location: Edinburgh Posts: 15 Casino cash: $545	pads Hi RS29's

23-05-2010, 11:58 PM	#4
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	hard to say, too many variables without looking at the car but road tyres will be slightly worse than cups but not to the degree you are explaining i guess i would start with checking the geo and most importantly check what settings you have the KWs on. Set up can affect braking quite alot and dont assume the last guy knew what he was doing or the garage that last dealt witht he car Also make sure the callipers are all working evenly on the front unless the pads and discs are new there should be some deposits enough to get the brakes working but like you say taking out the pads and giving them a sand down to clear the face might be a good idea (or buy a new set even better and never likely to be wasted) overall though dont forget stopping from 130mph aint easy and even with the Aps it needs some skill and precision to get the car stopped without fade or lock up. finally are you runnign with DSC on or M Track on!!!!!!!!!!! take it off if so and see what happens __________________ .

24-05-2010, 10:44 AM	#7
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	On the CSL, if you turn off DSC the ABS stays on but all other aids turn off. __________________ .

24-05-2010, 08:46 AM	#6
Fasteddie S4 - Getting the hang of it Join Date: Feb 2010 Location: Ashford, Kent Posts: 202 Casino cash: $1434	As I undesdtand it whether DSC is on or off it doesn't matter under braking the DSC function is ON. the pulsing suggests ABS is active is this the case or are you talking about another kind of pulsing? If it is ABS it could be tyres running out of grip as the wheels stop rotating the abs will release the brake pressure. If it isn't the ABS I find it hard to think it is the tyres. I'm not a brake expert, I thought I knew a bit about this but I know enough to know I don't know!! Sombody on here may know but Shimmy is right try new pads, if that's too much of a waste for you reface them and burnish the discs (look on this site for how to burnish your discs, tehre is nice video somewhere). God luck and don't forget to let us know what worked, cheers

24-05-2010, 11:40 AM	#8
glendog74 CSL Register Uber-poster! Tetris Champion! Join Date: Apr 2008 Location: Cornwall Posts: 8,861 Casino cash: $32299	As already said, clean off the brake pads - ditch the Goodyears! When was the brake fluid last changed/checked? __________________ Cha'mone Mother F**ker!

24-05-2010, 08:57 PM	#10
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	These days £1150 seems to be about the best you will get unless you have got a special friend in tyres generally the m3 has very good brakes and stops very well and with APs it dies it TWICE . Either your not used to the car yet or you have a fault with the pads or callipers. __________________ .