Go less low profile, will it help?

Go less low profile, will it help?

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70proof

Original Poster:

6,045 posts

154 months

Sunday 19th February 2012
quotequote all
Mate has a supercharged cooper s, loves the car but hates the ride...... We have worked out that switching to non rf tyres will improve things, but I also suggested buying 205/50 rather than 205/45 given he is having to buy new rubber... Will this help also? I have checked the rolling radius and the diff is not significant, 1mph.....

Ps. I specced a my011 c s with sports suspension and 16s.. And I am well happy

Miglia 888

1,002 posts

146 months

Monday 20th February 2012
quotequote all
Yep - ditching the runflats will transform the ride and also improve the grip & roadholding too, as the tyres will stay in contact with the road more often, instead of skipping from bump to bump like the ultra-stiff sidewalled runflats do. Horrible things.

Upping the profile will also improve the ride a bit more too. Just ensure both the speed and load rating are correct - check the tyre pressure chart sticker inside the drivers door.

Switching to 16's would indeed improve things further too.

I'm a former MINI racer and love a pointy car, but I also like a good ride for the other 99.9% of the time when not doing trackdays, so no prizes for guessing what wheels & tyres are on both our road MINI's...

Check out these other relevant threads for more useful info:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Edited by Miglia 888 on Monday 20th February 08:34

70proof

Original Poster:

6,045 posts

154 months

Monday 20th February 2012
quotequote all
thanks mate for that..... can you quantify the gains in ride....

ie will max benefit be from ditching run flats, and what will be the extra from going to 16's.... mate is trying to keep costs down as wife has recently lost her job...

nickfrog

20,874 posts

216 months

Monday 20th February 2012
quotequote all
If you give the ride 3 out 10 for compliance on RFTs, ditching them will get you to 7 out of 10. Massive improvement and that's not even talking about the grip benefits highlighted, as the car won't mind the bumps anymore.

I wouldn't change the "official" tyre profile as you would have to tell the insurance etc etc and the gain might be very small compared to the gain above, maybe just up to 7.5 out of 10.

Edited by nickfrog on Monday 20th February 10:51

70proof

Original Poster:

6,045 posts

154 months

Monday 20th February 2012
quotequote all
thumbup thanks guys...

Onedesi

91 posts

145 months

Monday 20th February 2012
quotequote all
After many years of lurking here I've finally signed up and thanks to 70proof for asking on my behalf smile

Could I ask one more question - we have the 17" bullet alloys and the debate is do we go to 205 50 17 even though they are not on the official mini approved tyre list for 17's ( the next recommended size is 215 40 17).

We were toying with going 16" but the look of the car is compromised.

nickfrog

20,874 posts

216 months

Monday 20th February 2012
quotequote all
Neither 215 in 40% nor 205 in 50% are the official size and are on both sides of the official size in terms of compliance so it doesn't really make sense to hesitate between the two when the official size is in-between and it won't make enough of a difference to justify having non-std size IMO.

Onedesi

91 posts

145 months

Monday 20th February 2012
quotequote all
NICK - just so I'm surer understand your post, are you saying that if I just went for non run flats 205 45 17 I would get the improvement from 3/10 to 7/10 as if so I'm sold smile

I'm happy to confess I have no understanding of tyre sizes LOL but staying with 17's appeases the other half and my pocket.

I'm more confused by statements like "2nd gen run flats are as good as non run flats".

As I said, I'm trying to get th biggest improvement in ride with the minimal fuss - road noise is intrusive.

nickfrog

20,874 posts

216 months

Monday 20th February 2012
quotequote all
Onedesi, yes I am saying exactly that, having just ditched my Conti SC3 Runflats 205 45 17 on a R56 2008 Cooper S for the same size Conti SC3 non-RFT (but amusingly, still BMW/Mini approved with the little star logo).

Benefits so far:

1 - much quieter ride.
2 - Less vibrations and less dashboard rattles.
3 - More grip as the wheels can now cope with bumps under lateral load and stay in contact with the road, even at the back !
4 - Much less crashy ride.
5 - Better traction and less torque steer.

Steering feel is different and some might feel a tiny loss in turn-in sharpness but that's a very small loss compared to the otherwise HUGE gain in handling.




SLacKer

2,622 posts

206 months

Tuesday 21st February 2012
quotequote all
I have to agree with the 3/10 and 7/10. The change to same size non runflats made the car so much more usable as an everyday car and grip has improved. Ditch them for same size and also don't forget the repair kit, I went for the Slime kit from amazon


Onedesi

91 posts

145 months

Tuesday 21st February 2012
quotequote all
Thanks slacker - I'm really encouraged by the relative improvement you guys say - going from 3 to 7 sounds like a revolutionary change smile

I will hopefully have something to report back on Friday wink

JD

2,769 posts

227 months

Wednesday 22nd February 2012
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My S is currently running on 60 profile 15"s and I still think the ride is crashy!

Onedesi

91 posts

145 months

Wednesday 22nd February 2012
quotequote all
JD said:
My S is currently running on 60 profile 15"s and I still think the ride is crashy!
eek

Now you've gone and scared me !

Have you had any experience of other mini's

Miglia 888

1,002 posts

146 months

Thursday 23rd February 2012
quotequote all
Our std suspension R55 is running on 65 profile 15"s, and rides like a limo in back to back comparison with the horrible, crashy, noisy, tramlining, skitting, zero bump absorbtion, 45 profile 17" runflats fitted to the R55 loan car we just had.

Onedesi

91 posts

145 months

Sunday 18th March 2012
quotequote all
We've had a bit of a hiccup but are now back on track to change tyres or tyres and alloys.

Just before (hopefully) I put my money down does anybody know if going to 16" alloys from the current 17"s will improve things further?

I'm thinking if going to 17" non run flats turns a 3 out of 10 to a 7 out of 10 then would going to 16" non run flats turn it into a 9 out of 10 or is that asking too much?

sad61t

1,100 posts

209 months

Monday 19th March 2012
quotequote all
Hi Onedesi,

I have driven R56 (post the supercharger) models on 15, 16 RF, 17 RF & NRF.

The 15" are comfortable but lose a lot of turn-in. Very good for winter tyres (for me, it handles better on 15" steel winters than the 15" alloy EcoContacts). The narrow section means that the MPG is close to official values too.

The 16" RFs were OK (but note the R56 chassis is tuned for a more compliant ride than the supercharged models).

The 17" RFs tramlined like crazy, a very fidgety ride on all but the smoothest road.
The 17" NRFs were grippy and predictable, massive improvement over the RFs. Still thumped over bumps (there's no disguising the overall weight) but less intruded into the cabin via the bum and hand contact points.

The conclusion I remember from threads some years ago was that 16" RFs or 17" NRFs were the sweetspot between ride comfort and handling.

It's also worth finding out if he has the sports suspension option. This was known to be seriously harsh and only worth speccing if you were a track day enthusiast. In a money-no-option world I'd spec Schnitzer suspension (lower but more compliant than sports springs), a Forge front strut brace (to minimise the flex across the dashboard) and 17" NRF tyres. This keeps the car flat through corners for better turn-in and grip while making it a more pleasant ride day to day. Of course, others' opinions will differ, hence the wide range of tuning options available.

Finally, the 16" wheels will not fit an S with the larger JCW brakes; so if you have (or are thinking of) a brake upgrade then stick with the 17" wheels.

Onedesi

91 posts

145 months

Monday 19th March 2012
quotequote all
Thanks Sad6it for the thorough response (I daren't ask how youve driven so many of them but I'm glad you have smile).

The r53 we have does have sports suspension and we are the 2nd owners of the car so not really a choice we had.

I think you've helped me come full circle and stick with the 17"s and go non run flat as we can always refurb the 17"s to white later.

The r56 probably irons out the quirks of the r53 and we did think about getting one but as my wife puts it - the r53 is cuter LOL

Hopefully it will get sorted this week!

JD

2,769 posts

227 months

Wednesday 21st March 2012
quotequote all
I wouldn't be surprised if part of the problem is the original wheels, if you have ever taken them off, you will see they seem to weigh as much as a small moon!

I'd like to test mine on some light wheels withot run flats, I'm betting the improvement would be massive, but I think I'll just sell the car instead!

Onedesi

91 posts

145 months

Wednesday 21st March 2012
quotequote all
Never taken the wheels off so it's a good point you raise.

We've finally decided to keep the car (it's seems to get under the skin unlike no other car we've owned - probably misguided loyalty) but I don't plan to put too much money into it.

Im taking heart from the relative improvement indicated in an earlier post, ultimately the mini will always be a go kart for the road so I think I understand it will never be an S class for comfort - I just like me teeth in my mouth and not rattling around the footwell LOL

Stedman

7,213 posts

191 months

Wednesday 21st March 2012
quotequote all
I have no mini experience, but going from 205/45 to 215/45s had no real disadvantages. Car had more lateral grip and was more comfortable. Maybe he needs to do that but keep to stiffer side walled tyres to keep decent turn in. The stiffer walled 215s would surely be a good compromise?