The BFG g-Force Rival tested out 1 second quicker than the Direzza II at NOLA
05-09-2013, 11:17 PM
#31
If I went 17", I'd go with 225/45ZR17 & 255/40ZR17. My 17" ZIIs are brand new, though, so I'll keep them mounted until they're done.
I plan on getting rivals for my track wheels instead, which are 987-sized 18" OZ Alleggerita HLTs (18x8+57mm & 18x9+43mm). The closest size is 245/40R18 & 275/35R18 which is about a quarter inch taller than OEM. (I used to run 245/35R18 & 285/30R18 Kumho V710s on these wheels) I know Rivals run wide, and am a bit concerned about rubbing in the front. Anyone running 18" rivals yet on a 986 or 996?
I plan on getting rivals for my track wheels instead, which are 987-sized 18" OZ Alleggerita HLTs (18x8+57mm & 18x9+43mm). The closest size is 245/40R18 & 275/35R18 which is about a quarter inch taller than OEM. (I used to run 245/35R18 & 285/30R18 Kumho V710s on these wheels) I know Rivals run wide, and am a bit concerned about rubbing in the front. Anyone running 18" rivals yet on a 986 or 996?
Recently I installed some 245 NT01's for track duty, and at 25.55" diameter they were a major problem until I decreased castor angle from 10 degress down to about 6 degrees. So, pay attentention to both diameter and width.
05-10-2013, 03:50 PM
#32
Drifting
Kumho V710: 245/35R18: 24.8" dia, 9.8" section width. 23lbs.
BFG Rival: 245/40R18: 25.7" dia, 9.8" sec width, 9.2" tread width. 25lbs
Dunlop ZII: 255/35ZR18: 25" dia, 10.2 section width, 9.6" tread width. 27bs.
I can't find numbers on the discontinued star specs, so ZII will have to do as a proxy.
So, if I went with this, I'd lose the gearing advantage the V710s provided. A set of 18" rivals is 8lbs heavier than the 17" ZIIs I have right now. But tread width would be a full inch wider in the front and probably about the same in the rear, so grip should be phenomenal. The 245 rival will be taller and narrower than what you're running. I'd basically exchange acceleration for cornering: good autocross compromise. Based on how your tires are rubbing, do you think this would rub?
BFG Rival: 245/40R18: 25.7" dia, 9.8" sec width, 9.2" tread width. 25lbs
Dunlop ZII: 255/35ZR18: 25" dia, 10.2 section width, 9.6" tread width. 27bs.
I can't find numbers on the discontinued star specs, so ZII will have to do as a proxy.
So, if I went with this, I'd lose the gearing advantage the V710s provided. A set of 18" rivals is 8lbs heavier than the 17" ZIIs I have right now. But tread width would be a full inch wider in the front and probably about the same in the rear, so grip should be phenomenal. The 245 rival will be taller and narrower than what you're running. I'd basically exchange acceleration for cornering: good autocross compromise. Based on how your tires are rubbing, do you think this would rub?
05-10-2013, 08:15 PM
#33
Kumho V710: 245/35R18: 24.8" dia, 9.8" section width. 23lbs.
BFG Rival: 245/40R18: 25.7" dia, 9.8" sec width, 9.2" tread width. 25lbs
Dunlop ZII: 255/35ZR18: 25" dia, 10.2 section width, 9.6" tread width. 27bs.
I can't find numbers on the discontinued star specs, so ZII will have to do as a proxy.
So, if I went with this, I'd lose the gearing advantage the V710s provided. A set of 18" rivals is 8lbs heavier than the 17" ZIIs I have right now. But tread width would be a full inch wider in the front and probably about the same in the rear, so grip should be phenomenal. The 245 rival will be taller and narrower than what you're running. I'd basically exchange acceleration for cornering: good autocross compromise. Based on how your tires are rubbing, do you think this would rub?
BFG Rival: 245/40R18: 25.7" dia, 9.8" sec width, 9.2" tread width. 25lbs
Dunlop ZII: 255/35ZR18: 25" dia, 10.2 section width, 9.6" tread width. 27bs.
I can't find numbers on the discontinued star specs, so ZII will have to do as a proxy.
So, if I went with this, I'd lose the gearing advantage the V710s provided. A set of 18" rivals is 8lbs heavier than the 17" ZIIs I have right now. But tread width would be a full inch wider in the front and probably about the same in the rear, so grip should be phenomenal. The 245 rival will be taller and narrower than what you're running. I'd basically exchange acceleration for cornering: good autocross compromise. Based on how your tires are rubbing, do you think this would rub?
05-11-2013, 12:47 PM
#34
Instructor
My 245/40/18 rivals rub slightly on the fender liner the last 1/4-1/2 turns before steering lock. I have 500 miles plus 1 autox with no ill effects. I will remove the front spacer today in hope to eliminate the rub. It only happens when I pull into a parking stall or my driveway. Shorter diameter would be nicer.
Square 255 VII's might be the hot setup, but 255 seems wide for the front wheel width.
Square 255 VII's might be the hot setup, but 255 seems wide for the front wheel width.
Last edited by allen_skillicorn; 05-12-2013 at 11:59 PM.
05-11-2013, 03:17 PM
#35
Drifting
My 245/40/18 rivals rub slightly on the fender liner the last 1/4-1/2 before steering lock. I have 500 miles plus 1 autox with no ill effects. I will remove the front spacer today in hope to eliminate the rub. It only happens when I pull into a parking stall or my driveway. Shorter diameter would be nicer.
Square 255 VII's might be the hot setup, but 255 seems wide for the front wheel width.
Square 255 VII's might be the hot setup, but 255 seems wide for the front wheel width.
