Clutch slip but only with passenger?

[R0162]

I think i experienced a bit of clutch slip tonight, the car normally pulls very hard, but it was revving but not propelling us forward like it would normally, still fast but lacking pull, plus there was a smell like something was overheated, is that clutch slip?

I had a passenger and i am guessing an extra 100kg was added to the weight of the car,i am wondering could this extra weight have played a part? and by the same reckoning if i remove weight does it help the clutch? I had always known i was very closer to the limits of torque on the clutch, but it is only today that is has occured to me that their may be a link to the weight of the car and the limits of the clutch? can anybody please confirm this?

If so i can easily shed a few Kilos

[Mike Tuckwood]

Increased vehicle weight will also increase the liklihood of clutch slip as it's increasing the workload of the Clutch.


Mike.

[R0162]

Cheers Mike, that is what i suspected, i have the exotic drive at the end of the month and will be going up against the 458, i will make sure to shed a few luxuries, and shed a few kilos myself on the treadmill

I am beginning to regret adding all the Dyanamat to the cabin now

Has anybody got anymore tips for improving the situation, without detuning or upgrading the clutch, i am waiting for the gearbox to get ropey before i change the clutch, refurbed gearbox + new clutch was fairly recent, i suppose the best way to improve weight is to change the alloys and do not allow passengers when racing + race on 1/4 tank.

Plus when i tuned it i knew i would get power loss on a hot day which means less power going to the clutch.

Btw while were on the subject of weight, how much weight do you save with the comp alloys over stock GTO3 alloys?

Edited by R0162 on Saturday 7th May 07:36

[GTO600]

Good job you never tried fitting the GT's, don't think there is much you do Chris & can't see that lighter wheels will help for road use.
Do you know what torque you are producing ?

[TuxMan]

As Kev has hinted when Trevor mapped mine we limited the torque to 440lbft to protect the clutch and box , perhaps you could do the same . Tux

[R0162]

If i was going to fit the GT's then that was going to be part of a 10-15k engine and transmission upgrade, i had big plans at the beginning of the rebuild but at the end there i had had enough

The Torque is 59kg-m we roughly calculated that to be about 440lb/ft, the car has been ok but an extra 100kg weight pushed it over the edge last night, and it only happened in 3rd gear and i did plant the accelerator a bit heavy and it did have about 40litres of fuel in.

It made me rethink things a little because i really don't want to take the engine out so soon, although it will need doing eventually, the doors were too heavy for the hinges when packed out with dynamat, so i started by stripping that back out of the doors, 5kg gone and the door closes perfect again. We live and learn Long term i have to get a stronger clutch and gearbox though.

Once a clutch has slipped, will it be damaged? Will the clutch fluid need replacing? Will it be more prone to slipping now, due to being weakened? Is the clutch more prone to slipping when hot or cold?

[GTO600]

Chris, you are right on the top of the maximum the standard clutch can take. Often if the clutch is an issue it's in the higher gears so suspect not too much to worry about & doubt any harm done, you just won't be able to squeeze those three girls in !

[R0162]

So will the clutch be ok or could it have been weakened? Does the clutch grip better when hot or cold? Because i had not warmed the car up much before the occurance last night, so i am hoping the more you warm up the clutch the better it grips?

[Mike Tuckwood]

Unfortunately not, performance will deteriorate with increased temp.

Mike.

[R0162]

Cheers for the info, now i know cold is best i can take that into account when choosing a battle ground favourable to my situation
I just wondered if it was like racing brake pads where they need to get up to temp before they start working properly.

[node]

Its going to be hard but try and keep away from those kebabs for a month

[swampy56]

Mine is exactly the same Chris get a big passenger next to me it slips on max boost! But ok on my own, it also slips if I go out at night and the air temp is cold, I'm going to try and make it last until the end of summer and then put a helix in it.

[R0162]

swampy56 said:

Mine is exactly the same Chris get a big passenger next to me it slips on max boost! But ok on my own, it also slips if I go out at night and the air temp is cold, I'm going to try and make it last until the end of summer and then put a helix in it.

Out of interest why does cold air temp make it slip?

[Mike Tuckwood]

R0162 said:

Out of interest why does cold air temp make it slip?

Colder air gives a denser charge so more power/torque hence it will breach the slip point more easily, sooner.


Mike.