[Z06] Installed BFG DR 315 35 18...problems
Melting Slicks
Joined: Sep 2003
Posts: 2,911
Likes: 1
From: Augusta GA
St. Jude Donor '05-'06
Originally Posted by Ranger
There's a fair amount of erroneous info on this thread.
At the drag strip, many members have run BFG DRs in 315.35.17s on Z06 Front wheels 17"x 9.5". The fit is fine. No rubbing. "Power Shifter" has cut many mid-1.6X 60' with this combo. I have done the same running a 12" wide CCW. So there definitely is not a penalty for running it on a 9.5 width wheel, despite the footprint theory.
Another successful combo is BFG DRs 315.30.18 on Z06 rear wheels 18"x10.5". Fit is fine and I've seen several Z06s so equipped cutting 1.6x 60'.
What 315s on a C5Z will do is extend out of the lower wheel well by .75" or so. That never bothered me and certainly wasn't worth tubbing the car for to me. If an owner is concerned about scarring the paint on the rear quarter panel aft of the wheel well, that area can be protected by painter's tape while the big tires are mounted.
Ranger
At the drag strip, many members have run BFG DRs in 315.35.17s on Z06 Front wheels 17"x 9.5". The fit is fine. No rubbing. "Power Shifter" has cut many mid-1.6X 60' with this combo. I have done the same running a 12" wide CCW. So there definitely is not a penalty for running it on a 9.5 width wheel, despite the footprint theory.
Another successful combo is BFG DRs 315.30.18 on Z06 rear wheels 18"x10.5". Fit is fine and I've seen several Z06s so equipped cutting 1.6x 60'.
What 315s on a C5Z will do is extend out of the lower wheel well by .75" or so. That never bothered me and certainly wasn't worth tubbing the car for to me. If an owner is concerned about scarring the paint on the rear quarter panel aft of the wheel well, that area can be protected by painter's tape while the big tires are mounted.
Ranger
Been there and done this as well as per Ranger's expert advise. Started with 295 35 18 BFGs and went to a smaller, 275 40 17 MT ET St rad on OEM Z fronts and dropped .13 on my 60s. I only went 1.70s with OEM clutch with the MTs (and LG Pro Lts) but added an Aussie Clutch, DTE brace and both output shafts and went 1.5s. IMO and experiance the 275 40 17 et st rads are awesome and can take quiet a hard launch with some pretty good results.I did go to a 16 CCW drag pack for the strip with MT ET streets and skinnies but have no passes yet. After my HC swap, I did overwhelm the st radials and was getting wheel hop on launches, spinning and was driving me crazy. When I did get it right it did go low 1.5s but no 1.4s yet. My 390s are rebuilt and waiting to install (thanks ZIP
and CAM )and my drag pack is ready for some passes.Now for the 3xx for the street. Been there too. I ran 305 30s (Kuhmo V700s yea I know R comp
) on 10.5 chrome Zs and they hooked great. Went to a 12 CCW clasic for the street and a Mich PS 335 30 and they do fit, but the brake ducts had to go. They do not hook in a straight line nearly as well as the smaller Kuhmos. IMO and experiance, a wide rear is mostly for looks. The 12s are much heavier than chrome Zrims and much worse then OEM rears. I lost 15 RWHP and added 2.5 seconds (look at the X axis in time instead of RPM) with the 12 inch CCWs in comparison to the chromes, and OEMs dropped another 2 seconds from chrome and over 8 RWHP. I have not been active here as of late as I have been laid up after an operation on my left foot (installed a new quicker shift foot
) and I am missing my car bad. I hope to drive again next week and maybe make passes again in May 
I hope.Enjoy my brothers as I am off to FMP to tape some passes for MSG Huff and Pray. Have a great day
Dave
Le Mans Master
Joined: Nov 2001
Posts: 8,080
Likes: 151
From: Toronto
Originally Posted by straatien
I agree. Not only do you hinder the ability of the tire to contact the road, but you rub, and you may suffer issues under hard cornering, e.g. auto cross. However, for those persons who don't auto cross, or even drive the car "assertively" AND wish to enjoy the "look" of wider tires (aesthetics), then the question is less academic. My position is to simply state that it can be done, not necessarily that it should be done. Which is exactly why I didn't. As you suggested, I'll be doing it right by having a Lingenfelter mini tub installed as I would like to have 345/30-19s.
345/25/20, 13x20 tubbed, and slammed, with everything 'inside' the lip.
