Another Tyre Thread - Swapping MPSS to PS4S

Another Tyre Thread - Swapping MPSS to PS4S

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stuart-b

Original Poster:

3,643 posts

226 months

Tuesday 18th July 2017
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Hi guys,

Another tyre thread.

I've never been happy with the MPSS on my Z4 - they almost seem to have less grip than the RFT that they replaced. After a lot of reading and talking to people in the know, it appears that they do not work well with high negative camber. I've tried to lower the rear camber to the minimum I can, within the adjustability of the OEM suspension setup, but it's still not good.

Even with throttle regulation the tyres spin up into 3rd gear, they create nervousness in the rear and do not inspire confidence at all.

They are also hard as nails. I mean, brutally hard. This set has done 20k miles and still has 3.5-4mm left !

This weekend I'll replace them with PS4S and will report back the difference after they run for a few hundred miles.

Anyone else fitted PS4S - opinions?

SebringMan

1,773 posts

186 months

Tuesday 18th July 2017
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I fitted PS4Ss to the front of my M3. Previously I had Falken FK452s up front. The only tyres I've probably have in the closest league to them have been the following:

-Nankang NS-2R on a Series 1 Escort RS Turbo running 230BHP.
-Goodyear Eagle F1 Asymmetric 3s on two MkIV Mondoe 2.5Ts
-PS2s all round on my Porsche 944 Turbo.
-MPSS on a B7 RS4 ; I'd need to drive that for longer to have a better idea.

I'd have to get onto a track to see if they have the dry grip levels of the NS-2Rs ; bear in mind they are a track biased tyre. But on the road they don't seem to fall that far behind.

Compared to the PS2s wet grip does seem to be better and if I am honest I'd say dry grip as well.

When the Falkens came off and the MPS4Ss went on there was a marked difference, after about the first mile of leaving the tyre shop! Much grippier ; it's killed most of the understeer from my M3 TBH (I suspect I'd need to induce more camber and get wider on the front to further reduce it).

Put it this way. When I came back from Germany the weather was wet and horrible. I'm very very glad that I fitted the PS4Ss literally weeks beforehand ; I'm surprised you can go that fast in such conditions!

But what kind of climate are you driving in? Is the car UK based or is it in warmer climates?

stuart-b

Original Poster:

3,643 posts

226 months

Tuesday 18th July 2017
quotequote all
Very good to hear. I'm a mixture of UK and Europe. It sees all temps.

What is frustrating is that other BMWs are getting traction where I am not, on the same bit of road - so it must be down to tyres/suspension setup.

I will report back how it goes and probably do a small gopro video before and after (but I will run them in a bit first)

jon-

16,509 posts

216 months

Thursday 20th July 2017
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Are you just talking about wet grip? There's no way a MPSS should be spinning in the dry in any gear.

Rdawson

152 posts

128 months

Thursday 20th July 2017
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Hi,

I very recently fitted a set of Michelin PS4S to my E90 335i. I have 19x9" and 19x10" wheels, and fitted 235/35R19 and 265/30R19. Previously I had 225/40R18 and 255/35R18 Hankook Ventus S1 Evo2 fitted to the original M193 wheels. The Hankook in itself is a highly regarded tyre and it quite regularly achieves a top three or four ranking in the usual magazine tests as featured on the tyre reviews website. It not as focused a tyre as the others that featured in the top five spots, but nonetheless it was a great all rounder and a good basis for comparison.

I have found the Michelins to be absolutely superb, and quite a different proposition to any other tyre I have had experience with. The best way I could probably describe them is that they provide an astounding level of confidence, especially in the wet. I'm sure the same could be said of other tyres, but there is something about how planted and stable the car feels now. They are quiet, responsive, and my 'seat of the pants meter' suggests that braking performance has improved too. They are a reasonably broad shouldered tyre, and they have in effect used two different compounds across the tread width to provide a best of both worlds offering. There is a visible colour difference between the rubber used on the very outer tread blocks and the rest of the tyre, which is interesting.

I'm chuffed with the tyres - I actually ordered mine from Camskill and had them delivered to NZ (where one PSS in my rear size was something like $800 for reference) so the price charged by Camskill including shipping was extremely competitive!

Not sure if it is visible in the photo below, but you may be able to see a very faint line that runs around the circumference of the outer half of the outside tread blocks.

As it stands, I wouldn't look anywhere else for a tyre now.



Edited by Rdawson on Thursday 20th July 22:25


Edited by Rdawson on Thursday 20th July 22:30

Smuler

2,286 posts

139 months

Friday 21st July 2017
quotequote all
stuart-b said:
Hi guys,

Another tyre thread.

I've never been happy with the MPSS on my Z4 - they almost seem to have less grip than the RFT that they replaced. After a lot of reading and talking to people in the know, it appears that they do not work well with high negative camber. I've tried to lower the rear camber to the minimum I can, within the adjustability of the OEM suspension setup, but it's still not good.

Even with throttle regulation the tyres spin up into 3rd gear, they create nervousness in the rear and do not inspire confidence at all.

They are also hard as nails. I mean, brutally hard. This set has done 20k miles and still has 3.5-4mm left !

This weekend I'll replace them with PS4S and will report back the difference after they run for a few hundred miles.

