20" wheels without PASM

[ATM]

bcr5784 said:

ATM said:

bcr5784 said:

DJMC said:

ATM said:

I have a 981 with standard passive dampers.

Best bit about the car now on 18 is you can attack speed bumps at ridicolous speeds like they're not there.

Also i can park the front over curbs without interference.

Do you mean bumping the car up onto the curb due to the higher profile sidewalls? Otherwise, how do 18s make the car higher at the front? A bit confused, probably me being thick!

You aren't being thick at all. If the tyres are to Porsches spec, then the higher profile of the tyres on the smaller wheels means that the diameter and therefore the ride height remains almost exactly the same. The extra compliance of the higher profile tyres might make speed humps more comfortable, but I wouldn't putting your nose over higher curbs.

PASM sits lower. Passive dampered car has higher ride height. So the nose easily clears curbs. For urban driving and parking its much easier to live with.

I think djmc and I both thought you were suggesting that wheel size affects ride height. As you say PASM lowers ride height by 10.mm

This

With all my other Porsche cars i was worried about curbs. The 981 sits really high. I've checked a few curbs and it clears them easily.

Combine that with the massive high profile tyres which give no fear of curb scrapes and smooth out speed bumps and whatever else and you have a setup which frees you from the normal worries you might have with lower profile tyres and lower suspension.

Think urban rally car and you're on the money.

Edited by ATM on Sunday 4th March 13:36

[DJMC]

ATM said:

This

With all my other Porsche cars i was worried about curbs. The 981 sits really high. I've checked a few curbs and it clears them easily.

Combine that with the massive high profile tyres which give no fear of curb scrapes and smooth out speed bumps and whatever else and you have a setup which frees you from the normal worries you might have with lower profile tyres and lower suspension.

Think urban rally car and you're on the money.

Edited by ATM on Sunday 4th March 13:36

Ah... now you ARE saying that small wheel plus higher profile tyre makes the car ride higher than large wheel and low profile tyre when the tyre diameter for 18, 19, 20 inch tyres is the same.

The only claim you can make is that non-PASM gives 10mm higher nose and spoiler. Nothing to do with wheels/tyres.

[ATM]

DJMC said:

ATM said:

This

With all my other Porsche cars i was worried about curbs. The 981 sits really high. I've checked a few curbs and it clears them easily.

Combine that with the massive high profile tyres which give no fear of curb scrapes and smooth out speed bumps and whatever else and you have a setup which frees you from the normal worries you might have with lower profile tyres and lower suspension.

Think urban rally car and you're on the money.

Edited by ATM on Sunday 4th March 13:36

Ah... now you ARE saying that small wheel plus higher profile tyre makes the car ride higher than large wheel and low profile tyre when the tyre diameter for 18, 19, 20 inch tyres is the same.

The only claim you can make is that non-PASM gives 10mm higher nose and spoiler. Nothing to do with wheels/tyres.

No the 2 are separate benefits but added together make it a better car for blasting round urban areas.

[DJMC]

ATM said:

No the 2 are separate benefits but added together make it a better car for blasting round urban areas.

Well, I never knew that changing wheel sizes would make my car higher or lower by increasing or decreasing the overall wheel/tyre diameter.

I wonder how that affects the car's gearing and acceleration?

For quickest acceleration I guess you'd advise fitting the 20" wheels with the low profile tyres as the latter will make the car lower and in the process its tiny tyres will get to 60mph the quickest?

Your 18" wheels with high profile tyres will be so huge that unfortunately they will slow you down off the mark against my 20" ones. Not so good for "blasting round" but at least the curbs and your spoiler are safe.

So much useful information on here which has escaped me over the last 40 years of motoring.

[Maxym]

DJMC said:

Well, I never knew that changing wheel sizes would make my car higher or lower by increasing or decreasing the overall wheel/tyre diameter.

I wonder how that affects the car's gearing and acceleration?

For quickest acceleration I guess you'd advise fitting the 20" wheels with the low profile tyres as the latter will make the car lower and in the process its tiny tyres will get to 60mph the quickest?

Your 18" wheels with high profile tyres will be so huge that unfortunately they will slow you down off the mark against my 20" ones. Not so good for "blasting round" but at least the curbs and your spoiler are safe.

So much useful information on here which has escaped me over the last 40 years of motoring.

Quite. Then there is the question of the need to have the speedo reading (reasonably) true regardless of wheel/tyre combo.

[ATM]

Maxym said:

DJMC said:

Well, I never knew that changing wheel sizes would make my car higher or lower by increasing or decreasing the overall wheel/tyre diameter.

I wonder how that affects the car's gearing and acceleration?

For quickest acceleration I guess you'd advise fitting the 20" wheels with the low profile tyres as the latter will make the car lower and in the process its tiny tyres will get to 60mph the quickest?

Your 18" wheels with high profile tyres will be so huge that unfortunately they will slow you down off the mark against my 20" ones. Not so good for "blasting round" but at least the curbs and your spoiler are safe.

So much useful information on here which has escaped me over the last 40 years of motoring.

Quite. Then there is the question of the need to have the speedo reading (reasonably) true regardless of wheel/tyre combo.

I seem to be misunderstood. The wheel and tyres combos on the 981 are all the same overall circumference pretty much. These do not affect the ride height. These do not affect gearing.

PASM and non-PASM do affect the ride height.

I would argue that a non PASM car - higher - with the 18 inch wheel and tyre combo - same circumference as 19 and 20 - is better for an urban environment where you need to navigate over speed bumps, park near / over curbs and deal with poor road surfaces.

