987 S, 18" wheels vs 19" , some unexpected developments !

[The_Voices1]

Just bought my first Porsche, a 2006 Cayman 'S' manual.

It has the 19" 'lobster claw' alloys, 235/35 front tyres, 265/35 rears.

Finding the ride quality a bit harsh on some of the dreadful local roads.

I don't mind firm suspension (doesn't have the active system) but I feels like some of the rough surfaces and potholes are going to do it some damage.

Wondering whether downsizing to 18"'s on a 40 profile tyre would give a significant improvement.

Any 'real world' experience would be great ?

 

[911hillclimber]

Just my experience.

I have a 2009 Boxster on 19" rims. I certainly can vouch for the discomfort at many times due to the rims, the tyres and the roads.
Some impacts are really hard on the low (35) section tyres, esp the fronts.

I wish I had 18" rims and taller tyre walls.

I also have a 1973 911, I used to use 50 profile tyres as I hillclimbed the car, but when I moved on to a faster car I put the 911 onto 70 profile more classic car tyres.

The comfort difference was amazing, SO much more compliance as to make the car nice on the roads in general and it can soak up many UK road imperfections.

I'm sure this would be the case with 18" on the Cayman too.

Not sure this helps, but my experience.

 

[ianthow]

Just bought my first Porsche, a 2006 Cayman 'S' manual.
It has the 19" 'lobster claw' alloys, 235/35 front tyres, 265/35 rears.
Finding the ride quality a bit harsh on some of the dreadful local roads.
I don't mind firm suspension (doesn't have the active system) but I feels like some of the rough surfaces and potholes are going to do it some damage.
Wondering whether downsizing to 18"'s on a 40 profile tyre would give a significant improvement.
Any 'real world' experience would be great ?

Jon,
I have a 2010 Cayman 987.2 S with 19" wheels and base suspension. I also have a spare set of 18s with winter tyres. I would not say the 19s are excessively harsh on the rural roads where I live. There is a marginal improvement on the 18s, but not enough to switch to 18s for all year. Is the suspension stock or has it been 'upgraded' by a previous owner (firmer shocks/springs and lowered ride height)? Have the suspension checked by someone who knows these cars.

 

[The_Voices1]

Thank you guys.

As far as I can tell, it is on standard suspension, no signs of coilovers or lowering springs.

I also have a lot of paperwork that came with the car and only invoices are for usual replacement bits.

Did notice bills for 2 x genuine replacement front springs due to breakage in the past.

At some point it will need a set of tyres, didn't want to replace the 19's and then end up buying a set of 18" rims and new tyres as well.

Only experience I have to compare is on my Jaguar XE V6 'S', which came on optional 20" rims, had to replace several tyres due to pothole damage (sidewall bulges)

Swapped it onto the bog standard 18" rims, with the correct profile Michelin PS4's, reprogrammed the system to tell the car it was on the smaller wheels and all fine since then.

Ride is more compliant and the handling does not seem to be affected (I don't tend to hang about !)

 

[Motorhead]

I have a 2009 987.2 CS on 19” wheels with PASM and can’t say that the ride is unduly harsh. Unlike your Jag XE saloon the Cayman is a sports car with a firmer ride and handling setup, so maybe you just need to recalibrate your backside accordingly!

Enjoy your new purchase.

Jeff

 

[The_Voices1]

You could be right Jeff but my previous cars have included all sorts of stuff, so I have plenty to compare it to

The ride quality is fine on average surfaces but on the really nasty stuff, feels like one of my old Impreza STi's on coilovers !

Probably getting too old for all that kind of thing, I might drop my pipe, or my slippers could fall off !

As an aside, my XE is the 3.0 V6 Supercharged version with adaptive suspension, so doesn't ride and handle quite like traditional Jaguars

 

[Motorhead]

Ha,ha! Yes, my comment was a bit tongue-in-cheek, and Jaguars have a good reputation for combining good handling qualities with ride comfort. For reference my other car is a GR Yaris, which on certain surfaces might be considered jarringly firm … at low speed in particular!

You don’t mention the mileage on your CS, but if it’s on the high side then you may want to consider a damper refresh which could give you an improvement in ride comfort, although not guaranteed?

Jeff

 

[Wollemi]

Whilst the ride on 19" wheels with passive suspension is never going to be soft, it might be worth considering how old the tyres are. Tyres get harder with age, and worn tyres ride harsher that tyres with a more tread depth. I never found the ride on my 987.2 with 19" Michelin PS2 tyres to be unacceptable.

 

[The_Voices1]

Mileage is 112k, so not a spring chicken !

Suspension refresh could be one possibility, the age of the tyres did occur to me as well.

The front ones in particular are Continental Sport Contact 3's, legal tread but I suspect they last saw action on King Tut's chariot

Would probably replace all 4, which is what prompted me to consider a set of used 18" alloys and spend the money on new tyres for those instead.

At my first club meeting tomorrow, so will see if anyone else there is driving something similar and get their views as well.

 

[The_Voices1]

Some unfortunate developments regarding my concerns about the ride quality !

