Tyre Pressures

survivalist · Post by **survivalist** » Sat 03 Jul, 2010 10:02

Hi

Just wondering what tyre pressures everyone is running?

Can't lay my hands on the manual right now, but planning on taking the Z1 to the Le Mans Classic next weekend and want to make sure the car is on top form for the long drive.

Also, spotted a lovely Z1 at the Goodwood Breakfast Club last weekend - anyone on here? Would have driven mine in as well, but wasn't clear on the rules and so ended up in the normal carpark

Budget M3 · Post by **Budget M3** » Tue 06 Jul, 2010 03:39

I run 32 psi (~2.2 bar) around town and pump it up to 35 psi (~2.4 bar) for long distance and canyon carving. Hope that helps...

Jet · Post by **Jet** » Tue 06 Jul, 2010 07:38

Not sure how accurate this is, but I have been advised to run 30 and 32 on the 17".

BBZ149 · Post by **BBZ149** » Tue 06 Jul, 2010 10:50

Any idea's on rear 245x 35x 18 and front 225x 40x 18

Cheers in advance

Racing Tortoise · Post by **Racing Tortoise** » Tue 06 Jul, 2010 13:05

For the standard wheels and tyres, I understand it should be 2.0 bar (29 psi) at the front and 2.2 bar (32 psi) at the rear.

Saw a red Z1 on the A4/M4 out of London looking like it was heading for the FoS on Sunday morning. First one I've seen on the road for ages - was it you?

Bluebaur · Post by **Bluebaur** » Tue 06 Jul, 2010 14:37

To add further debate to the tyre pressure issue, I am running 1.8 bar (26) and 2.1 bar (30) on a standard set up, as this is listed as the pressure in my handbook. However at MOT last week I had the rear tyres tread depthed over the whole circumference whilst the car was suspended and it clearly showed a lesser depth in the middle of the tyre. Centre wear is due to over inflation ! If my tyres are under inflated and I am getting centre wear, what ever is happening to the over inflaters?

felix · Post by **felix** » Tue 06 Jul, 2010 16:10

Higher centre wear also comes from under inflation on low profile tyres with their stiff sidewalls. There isn't enough air pressure to prevent the tyre from ballooning slightly at speed.

anbei · Post by **anbei** » Tue 06 Jul, 2010 16:25

survivalist wrote:Hi
Just wondering what tyre pressures everyone is running?
Can't lay my hands on the manual right now, but planning on taking the Z1 to the Le Mans Classic next weekend and want to make sure the car is on top form for the long drive.

I am running 2.1 bar front side and 2.3 bar on the back side. But imho your tyre pressure also depends on your supspension to get the correct track (?) for your car.

survivalist · Post by **survivalist** » Tue 06 Jul, 2010 21:41

Thanks for all the reply's.

Should have said that I'm running the original wheels with 225/45 ZR16 tyres. A search for some other stuff revealed (by complete chance) the manual, which does indeed say 1.8 BAR (Front) and 2.1 BAR (Rear). Having inflated them to these pressures they do look a little soft to me, so may have to do some experimentation.

How likely is it that 1.8/2.1 is low enough to cause ballooning at speed though?

Also, not me on the M4 - mine is green (any opportunity for a pic - will hopefully get some better ones in France this weekend)

Sadly, I've had to miss out on the Festival of Speed this year. Still, will be at the classic this year and hopefully the Goodwood Revival as well.

Budget M3 · Post by **Budget M3** » Wed 07 Jul, 2010 03:13

In my experience, staggered tire pressures (i.e. lower in front than rear) will make the car push (understeer). Tire brand/quality will make a difference, too, so experimentation is almost a must.

I run the same pressures all around for two reasons: 1) I think it makes for a better handling car, and 2) it's much easier to remember just one number!

Racing Tortoise · Post by **Racing Tortoise** » Wed 07 Jul, 2010 08:46

survivalist wrote:

Nice photo!

Holland Harry · Post by **Holland Harry** » Wed 07 Jul, 2010 09:30

Budget M3 wrote: I run the same pressures all around for two reasons: 1) I think it makes for a better handling car, and 2) it's much easier to remember just one number!

Are you getting old mate!

WB · Post by WB » Wed 07 Jul, 2010 12:24

what type of pressure guage do people like/trust. I find that they all vary and some quite a bit.

Racing Tortoise · Post by **Racing Tortoise** » Wed 07 Jul, 2010 12:52

The one at the local petrol station.......

survivalist · Post by **survivalist** » Wed 07 Jul, 2010 14:59

I use one of these, after finding out that the local garage one was out by 6/7 PSI. That said it lives in the glovebox so I guess rolling around all day might have made it less accurate over the years.

Nice and easy to use though, as it "holds" the pressure on the display until you hit the reset button.

http://www.amazon.co.uk/RACE-PROFESSION ... B000VZ8S26

Was about £8 when I bought it, so may be worth shopping around.

sfh3l · Post by **sfh3l** » Wed 07 Jul, 2010 17:58

Hey Survivalist,
I shall be at the Le Mans Classic too! Not in the Z1 though. Instead, I'll be in the 3.0csl, which is an absolute must for that particular meeting. If you fancy meeting up (and viewing some of the meeting from a cool vantage point) text me on 07860 324562 and we can sort something out - it would be good to meet up during the weekend sometime. We have a house ON THE CIRCUIT and also secure parking.
Hope to see you there,

survivalist · Post by **survivalist** » Thu 08 Jul, 2010 15:56

Sounds Amazing. Four of us will be camping somewhere - not quite sure which campsite yet, but we're taking bikes so getting around should be easy. Will definitely get in touch.

