Tyre pressure help.

[cdco]

Right first off I've tried a forum Search and happy for a forum ninja to show me the error of my ways and inferior search ability... But help is needed. 

First Track Day in the Evora on Saturday at Blyton , and would like advice / direction on tyre pressure as a starting point. N/A 18/19s still on PZeros . Cold and Hot suggestions would be appreciated.

 

And yes once I've killed them I'll be looking at switching the the forum favourites....

 

C.

[21gg]

I've always started with lotus recommend cold pressures, but when the tyres are warm. Check them after each session as they may need adjusting. 

Gav

[cdco]

Thanks Gav, that's the approach I took in the old Elise , just looking to short cut the process if I could , at least with this one I've got a live view of what's happening.

C

[TomE]

I did some experimenting a few years ago when still running P-Zero Corsas on my 19/20" 2011 Evora S.  I'd been advised to start with handbook pressures -3 when cold, so set to 32 front and 35 rear when cold.  At the end of each of three 15-minute session in the morning they were at 35F and 38R, so exactly on handbook pressures but hot.  Air and track temperature was cool - Goodwood in early May.

For the final morning session I had a passenger and on the last lap had pushed to catch and pass another Evora, with post session pressures higher at 39F and 40R.

90 mins later at end of lunch break the tyres were cooler but not cold and showed 33/36.  I then set to 35/38 and by the end of session 1 they were 37/41.  I left them unchanged and at end session 2 they were 37/41 and for sessions 3 and 4 ended at 38/42.  Subjectively I'd say that the 37/41 sessions felt best in terms of handling and had marginally quicker lap times - difficult to be precise as traffic was different in each session.

[Will 1-2-1]

1 hour ago, TomE said:

I did some experimenting a few years ago when still running P-Zero Corsas on my 19/20" 2011 Evora S.  I'd been advised to start with handbook pressures -3 when cold, so set to 32 front and 35 rear when cold.  At the end of each of three 15-minute session in the morning they were at 35F and 38R, so exactly on handbook pressures but hot.  Air and track temperature was cool - Goodwood in early May.

For the final morning session I had a passenger and on the last lap had pushed to catch and pass another Evora, with post session pressures higher at 39F and 40R.

90 mins later at end of lunch break the tyres were cooler but not cold and showed 33/36.  I then set to 35/38 and by the end of session 1 they were 37/41.  I left them unchanged and at end session 2 they were 37/41 and for sessions 3 and 4 ended at 38/42.  Subjectively I'd say that the 37/41 sessions felt best in terms of handling and had marginally quicker lap times - difficult to be precise as traffic was different in each session.

I’ve just done my first track day and at Blyton too, last Thursday 8th April. I’ve a Evora SR on 20’’ rear and 19’’ front.  I started the day running on cold setting pressures as recommended by the book. Ie 2.6 bar rear and 2.4 bar front. 
It didn’t take long before the rears were at 2.9 bar and front 3 bar and the car was sliding a lot on the corners due to the increase in pressures. 
 

I reduced the pressures to 2.6 bar rear and 2.4 bar front while the tyres were still warm and carried on enjoying the day with the pressures increasing to approximately 2.7 bar rear and 2.5 bar front due to the Corning speeds and it stopped it sliding in the corners too.  
 

obviously this is still work in progress for when I do my next track day. 
 

you will also need to check your wheel bolt torque settings after they’ve got hot  to make sure they’ve not loosened off. 
 

enjoy your track day, Blyton is a great track. 
 

regards Will 

[TdM]

I know it's on different tyres and all but as the newer cars have lower recommended pressures on the same size wheels and essentially the same car, I suspect originally recommended pressures are (quite a bit?) too high to be optimal.

[Bruss]

20 minutes ago, TdM said:

I know it's on different tyres and all but as the newer cars have lower recommended pressures on the same size wheels and essentially the same car, I suspect originally recommended pressures are (quite a bit?) too high to be optimal.

I have found this on track. The heat builds up quickly and you really want to let a lot of air out. When they cools over lunch my tyres are decidedly flat and I put a bit of air back in to start the afternoon session.

 

 

[TomE]

Good point about the wheel bolt torque.  Also on some of the older cars the Lotus logo wheel centre caps can come out when the wheels are hot.  if you can move them when the wheels are cold then worth taking them out.  If like mine they won't budge then they'll probably stay in!

[cdco]

30 minutes ago, TomE said:

Good point about the wheel bolt torque.  Also on some of the older cars the Lotus logo wheel centre caps can come out when the wheels are hot.  if you can move them when the wheels are cold then worth taking them out.  If like mine they won't budge then they'll probably stay in

I'll keep an eye on mine , the proper ones are not on the car. I didn't like the green and yellow in the monochrome scheme I've ended up with so 3D printed some new ones  and got the logos from Dan at Divine Handicrafts .. if the go AWOL I'll print some more. I did make the lock tabs a bit bigger than the standard ones though so we will see.

 

As for the torque in the bolts , yep will be doing that always did it on the Elise previously but a good reminder.

[Bruss]

Take the centres out.

They are made of a plastic that will take a new shape when heated. They will fall out and never regain their original shape and size. 
 

 

[nigelh]

Was good to meet you at Blyton today Carl.  Hope you enjoyed your first time out in the Evora - you seemed to get plenty of track time in. 

I've only been to Blyton once in an Evora, but have taken them to a few other circuits and I do think a bigger circuit suits them more.

Nigel (with the blue S1 Elise)

[cdco]

23 hours ago, Bruss said:

Take the centres out.

They are made of a plastic that will take a new shape when heated. They will fall out and never regain their original shape and size. 
 

 

Ha didn't bother Bruss,  lost all 4 , but as they're home printed copies with stickers from Dan not too worried,  will tweak the design before I print the next one's to make the retaining lugs a bit deeper...the originals are safe in a box at home anyway.

 

Good to meet you too Nigel, had a great day improved loads when I tweaked my driving from the Elise and stopped cooking the brakes .. Didn't get on top of thee tyre pressures but if I'm honest that would have made bugger all difference today as I was definitely learning the car.

Your S1 looked and sounded the part.