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Another bl**dy tyre thread!

Peter B

Montreal
Joined
18 Aug 2003
Messages
504
I've finally given up with my 18" hollows spokes - I just cant find a decent driving compromise. The tyre pressures have been up and down like a fiddlers elbow, I'm running on almost new full suspension rebuild (-10mm OE factory) and I can still get from A to B in less of a sweat in a 2 litre diesel than my semi-precious garage queen.

When I bought the car it was fitted with 17" Cups and Nokian M&S tyres resembling Goodyear G800s. They were truly frightening and by the grace of God I avoided several trips into the scenery backwards. So I found a set of hollow turbos and fitted Pirelli Assimetrico N3s. I know, I know, they don't like English temperatures...

So, I've bought another set of 17" Cups 7/9J 993.362.124.00 and 128.00

These are fitted with legal but mismatched non-N rated tyres so the next job is choosing a suitable tyre.

First question - do I stick to 205/50 fronts and 255/40 rears

Second question - Contis.....

??

All advice greatly received except for any suggestions to use the search button.....again!

Pete
 
Hi Pete, as a newbie to the 993 and Porsche world... do you think there could be another issue with the handling and set up?

I bought my car about 6 weeks ago, changed the shocks to new Bilstein B6 and M033 springs and the car handles like a bag of spanners, over bumps the back end seems to step out and it really isn't confidence inspiring. I have it booked in to Centre Gravity in a month or so and i have great confidence that they will sort it...

To me it just sounds like this could be your issue and not tyres..??

Just my thoughts...

Lig.
 
I predict a string of posts telling you to get your car to Center Gravity to have the suspension set-up checked and maybe corrected by the acknowledged guru in the field, in spite of the recent suspension refurb mentioned.
Have not (yet) personally been to CG, but I'm inclined to think it would be my first move in your situation.
911s (of all generations and variants) live or die by a good suspension set-up.


PS: Lig beat me to it by a minute in recommending CG as I'd predicted. :thumb: :D
 
Peter B said:
First question - do I stick to 205/50 fronts and 255/40 rears

Second question - Contis.....


Definitely stick with those sizes. Contis are absolutely fine too, 36 psi all round.

That's a good starting point and if the car doesn't behave with that lot fitted you know to look elsewhere for the problem.

993's are VERY tyre sensitive - mismatched ones or tyres with the wrong pressure can throw the handling right out.

N-Rated is all nonsense though, but you may as well get the Contis as they are n-rated too.

CG is good, but there are plenty of places that can set up a 993 properly.
 
I have just changed from 18" 997 turbo replicas ( I know - fitted by previous owner) fitted with Pirellis N4's for Cup 2's fitted with Bridgestone SO2's and the difference is night and day!

Car feels much less twitchy and I feel far more confident to push on......went for 205's on front and glad I did :thumbs:
 
18" for show, 17" for go...
 
Ive 18's, VERY happy with them, have you inspected the rear toe control arms, remember the 993 has passive steer and if theyre worn, well good luck!
 
Red993C4 said:
I predict a string of posts telling you to get your car to Center Gravity to have the suspension set-up checked and maybe corrected by the acknowledged guru in the field, in spite of the recent suspension refurb mentioned.

What he said... I wouldn`t give up on the wheels without making sure I had got a proper GEO done. :thumb:
 
.. as a side note, are you aware of the value of hollow spokes :)
 
Peter, when you say you're running on a new suspension rebuild, did you have that done or a previous owner?

If a previous owner, how long ago and any bills for Geo?

If you do have a Geo bill, it will have been done with the 17" wheels that you bought the car with?

Sticking 18" wheels on a car that's been geo'd for 17" wheels could result in a scary ride.

If it were me, I'd start with a set of 17" Cup 2's, some Contis or Rainsport 2 tyres, then work from there.

I had Hollows on my car when I bought it and went round in circles trying to get it to ride nicely. You might get a grand if the tyres are good.
 
New engine mounts (RS) transformed the handling of my car.

Rear end grip and general confidence in the car improved no end.
 
Kimbo said:
I had Hollows on my car when I bought it and went round in circles trying to get it to ride nicely. You might get a grand if the tyres are good.

Haven't done any research, but would have thought that a set of hollow spokes in good condition would be worth a grand even without tyres? :dont know:
 
Owner of approximately 14 weeks. Running Pirelli's all round, on (as far as I am aware) stock shocks and springs. Car has been maintained by Hartech for the last 6 years. Tyres on the back were new N3 Rosso's, tyres on the front were 2004 N2 Directional (Italian descriptive name I cant remember :oops: ). Handling in a straight line was interesting :eek: to the point of trying to throw the car off the road on fast, poorly surfaced straights. The fronts were 2mm different inside to outside (2 mm inside, 4 mm outside). Upon checking the history, there had been a recent camber change to the front geo, reducing a strong negative bias. Chris W supplied me with a superb set of "part worn" front Rosso's (how 7mm of tread can be described as part worn I don't know. Thanks Chris :thumb: ). The difference is completely amazing. The car now tracks straight (unsurprisingly) but the cornering ability and feedback through the steering and seat is exactly as I was hoping for. Certainly not in the two litre diesel class! I can hurtle through the back lanes over widely differing surfaces at ridiculous speeds (not really, just making this up Mr Police Plod man :cop: ). Don't know if this will help but a decent set of matched tyres is a good staring point. Good luck, G.
 
Ohh, forgot, running on 17" Cup 2's :thumbs:
 
Kims comments are misleading, the stock geo represents all wheels sizes offered on the 993, whether 16, 17, 18, the odd geo exceptions relate to the RS ect. Alternative Tyre profiles give the impression of a more cosseted ride, I've no idea what the OP has had replaced, as in the rubber bushes of various suspension components front and rear, mounts etc, there's plenty of them, they're all old, past their sell by date, and expensive, yet critical to good road manners, attention needs to be given on a broad spectrum rather than just blame the dampers, wheels and tyres.
 

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