Chaz

Umm, 48.26cm wheels, just doesn't sound as good as 19in, does it!

Chaz

In case anyone is interested, I have now tried the Etenwolf calibrated tyre pressure gauge.  It reads Bar to two decimal places (PSI to one), which is actually a bit disconcerting.  After a few wheels, getting a good seal is relatively easy and easing off that to let some air out is also OK; I've had several gauges where I find that (rather essential) task to be nearly impossible.  The gauge does make you feel daft, trying to get .01 Bar accuracy, but hey.  Overall, the tool feels robust and long-lasting (with the two AAA batteries being easier to change than the CR2302 on my Halfords gauge, which gave up the ghost a few weeks ago, new battery or not).

Cheers

Chaz

When I was looking at this a few months ago, out of idle curiosity, I found the online advice a bit confusing and impractical.  I think the difficulty arises from theory versus practice.

The advice not to increase your tyre pressure because the gauge reads under the "correct" pressure when it is colder than 20 deg, is based on the assumption that your tyres are correctly inflated and have maintained that pressure before you check.  Same for the advice on not letting air out of the tyre when checking in hot conditions (mainly found in Californian-based tyre advice websites!).  Since tyre pressure is relative to ambient temperature, what you would need to do is deflate the tyre to less than the temperature-adjusted pressure and reflate to hit that target.  

What I can't see any of us doing is waiting until the air temperature is 10 deg and then adjusting tyre pressures to 0.1 Bar less than the manual's stated numbers!  In practice, if we are checking and adjusting tyre pressures weekly or so, it makes sense to adjust to the manual's recommendation (or your preferred, experience-tested settings).  At worst (for the UK) you'd be 0.2 Bar over-inflated when warm (assuming you adjust at zero degrees), which is 10%ish.  Would that matter?

Cheers

Chaz

Thank you all.  Good to know that the thinking is correct, even if the minor variances are too small to care about.

I was also trying to get my head around the recommended pressure at 20 deg C and what you should set if the ambient temperature was 0 deg or 10 deg, in broad terms.  On the basis of 0.1 Bar difference for each 10 deg change, you'd try to set at 2.1 Bar when it was 10 deg (front for 19 inch) and 2.0 when the temperature drops to zero.  Trouble is that temperature never does drop in convenient 10 degree leaps!

On the question of a calibrated tyre gauge, the Etenwolf (https://www.etenwolf.com/products/digital-tire-pressure-gauge?variant=44165534351574) is the only one I've found that says it is calibrated.  

Cheers

Chaz

Warning, this is a really nerdy and ultimately not particularly real-world relevant post... but since I have thought about it and failed to find an answer online, I thought I would ask.

I was doing my usual tyre pressure check and forgot that the recommended pressures for 18 inch winter tyres are not the same as the 19 inch summer ones.  At the same time, my pressure gauge failed and I went hunting to buy a new one.  As a result, I was checking the Bar to PSI conversion and came across a note on Black Circles, which said that measuring in Bar with a digital meter that can report to a decimal place is more accurate than PSI.  I realised that was nonsense, since there are 14.50774 pounds per square inch pressure to every 1.0 Bar (also stated on the Black Circles website!) an therefore a single PSI is 1/14th of a Bar versus 1/10th.  Besides which, the digital gauges I've used for ages reads at 0.5 PSI.

All of that took me back to the numbers in the manual and they are given in Bar, with the PSI in brackets.  Trouble is that the conversions to PSI are not accurate and that made me think that Porsche must "think" in Bar, being metric/European.  Here's what I mean:

The manual gives 2.0 Bar (30 PSI) front and 2.1 Bar (31 PSI) rear for 18 inch wheels.  Using the correct conversion, I make that 29 PSI and 30.5 PSI (30.466 in fact). 

For the 19 inchers, 2.2 Bar (32 PSI) front is fine, but "2.3 Bar (34 PSI)" rear, is closer to 33 PSI (33.3678).  There is a note in one of the books about developing the 987 that remarks on the improve tyre pressure balance front and rear, compared to the 986 - about which I have no idea if it matters or is just marketing puffery.

* * * 

So, when we say or when you read 32/34 as standard pressures for 19 inch wheels, should we really be saying 32/33 PSI?

Like I say, totally not at all relevant, but I thought I would get my maths checked at least!

Cheers

Chaz 

Wow, amazingly detailed advice from all, particularly the last post (thanks, Richard).  I will check the software version I have, but from what you say mine should be late enough.  However, I think I may have the i666 phone module from a quick google on what that is - my PCM looks the same as the picture above, with the SIM socket.

Will report back.

Thanks

Chaz 

Hi,

Looking for an answer to this seems like finding a needle in a haystack.  The PCM I have in the MY 20210 987.2S has a manual from 02//10 and a SIM card slot (not the bulky phone handset, thankfully).  The manual says that the phone needs to support Bluetooth Hands Free Profile 1.0 or higher and I've got an iPhone 13 mini (which must clear that bar by a country mile).  I've only tried connecting it a couple of times, but no luck and it just times out.

Does anyone have a magic wand or other tricks to get this to work?

Thanks

Chaz   

Hi, back from my operation and still havn't applied the knowledge gained from the helpful posts above.

I completely endorse the views here, btw, on the friendliness, quality and UK-focus of this forum.  Great place to be.

