Re: staggered or square for the track?
PerverTT;328492 said:
Danng – I think it is not just a matter of front or rear drive. You also have to look at the weight distribution of the car. In my opinion, most Bimmers are better off with the same size tyres all round. With their trademark 50 – 50 weight distribution, there isn’t a persuasive case to be made for wider rears, unless you are driving something with an unruly rear end (think E36 M Coupe).
Personally, I think that the only cars that really require wider rears are Porsche 911s, which have the engine at the wrong end of the car. They need the fatter tyres to reduce inherent oversteer. While this set up looks damn sexy, it isn’t suited to all front engined cars, many of which have a front weight bias.
I’m putting my money here my mouth is. I’ve recently picked up a set of alloys to replace the kerbed ones on the 330i. I made sure the wheels were the same size all round, even though the staggered option was available for the wheel that I bought. For me, function comes before form. Plus, I can rotate my wheels. Try doing that with staggered set up …
Pervert, what's your real name BTW? Earlier I listed just a couple of the advantages going staggered even on a 50:50 distribution. You're right in that the steady state portion of a corner with a 50:50 car gives the least or no benefit to going up on tire at either end, but steady state makes up an extremely small portion of a performance drive or lap. When you adapt the setup to make use of extra tire, the gain at steady state is increased.
The type of car, course and driving, will all affect how much gain there is to be made from extra tire, but there almost always is a gain, most often significant ones. It takes a weird stock vehicle to end up with zero or negative gain after adding tire. So it is almost a rule that where free to, adding tire while keeping affected parameters sane, it always a performance plus.
Rastaman;328493 said:
not sure if they had maximised the width..but i did get the feeling that the more senior chaps there were encouraging the newer guys to go square ! like 265 all around ? would that be rite having 265 in e front ? seems strange to me !!
Ah so it is square, but they've gone up on tire all round so it ends up square. The limits on tire size probably were practical (packaging, price). So it is inline to the more tire = better rule (within broad limits).
In the original comparison I was picturing stock square, vs adding tire to the rear only. If you can go up on tire front and rear and it just happens to be square, I wouldn't really care either until the rest of the car was worked into the portion of last single digit percent efficiencies. What's important is that you get as much tire under the car as possible and then set the car up to make best use of it all. Staggered or square is secondary as long as the driver is roughly aware of what the car is going to do at the limit and beyond. The stock cars that come staggered (like the Porsches Pevert mentions) come that way to keep handling at the limit on the safe side for the everyday driver. If you matched the front on those cars to the rears (square), you could still do things to make the car quicker despite that FF or RR cars are among those that benefit the least from adding tire at the R and F respectively.
In general the smoother the roads and course are, the more you can take advantage of extra tire without too badly compromising how the car moves in its other modes. Smooth enough surfaces with a car with enough travel and you can completely disregard certain modes. It gets a lot more involved than this but that's the gist of it.