staggered wheels vs same all round

Discussion in 'Non Technical' started by BLACK BEAST, Dec 5, 2010.

  1. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    Been looking into wheel sizes for the track.

    Have been getting conflicting answers .

    instead of running the usual
    10.5 with 295
    9.5 with 265 ..

    I cant see a problem with 10.5 with 285 all round .

    PROS
    1/The Z32 (both 2+2 and 2+0) suffers from slight understeer so the bigger on front will work well


    2/good to rotate wheels front to back


    CONS
    1/ a little more unsprung weight



    anyone can shed some light on this... V8 SUPERCARS run 11 all round
     
  2. AndyMac

    AndyMac Better than you

    I'm not sure on the exact physics of it all, but in most forms of competitive motorsport with front engined cars, they tend to run same all round due to the tendency to understeer. Like the V8's, also back in nations cup days, the vipers ran 305's all round, USA GT championships the astons and vettes all run the same all round (i was watching the pit lane discussions during lemans).

    Rear engined cars in those catagories, like the GT3's the Fezza's, lambo's, etc all seemed to run larger on the rears.



    I'll be trialing 275 all round on 10" next year, it also makes it more cost effective to be able to switch rubber around.


     
  3. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    thats exactly what I have come up with ,reason why I believe the same all round is better for our cars
     
  4. Wizard

    Wizard Kerb side Prophet

    I run

    Staggered, 245 front and 285 rear on the track, and never had any understeer issues yet, some oversteer, but thats just comming into the corner to hot.
    I'm happy with my set up as it goes pretty much where i point it, when the Rubber wears out just buy some new ones.:)
     
  5. rob260

    rob260 Administrator Staff Member

    Hey Wiz what offsets are your track rims? I am running 245s on the front and they scrub on full lock. Fitted a set of 5mm spacers last weekend (had them laying around from a previous set of rims) and it's better, but not fixed.
     
  6. Wizard

    Wizard Kerb side Prophet

    + 38

    Rob, where are they scrubbing? not a fan of spacers.
    Also not a fan of swapping wheels front to back as they will have different wear characteristics due to camber, toe, etc.
    which will give you a completely different footprint front to back and mess up your handling at the track.:)

     
  7. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    thats a good point too.
     
  8. rob260

    rob260 Administrator Staff Member

    Thanks Wiz, mine are +30 maybe that is the problem? Not sure where exactly, they don't seem to scrub when the car is on stands, only when under compression.
     
  9. Wizard

    Wizard Kerb side Prophet

    Welcome to

    Try mine, might need to raise it up a touch Rob.:)

     
  10. revhead

    revhead New Member

    generally a wider back wheel is only that ,if you fit wider offset,it means there more weight away from the bearing instead of directly over the bearing thats it,bearings tend to get hotter as load is out n away from them and they will wear out fast,,but you could get rims with the same inner and outter offset no probs then
     
  11. Tektrader

    Tektrader Z32 Hoe, service me baby

    I am going to run 245 18 inch slicks all around on the track car. Zeds have a lighter rear end and therefore have a tendancy toward understeer.

    Putting a narrower tyre on the back can tend to counteract that somewhat but inserting a a small amount of oversteer.

    245 slicks are very grippy tyres, so not an issue with putting power down.
     
  12. UNIQUE ZED

    UNIQUE ZED Zed Racing World

    Wheels sizes

    V8 Supercars are regulated and rears are under tyred.
    I have been running 18's with 10.5 rear with 295 and 9.5 front with 265. Thinking of going 10.5 front 285 or 295 and 12 rear with 335, which will fit with wide body kit we are working on. Even considering 17 's on rear for more sidewall, but I don't know who makes strong light wheels in 17 x 12?

    On rear wheel drive front engine you should always run wider rear. Otherwise over tyred in front which means tyre temps will be less than rear, or take longer to get up to temp for sprints. SO less grip. Also car has to turn excess weight and suspension carries more weight than required.
    Also you should run a wider front wheel track.
     
  13. mungyz

    mungyz Well-Known Member

    I'm running 8.5" wide front wheels with 235 tyres, 9.5" rear wheels with 275 tyres

    In my opinion that seems to work pretty well, I could do with 245 on the front perhaps but generally it is very well balanced (two seater remember) it will under steer if you don't drive it well but then it will over steer just as easily.

    I can make small changes in the camber on the front to adjust the tendencies one way or the other but generally with it the way it is now it's very predictable - almost boring in fact as the car seems to have way more ability than the tires at present.

    Tyres are down to .4mm left until not road legal so will hunt down some better rubber for next time :)
     
  14. MrTwinTurbo

    MrTwinTurbo Account Disabled

    no - you covered pretty much all of it

    I think you covered it all mate with the pros cons included
    As you rightly pointed out the V8s run 11s all round - cant be too much of a problem with it
     
  15. Benny_C

    Benny_C About as subtle as...

  16. mungyz

    mungyz Well-Known Member

    Can I flame him please guys!?

    How far can I go before I get in to trouble?

    New forum rule: NO IDJIOTS IN MOTOR SPORT SECTION!!!!
     
  17. heavytrevy

    heavytrevy "Hammer time "

    Fleet had 305 slicks on the rear and at times it wasnt enough grip.
    Ive got footage of him frying the rears at over 140klm on a sweeping corner and totally losing it .
    If your running over 400rwk you need all the tyre you can get.
     
  18. AndyMac

    AndyMac Better than you

    Tyres will only ever give you so much grip, there's also mechanical grip as well. The ideal width of tyre isn't all to do with HP, weight is a significant player in tyre selection as well.
     
  19. UNIQUE ZED

    UNIQUE ZED Zed Racing World

    Forget V8 Supercars being same front and rear. THEY ARE REGULATED AND RUN CONTROL TYRES. You can't even buy used V8 Supercar tyres. If they could they would flare the guards and run wider rear and would be faster. Anyone notice they change rear tyres much more often than front. Like many teams did last weekend in Sydney.

    It is all about weight verses grip verses tyre temps and thus grip. If you ran equal wheel and tyre size front and rear on a zed I highly suspect front tyres would not get up to temp across the tyre enough compared to rear. This means less grip as ideally slicks and semi slicks have an ideal temp for grip which is around 75C. More than this less grip less than this is less grip, generally speaking. Then factor in if too big and what is termed being over tyred, the car has to turn excessive weight and the steering and suspension also carries excessive weight, as well as more friction slowing the car down. The other factors to consider is power, weight, weight distribution and aero.
    Also keep in mind, " Good is the enemy of better" If you ran same wheel and tyre size front and rear, yet say both larger than you had, you might go faster. However if you then ran smaller front but still wider rear than you had, you might go faster again. Checking tyre temps is a good indicator plus checking lap times and comparing.
     
  20. heavytrevy

    heavytrevy "Hammer time "

    I can comfirm that a staggered setup on fleets Zed gave pretty consistent temps front to rear.
    On another note Fleet needed more neg camber than midori style arms provided,(temps across the front not quite even.)

    best bet is to get a set of JP's race camber arms to wind on more than 3.5 deg neg camber.



     

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