Yes I do drive up curbs in my 981. Not at speed.

Yes I do drive over savage speed bumps in my 981. YES at speed.

Yes I do parallel park in my 981 near to / touching curbs. Not at speed - but I do this without fear of curbing a wheel as the 18 setup has massive 45 profile tyres making it virtually impossible to connect the wheel itself with the curb. This means I can park quicker and easier.

Is this clearer?

[Pinball]

I test drove a 20" non PASM car alongside one with PASM. PASM is a better ride, but I didn't find the non-PASM one a massive issue. On occasion I've driven around in mine with the PASM set unknowingly to sport mode and it hasn't bothered me.

[bcr5784]

Pinball said:

I test drove a 20" non PASM car alongside one with PASM. PASM is a better ride, but I didn't find the non-PASM one a massive issue. On occasion I've driven around in mine with the PASM set unknowingly to sport mode and it hasn't bothered me.

PASM sport on the 981 is fine on good roads, but not on bad ones.

[Pinball]

bcr5784 said:

PASM sport on the 981 is fine on good roads, but not on bad ones.

I must have a particularly stout spine . Driven over some bad roads round here and I don't have a problem. That said, it's probably down to what and individual has experienced and feels acceptable. I had a Z4 before and the ride on that was like being dragged down a set of stairs.

[bob2146]

Pinball said:

I had a Z4 before and the ride on that was like being dragged down a set of stairs.

[ATM]

bcr5784 said:

Pinball said:

I test drove a 20" non PASM car alongside one with PASM. PASM is a better ride, but I didn't find the non-PASM one a massive issue. On occasion I've driven around in mine with the PASM set unknowingly to sport mode and it hasn't bothered me.

PASM sport on the 981 is fine on good roads, but not on bad ones.

I dont understand how it works - as in normally you match springs to dampers. You can tweak tricky dampers slightly while using the same spring but its not night and day difference like PASM. Surely all PASM can do is alter the damping. Unlike air suspension which can alter the spring rate.

[jonnyb16]

bob2146 said:

Pinball said:

I had a Z4 before and the ride on that was like being dragged down a set of stairs.

I had a z4 coupe with 19" csl wheels - know exactly what you mean!

[bcr5784]

ATM said:

bcr5784 said:

Pinball said:

I test drove a 20" non PASM car alongside one with PASM. PASM is a better ride, but I didn't find the non-PASM one a massive issue. On occasion I've driven around in mine with the PASM set unknowingly to sport mode and it hasn't bothered me.

PASM sport on the 981 is fine on good roads, but not on bad ones.

I dont understand how it works - as in normally you match springs to dampers. You can tweak tricky dampers slightly while using the same spring but its not night and day difference like PASM. Surely all PASM can do is alter the damping. Unlike air suspension which can alter the spring rate.

Yes pasm only affects damping, but it does so depending on speed and g sensing. So, for example, around town in Normal it is softly damped, but stiffens up markedly as speed rises and the driver gets sporty. In sport it starts slightly softer than the stiffest normal setting but again gets even stiffer in response to speed and driver behaviour.

[DJMC]

bcr5784 said:

Yes pasm only affects damping, but it does so depending on speed and g sensing. So, for example, around town in Normal it is softly damped, but stiffens up markedly as speed rises and the driver gets sporty. In sport it starts slightly softer than the stiffest normal setting but again gets even stiffer in response to speed and driver behaviour.

I thought this was smoke and mirrors stuff, but it really does work. After a while pootling around town with PASM accidentally left in Sport mode it realises what you're up to and adjusts the settings more to Normal to comply with your driving inputs and other data.

Clever stuff.

Edited by DJMC on Tuesday 6th March 16:24

[DaveGB]

Have driven with and without PASM and let’s say I turned around within a mile of test drive of latter as didn’t like it in comparison.

I would only buy a car with PASM, but appreciate we are all different

[Maxym]

DaveGB said:

I would only buy a car with PASM, but appreciate we are all different

Me too. Had it on a 997 C2 and 981 Cayman S. Both had 'magic carpet' ride for sports cars. Interestingly the ride in my 981 CGTS isn't as good (I think) despite the two cars having identical suspension set-ups supposedly. Down to tyres? The S had P Zeros, the GTS has Eagle F1s.

[ATM]

Maxym said:

DaveGB said:

I would only buy a car with PASM, but appreciate we are all different

Me too. Had it on a 997 C2 and 981 Cayman S. Both had 'magic carpet' ride for sports cars. Interestingly the ride in my 981 CGTS isn't as good (I think) despite the two cars having identical suspension set-ups supposedly. Down to tyres? The S had P Zeros, the GTS has Eagle F1s.

My current summer setup is goodyear eagles in 19 inch and I think they're quite hard.

[gronk]

I picked up a 718 with the 20in option earlier this week.

I was expecting to find my fillings to be loosened and was pleasantly surprised. IMHO the ride quality is better then the ride on the 19ins I had on the 987 and surprisingly better than the 19in shod C220 family car.

[gronk]

I picked up a 718 with the 20in option earlier this week.

I was expecting to find my fillings to be loosened and was pleasantly surprised. IMHO the ride quality is better then the ride on the 19ins I had on the 987 and surprisingly better than the 19in shod C220 family car.

[ATM]

gronk said:

I picked up a 718 with the 20in option earlier this week.

I was expecting to find my fillings to be loosened and was pleasantly surprised. IMHO the ride quality is better then the ride on the 19ins I had on the 987 and surprisingly better than the 19in shod C220 family car.

Pics

Which suspension?