Clutch Slur - Page 2

**shimmy** · 29-01-2010, 10:39 PM

my first clutch was changed due to slur

second one has started to do it now and bmw are monitoring it

it is when the car is under heavy load when changing gear

Bounce · 29-01-2010, 10:56 PM

Quote:

Originally Posted by lawsy

Says the man who drives it "in s1 for a few days"

That was just to cure the problem,i didnt say i liked it.

Thorney · 30-01-2010, 01:08 PM

If you time it right a slight lift on upchanges is quicker than a full throttle shift.

Seemed to work for me in the CSL Cup races

shane@mbtech · 30-01-2010, 01:09 PM

Quote:

Originally Posted by Thorney

If you time it right a slight lift on upchanges is quicker than a full throttle shift.

Seemed to work for me in the CSL Cup races

With a little help from your aero package

**shimmy** · 30-01-2010, 01:15 PM

John, do you run updated clutch and flywheel in your Cup car last year?

weedavey · 30-01-2010, 01:18 PM

Quote:

Originally Posted by Thorney

If you time it right a slight lift on upchanges is quicker than a full throttle shift.

Seemed to work for me in the CSL Cup races

Really! I'll be experimenting with this next time im out then..

At what point did you lift? Just before, bang on or just after you clicked to shift?

The Gorilla · 30-01-2010, 03:55 PM

Hi,

I have always slightly backed off the
Throttle, when changing
gear, and find its much better.

Smoother, quicker, and less
issues.

Plus you do not transmit such aggressive
shock loads through the Transmission
drive train.

I believe all SMG 2 cars suffer some clutch
slur under heavy load, when warmed up,
its just that some drivers are better than others
at actually detecting it at full chat.

If you 'feather' your throttle pedal inputs when
driving the bends on circuit, ala the Senna / Schumacher club,
even on a CSL with SMG updates, you can actually
get ahead of the E.Gas [fly by wire] to the point
where the throttle pedal is being dabbed, but the
engine is no longer actually responding to the inputts.

ie, Throttle pedal is lifted but engine is still increasing revs.

Then go drive a S54 with a throttle cable, not E.Gas
and its a whole new world.

I think that some clutch slur is detected when
under load you have up-shifted quickly but the
stepper motor activated by the throttle pedal petom
are to a point still catching up,
so the ECU/DME 'hangs' for a split second which
gives the impression of clutch slur, or a slight delay
on upshifts, as its not instant.

As the CSL works on a Throttle load input, no MAF,
this combined with E.Gas, is I beleive more to do with
slow shifts or perceived 'clutch slur', than the actual clutch,
until the clutch is actually nearing its life cycle end.

This is borne by the claim, that 'clutch slur' can in
part be rectified by driving hard'

Regards,

The Gorilla.

Dan · 30-01-2010, 05:33 PM

Quote:

Originally Posted by Thorney

If you time it right a slight lift on upchanges is quicker than a full throttle shift.

Seemed to work for me in the CSL Cup races

Totally agree there...

Unless ABSOLUTELY FLAT OUT in either 4th gear or upwards I always slightly lift as well, was told to do this when I bought it and it would change better, and IMO it does

weedavey · 30-01-2010, 06:32 PM

Quote:

Originally Posted by The Gorilla

Plus you do not transmit such aggressive
shock loads through the Transmission
drive train.

I Have been concerned with this since buying the car.

SpineOnABap · 31-01-2010, 11:57 AM

Quote:

Originally Posted by lawsy

Never experienced clutch slur myself,

Maybe we drive them properly, Rob

Sadly it's not caused by driving style, otherwise we could prevent it. It's caused by shit design. It's the only thing I really HATE about CSL, and it's been bugging me since 2003 so it's a good job I really like the rest of the car

30-01-2010, 01:08 PM	#13
Thorney S5 - Full Throttle Join Date: Sep 2007 Posts: 469 Casino cash: $3876	If you time it right a slight lift on upchanges is quicker than a full throttle shift. Seemed to work for me in the CSL Cup races __________________ http://www.thorneymotorsport.co.uk

29-01-2010, 10:39 PM	#11
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	my first clutch was changed due to slur second one has started to do it now and bmw are monitoring it it is when the car is under heavy load when changing gear

30-01-2010, 01:15 PM	#15
shimmy CSL Register Uber-poster! Join Date: Apr 2008 Location: Uk Posts: 14,646 Casino cash: $43909	John, do you run updated clutch and flywheel in your Cup car last year?

30-01-2010, 03:55 PM	#17
The Gorilla S5, Sport Off, DSC M-track Join Date: Apr 2008 Posts: 740 Casino cash: $14401	Hi, I have always slightly backed off the Throttle, when changing gear, and find its much better. Smoother, quicker, and less issues. Plus you do not transmit such aggressive shock loads through the Transmission drive train. I believe all SMG 2 cars suffer some clutch slur under heavy load, when warmed up, its just that some drivers are better than others at actually detecting it at full chat. If you 'feather' your throttle pedal inputs when driving the bends on circuit, ala the Senna / Schumacher club, even on a CSL with SMG updates, you can actually get ahead of the E.Gas [fly by wire] to the point where the throttle pedal is being dabbed, but the engine is no longer actually responding to the inputts. ie, Throttle pedal is lifted but engine is still increasing revs. Then go drive a S54 with a throttle cable, not E.Gas and its a whole new world. I think that some clutch slur is detected when under load you have up-shifted quickly but the stepper motor activated by the throttle pedal petom are to a point still catching up, so the ECU/DME 'hangs' for a split second which gives the impression of clutch slur, or a slight delay on upshifts, as its not instant. As the CSL works on a Throttle load input, no MAF, this combined with E.Gas, is I beleive more to do with slow shifts or perceived 'clutch slur', than the actual clutch, until the clutch is actually nearing its life cycle end. This is borne by the claim, that 'clutch slur' can in part be rectified by driving hard' Regards, The Gorilla.