Overthinking

Started by Petrus, September 25, 2022, 08:45

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Petrus

#25
The plot has thickened.
We have reached a compromise.
As the rears are quite close to the wear indicators MG is ok with replacing thóse. To prove my point about tail wind, she will even pay for that  :o  so have ordered them.

Apart from being less worn, the fronts do not heat up as much thus should not be heat cycled out as much. Also them being the R version will I hope compensate a bit for the ultimate traction lost.

With all overthought I get two new rears for free  8)  and almost perversely the fronts which started it all stay as is ....

With another week of warm dry weather in the forcast, it all being pretty much ceterus paribus so am looking forward to compare the well used Rs with new RSs.

Iain

Very interested to hear your thoughts on the RS. Some good, some not so good reviews out there.

Ardent


Petrus

#28
Should, knocking wood with fingers crossed, have them fitted at the end of the week.
Weather forecast says 30!!! degrees for Sunday yet 10 for the night. As we tend to have several degrees less in the morning, it is as close to ideal comparison as I can think of.

Got a bit of a complicated hectic next week but the forecast is unusually ´good´. No rain and pleasant temperatures so a unique opportunity to try get above 2.000 meter (6.000 ft) in the Sierra Nevada. Normally there is already snow and ice up there around now and it is also quite late in the season for cyclists on workdays to be up there.
Would lóve to take the MR2 as high as 2500 meters, to the Hoya de la Mora. That is abóve the ski station. Would be cool. Toes crossed too.




As I wrote; best test imaginable  8)  8)


p,s. tyre shop confirmed and MG has already given me the cash.

MikeBoo

I'm also looking forward to your thoughts on the RS as I only recently bought my MR2 which already came with a barely worn set (185/55R15/205/50R15) fitted.

I've pushed it hard around corners and I can feel that rears begin to loose traction without the front running wide as I power through the bends.
However I've only known this tyre on the MR2 and also mine has a few suspension mods, so you could well have a different experience.
2001 Toyota Liquid Silver (1D0) with hard top & original soft top.
Yokohama AD08RS all round.
Replacement manifold, BC coil overs,
Whiteline anti roll bars front & rear & Ultra Racing front strut brace.
Location = East Hampshire, UK

Petrus

Quote from: MikeBoo on September 28, 2022, 14:35also mine has a few suspension mods, so you could well have a different experience.


Mine is seriously unbalanced  ;D  : A bit more modified than yours.
Also front and rear will be a mismatch.
My observations will thus be limited to the difference between R and RS at the rear. For what that is worth as the R is pretty much temperature cycled out.

Petrus

Preliminary report.
Went out to warm up the tyres and then a spin over the local industrial estate, my norm test track  ;)
As observed quite a bit of oversteer possible. Still pleasantly predictable, still quite grippy, just a tad too easy to provoke sliding.

The old:





With the new fitted, went for a slightly longer spin the scrub the protective coating off. The warmed up nicely too.
Then the industrial estate.
WOW  :o
Ok, I knew/know the tyres had lost grip but thís much difference was still a bit of a surprise.
The new rubber is just as predictable and seems to let go more gradually but that I do remember from when the old were new.

I have come to appreciate the gentle provoking of ´lift off oversteer´ when smooth with the loud pedal. In this too much more traction and again nicely gradual.

Sofar my impression is that the RS is a predictable grippy tyre. WAY more so than the R past its heat cycle sell by.

That is the good.
The bad is doubt about the fronts now  :-*
Should put that out of my mind though because the balance still has not shifted to understeer. Ergo they must still grip good.

The new:





Mountain Girl is véry happy with the difference in profile depth.

On a side note there is less warning blurp on the new ones. The whole paragraph about not overinflating to set the bead etc. is gone.

Dev

From what I read from a performance book long ago is the real differentiation between budget and top tier tires is not the grip. Its the way they behave both in feel and when they let go. Both cheap and expensive alcohol gets you drunk but they are not necessarily the same experience.

Petrus

#33
Quote from: Dev on September 30, 2022, 17:36From what I read from a performance book long ago is the real differentiation between budget and top tier tires is not the grip. Its the way they behave both in feel and when they let go. Both cheap and expensive alcohol gets you drunk but they are not necessarily the same experience.

Dunno how long ago it was Dev but wubbah compounds have made progress in great leaps and bounds. Currently a bit retrograde in the limits of traction because of eco stickers but overall still developing.

Nevertheless I agree. A key difference is predictability. Imo that is thé most outstanding quality of the AD08R(S).
So, a great investment today  :))



Gibla

#34
Not strictly 'on-point' here https://www.topgear.com/car-news/opinion/opinion-are-we-overthinking-car-buying

but does tell an interesting tale.

Back to something of more relevance here  ;)

I have been selling sets of wheels and just happened to have to temporarily fit some 215/45/16 (Hankook 125's) Front and Rear

Went out in the car yesterday with very low expectations of what it would be like, other than a very vague floaty sensation at the front at quite high speeds it was surprisingly good with loads of grip,retaining the typically pointy darty MR2 steering sensation.

