Last weekend, I did an excellent autocross school, put on by the Houston SCCA. My GF and I showed up with my AP1 and her 1991 300ZX. First, a bit of background.

I bought my 03 S a month ago, and it had OEM type S-02s on the front, but they were worn and the manufacture code was 1703, so they were quite old. In the rear, the car had brand new 225/50-19 Kumho 711s. Just before the school, I changed the front to BFG g-Force Sport 205/55-15. The rear remained 711's (yes, I know this is not optimal). The 300ZX has new Fuzion ZRi's in OEM sizes (the car is bone stock and has 21K miles!).

We are in Houston, so it is very sunny and 88-95 degrees.

Immediately upon driving on the street with the BFGs, the difference was substantial. Bear in mind that the old S-02's were very old, but the BFGs rode quite a lot smoother. The sidewalls appear to be much softer. Turn in was noticeably slower. But the ride improvement more than made up for it, given how quick the S turns anyway. It went from a lightning fast turn in rough rider to an almost lightning fast turn in almost comfortable rider. Very noticeable improvement over expansion joints and bots dots.

On to the autocross. With pressures set at 38psi cold all around, the car pushed pretty badly. Increasing the front by 3psi resulted in a much more balanced car. Hot pressures at the time were 47psi front, 43psi rear. Sounds like a lot, but the grip was a lot better and the specs on the tires say 44psi cold. So it should be safe. Once cooled down, they rear 41 front and 38 rear.

I was surprised to find that the BFGs do not appear to have any notable advantage over the 711's. tough to say for sure, because one is on the front and the other on the rear. Perhaps the 711's would have much different steering feel. I will say that the car has incredible balance right now. I expected it to be more tail happy, but I don't think it is. True, I was a drifting fool on Saturday, but not once did I spin. It was incredibly easy to throw the tail out, then gather it in. I've found the Ho's to be a little jerky on the street in the past, but with the extra 5 psi in them, they are easy as pie to throw around.

When it came to the autocross, the biggest issue was push in the front and precision in the slalom. Certainly, better tires would have netter another second. But improved skills on my part would be worth 2 seconds with the tires I've got. In the end, I went pretty fast. I was only beat by a few STi's, an Evo, a Z06 and an M3 - all on top class tires (Neovas and such). I'm not sure how much of an improvement better tires would have been for me. Surely, my turn in would have helped on the slalom and being able to stick it in some tight 90 degree turns would have helped, but the forgiveness that comes with these tires probably saved me from several spins.

For the street, I love the setup. The softness allows me to throw the car around over bad pavement. It also allows much forgiveness. The car is still a sharp instrument, especially compared to the Z.

Speaking of the Z, it is an automatic 2+2 running the Fuzions. Compared to the S, it is a boat. Nice, though. One thing I can say is that it feels much more composed going fast, especially on choppy pavement. The ZRi's seem to grip very well. We didn't get around to swapping cars on the track, so I can only comment on street driving.

My impression is that the Fuzions are noisier, but slightly faster than the BFG/711 deal. I can't say for sure, though. Perhaps the Z wheels can be put on the S and I could mess around. If so, I'll let you know.

In summary, I like the BFG's for street tires, but really can't say that they are better than the Ho's. Being able to save slides is more important to me than having a higher limit, then a cliff. As far as racing, the driver matter more than the tires, at least until you get fast. So go with comfy tires and learn to drive better. That's my plan.

 

If you get to a 245/45R16 rear tire the car is going to handle better. Also if the tires match the car is going to be more predictable and handle better.
You are correct in that the driver is the biggest part of the equation.

 

I expected the car to be pretty unbalanced with the mix and match tires. I really thought that the 711's would grip so much less than the BFGs that I'd be Dr Spin. Suprisingly, though, it is not bad and easy to control.

I'm sure that doing as you say would hold the rear in line better, but I really can't imagine it being more predictable. My name ain't Tarzan, but I set my fastest lap on a run where I threw the rear end out 40 degrees on two occasions. I could drive it like a rally car, and not because I am terribly skilled either.

Maybe I'll change my tune when I replace the rears or go with a new set of four, but it seems like I stumbled on a good match right now.

Also, from the Tire Rack spec sheets, it seems that the g-Force Sport measures much like the S-02.

For the 225/50-ZR16

Tire-----Rim----Section----Tread
S-02----7.0------9.2---------8.5
BFG-----7.5------9.4---------N/A

It doesn't list a tread width for the BFG, so I don't know whether the Section vs Tread difference is that much different between the tires, but the BFG is wider at the section than the S-02.

 

Interesting review.

I have a set of AP1 wheels with ZRis on them....and they are pretty nice. Great in the rain, quiet in all conditions, and good tread wear. Also a very stable tire at high speeds.

I will say that the S02 is far better on a track than the ZRi. I have ran both at a road course, in fact, the road course that the SCCA national run offs will take place at....Heartland Park in Topeka, KS.....and the grip of the S02s is unbelievably better in the turns than the ZRi. The ZRi is a fairly grippy tire, but in the three sessions so far this year, the one time I spun out the ZRis were the tires on the car at that time.

ZRi.....great tire for the money.

S02s.....you get what you pay for, except in the rain.

EDIT: The spin out was with a 225/50/16 ZRi.....Jim recently set me up with 245/45/16....so we will have to see how they do with a closer to stock rear tire width.

 

The turn-in issue I mentioned indicated to me how much different the S-02s would be when new. The ancient S-02s on the car were much sharper than the new BFGs. So, your S-02 v ZRi experience fills in the rest.

Do you find that the S-02 is easy to gather up after the tail has stepped out? That's the thing that has me surprised - I expected to have less grip, but I didn't think it would be so easy to control when sliding.

BTW, I did a quick seach on the Z forums and the Z32 wheels seem to be the same offset as the S. I dunno about bolt pattern. But I may well be able to swap wheels and fool around with the ZRis on the S.