03 Track Model Wheel Question
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Originally Posted by streetracer
Interestingly enough, in the zenophile reading, no one uses wider than 265.
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Originally Posted by Alberto
Run 245/40 in front and 265/40 in rear. Looks and handles amazing, no pudging!
+1
I run a 245/40 in the front and a 275/40 in the rear and I would say the 275 is just a tad too big. You end up getting noticable sidewall flex that makes for a pretty bumpy ride. On the next set I will be going with a 265/40 and I suspect it will be just about perfect. This is with the BFG TA\KD by the way...
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Originally Posted by ANXIOUZ
Because you can rotate all 4 of them if they start to wear unevenly or something. That'll get you a few extra miles of use. With a staggered setup you can't = buy new tires instead of rotating them.
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Unsprung weight is definately a huge factor with regards to the performance of the suspension, but on the track model the car has 18 inch rims stock and the OEM Volks are actually pretty light. With that in mind using the stock track rims with a proper tire should be great for most track aplications. The problem is what is the best set up for the rims.
There are two schools it seems:
Wide rim narrow tire for sidewall strength.
Like 225 tires on an 8 inch rim
Wide rubber equals more traction, but sidewall strength is sacrificed.
245 tires on 8 inch rim
Does anyone know if going with a 245 30 profile tire instead of 40 would enhance the sidewall strength to get the best of both worlds? Also this would make the overall tire hight lower so I have no idea what the implications would be on the Speedometer although I guess you would get a fraction better accelaration out of it?
Does the 350z speedometer react to different tire sizes or does it adjust?
There are two schools it seems:
Wide rim narrow tire for sidewall strength.
Like 225 tires on an 8 inch rim
Wide rubber equals more traction, but sidewall strength is sacrificed.
245 tires on 8 inch rim
Does anyone know if going with a 245 30 profile tire instead of 40 would enhance the sidewall strength to get the best of both worlds? Also this would make the overall tire hight lower so I have no idea what the implications would be on the Speedometer although I guess you would get a fraction better accelaration out of it?
Does the 350z speedometer react to different tire sizes or does it adjust?
#49
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Originally Posted by 350Zenophile
guitman32 give us an update mang! How you likin the new rubber?
To reiterate, my sizes are 245/40/18 in the front and 255/40/18 in the rear on factory 03-05 track Rays (8in front, 8.5in rear). Pics are on page 1. The balance of the new setup coming from 225 fronts and 255 rears is more neutral (obviously). The sidewalls, however, are a bit less responsive than the Potenzas in 225 (Front) and the Pilot Sports in 255 (rear). I think this is a result of two things:
1. The increase in sidewall flex under hard cornering due to more sidewall bulge of wider tires
2. The Azenis sidewalls aren’t the stiffest
That being said, I think this has an almost negligible effect on the handling of the car. To elaborate, the reduction in responsiveness due to the above reasons is more than offset by the increase in grip (attributed to the tires - these Azenis grip like crazy...really night and day from any other street tire ive driven) and the improved balance from the wider front track.
For the event, I left my sway settings unchanged and only played with tire pressures as I ran throughout the day. I noticed that I can take slaloms a bit faster (car rotates better) and also in long sweepers (there was a wide U designed into the course - really comparable to a track turn - almost) the front end really turns better.
In summary, I think the net effect of the wider front tires is a slight decrease in responsiveness and a greater increase in positive handling characteristics (realized in the form of less understeer and more car rotation).
Cheers.
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I run 255/35/18 and 265/35/18. This low of an aspect ratio makes the car feel every little road imperfection and the car is noisier. The car feels very rough with the 03 hard suspension and this small aspect ratio. However, the grip in the twisty roads is definitely increased by a good margin. You feel the car letting go when the rear begins to slide a little. The turn in is way more sharp and the understeering characteristics of the vehicle are diminished. The cars also has better dive in braking and it sits lower to the ground. Is like it has sport springs. I don’t like that the wheel gap is increased between the tire and the fender. It makes the car look toyish and wheels look disproportionate relative to the car. The overall diameter is decreased by about half an inch. So acceleration is noticeable faster although traction is an issue. First gear looses traction even if the clutch is rolled. At 4000 RPM if you go WOT, traction is lost. Second gear has to be pressed gently to keep traction and as RPM fly by open it up completely. There is no noticeable difference in the reading of gauges, but I have noticed that the car revs faster due to smaller wheels.
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Hmm that is interesting. That way you can go witha wider tire but still keep your sidewall strength, at least I assume you get more sidewall stiffness with a lower profile tire.
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Yes. But you'll need sport springs to compensate for the increased wheel gap. If the streets were you live are ok, then I say do it. If they are f*uked up, don't.
Last edited by streetracer; 12-12-2006 at 10:50 AM.
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Originally Posted by 350Zenophile
Thanks Guitman32, very helpful review.
However, don't the RT615s have stiffer sidewalls than your average high performance summer tire?
Also, what do you have you sways set at currently?
However, don't the RT615s have stiffer sidewalls than your average high performance summer tire?
Also, what do you have you sways set at currently?
I have the Hotckis sways set at 3 (3rd hole from full soft in the front (I have the newer 4-way) and at medium in the rear (middle hole - 3-way). I might be able to get away with full stiff in the rear, but right now the car is balanced nicely and is somewhat forgiving to brutish inputs.
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Originally Posted by DavesZ#3
guitman32:
Do you run that setup on the street too or is that strictly an autocross setup?
If autocross only - why not run the same size on all four?
Do you run that setup on the street too or is that strictly an autocross setup?
If autocross only - why not run the same size on all four?