Cheers

Chaz

Agree with the finger in the corner trick.  The fact that the boot lid is aluminium was borne in when I drove to Belgium the first weekend after getting the car, only to realise in the tunnel that my magnetic UK sign wouldn't stay on!

Chaz

Hi all,

Thanks for the excellent advice.  What with work and building works, I've done no more with the car than drive it and wash it.  What more can be needed, you ask?  Well, taking a look at the deflector clips is on the top of my to do list now.  I foolishly assumed they were OK and it was a thinner perspex or different profile that was the issue.  Let me check the basics first.

Boot lid sits flush when closed and locks and unlocks with satisfyingly clear sound.  I'll check the rubber stops to see what you mean about them screwing in and out.  

Thanks

Chaz

I’ve been enjoying the new (to me) red Boxster 987.2, which my wife persuaded me to buy (honest) a few months ago.  Haven’t had time to tinker or post questions, but there are a couple of things I wanted to check with the board.  

1.  I’ve noticed that the wind stop rattles a bit at the top edge of the Perspex, at some speeds.   This didn’t happen on the old 986s (both of them).  The car doesn’t have the mesh insert for the roll hoops and I don’t know if that is contributing to the air flow and causing the rattle?   Obviously hard to turn head and look at what’s going on when driving fast enough to cause the noise, but it sounds like the top edge of the deflector is vibrating rapidly - like the end of a plastic ruler held of the edge of a desk and flicked.  

2.  When I open the boot lid, it spring up as you’d expect but the gap is really small.   I can only just get a finger tip in, mostly, and it can actually be hard to lift the lid because you don’t get enough purchase.  Is there a spring that may have gotten less springy with age?  

I also need some advice about winter wheels and tyres but will post that in the appropriate forum.

thanks

Chaz

Thanks K.I.T.T, that's handy to know.

Chaz

Hiya,

Yes, that's the bit.  Relevant text is:  

"Existing halogen headlamp units on vehicles first used on or after 1 April 1986 must not be converted to be used with high intensity discharge (HID) or light emitting diode (LED) bulbs. If such a conversion has been done, you must fail the headlamp for light source and lamp not compatible.

This does not refer to complete replacement headlamp units which may be constructed with HID or LED light sources."

(My day job is lawyering, so....)

Cheers

Chaz

PS: for those that wanted to know what's in the kit, see here:

https://www.fvd.net/ch-en/FVD04490039/986-996-litronic-headlight-kit-european-version.html

(The kit is available for less money, but this has a good picture).

Chaz

Hi all,

Thanks for all the suggestions and help.  Yes, the Litronics are expensive but I have a particularly understanding Father Christmas this year and I don't have K.I.T.T's skills at restoring secondhand units.  Also yes, the control module and wiring harness are not necessary for being road-legal, but the kit price is actually cheaper than buying two new Litronic headlights alone (which surprised me and if it had been a few hundred pounds more, I'd have been OK with that).  Someone commented on US RennTech.org thread that the value of filling in the main beam is  marginal if you live in the city and can't have the main beam on permanently; I do enough driving on country roads that it would be a nice bonus.

With regard to the factory-fit dynamic leveling and headlight washers, you don't need to fit those for the car to pass its MOT.  There is a lot of confusion about this subject on the 'net, but the right answer is out there and I've checked it with the MOT manual and via Paragon.  There was a recent update to the MOT manual which made it clear that fitting HID lamps in place of halogen lamps in what was a halogen housing, would be an automatic fail.  The pre-update rules seemed to have been unclear on this.  However, replacing the whole headlamp unit is legit and the manual says that there is no reason to fail such a change, if it works correctly for all other purposes (such as alignment).  This is in 4.1.4 of the MOT manual, if you want to look it up (though I can't remember the name of the update, they are both available from the government website).  4.1.6 of the manual says that headlight washers have to work if fitted and should be fitted to cars first used after 1 Sept 2009. 

Thanks for the tip on upgrading the fuses; had seen the same advice on the Pelican Parts guide.

Finally, to my original question.  Probing of the Porsche database suggests there may be a wiring change on the 2002-onwards Boxsters which would have to be worked around, but my hope is that the information is mixing up the 996 facelift which happened in 2002 with the 986.  On the Classic Porsche Shop pages, the Litronic headlight units are shown as applicable to the 996 from 1998-2001 and the 986 until 2004.  Since the retrofit kit was sold to upgrade either car, I'm hoping that the MY information is derived from the 996 in Porsche's database. 

All best

Chaz 

Hi all,

I've done a lot of research on this topic, but have one very specific question remaining.  I'm considering asking Father Christmas to buy me the Porsche Retrofit Litronics kit, to replace the aging halogens on my lovely 2004 Boxster.  The kit is marked as applicable to model years to 1998-2001, but I can't think of anything that changed on the later Boxsters that would affect the installation.  Can you?

Just to avoid other answers: yes, I've considered an HID kit and want the car to be road legal, so will have to pay for the whole headlight unit to be changed.  I've also looked at secondhand headlights and considered doing this without the wiring harness and control unit for rotating the Xenon dipped beam into the main beam, but fancy doing it the authentic, if expensive, way. 

If anyone has a recommendation for a Porsche electrics specialist, that might know something about this, if no one on here does, please let me know? 

Thanks

Chaz