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Rear suspension advice please
https://forums.tipec.net/viewtopic.php?f=25&t=24409		 Page 1 of 1
Author:  OldEnglish68 [ Thu May 14, 2020 6:12 am ]
Post subject:  Rear suspension advice please
I have an early-'85 944 Lux in great condition. Low-ish mileage and good history. All factory-standard as far as I am aware.

It drives and rides really nicely, apart from what seems to be rock-hard rear suspension!

It's OK most of the time, but when running over anything taller than a painted line (like a cats-eye) you get a marked jolt at the rear.

There is no play, knocking or other movement. It's the same whether driving straight or round a bend.

Tyres are Firestone (not my first choice but loads of tread so they'll be there for a while...)

Is very stiff rear suspension normal on a 944 please? If so, I can live with it but would like to get it sorted if not.

All help very gratefully received.

Thank you.
Author:  Waylander [ Thu May 14, 2020 7:52 am ]
Post subject:  Re: Rear suspension advice please
Can you check the DOT age of the tyres

Just google how, these cars are really sensitive to tyres, and pressures

The rear can seem quite jolty
Author:  OldEnglish68 [ Thu May 14, 2020 4:08 pm ]
Post subject:  Re: Rear suspension advice please
Thank you.

I made a mistake - only fronts are Firestones. Rears are Bridgestone Turanza. Looks like pre 2000 from DOT number. 32psi.

It has the 15" Fuchs wheels and 215/60/ZR15 tyres.

Time for new rubber?
Author:  tr7v8 [ Thu May 14, 2020 5:21 pm ]
Post subject:  Re: Rear suspension advice please
OldEnglish68 wrote:
Thank you.

I made a mistake - only fronts are Firestones. Rears are Bridgestone Turanza. Looks like pre 2000 from DOT number. 32psi.

It has the 15" Fuchs wheels and 215/60/ZR15 tyres.

Time for new rubber?

Bridgestone are harder riding with stiffer side walls than most. The 15" wheels are a pain as there is a very limited range of tyres in this diameter & what is around isn't really sports car rubber.
This is why many upgrade to the 16" D90, much better range of tyres & cheaper as well.
Another point is what tyre pressures you are running? The book numbers are fine on billiard table smooth German autobahns but rubbish in the UK. From memory I think I ran around 34-38 all round.
Author:  Waylander [ Thu May 14, 2020 8:07 pm ]
Post subject:  Re: Rear suspension advice please
20 year old tyres are next to suicide, yes new rubber, but the range of tyres in your size is very small

I know going up in rim size sounds counter productive but as Jim points out there is a much bigger selection

I just changed my tyres and they were only 6 years old and pretty worn, the new ones have transformed the car, smooth quite
Author:  OldEnglish68 [ Fri May 15, 2020 5:18 am ]
Post subject:  Re: Rear suspension advice please
Thanks again for the replies, much appreciated.

I have some P6000s in the correct size (from a Jaguar), I'll try them next.

Interesting that tyre choice is so significant but a relatively easy fix so worth investigating.

I also have a set of 16" D90s for the 944, but with winter tyres only. I was planning to sell them as they're no longer needed but should hang on to them by the sound of it...

Best wishes to all
Author:  tr7v8 [ Fri May 15, 2020 7:13 am ]
Post subject:  Re: Rear suspension advice please
OldEnglish68 wrote:
Thanks again for the replies, much appreciated.

I have some P6000s in the correct size (from a Jaguar), I'll try them next.

Interesting that tyre choice is so significant but a relatively easy fix so worth investigating.

I also have a set of 16" D90s for the 944, but with winter tyres only. I was planning to sell them as they're no longer needed but should hang on to them by the sound of it...

Best wishes to all

My first Jaguar S Type had P6000s they were in fact factory fit at that time. They were awful, I suspect these will be fairly old as well.
On the D90's I ran a variety of tyres when I ran mine. The Bridgestones were good performance wise but terrible ride. From memory I ended up on Goodyear F1s I think the GSD3, but there will be a newer version now.
Author:  Waylander [ Fri May 15, 2020 7:34 am ]
Post subject:  Re: Rear suspension advice please
In Europe it is illegal to sell tyres with a dot of more than five years as new, no matter how these are stored

So any tyre over 5 years old even if brand new is still a step down in safety, I personally cannot understand why anybody would risk their car and their life for a a few quid and run crap old tyres on a car

But as we all know opinions are free and everybody has one
Author:  OldEnglish68 [ Fri May 15, 2020 11:55 am ]
Post subject:  Re: Rear suspension advice please
Waylander wrote:
I personally cannot understand why anybody would risk their car and their life for a a few quid and run crap old tyres on a car



I agree, and end up buying way more tyres than anyone should ever have to - hence I have a rather large collection of perfectly good wheels and tyres!

(Now I know about the DOT system, I will go through everything and get rid of any that are too old)

The 944 only had one mission when I bought it - LeJog 2020 - but sadly we will not be doing that now as we have not been able to run in this years other events and LeJog is not for novices!

The tyres on it didn't matter as they were going to be changed for winter tyres (a requirement on the event), which I have now bought (they're on the D90s)

I've only driven the 944 a couple of times and do quite like it. I should sell it really but will try to keep it if I can. In truth, it's way too nice for the rough treatment handed out on LeJog.

Great news (thanks again!) if the tyres are causing the hard ride, it's a win-win for me as it's easy to change them and I can choose what looks and drives best.

Thanks, TR7V8, for the Goodyear F1 suggestion. I was always happy with the NCTs and will have a look at the F1s.

Sorry to D90/16" fans, but I do think the Fuchs wheels look spot-on so they will stay on for now :D
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