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 Post subject: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 5:01 pm 
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Joined: Wed Nov 07, 2007 11:43 am
Posts: 347
Location: Banbury
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Evenin'

The handbook says 36 psi front and 44 psi rear for the standard 944 wheels, but I've got Boxster alloys on my 944 Cabby with 205/50/17 front and 255/40/17 rear.

I've only had the car a few weeks and I finally got round to checking the pressures. Looks like the previous owner was running 30 psi all round which seemed a bit low to me, so I put the standard pressures in. Ride is a bit firm now. :bounce:

Is there a formula for working out what pressures should be put in for different size tyres or are we talking old school egineering of suck it (or blow it) and see?


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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 5:40 pm 
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Joined: Fri Nov 09, 2007 6:40 pm
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Location: Northants
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Earlier S2's and Turbo's had book pressures of 36 all round. Some say the rear increase was to counter lawsuits for high speed blowouts on the Autobahn, but whatever the reason the cars feel horrid with 44psi at the rear and the centre of the tyre wears out too quick.

I personally use 34F and 36R on the exact same wheel and tyre size as you, others go slightly lower at 32psi all round.

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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 5:40 pm 
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Joined: Mon Nov 05, 2007 9:36 pm
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Location: Kent
I would keep the rears a little higher than the fronts as porsche intended, but maybe experiment with 30 front, 32 rear.

iirc you're in Ireland so if the roads are a bit rough 'n' ready like over here in kent then you'll probably find the standard pressures of 29front 36 rear a little hard.

HTH


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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 6:00 pm 
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Thanks guys, I'll try Paul's pressures and avoid the Autobahns :shock:

I'm on the border of Oxfordshire and Northants. You don't need a road sign to tell you when you've crossed the border into Oxfordshire from Northants as the pot holes suddenly disappear.

What do Northants council do with their road maintenance budget? Smoke it? :drunken:

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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 6:20 pm 
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I run 32 all round but mines a bit of a hybrid so may very well be different. You may need to play around to get a balance as turn in suffers with softer pressures, but your spine takes a hammering at higher pressures.

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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 9:11 pm 
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if its worth anything i run 32 front, 36 rear on 16 inch rims, only thing i can suggest is looking in a 968 manual as they came with 17s as standard

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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 9:33 pm 
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lindsayhbrown wrote:
if its worth anything i run 32 front, 36 rear on 16 inch rims, only thing i can suggest is looking in a 968 manual as they came with 17s as standard


968 Coupes came with 16s as standard or 17s as an option. The CS and Sport came with 17s as standard though.
Mine has the optional 17s and the pressures are 36 all round.

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 Post subject: Re: Boxster alloys on a 944 Cabby - What tyre pressures?
PostPosted: Mon Oct 06, 2008 10:30 pm 
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I had cup 2's on my turbo and ran 32 front/35 rear.

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