Jump to content
SAU Community

Recommended Posts

mythbusters isnt needed dude. some common sense and thought is all that is needed :P

the inner and outer circumference cant be changed. the inside being the rim size, ie 18". no matter how wide that rim is (within reason) its always 18"

the outside, the rolling diameter also remans the same because only the sidewall angle changes. it doesnt get longer, or shorter.

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967232
Share on other sites

  • Replies 49
  • Created
  • Last Reply

Top Posters In This Topic

mythbusters isnt needed dude. some common sense and thought is all that is needed :P

the inner and outer circumference cant be changed. the inside being the rim size, ie 18". no matter how wide that rim is (within reason) its always 18"

the outside, the rolling diameter also remans the same because only the sidewall angle changes. it doesnt get longer, or shorter.

ahhhh lol but thats why the rolling diameter DOES change!

i give up. you win by default lol

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967240
Share on other sites

i dont want to win im trying to explain how it doesnt change

its also steel belted so it cant change.

only the sidewall angle can change to suit the rim width, yes the sidewall will flex. but thats half the reason why the tyres are filled with air.

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967242
Share on other sites

something would have to change as you get some pretty big angles when stretching tyres (big angles for engineering are anything over 5°)

but you are correct, the cylinder that makes the tyre cannot get that much smaller (but the rubber is elastic so it can contract a little bit)

so the sidewalls must either get dragged inwards on the rim or stretch a little

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967248
Share on other sites

i dont want to win im trying to explain how it doesnt change

its also steel belted so it cant change.

only the sidewall angle can change to suit the rim width, yes the sidewall will flex. but thats half the reason why the tyres are filled with air.

based on the fact that the sidewall will physically stretch, and that rubber is softer that the steel belts, your right. makes sense now. if it was all rubber, physics simply wouldnt allow it.

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967250
Share on other sites

the sidewal is designed to flex and distort. its normal for a tyre to do that (within reason) but when you stretch them, youre not allowing much movement. thus the tyre is 'firmer' and doesnt allow it to..... squirm?

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967640
Share on other sites

i know im goin to get flamed to death for saying it, but IMHO the federal 595 is highly over rated on a daily drive car. they are great for a weekend warrior or if u do ALOT of hard cornering. but for the daily commute i'd suggest something thats a little better in the wet and maybe wears better. i also agree with the other guys a 245 is pretty narrow on a 9.5 inch rim. id be goin a 265 to protect the rim a little better.

I'll be flamed with you then. The wife had a big accident on Bells Line of Road going down into Lithgow on these. Conditions were wet. Now, not saying that it was entirely the tyres fault, thats impossible and stupid to even consider that. However, I believe tyres play a big part of the dynamics of a car. Needless to say, post accident, Pirelli tyres went on all 4 corners.

I wouldn't consider buying them again, but thats just my opinion/experience.

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5967693
Share on other sites

  • 2 weeks later...

mythbusters isnt needed dude. some common sense and thought is all that is needed :P

the inner and outer circumference cant be changed. the inside being the rim size, ie 18". no matter how wide that rim is (within reason) its always 18"

the outside, the rolling diameter also remans the same because only the sidewall angle changes. it doesnt get longer, or shorter.

i understand what your saying. but they are right. try it for yourself. head down the tyre shop with an 8inch and a 9inch rim and have 2 identicle tyres fitted and inflate them to the exact same pressure then messure the circumference. there will definately be a difference. it wont be much (0-5mm), but they will be different. you answered it yourself when u said:

"the sidewal is designed to flex and distort. its normal for a tyre to do that (within reason) but when you stretch them, youre not allowing much movement. thus the tyre is 'firmer' and doesnt allow it to..... squirm?"

the stretched tyre is under tesion and cant balloon out where as the unstretched tyre will. thus changing the circumference

Link to comment
https://www.sau.com.au/forums/topic/373541-tyres/page/3/#findComment-5988174
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Yeah the ACL and similar formable heat shielding materials are really nice. But most people do not have the patience or talent to do a good job like that. Almost anything is better than nothing though. Even if you didn't form it closely like that and just had a slab of it slipped in between the manifold and somewhere/thing you wanted to protect, you would gain benefit. There has to be a market opportunity for people like Artec to make formed heatshields to suit their cast manifolds. The fact that they are cast means that they are consistently the exact same dimensions and they could add bosses to the castings like you see on stockers to allow heat shields to be firmly attached yet floating away from the manifold itself.
    • I've seen some stuff like this as well, not sure if it's a good idea or anything but it does have more standoff from the piping than the conventional fiberglass wrap:  
    • Jap premium will be 100 RON. You should use 98.
    • The exhaust gases are at their highest temperature as they leave the exhaust port and enter the manifold. They cool as they flow through the manifold because they transfer heat to the manifold and the manifold loses heat to the surrounding environment. Thus, inevitably, the exhaust gases are cooler as they enter the turbo compared to when they entered the exhaust manifold. So, yes, the exhaust manifold can easily get as hot as the turbine housing. Having said that, you will generally see the highest temperatures where the exhaust gases have to slow down or they are concentrated into one area - which is usually the collector on the manifold and in the turbine housing, because the gases slam into the metal at those places, increasing the convective heat transfer coefficient and transferring even more heat to the metal than they might just flowing past elsewhere. Exhaust manifold heat shields are a good idea - certainly for the stock manifold they are there from the factory. People seldom have anything like that on a tubular manifold because they are hard to achieve. Some might wrap a tube manifold with fibreglass tape - but this has a reputation of leading to cracked welds. The best case is generally to put ceramic coating onto the manifold to prevent it getting as hot (internal coating) and radiating/convecting heat into the bay (external coating). All the real heat from a turbo comes from the exhaust side. The gases entering are at ~800-900°C and the steel/iron gets nearly that hot. The compressor side is only going to heat the charge air up to <<200°C (typically not much more than 100°C). So that's nothing, by comparison. The compressor is not a significant source of engine bay heat.
    • Late to the party, specifically joined this forum as I just bought one of these and this thread has been a gold mine of info. If the OP is still around, mind if I ask what gas you been putting in yours? Mine has a Japanese sticker in the cap saying premium but it seems to get way worse mileage on premium (95) than 91. I always thought it was meant to be the other way round🤷 I do think Nissans claimed "6l/100km" is a bit fantastical 😂
×
×
  • Create New...