Anyone else fitted PS4S - opinions?
Yes.
So far very impressed, on my E46 M3. more grip more feedback than what was on it when I bought it: Continental 5Ps
I had the Michelin Pilot Super Sport in 2015 on my 335i, found them a massive improvement over the RFTs.
Six months later tho, I'd put 17s rims on for winter tyres and the following Spring I kept the 17s on and tried the Michelin Pilot Sport 4.

That combo was even better, tho it's not exactly a like for like comparison.

But gave me confidence the PS4Ss would be the best yet, I'd say they are smile






stuart-b

Original Poster:

3,643 posts

226 months

Friday 21st July 2017
quotequote all
jon- said:
Are you just talking about wet grip? There's no way a MPSS should be spinning in the dry in any gear.
Hi Jon, I thought I was quite detailed in my initial post.
The person overseeing my camber adjustment and 4 wheel laser alignment is rallying and was regularly winning country level drift competitions. He has driven a lot of cars and has a lot of knowledge about suspension and wheel setups. The car is setup as good as it can be - you take only take my word for that. I've changed the wheels (less unsprung weight), changed the springs, changed the tyre width (increased to 265 which is what the current MPSS are).

His feedback is, the tyre is too stiff and provides more cornering grip than straight line in my case.

Whether that's Z4 specific or not, I don't know - perhaps it's the weight on the rear, but I'm not a prat who gives it WOT a few times and jumps to irrational conclusions either. I've driven the car for 20,000 miles in various conditions, in more than 10 different countries, across a mixture of tarmac types.

I've tried different camber, different tyre pressures, different maps - the result is the same, the car cannot put down the power and is severely limited up to 60 mph. Even after 60 mph it will wiggle and move around at full boost FROM 60 mph up to 85-90 mph.

Other owners are seeing 4.1/4.2 seconds 0-60 with a basic map - I would be lucky to see 5.5-6 seconds since these tyres are on. Only with traction control and stability completely off will I get anywhere near that, but it's rather lively for public road use in that case. I'd rather have a more predictable acceleration.

I have noticed some surfaces in the UK where the tarmac is so rough and grippy, it performs a lot better on this surface - but within Europe, many tarmac surfaces are almost smooth. However, you would expect everyone to suffer, but I'm not seeing that when driving alongside other BMWs.

My question is, would you expect UHP tyres to still have almost 4mm of tread left after 20k miles? I'm not driving like a daisy, I've already gone through one set of rear pads because of the ediff.

stuart-b

Original Poster:

3,643 posts

226 months

Friday 21st July 2017
quotequote all
Smuler said:
Yes.
So far very impressed, on my E46 M3. more grip more feedback than what was on it when I bought it: Continental 5Ps
I had the Michelin Pilot Super Sport in 2015 on my 335i, found them a massive improvement over the RFTs.
Six months later tho, I'd put 17s rims on for winter tyres and the following Spring I kept the 17s on and tried the Michelin Pilot Sport 4.

That combo was even better, tho it's not exactly a like for like comparison.

But gave me confidence the PS4Ss would be the best yet, I'd say they are smile
Interesting, thanks. The 335 guys do seem to have an easier time putting the power down than the similarly engined Z4. I priced up a mechanical LSD so that I have a similar power chain to that of the M cars (it's the same engine as the 1M, and the basic Getrag unit is used within the M3 among others), but it's using a crap ediff (if you can even call it that, rear brakes providing a simulated diff) and cheap suspension components, which as we know, make all the difference.

There is one owner on the Z forums who has put parts of the E92 M3 front suspension in place and E46 M3 rear (where he could, bushing if I recall), along with swaybars and special trailing arms and it made a significant improvement - but that's a bigger project than I can stomach at the moment as there is some customisation required.


Edited by stuart-b on Friday 21st July 11:36

va1o

16,032 posts

207 months

Saturday 22nd July 2017
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jon- said:
There's no way a MPSS should be spinning in the dry in any gear.
They will if they're worn out! I've just replaced my rears with a new set today after 24k miles and have noticed a huge difference already. Lesson learnt to replace them sooner in future!

mikeyscott

1,200 posts

208 months

stuart-b

Original Poster:

3,643 posts

226 months

Friday 28th July 2017
quotequote all
Update on the tyres.

Turns out that the MPSS i was running, I thought it was 265 already, it was actually 255. Looking back at the emails, the provider of the tyres was trying to tell me that I was ordering the wrong size, but I was insistent since I'm running 9.5 inch rear now, not 9 inch. I guess it doesn't matter how often you look at something, as I've checked those tyres probably more than 50 times whenever I clean the car!

The new tyres are 265, meaning no stretch. The old tyres were completely knackered on the very inside edge, being a very stiff tyre, and stretched, this was not a good combination. 5mm left in the middle and bald completely on the very inside (difficult to see when looking under the car, only became apparent when the tyres were off). It should be noted that traction wasn't very good even when the tyre was new.

These are the new tyres are night and day. I can manage full throttle second gear pulls without losing traction - finally after 2 years !

I've taken the plunge and will be replacing the fronts too, with 235 size, even though the old tyres have 7mm left - will throw them in the garage.

Anyone else considering PS4S - do it !