Just about to leave for the eurotunnel now.

Rupert

sfh3l · Post by **sfh3l** » Thu 08 Jul, 2010 16:03

Ah, Bikes eh?
I always used to take my bike, but the Z1 made that a bit tricky. I did borrow my sister's Brompton for couple of years but even that wouldn't really fit in the car!
I'm gessing you are either in another car or have a mate with a 'support vehicle'.
Good luck and perhaps see you there.....
DO NOT speed in France - they are now well aware and ready for us!

Budget M3 · Post by **Budget M3** » Fri 09 Jul, 2010 03:43

Holland Harry wrote:
Budget M3 wrote: I run the same pressures all around for two reasons: 1) I think it makes for a better handling car, and 2) it's much easier to remember just one number!
Are you getting old mate!

Physically, yes, but I am happily regressing mentally

sfh3l · Post by **sfh3l** » Tue 13 Jul, 2010 19:50

I returned from the Classic yesterday safe and sound in the CSL. The meeting was as fabulous as ever, though not quite so well attended this time around.

I have to say that by the time I arrived on Friday afternoon that I felt a bit like a jacket potato. The old car has a black vinyl interior, lots of glass, incredible heat-sink and no air-con! Add to that the fact that it was 32 centigarde outside and the combination heats up better than a microwave!

That said, we had a great time. I saw one French Z1 (Top Red) and the only other 3.0csl's were the two that were racing! Oh what it is to have special cars!

Anyone going to the Silverstone Classic I wonder?

TJS · Post by **TJS** » Wed 14 Jul, 2010 20:39

Hi Sam,

Yep .. 99% certain of heading to Silverstone in the Z1 on the Saturday (24th). Most years I end up parking with various classic cars behind the grandstand on the start / finish straight rather than inside the circuit. Last year however I was banished to the public car parks with the riff raff where I parked opposite a French Z1 in an act of solidarity.

I assume you will be on the BMW Car Club stand inside the circuit.

I am sure a convoy of Z1s would grab the organisers attention !!

TJS

sfh3l · Post by **sfh3l** » Mon 19 Jul, 2010 16:02

Tony,
Jake and I will be in the 3.0csl. We're doing the RetroRun with a start time just before 9AM, so we should be back to the circuit by noon all being well with the old girl. RetroRun parking is on the infield behind where the old Bridge corner is.
See if you can blag a pass onto the Car Club stand (contact Bernie Howell) as that is in the centre and avoids parking outside with cars of inferior aero

Hope to see you on Saturday.......

Stoertie · Post by **Stoertie** » Tue 27 Jul, 2010 06:53

survivalist wrote:Thanks for all the reply's.

Should have said that I'm running the original wheels with 225/45 ZR16 tyres. A search for some other stuff revealed (by complete chance) the manual, which does indeed say 1.8 BAR (Front) and 2.1 BAR (Rear). Having inflated them to these pressures they do look a little soft to me, so may have to do some experimentation.

Hi,

my Z1 has the same original tire size with Bridgestone S-03 I'm using the following, cold pressure:
2.2 bar at the front and 1.9 bar at the back.

I know it sounds a little bit strange but it's worth to try this...

With my set of Bridgestone RE-540S I'm using a cold pressure of 1.4 bar at the front and back ( the pressure automatical raises to 2.3 bar when the tires are on working temperature

)

Best regards
Michael

Holland Harry · Post by **Holland Harry** » Tue 27 Jul, 2010 09:11

Stoertie wrote:
survivalist wrote:Thanks for all the reply's.

Should have said that I'm running the original wheels with 225/45 ZR16 tyres. A search for some other stuff revealed (by complete chance) the manual, which does indeed say 1.8 BAR (Front) and 2.1 BAR (Rear). Having inflated them to these pressures they do look a little soft to me, so may have to do some experimentation.

Hi,

my Z1 has the same original tire size with Bridgestone S-03 I'm using the following, cold pressure:
2.2 bar at the front and 1.9 bar at the back.

I know it sounds a little bit strange but it's worth to try this...

With my set of Bridgestone RE-540S I'm using a cold pressure of 1.4 bar at the front and back ( the pressure automatical raises to 2.3 bar when the tires are on working temperature )

Best regards
Michael

Hi Michi,

How is the car than performing in the corners? Will this not give a very instable rear end drive of the Z1? You aren't getting old are you??

Regards from Assen,

Harold

Stoertie · Post by **Stoertie** » Tue 27 Jul, 2010 11:04

Hi Harry,

at my car and with my setup it works very fine!

But you know, my car is not original and the setup is made for me and my personal taste.

regards
Michael

senna · Post by **senna** » Thu 26 Aug, 2010 22:32

zroadster.net

Tyre Pressures

Tyre Pressures

Re: Tyre Pressures

pressure readings...

Le Mans Classic