Square vs. staggered setup for track

[Hujan]

Looking to get a set of track wheels and assumed I'd get a square setup. But a few very excellent drivers whom I respect immensely seem to prefer a staggered setup and have me reconsidering.

My impression is that a square setup reduces understeer and therefore makes the car more tail happy which would seem to make the car navigate better around tighter, twistier tracks. The downside is that it might be less stable at speed and more prone to have the tail come around on you. By contrast, it's my impression that the staggered setup would be a little more stable at speed and less prone to having the back come around on you.

Handling aside, the obvious advantage of the staggered setup is being able to rotate tires.

I thought I'd get some more feedback opinions on the subject. I'm particularly interested in people who tried one and went to the other and can therefore provide a comparison.

Note that I will be running camber plates and coil overs, so the suspension will be pretty well dialed. Not sure if this negates some of the effect of the understeer inherent in a staggered setup.

[aus]

Just keep in mind this car doesn't understeer like the E46 did. Staggard is probably better for ultimate balance, but square just makes so much more sense. My buddy with an E46 runs square and he just brings one extra wheel to track events in case he gets a nail or flat while driving to the track. I have my full set of street whees in the back seat while, or vise versa if I drive up a day early. It's a pain to load the wheels.

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[The HACK]

My philosophy. Don't reduce grip in favor of achieving a balanced handling.

Say, if the only way to go full squared means you'll have to run skinnier tires in the rear due to clearance issues, then it makes no sense to run squared, since it's easier for the driver to adapt to the difference in grip between the front and the back.

However, the E9X seems to be able to accommodate very wide tires up front, unlike it's predecessors. So if the current setup can accommodate square setup without giving up grip in the rear to do so, squared setup does have it's advantages.

Having said that, unless you fall within that tiny sliver of drivers who can expertly keep their tires at the optimum slip angle as described by billj747 here in this forum, obsessing over staggered vs squared has little real world applications.

[1MOREMOD]

Originally Posted by The HACK

My philosophy. Don't reduce grip in favor of achieving a balanced handling.

Say, if the only way to go full squared means you'll have to run skinnier tires in the rear due to clearance issues, then it makes no sense to run squared, since it's easier for the driver to adapt to the difference in grip between the front and the back.

However, the E9X seems to be able to accommodate very wide tires up front, unlike it's predecessors. So if the current setup can accommodate square setup without giving up grip in the rear to do so, squared setup does have it's advantages.

Having said that, unless you fall within that tiny sliver of drivers who can expertly keep their tires at the optimum slip angle as described by billj747 here in this forum, obsessing over staggered vs squared has little real world applications.

Agreed, don't take a skinnier rear to make it happen. That said I went with square on my e90 and now on my e46. Love the versatility and never felt the e90 was tail happy only more neutral with slight understeer still there. rarely see anything but square set ups on any track prepped car.

[GTB/ZR-1]

I'm thinking abt running square tire sizes on my stock ZCP rims for track duty--probably 265s. Not too big for front rim width & ability to swap @ tire shop after a few DEs.
Although, I would give up some slight understeer tendency to have a more stable car @ the limits--since I'm there every lap (except the warmup) lol.

Like the OP, I'd like to hear from advanced/instructor level drivers on the square setups, that have gone that route.

[4M]

OP - Went through this exact debate through the winter and was on the fence until I ultimately pulled the trigger on a staggered set for track and autocross. My body of work (switching from OE) is only two events so far (3 hours of track time, 12 AutoX runs) but I've been very happy with the results.

Can't help you on the square comparison having not had it since my E46 days, but like you are hearing, I relied on the advice of those with greater experience in the E92. Key points were the fact that staggered is the way most race teams go, the "tail happy" point, giving up some on AutoX in return for a better track car where I hope to spend more time. Just on the math so far this season, that's borne out - 3 hours vs. about 12 minutes. Finally, tires are way less expensive that body work. Reducing the chance of the "big one" while I get more comfortable at the limits in a staggered setup was important.

[AxisMagi]

I went with square apex 10" with 275/35 nitto01 setup and much prefer the
balance over staggered. Dials out the push and makes it much easier to
rotate the car through the corner with slip angle. I don't find it too tail happy
or unstable at higher speeds. In fact I like the square 18 setup so much that
I'm thinking to sell my oem comp 19" wheels to get a new set of street wheels
to run square all the time. It's really a driving style preference, talked to
advanced drivers from both camps. I started out learning with staggered which
was probably helpful. Recommend you try both at some stage.

Axis

[Groundpilot]

I prefer staggered set up for e9x m3. As someone mentioned, these cars dont understeer like e46, and you can dial understeer completely out with c.plates and coilovers. On the other hand, you should always fit widest tires possible in the back for altimate rear grip. You dont want your car loose in 90+ mile corners.

