Hi All,

I just purchased a set of 15x7/8 BBS basket type rims. I am having a hard time figuring out what size tire to put on that will be close to stock diameter.

From the information that I have gathered from Tirerack I see that the pickings in 15" are limited. I use the car as a daily driver & live in NJ, (no wise cracks). I plan on doing some DE, some meaning 2-4 a year.

I am looking at the the Potenza SO-3's. They got a very favorable review.My concern is that it looks like they are about 1"less in diameter.
The size's I am looking at are 205/55/15 & 225/50/15. I have a 77 Euro, which I am told for all purposes is just like a 78 S/C.

I would like to accomplish a wider look and may go to spacers in the rear. Am I going to have to do the bat thing or will all go well with the fit?

Or does anyone have any other reccomendations for brand & size? Let me also add that after the tires I will be getting an alignment.

Thanx for any input.

Regards,
Rich

 

Hi Rich,

My 73 with Cookie Cutters has 205/60/15's all around. They are Toyo Proxes H4. Not a true peformance tire but a nice one for street use.

 

Determine the proper rolling radius or revs/mi. for the factory recommended tire sizes on your wheels... stick to those figures (+/- 3%) to maintain adequate clearance (assuming the wheel offset is correct) & correct final gearing.

Bruce Anderson states the factory stock fitments on pg. 16 in current "Excellence"...

frt 7x15 used 185/70-15
rr 8x15 used 215/60-15

the issue as you note is that there may no longer be many selections available for 15" rims that meet all your requirements...

 

IMHO, you should ignore the original factory fitted sizes - these will look like balloon compared to modern low profile rubber. I would run a 205/50 on the front and the same size tyre on the back, if you do not have SC rear wheel arch flares, or if you do have the flares and wish to run a bigger tyre then a 225/50. If you have the flares and run the 205/50 on a 15x7 BBS rim, you may want to run a small spacer to fill the flares. The difference in grip between a 205/50 and the 225/50 will be negligible with the amount of horsepower a 1977 Euro car produces. My experience with classic race cars is that the smaller size almost always works better when running 7 inch rims - the 7 inch rim is a little narrow for a 225.

Given that you are planning to do some DEs, the lower profile (and indeed the smaller rear tyre) will have two main beneficial effects. First, the smaller rolling circumference lowers your gear ratios and increases your acceleration and secondly, shorter sidewalls give sharper suspension response and sharper steering and turn-in. Downsides are an optomistic speedo, due to smaller rolling circumference, slightly harsher ride and the possibility that you may want to lower your car a little to make it look "right" given that the diameter of the tyre is smaller.

Hope this helps. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />