Road noise

[Stivino]

2 hours ago, APS said:

😉 80% - it is often not explicitly stated. i.e. if it says 185R14 on a tyre then 80 (185/80R14) is implied. 

I've always known that and, thought everyone else did, too.

I thought you were going to reveal some inside knowledge. 😀

[Cyker]

3 hours ago, APS said:

😉 80% - it is often not explicitly stated. i.e. if it says 185R14 on a tyre then 80 (185/80R14) is implied. 

Well I didn't know what that was - Never heard that term before!

And no wonder - Flippin' heck, 80 profile tyres?! That's too extreme even for me!!  

I'd expect that on a 4x4 or something!!  

 

re. rims, assuming the overall tyre size is the same, there are pros and cons.

Main benefits of bigger rims/lower profile tyres are they give more direct handling feel and responsive steering input, and the ability to use larger brake discs. They also tend to be more stable - Less unwanted movement. Some people also think they look better (Not me ).

Smaller rims/higher profile are lighter so acceleration and braking is slightly improved as they require less energy to change momentum. They also have less tendency to break traction as a sudden steering input will be absorbed by the sidewall flex, giving the rubber more time to flex and grip, whereas with a low-profile tyre the input will be much more direct, and without the ability to flex as much it will be easier to make it break traction. A professional driver will prefer this as they can control the car more precisely, but a normal driver panic steering to e.g. avoid a moose will have a higher likelihood of triggering understeer with a low profile tyre than a higher profile tyre.

That extra sidewall also provides more of a cushioning effect, which can improve ride comfort, although this can be undesirable if trying to tune suspension and shocks precisely. However, that is also why feedback and steering inputs feel more dulled with high profile tyres vs low.

And this is without getting into wider vs narrower rims - Larger rims tend to be wider, which has its own set of pros and cons...!

[RobertR]

19 hours ago, Yugguy1970 said:

Performance cars have rubber band thin tyres because the car buying public expects them to, as thinner is faster right? 😀

No, they are much stable on high speeds, that's why.

 

18 hours ago, TonyHSD said:

You probably got me wrong on that. I am not comparing an  f1 to a standard tyres, just an example of pure physics. Low profile tyres loose grip by much in all surfaces. I have a direct comparison with my car and with previously owned cars. If you take two same cars with same width tyres one on lower profile tyres and one on higher the later will have better performance. No argument, just something that its a fact and many people doesn’t know and believe the other way around. The lower profile tyres are only good for Tokyo drifters as it’s way easier to drift with them. Perhaps if you speak to a rally drivers or teachers they will confirm that. There did the sweet spot you need to look for and for your cars perhaps it’s the middle 17” wheels set up. 

Well, what are you considering a low-profile tyre? because mine 215/50R18 has 107mm sidewall thickness. That exactly the same as BTCC used on daily basis, do you consider they use the wrong rubbers? Yes, yaris cross on these is on the hard side but still for me an acceptable rate.(advantage for me is handling and look) In general, for people who don't care, R17 or R16 will be a better option.

It's the whole science about this, you can't generalize a side wall thickness as the only parameter for vehicle response. I just don't agree on this with you that standard street-legal balloon tyres have better handling and traction. Do you really think every tyre manufacturer and every hot hatch cars manufacturer put high-performance street legal tyres (usually very low wide wall profile) only because the "people" expect to be big rims with electric tape on it? 😄 and don't regard any other parameters. Also, performance shocks are very hard because you don't want any un-dampened mass(balloon tyre is a big un-spring element).

[corradovr6]

19 hours ago, Yugguy1970 said:

Performance cars have rubber band thin tyres because the car buying public expects them to, as thinner is faster right? 😀

That's also partly true, but lower profile tyres have less sidewall flex and thus a more precise turn-in. This in turn means the car is more precise to drive especially in twisty turns.  The payoff though is a harder ride, and, if lightweight wheels aren't used, a longer wheel spool-up and higher corner weight

I think it really depends on use preference 

[Yugguy1970]

Indeed.  My use case, and many people's these days, is comfort and reliability.  The RAV can take corners as fast as I ever want to and feels stable at whatever speed I'm doing.  I've had it at 100 leptons per hour, on a private road of course, and it felt solid.

