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Mixing Tyres/Poor Handling

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flimper
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Mixing Tyres/Poor Handling

Post by flimper » Sat Mar 09, 2019 1:56 pm

The M doesn't feel like it's handling properly at the front end at the moment, I have just put some new PS4's on the back with existing Supersports on the front. Could this be the problem or is it ok to mix these? Or is it more likely to need an alignment done?
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Mixing Tyres/Poor Handling

Post by wonkydonkey » Sat Mar 09, 2019 2:09 pm

Mine has been unpleasant since I bought it. I fixed three issues relating to the steering and handling on the front end, as well as having a four wheel alignment, but the front was still nervous on all road types (particularly with changing camber).

I fitted new Toyo Proxes on the rear a few weeks ago but swapped them to the front out of interest...totally different car. The fronts and rears have never been matched on my Z4 in my 10 months of ownership, and they still aren't, but the front tyres were ruining the steering. They had worn with a raised band roughly in the middle of the tread, about 5 mm wide and 1 mm tall, and this band wandered from side to side across the face a little as you rotated the wheel. None of the tyres have been run flats, and all premium brands, but this was my final issue.
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Mixing Tyres/Poor Handling

Post by Jembo » Sat Mar 09, 2019 3:05 pm

What tyre pressures & tyre sizes you running, as find pressures seem to drop over the winter months the colder it gets & rise in summer, so constantly am watchful
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Mixing Tyres/Poor Handling

Post by flimper » Sat Mar 09, 2019 3:46 pm

Jembo wrote: Sat Mar 09, 2019 3:05 pm What tyre pressures & tyre sizes you running, as find pressures seem to drop over the winter months the colder it gets & rise in summer, so constantly am watchful
Standard 18s, 32F 34R
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Mixing Tyres/Poor Handling

Post by Jembo » Sat Mar 09, 2019 4:08 pm

flimper wrote: Sat Mar 09, 2019 3:46 pm
Jembo wrote: Sat Mar 09, 2019 3:05 pm What tyre pressures & tyre sizes you running, as find pressures seem to drop over the winter months the colder it gets & rise in summer, so constantly am watchful

Standard 18s, 32F 34R
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2.1 bar 225=30.458 (30.5)
2.2 bar 255=31.908. (32)

is 32/34 in the manual?
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Mixing Tyres/Poor Handling

Post by flimper » Sat Mar 09, 2019 4:29 pm

is 32/34 in the manual?

No, that's just 10 years of ownership experience, always worked well until now
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Mixing Tyres/Poor Handling

Post by Ed Doe » Sat Mar 09, 2019 6:56 pm

Flimper supersports are better in the summer in warmer temps and the dry. Ps4s are better in the wet but marginally worse in dry conditions where you're really loading them up. What you could be experiencing is more understeer and a bit less predictability in the wet/cold weather currently, as you have a more wet/winter optimised tyre at the rear compared to the front.

That being said, I used to run ps4 rear and supersport fronts on my 3.0si with no real issues at all - if you've not done alignment in a while I'd definitely recommend that as a starter!
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Mixing Tyres/Poor Handling

Post by Ed Doe » Sat Mar 09, 2019 7:01 pm

Just to be clear I'm not suggesting the ps4 is a winter tyre by any stretch - just that the ps4 tyre is supposed to sit below the ps4s, which was supposed to replace the supersport as the summer/sport tyre. The ps4 is supposedly more comparable to the older ps3 which was far more an 'all-rounder' tyre....
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Mixing Tyres/Poor Handling

Post by buzyg » Sat Mar 09, 2019 9:29 pm

Can't see any reason why that combination should not work fine. Are the new tyres bedded in? I have had the SS take 150 miles to feel right in the past. No harm done playing with the pressures a little either. :wink:
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Mixing Tyres/Poor Handling

Post by MrPT » Sat Mar 09, 2019 11:41 pm

Can you describe what’s wrong with the handling?

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Mixing Tyres/Poor Handling

Post by flimper » Sun Mar 10, 2019 10:53 am

@eddoe @MrPT @buzyg Not been pressing on at all, noticing it at a sedate pace, feels like it's tramlining a bit more than normal, nothing serious just slightly irritating and want to get it cleared up for when the weather improves. The rears have not been run in at all yet.
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Mixing Tyres/Poor Handling

Post by Ewazix » Sun Mar 10, 2019 1:06 pm

Two things have become clear since running my Z4 and hanging around the forums, these cars are unusually sensitive to changes in tyres/pressures, suspension/bushes, alignment and wear of course.
2nd, sorting it out based on others experience is hit-and-miss. Few cars are alike now, what with swapping from RFT's, wheel size changes, non-OEM springs and bushes, alignment changes and wear, then it's always proven difficult to do anything other than work through the list of possibles.
It took me ages! Replacing a broken rear spring, saggy bushes, new non-RFT tyres, a Hunter 4-wheel alignment and tyre pressures got rid of 80% of the problem, it took 2 alignments with someone who knew what they were doing and was able to take account of changes (rather than sticking to the computer's specs) to finally sort it.
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Mixing Tyres/Poor Handling

Post by Jembo » Sun Mar 10, 2019 1:17 pm

Ewazix wrote: Sun Mar 10, 2019 1:06 pm Two things have become clear since running my Z4 and hanging around the forums, these cars are unusually sensitive to changes in tyres/pressures, suspension/bushes, alignment and wear of course.
2nd, sorting it out based on others experience is hit-and-miss. Few cars are alike now, what with swapping from RFT's, wheel size changes, non-OEM springs and bushes, alignment changes and wear, then it's always proven difficult to do anything other than work through the list of possibles.
It took me ages! Replacing a broken rear spring, saggy bushes, new non-RFT tyres, a Hunter 4-wheel alignment and tyre pressures got rid of 80% of the problem, it took 2 alignments with someone who knew what they were doing and was able to take account of changes (rather than sticking to the computer's specs) to finally sort it.
+1 +2 +3 to that from my past experience with M sport suspension on my old 3.0.

M’s still work in progress.
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Mixing Tyres/Poor Handling

Post by ben g » Sun Mar 10, 2019 2:11 pm

Ewazix wrote: Sun Mar 10, 2019 1:06 pm Two things have become clear since running my Z4 and hanging around the forums, these cars are unusually sensitive to changes in tyres/pressures, suspension/bushes, alignment and wear of course.
2nd, sorting it out based on others experience is hit-and-miss. Few cars are alike now, what with swapping from RFT's, wheel size changes, non-OEM springs and bushes, alignment changes and wear, then it's always proven difficult to do anything other than work through the list of possibles.
It took me ages! Replacing a broken rear spring, saggy bushes, new non-RFT tyres, a Hunter 4-wheel alignment and tyre pressures got rid of 80% of the problem, it took 2 alignments with someone who knew what they were doing and was able to take account of changes (rather than sticking to the computer's specs) to finally sort it.
Can you do my car too? :lol: mines terrible. It actually feels like something is broken! I have been driving in sport mode and that seems to sort it to some extent.

These cars with their electric steering are shockingly bad. At least the M's have proper hydraulic steering.
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Mixing Tyres/Poor Handling

Post by buzyg » Sun Mar 10, 2019 5:53 pm

ben g wrote: Sun Mar 10, 2019 2:11 pm These cars with their electric steering are shockingly bad. At least the M's have proper hydraulic steering.
:D :driving: :thumbsup:

You know the answer then. :wink:
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