Can we fit hooter 255's up front?
10-03-2009, 05:14 PM
#18
Rennlist Member
Nothing to do. The 255 Hoosier is shorter in diameter compared to the 235 stock PS2 tire (15mm shorter diameter). The 255 goes on the stock 8.5" wheel, or wider if you run wider wheels.
Wheels up to 1" wider than stock can run the stock offsets. Beyond 1" wider wheels, you need to start playing with offset to avoid inner rub front (strut) and rear (trailing arm).
Shims in the control arm add caster, move the wheels forward and increase rub against the plastic liner). Lowering the car helps to eat the plastic liner as well. There are plenty of discussions in this forum about caster/camber and plastic liners and plastic rivets and upper brake ducts flying away.
Wheels up to 1" wider than stock can run the stock offsets. Beyond 1" wider wheels, you need to start playing with offset to avoid inner rub front (strut) and rear (trailing arm).
Shims in the control arm add caster, move the wheels forward and increase rub against the plastic liner). Lowering the car helps to eat the plastic liner as well. There are plenty of discussions in this forum about caster/camber and plastic liners and plastic rivets and upper brake ducts flying away.
10-06-2009, 12:41 PM
#21
Rennlist Member
Folks the 255/35 18 Hoosier is 24.8" diameter if you run a 315 o5 335/35 18 rear 25.6" diameter you are pushing the envelope @ .8" front to rear difference and can incur ABS issues, ie ice mode. Been there, done that, and got the T Shirt.
Peter
Peter
10-06-2009, 04:45 PM
#22
Three Wheelin'
Super super important to match front to rear sizes within .2 inches. If not, the ABS will NOT perform properly and you run the risk of the computer "crashing". If it does, which has happened to a few of us over the years, the ABS valve will be stuck in either open or closed for 1-2 seconds. You will have either wheel lock or no brakes for that period and there have been a few cars "lost" as a result.
10-06-2009, 10:28 PM
#24
Addict
Rennlist Member
Rennlist Member
I ran the 285/30R18 A6 that is as tall as the 255/35R18 A6 (which is really a 275/30R18), combined with the 335/30R18 A6 in my 996 GT3. No ABS issues at track days, time trials or autocrosses.
The 315 and 335 Hoosiers on 18" have the same overall diameter.
At the 2009 SCCA Nationals, a good friend was running 255/315 in his stock 996 GT3, no ABS issues either.
The 255/315 Hoosiers are within the tolerance of the F/R diameters for the ABS computer. No problems at all.
The 315 and 335 Hoosiers on 18" have the same overall diameter.
At the 2009 SCCA Nationals, a good friend was running 255/315 in his stock 996 GT3, no ABS issues either.
The 255/315 Hoosiers are within the tolerance of the F/R diameters for the ABS computer. No problems at all.
10-07-2009, 01:01 AM
#25
Super super important to match front to rear sizes within .2 inches. If not, the ABS will NOT perform properly and you run the risk of the computer "crashing". If it does, which has happened to a few of us over the years, the ABS valve will be stuck in either open or closed for 1-2 seconds. You will have either wheel lock or no brakes for that period and there have been a few cars "lost" as a result.
What an example size that would do that.??
10-07-2009, 01:07 PM
#26
Rennlist Member
I ran the 285/30R18 A6 that is as tall as the 255/35R18 A6 (which is really a 275/30R18), combined with the 335/30R18 A6 in my 996 GT3. No ABS issues at track days, time trials or autocrosses.
The 315 and 335 Hoosiers on 18" have the same overall diameter.
At the 2009 SCCA Nationals, a good friend was running 255/315 in his stock 996 GT3, no ABS issues either.
The 255/315 Hoosiers are within the tolerance of the F/R diameters for the ABS computer. No problems at all.
The 315 and 335 Hoosiers on 18" have the same overall diameter.
At the 2009 SCCA Nationals, a good friend was running 255/315 in his stock 996 GT3, no ABS issues either.
The 255/315 Hoosiers are within the tolerance of the F/R diameters for the ABS computer. No problems at all.
I have a theory about ABS and diameter. I have run PS2's 245/35 18 24.8" front and 315/30 18 25.5" rear GT2 on the track and not had ABS issues. Ian driving the same setup has had ice mode issues.
Driving the GT3 with AD07'S 235/40 18 25.3" and 295/30 18 25" neither of us ever had Ice Mode Issues on the track.
I am a progressive brake with a very quick ramp up to full. Ian is much harder initial application and ramp up to full. Getting more weight transfer to the front under heavy braking, ie don't slam on the brakes, will decrease the instance's of ice mode IMHO.
The closer you are in diameter the less ABS issues you may have. I have gotten Ice Mode in AutoX running A6 245/285 18 @ 24.8" both so diameter is not the whole cause but it does contribute.
Peter
10-07-2009, 01:18 PM
#27
Three Wheelin'
If you don't brake as hard, it is less likely to happen. When you are going 140mph and trying to brake to 80 in 200', you are asking a lot more of the car. The GT3 may also be less sensitive as the ABS is tuned differently from the factory.
10-07-2009, 02:28 PM
#28
Peter I take the same approach Ian does in that sense, carrying a lot of speed into a late braking zone, hitting brake hard getting that weight transfer up front then getting back on the gas turning in carrying so much entry speed on let's say thunderbolt, coming down that straight, late braking then on throttle carrying out crazy speed up the little hill... Everyone has different approaches and comfort levels I guess, I'll post up my video of it, everyone I was with at the track did something different when comparing videos lol
10-07-2009, 03:53 PM
#29
Rennlist Member
Peter I take the same approach Ian does in that sense, carrying a lot of speed into a late braking zone, hitting brake hard getting that weight transfer up front then getting back on the gas turning in carrying so much entry speed on let's say thunderbolt, coming down that straight, late braking then on throttle carrying out crazy speed up the little hill... Everyone has different approaches and comfort levels I guess, I'll post up my video of it, everyone I was with at the track did something different when comparing videos lol
Peter
10-07-2009, 04:21 PM
#30
I would think your approach is def smoother with less balance upset but for some reason the way I do it is just wired into me!
What setup are you going to be running? I love my 245/40-18/335/30-18 setup.. Tried the 35 sidewalk up front with 245-255 front, way too sharp and edgy with th lower sidewall, and the 335 rears I felt were unnecessary with the grip they generate, with the r888s I needed the 335s for grip!
What setup are you going to be running? I love my 245/40-18/335/30-18 setup.. Tried the 35 sidewalk up front with 245-255 front, way too sharp and edgy with th lower sidewall, and the 335 rears I felt were unnecessary with the grip they generate, with the r888s I needed the 335s for grip!