Mazda MX5 differential question

[tibimakai]

You are completely right. I wasn't even thinking about that, that he maybe is lowered.
I misunderstood the people on the Miata forum.
Also, it looks like there are two NC1 NC2 Miatas with 9.5 and 10" at that point at the crossmember.
I will adjust it, it is not to late.

[skidzzz]

Hello Tibor, It’s good to see you asking all these questions….. this should help you avoid a lot of “weld it in/ cut it out “…… although we all have done some of this .
I may step on some toes here, but here goes . . . I noticed you discussing tire sizes, a stock NC being 205 wide, and at 17 rim, probably a pretty big contact-patch on the ground. For a 2400 pound car this is probably appropriate. I’m just wondering, when we build our sevens with 1200 to 1300 pounds (roughly half of an NC) if driving it on 205’s will generate enough heat in the tires to make them effective. Many Caterhams , and other builders have used something more in the sizes of 185 width, 195 width . A 205 would probably warm up ok, especially with a softer, stickier compound summer tire, but a 245, while it looks cool, may not be ideal for performance. They may fall short in traction if they don’t get up to optimum temperature. If they don’t work well, you might as well have a smaller tire that does work. Just something to think about.
I expect my weight to be about 1300 pounds, and I will be running 205/50-15’s in a summer compound, Bridgestone Potenza RE-71R, I’m hoping theses are not too big.
Skidzzz

[tibimakai]

Thanks for that, but I'm not looking for performance, it will be a weekend street cruiser.
I have just placed the order for some 8" wheels, and almost pulled the trigger on some 215/50 and 245/45 tires, but now you made me rethink this.

[skidzzz]

Keep in mind, each diameter tire will dictate a different radius and may effect your centerline of axle shafts, possibly changing your ride height, unless you allow for that in the relationship of subframe to chassis frame, front suspension pivot points, etc.
Something to ponder on a swift drive through the countryside in your Alfa !!
Skidzzz

[tibimakai]

I have 0 knowledge about suspension setup. Soon I will need a lot of help in that department.
You are saying that I should run a square setup, instead of a staggered one?
There is not much difference between the front and rear tire diameters. 25.5" vs 25.7".
Earlier today I have bolted(loosely) together the Miata rear suspension. I have almost 8" from the wheel mounting surface, to the side of the car.