I was looking at the car today whilst it was parked on the driveway and thought to myself 'I didn't realise that my drive was on an angle ?'

Closer inspection reveals that the passenger side front has a much larger gap from the top of the tyre to the wheel arch than the drivers side front.

First thought was a snapped coil spring, but from a limited inspection, I can't feel a break in either of the springs.

What I did find on the passenger side is what feels like oil in the spring seat, oil marks on the inner wheel arch and what looks and feels to be the same substance all over the inside surface of the wheel.

This would also explain some marks that I noticed on the driveway the other day in line with the back edge of the front wheel arch.

My suspicion is a 'blown' shock absorber on the passenger side ?

If so, I will need to replace both front ones to match (potentially the springs as well as a precaution ?)

Looking back through the paperwork, it had two new front springs in 2017, due to breakage.

Any suggestions as to best course of action or a reasonably priced source for the parts ?

One option could be to fit a set of budget coilovers all round, I know that generally they have a reputation for a harsh ride, but the BC Racing ones had a good reputation in my Subaru days.

With the correct choice of spring rate, dampers set to the softer end of the scale and ride height set to standard or slightly lower, I wonder if they might be workable.

£3k on a set of Bilstein ones isn't an option !

 

[ianthow]

Sounds like you do have a broken spring as well as the leaking damper. Based on my experience, replace the spring and damper on both sides with std spec. Ask you nearest OPC to check the car and quote. There will almost certainly be other parts needed, e.g. drop links, bump springs but should be doable for around £2K. Alternatively, ask a reputable local garage to quote, it does not need specialist tools/skills. Follow up with wheel alignment check.

 

[911hillclimber]

^^ Could not agree more.
Standard springs and dampers will keep the car very usable over school road speed bumps and all that.

A 4 wheel alignment essential using Porsche geo settings.
Ask your local region members for good reliable specialists to contact/use.

Good luck!

 

[Motorhead]

+1 on all the above comments, especially getting advice from a local Porsche Independent rather than official dealers who are bound to be significantly more expensive due to their high hourly labour rates [£250+?] and the fact that they will only fit genuine Porsche parts. Plus, the Indys will have more experience dealing with the earlier cars like yours.

Just one other point to bear in mind is that at 112k miles the rear springs and dampers will be well past their best, so it’s worth considering replacing them too [more expense!] in order to maintain a good handling balance. Also, if you don’t replace them you may find that the car presents a “front high” attitude due to rear suspension sag.

Jeff

 

[911hillclimber]

I was going to suggest that too Jeff, but thought of his wallet, but with the car on the ramp some of the work is done already (man=maths kicking in) so you may as well do the lot.
Car will feel great after!
Sorry to the original poster.

 

[The_Voices1]

Local 'indy' suggests £1500 for shocks, springs , top mounts.

I wouldn't even consider going to a main dealer !

Pricing up the parts and might do it myself, then get the 4 wheel alignment done professionally

 

[The_Voices1]

Some further (embarrassing) developments !

When I park the car on the road rather than my drive, it sits 'flat', wheel arch gaps are within 5 mm of each other (when comparing L-R front and L-R rear)

It appears that when parked on my driveway, the Porsche sits differently to the Jaguar XE that was previously in the same spot.

This is possibly due to where the engine / weight distribution falls on the two cars ?

Driveway seems to have less of a Left - Right slope at the top, which increases as you move towards the back wheels.

Thought I was going mad, but my wife and a friend who is also a car nut both verified my findings.

This still doesn't explain the 'oily' substance found on the front passenger side.

I am off again at the weekend and will jack it up and remove the wheel to take a closer look.


The even more embarrassing confession, is that I fell into the oldest trap in the book, 'never rule out the obvious'

The gentleman that I purchased the car from was particular about the car, but had only covered approximately 5k miles in the last 5 years.

He decided to sell it as it wasn't getting much use and the funds would be better spent on the motor home that he and his wife were looking to buy.

Given the amount of bills and paperwork, general condition and the overall 'vibe' that I got, I 'assumed' that he kept up with general checks and maintenance between workshop visits.

Checked the tyre pressures today and found significant differences between all four wheels, and between 5-10 psi under inflation.

I feel like an absolute idiot, and rightly so !

Will now see how it goes with correct pressures all round and evaluate the next move.

Suspension replacement could still be on the cards, as could a swap to 18" wheels.

 

[Motorhead]

Sounds like a plan.

Something else to consider is that if the car hasn’t seen much use then apart from the age of the tyres it’s likely that they’ll have been flat-spotted, possibly leading to a degradation in ride quality.

Jeff

 

[malarcy]

oily stuff - power steering fluid ?

If more soapy than oily - screen wash. ?

Oily ish and not soapy - coolant.

Have a look at the crossover coolant pipes - out wheels on hard lock and look for crystals around the and of the pipes you can see.

Power steering pipes are known to weep at the joins. - jubilee clips on the joints at early stages of failure can increase life span by a number of years.

 

[The_Voices1]

Thanks for the suggestions.

Hopefully get chance to have a better look this weekend.