For the past month or so I've been using a stagged Azenis for about 4 autocrosses. 215/45x16" Azenis on 16x7" Rota Circuit 8s (40mm offset) on front, and 205/50x15" Azenis on 15x7" Kosei K1s (45mm offset) rear.

The front Azenis were used by Corey Ridgick, who graciously sold them to me with about 1mm of tread left.

1st event at Ripken I used all 4 16" Azenis and it rubbed so bad that I melted the rear lip. Whoops!

2nd event was with the Bel Air Corvette Club in Baltimore, but this time I stagged the sizes. And it handled great. Front shock on 1/2 turn, rear shock on 1 turn, pressures I ended up with was: 40f/42-44r. Sway bar on full stiff. Car pulled through a turn so much better it felt like a different car.

3rd event was PA States but in the rain. And I couldn't decide whether to use 205/50x15" since those have 3-4mm of tread compared to the 1mm of tread on the 16s. I decided to go for broke and use the 16s since the course was only damp. I took 3rd getting the closest I have ever gotten to Corey and Jeff Hurst.

4th event was today with National Road Rally/Cumberland Auto Sport in WV/MD. There was everything from fast sweepers, to 180 degree turn arounds, slaloms, a Chicago box too. Every section provided tremendous grip.

I wish I was able to do a test and tune and see the difference between the 15s and 16s. But it seems like this setup is working so far. Tires are definitely wider by about 1/2-3/4" and the gearing hasn't changed much since the tires are next to bald. I freshened them up with some Traction V for about 3-5 days too. My only complaint is that the 16s are far heavier than the 15s. I haven't weighed them but my guess would be:

16x7" with 215/45x16" = 40lbs
15x7" with 205/50x15" = 34lbs

 

are you speaking of with the wheel or without on those weights ?

 

On a slightly heavier car like the Subarus or your later Si, the 215's extra weight, and therefore, thermal mass may be helping to not overheat the Falkens.

 

Yes that's the other thing too, but it hasn't been hot enough to really tell. Even after my 3rd run on Sunday the tires still felt cold, which is good for these tires.

 

The only way this test is going to be valid is if you run back-to-back with the smaller tires on the rear vs the larger tires on the rear.

But then again, with adjustable camber, tire pressure and springrate I still think you can achieve the same result as putting the smaller tires and wheels on the back.

 

Several months ago I rotated tires putting badly camber worn fronts on the rear and it induced perfect understeer on some hard mountain runs (yes street driving, sorry)...kinda the same idea with the width differance. It got me thinking about doing the same thing you are now...just afraid that once I get my suspension worked out and the rear stiffened some then the rear would be wayyy too loose.

Do you have any pics of your car with the 16" C8's and 215/45 Azenis? ...that is the exact same setup I am wanting to run.

 

There is no way to simmulate rubber on the ground though.

Like has been said before staggering is being able to stuff 225's in the front but only 205's in the rear IMO

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by abaku &raquo;</TD></TR><TR><TD CLASS="quote">There is no way to simmulate rubber on the ground though.

Like has been said before staggering is being able to stuff 225's in the front but only 205's in the rear IMO </TD></TR></TABLE>nawww, donuts on the rear

 

Why would you want to? Aside from being able to rotate tires you're just adding the worst kind of weight to the car. Staggering makes sense. Most of the people posting in this thread do not. (everyone but todd, jesse and the creator)

 

Well I tried several different air pressure settings today to get the car to rotate.

Shocks were at full soft front and full stiff rear.
1st run 40f/42r
2nd run 40f/43r
3rd run 38f/42r
4th run 36f/42r
5th run 38f/43r
6th run 34f/43r

And at no time during my runs did the car feel tail happy. Very weird. Course was very sandy (South NJ @ Atco Raceway). With the tires down at 36f the turn-in felt mushy - didn't like that at all. In the rain last week at PA States I had the even lower pressures and it felt fine.

Today was my last event though. I am looking forward to trying to setup on a faster and longer course.