Stickman wrote:
...and if your running a 6-6.5 inch wide rims +15 offset, 7 inch +25 or if you do a slight massage to the rear you can fit an 8 inch wide rim with +35 offset (max tyre width 205 though on 8 inch rim or it won't fit in
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I have squeezed a 225 wide tyre under Donkey on custom made 6.75 wide rims but there was no clearance to the inner or outer of the tyre and had a bit of rubbing when I hit bumps. Made him look as though he was mini tubbed.
This is the wheel fitment information I was looking for some years ago. As things have happened, I have had a very long time to research with no hurry to act... And I have been doing some other research that is telling me that wider tires are not always better.
The Bellett was designed to ride on skinny, bias ply tires (with positive camber that has to be resolved to negative camber for modern radial tires). Racing in the 60's involved lots of sliding around corners. They must have spent a lot if time getting everything balanced and neutral.
Skylines would have been in the same situation, and there is a video of one of the Nissan factory drivers taking a 60's Skyline out on Fuji Speedway for the last time (just before the track layout change? or just before he permanently retired?), and the driver commentary makes a point to complain that the new, stickier tires and modified suspension give the car a very different and wrong feeling compared to what he was driving in the 60's.
Many years ago, I was taking FWD cars to the local drag strip once a week for test-and-tune events. I noticed that my speed at the end of the quarter mile was highest if I was on 185 tires, but my acceleration time at the 50 foot mark was best if I used 205 tires, or 8 inch wide drag slicks.
I also noticed that the purpose built drag race cars ran skinny wheels and tires on the non powered end of the car, and salt flat speed cars ran skinny tires on all four corners.
I concluded that the added friction sucked more power to turn and push a fat tire across the pavement once the car got moving, than could be picked up with the quicker acceleration from a standing start.
I just finished out the life of a set of very expensive, 8 1/2 inch wide, 205 width race tires, on another little FWD car, at the end of the "gymkhana" season. The wear rate on the tires was slow, due to the weight of the car (2,000 pounds) and power of the engine (130, maybe 140 HP). They should have lasted 10 races, but actually lasted 16-17 races. So they were hard and slippery for the last half of this racing season, and hurt me more than they helped. In addition to this, I looked at my tire temperature notes. According to the manufacturer, the operation range is supposed to be 140-160 degrees. My notes show they were normally getting up to 127 degrees, and 135 degrees when we had the six weeks of dangerously hot daytime temperatures. Even the tire manufacturer agreed that I would be better off on a narrower tire, but they don't make a narrower size...
I tend to hold function quite a bit higher in importance than form. Street tires are something to keep the car off the ground between race tracks, and as long as they stop on wet streets, and have a low enough cost and last long enough to not suck money away from racing, then they are good.
Belletts are light weight and lower powered cars, similar to the FWD cars I have experience with. I have to conclude that there is going to be a point where the wider tire becomes more of a problem and looses its benefits.
For the Bellett, I had been shooting for a 14x6 wheel with a 195 width tire, just to standardize it to the street tire size on all the other cars I have. But looking at tire availability, I will probably have to move back to a 185 width, because 195 is not too common in this country any more. Also bringing me back to the theme "narrower, sticky tire for the small, low power car".
), so I have about 4 sets of rims and tyres that I alter between depending on what driving I 