Jump to content
SAU Community

Big in the rear but small in the front end?

monkeykplunk
 Share

Recommended Posts

monkeykplunk Mentor

monkeykplunk

Posted
Posted

Ok, so I need new tyres as the ones on the rear are pretty much at indicators on the inside of both tyres.

At the moment I'm running 255/40 17 on the rear and 235/45 17 on the front.

I've gotten some really good prices off people I know, but I thought I'd check em out against prices just over the phone with shops.

I got one old bloke who asks me why the hell I would want to run 255's with a 235 on the front.

He carried on for a while about how having such a large tyre on the rear will put more pressure on the front of the car and make things like the front suspension work harder and stuff it in the long run.

Then he tells me that I won't get any decent mileage out of any tyre anyway, so I may as well just buy cheap ones instead of spending my moeny on expensive things that won't be any better.

Whilst I ignored his banter at the time and wondered why he wouldn't just give me a price on what I asked for and take my money instead of talkign me out of something and into something cheaper, he got me thinking.....

Is there any truth to what he was saying about the front having to work harder and thus ****ing other things by having larger tyres on the rear?

Or was he just full of bullshit?

nmcmahon83 Proficient

nmcmahon83

Posted
Posted

wider rear tyre gives bigger contact patch = more grip at the rear... your car is RWD, so u need more grip at the rear when launching... If anything, I would have thought that a wider tyre would put more stress on components since there is a greater resistance to movement, so the shock goes through those parts that can move. eg... bigger rear tyre puts more stress through gearbox cos instead of just spinning, the tyre sticks and causes resistance against gearbox/diff...

as for the fronts... i cant see how turning with less resistence is going to stuff anything up in the long run... maybe if you had super wide tyres on the front there'd be more stress because instead of the tyres just scrubbing along (understeer) they are gripping and the suspension is left to disapate more of the energy... i dunno...

sounds like a retard to me.

inissane Proficient

inissane

Posted
Posted

there are bits of truths here and there but generally bs - just get some 245s on the back and u will be fine they will fit on sweet. The quality of the tyre you put on depends on ur driving habits etc and say what tyres you got on the front? std suspension? large wheels/tyres been put on skylines since blot, hes probably old school

you get what you pay for usually in terms of grip, a quality michelin tyre of 225 diameter would kill a 255 falken but you may wear it quicker and it not be worthwhile - depends

monkeykplunk Mentor

monkeykplunk

Posted
  • Author
Posted

yeah i figured it was mostly bs

I mean, the logical way of looking at it is that a wider tyre will give you a bigger area of rubber on the road and therefore improve the way in which the car contacts the road.

I spose the crucial thing is that you get a decent tread pattern with regard to water displacement when the tyre is that large, because some may be ineffective in channelling the water away from the centre of a wider tyre.

At the moment I'm running Kumho Supra 712's, and they're pretty good at that, but in my travels shopping around I've seen patterns that just wouldn't work on a wide tyre.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • MBS206
      NC MX5

      By MBS206 · Posted

      Have you not seen geospy.ai? It can now give GPS co ords to within a metre from a photo, even if it's a random photo you take inside. Supposedly at the moment only the government/law enforcement has access to that... Supposedly...
    • Komdotkom
      Crank Motorsports Front Axles

      By Komdotkom · Posted

      I've got the rear ones, they're certainly beefy. I need to take them to my driveshaft guru to check over, he's very fussy about the quality of components so I'll let you know if they are made of cheese by a blind man.   Are you in Australia? A mate just had a set of EN26 shafts made for his K20 Lotus by our fabricator which were quite cheap (compared to Driveshaft Shop) so if you can procure the CV's and draw what you need he'd make them for ~$800 for the pair.
    • Josh K.
      Crank Motorsports Front Axles

      By Josh K. · Posted

      Had I known the diff between R32 and R33 suspension I would have R33 suspension. That ship has sailed so I'm doing my best to replicate a drop spindle without spending $4k on a Billet one.
    • Josh K.
      Crank Motorsports Front Axles

      By Josh K. · Posted

      OEM suspension starts to bind as soon as the car gets away from stock height. I locked in the caster and camber before cutting off the kingpin. I then let the upright down in a natural (unbound) state before re-attaching it. Now it moves freely in bump and droop relative to the new ride height. My plan is to add GKTech arms before the car is finished so I can dial camber and caster further. It will be fine. This isn't rocket science. Caster looks good, camber is good, upper arm doesn't cause crazy gain and it is now closer to the stock angle and bump steer checks out. Send it.
    • GTSBoy
      Crank Motorsports Front Axles

      By GTSBoy · Posted

      Pay careful attention to the kinematics of that upper arm. The bloody things don't work properly even on a normal stock height R32. Nissan really screwed the pooch on that one. The fixes have included changing the hole locations on the bracket to change the angle of the inner pivot (which was fairly successful but usually makes it impossible to install or remove the arm without unbolting the bracket from the tower, which sucks) and various swivelling upper arm designs. ALL the swivelling upper arm designs that look like a capital I (with serifs) suck. All of them. Some of them are in fact terribly unsafe. Even the best one of them (the old UAS design) shat itself in short order on my car. The only upper arm that works as advertised and is pretty safe is the GKTech one. But it is high maintenance on a street car. I'm guessing that a 600HP car as (stupidly, IMO) low as you are going is not going to be a regular driver. So the maintenance issues on suspension parts are probably not going to be a problem. But you really must make sure that however your fairly drastically modded suspension ends up, that the upper arms swing through an arc that wants to keep the inner and outer bolts parallel. If the outer end travels through an arc that makes that end's bolt want to skew away from parallel with the inner bolt, you will build up enormous binding and compressing forces in the bushes, chew them out and hate life. The suspension compliance can actually be dominated by the bush binding, not the spring rate! It may be the case that even something like the GKTech arm won't work if your suspension kinematics become too weird, courtesy of all the cut and shut going on. Although you at least say there's no binding now, so maybe you're OK. Seeing as you're in the build phase, you could consider using R33/4 type upper arms (either that actual arm, OEM or aftermarket) or any similar wishbone designed to suit your available space, so alleviate the silliness of the R32 design. Then you can locate your inner pivots to provide the correct kinematics (camber gain on compression, etc).
×
×
  • Create New...