I will undoubtedly end up with 195/55/16 on the front with 215/45/16 at the rear (even though it's an MR-S, thus maybe may lose a tad of initial acceleration)but am quite sure this will give me a decent result, even if its counter to perceived wisdom.

Why would I choose to do this? < using up the 'stuff' I already have, and not blow yet more £$ on either wheels or tyres
stock 2001 Dark Green MR-S (6R4)
stock 2004 Black - repurchased from guy who bought yellow 'un
stock 2000 Light Green(Cape Green)

Petrus

The 195/55-16 and 215/45-16 will probably rub rather annoyingly. I managed to rub even the OEM 185/55-15 and 205/50-15 when really pushing the AD08Rs through an undulating bend. And mind that is with a 150 kg lighter car!

Gibla

#36
Quote from: Petrus on October  3, 2022, 16:35The 195/55-16 and 215/45-16 will probably rub rather annoyingly. I managed to rub even the OEM 185/55-15 and 205/50-15 when really pushing the AD08Rs through an undulating bend. And mind that is with a 150 kg lighter car!

Come to think of it,there are 2 local left-hand bends that I do manage that, there was me thinking it was purely down to 'tubby' sitting in the driver's seat.

What would be your suggested solution, other than the driver going on a crash diet  ;D ?

I wish to stick with 16's , and my MR-S is maybe not 150kg heavier.
stock 2001 Dark Green MR-S (6R4)
stock 2004 Black - repurchased from guy who bought yellow 'un
stock 2000 Light Green(Cape Green)

Joesson

Quote from: Gibla on October  3, 2022, 17:04Come to think of it,there are 2 local left-hand bends that I do manage that, there was me thinking it was purely down to 'tubby' sitting in the driver's seat.

What would be your suggested solution, other than the driver going on a crash diet  ;D ?

I wish to stick with 16's , and my MR-S is maybe not 150kg heavier.


Iirc @StuC ran 16's all around, maybe he will see this and comment. Otherwise @Topdownman I believe has rolled his arches (hopefully recovered by now) for a similar purpose.

Gibla

These are high-speed left-hand bends I refer to ^^ ie 75mph + and perfectly possible to take a slightly wider smoother line + be unaffected. Asking what isn't meant to be a dozy ? would a tad more or less pressure into the rears help? (only the drivers side rear seems to ever give this sensation)
stock 2001 Dark Green MR-S (6R4)
stock 2004 Black - repurchased from guy who bought yellow 'un
stock 2000 Light Green(Cape Green)

Petrus

#39
Quote from: Gibla on October  3, 2022, 17:04Come to think of it,there are 2 local left-hand bends that I do manage that, there was me thinking it was purely down to 'tubby' sitting in the driver's seat.

What would be your suggested solution, other than the driver going on a crash diet  ;D ?

I wish to stick with 16's , and my MR-S is maybe not 150kg heavier.

Apart from the suggested rolling, nothing to it if you want those tyres/rims but to ignore it. The plastic will wear down a bit so rub less but still rub.

And concerning weight the easiest is driving with the minimum of fuel; like (try) drive on the lower half of the scale instead of the upper; 20 kilos that for free and no diet  ;D


p.s. when I replace them will go to 195/50-15  for less rubbing, stiffer sidewall instead of the current 55 hight. I have 195 because it understeers just that bit less than 185.

StuC

Quote from: Joesson on October  3, 2022, 17:14Iirc @StuC ran 16's all around, maybe he will see this and comment. Otherwise @Topdownman I believe has rolled his arches (hopefully recovered by now) for a similar purpose.

Banana runs 17" all round. Which is not to most people's liking.
I am happy with how my car runs though. Think she looks pretty cool too. Especially now she is lowered.
I am sure I have a piccy somewhere!  8)
URBAN CUSTARD COLLECTIVE FOUNDING MEMBER

Petrus

Quote from: StuC on October  4, 2022, 23:00Banana runs 17" all round. Which is not to most people's liking.
I am happy with how my car runs though. Think she looks pretty cool too. Especially now she is lowered.
I am sure I have a piccy somewhere!  8)

It´s your car so your choice. You like it so all well!

17" are significantly heavier though. Other aspects apart it will need more damping for same roadholding.
Apart from looks the larger diameter only has one technical benefit; space for larger discs. This is the main reason for the marketing of them; because cars have become increasingly heavy.
This is why it has been forced upon F1; the marketing of larger diameter rims as something desirable.

If maintaining the same circumference it means a significantly lower sidewall, most likely less conforming.
Lowering means less wheel travel, demanding stiffer springs.

I remember that Adam went for 13¨ rims and smaller overall circumference on track for a handful of sound technical reasons.

Petrus

Right, went up many bends up to 2.650 metres altitude and down again a different route with may móre.
The used AD08Rs up front have less grip than the scrubbed new AD08RSs at the back.