I also don't get my spine rammed through the roof of my mouth on every journey.  British roads are horrendous, who wants rock hard suspension and tyres outside of a mirror smooth track?

 

[PMW]

On 3/19/2023 at 1:21 PM, anchorman said:

Others have fitted smaller wheels and high profile tyres.  I’m very satisfied with the ride on my 18 inch wheels - perfect I would say but I soon worked out that none and I mean none of the panels have sound deadening.  I’ve done mine and it has transformed it.  The only panels I haven’t done are the floor.  In summer I’ll have the underside panels off and do the floor at the same time.  I’m just giving you something else to consider.  If you get to Derbyshire any time you’re welcome to ride in it.   

@anchorman: Can I please ask what type of sound deadening you have gone for and how straightforward or complicated was the installation process? Thank you!

[Cyker]

8 hours ago, RobertR said:

Well, what are you considering a low-profile tyre?

That's a good question actually... is there an official number for this?

I've mostly just gauge it on how it looks (Rubberband vs F1/4x4/Bus/Coach/HGV tyre  ), which generally worked out to anything less than 50 to be low profile and anything 60 or above to be high profile.

 

[Stivino]

10 hours ago, RobertR said:

Well, what are you considering a low-profile tyre?

Anything with a profile less than 80% of the width.

[anchorman]

9 hours ago, PMW said:

@anchorman: Can I please ask what type of sound deadening you have gone for and how straightforward or complicated was the installation process? Thank you!

Yes, I used Dodo Mat which is easy to apply if you’re ok removing panels etc.   

[Yugguy1970]

I like that, there's fair bit of noise from the RAV boot too.  Tempted to have a go at that myself.

I'm finding Toyota trim quite easy to work, well thought out without any gotchas.

Had to replace inner rear tail light unit as someone had cracked it for me, and I had the whole boot lid and strut lining off quite easily.  

I'm pondering upgrading the rear Speakers as they are pitiful but I've always found doors to be quite problematic so not sure about that one, would want to watch a few youtube videos first.

[anchorman]

27 minutes ago, Yugguy1970 said:

I like that, there's fair bit of noise from the RAV boot too.  Tempted to have a go at that myself.

I'm finding Toyota trim quite easy to work, well thought out without any gotchas.

Had to replace inner rear tail light unit as someone had cracked it for me, and I had the whole boot lid and strut lining off quite easily.  

I'm pondering upgrading the rear speakers as they are pitiful but I've always found doors to be quite problematic so not sure about that one, would want to watch a few youtube videos first.

Let me know about the Speakers pls.  I’ve pondered changing mine because the magnets are tiny but somebody said they’re a something or other cone which doesn’t need a big magnet.   I can turn mine right up and they don’t distort and they have reasonable bass.  The only vids I’ve seen are selling Speakers so they’re bound to say it’s worth it.  

[Roy124]

Potholes, what potholes?

Where I drive there are very few potholes.  I like to think this is because I report many, I highlight the safety aspects, and as a regular poster I hope they repair them to shut me up.

On the roads I do not use frequently I do find more potholes.

Use Fix My Street.

[corradovr6]

with products like dodomat etc these just reduce panel vibration.  You only really need around 25% coverage of the panel.  Sound absorbers and blockers are also useful to have, but the sequence of installation is also quite important, viz: vibration damper on outer skin, closed cell isolating layer, mass loaded layer, open cell absorbent layer.  I put some points up a while back, but not sure where!  I'll dig them out again, hopefully might be of use to anyone looking at improving NVH.

[anchorman]

17 hours ago, corradovr6 said:

with products like dodomat etc these just reduce panel vibration.  You only really need around 25% coverage of the panel.  Sound absorbers and blockers are also useful to have, but the sequence of installation is also quite important, viz: vibration damper on outer skin, closed cell isolating layer, mass loaded layer, open cell absorbent layer.  I put some points up a while back, but not sure where!  I'll dig them out again, hopefully might be of use to anyone looking at improving NVH.

I also bought a roll of Dodo Mat which is really an insulator but I’ve back filled voids with it after fitting the deadening mats.  It’s quite a tangible improvement.   

[Tel 2]

Remember to Set your Tyre Pressures too as a 10 degree rise in ambient temperature will raise pressure by a couple of degrees.

Tel