[slicer]

I have not tested a square wheel/tire set but I have also not felt the need. I always run 275's in the front and I have ran 285's and 295's in the rear. Tires are certainly a big component to handling but, as others have stated, there are other factors. I noticed some understeer on certain corners with my Hankook RS3 275/285 tires on the track. I added a Mode Carbon GT4 front splitter (awesome product BTW) and went to 275/295 BF Goodrich G-Force Rivals. I didn't experience any understeer with the new set-up. It could be attributed to better tires with more ultimate grip (maybe I wasn't reaching the top end of the front grip threshold with the Rivals) and the added front downforce from the splitter. I will soon be adding a Mode Carbon GTS rear wing. I will be curious to see if the added rear downforce from the wing results in a re-introduction of understeer at the limit.

I understand the motivation to run a square set for the ability to rotate tires but I have found that as long as I keep the front to rear stagger equal to or less than 20mm then there isn't a huge amount of understeer. Bear in mind that I'm a decent driver but certainly not putting down top lap times. More experienced drivers may see things differently.

[GTB/ZR-1]

Originally Posted by slicer

More experienced drivers may see things differently.

Even drivers that put a race suit on for a living all want the same thing as we do in a car--confidence...

If a car is too loose & nervous approaching the limit, then any help, that grants extra rotation, will still (in most cases) end up w/ slower lap times than a car w/ very mild push, that can be driven more comfortably @ the limit.

Randy Pobst will preach this all day long--and look @ his creds ;-)

[Hujan]

Thanks for the replies everyone. I really appreciate it. It looks like there is no easy answer here.

To clarify, if I went with a square setup, it would likely be 18x10" w/ 275 tires. If I went staggered, I'd probably go 18x9.5 front and 18x10.5 rear. Not sure on tires, but either 265 front and 286 rear, or 275 up front and 295 in the rear. Either way, I'd maintain the 20 mm delta between front and rear.

My impression even before I started this thread was that some of the people who advocate a square setup are also very much into autocross which, for whatever reason, I'm just not into. Perhaps it would make me a better drive on the track, but I just have a hard time getting excited about the idea.

After reading the above and thinking about it, I am really leaning toward going with the staggered setup. Perhaps the most important thing for me is maintaining confidence in my car. Nothing would kill my enthusiasm faster than losing confidence in the car, be it the breaks or the handling. I am thus perhaps willing to give up the more neutral handling and ability to rotate tires of the square setup for the increased confidence of the staggered one.

[CSBM5]

I have my M3 setup with a Dinan front sway bar and the alignment pins out for max negative front camber, toe at almost zero. It is setup like that for SCCA F-street class type autocross legality. For F-street competition, I have to run stock width wheels also, so while I have 275/35-18 BFG Rivals all around, they are mounted on 8.5/9.5 wheels...in other words a tad pinched up front, but they work fantastic. With the front bar, camber setting, and square Rivals, the car is very well balanced.

Last season, since the 275 Rivals weren't available, I ran 245/40s all around. Switching to the 275s all around, two things were immediately apparent: much better rear traction on track out from the apex and/or element; and noticeably improved braking especially from high speeds (90+). Not much of a surprise of course.

I also have a set of 10x18 wheels with 275/35 NT-01s which I use a CCA events. The car by no means is too loose with my setup, likely due to the larger front bar which really helps in many ways including putting down power coming off tight turns/elements.

On a totally stock M3, I could see the possibility of it being too loose with just changing to a square tire/wheel setup. I've not tried that combo, but it given how well my car is handling setup like it is (nicely controlled rotation with heavy trailbraking, still easy to rotate the tail with throttle as needed on track out, etc), it wouldn't surprise me that a stock car with just square wheels/tires isn't the best idea.

FWIW, almost 40 years autox, 34 years track experience.

I've run a square setup on my E39 M5 since it was new almost so long ago, but that car has a much more understeering balance than the E9x M3 not to mention an additional 400 lbs and 52/48 weight distribution. It transforms the handling the M5 beast (which comes stock with 8/9.5 245/275 setup). Tire rotation to extend wear life is hugely beneficial of course too.

Regards,
Chuck

[OC3]

Originally Posted by The HACK

My philosophy. Don't reduce grip in favor of achieving a balanced handling.

Say, if the only way to go full squared means you'll have to run skinnier tires in the rear due to clearance issues, then it makes no sense to run squared, since it's easier for the driver to adapt to the difference in grip between the front and the back.

However, the E9X seems to be able to accommodate very wide tires up front, unlike it's predecessors. So if the current setup can accommodate square setup without giving up grip in the rear to do so, squared setup does have it's advantages.

Having said that, unless you fall within that tiny sliver of drivers who can expertly keep their tires at the optimum slip angle as described by billj747 here in this forum, obsessing over staggered vs squared has little real world applications.

+1

Originally Posted by Hujan

My impression even before I started this thread was that some of the people who advocate a square setup are also very much into autocross which, for whatever reason, I'm just not into. Perhaps it would make me a better drive on the track, but I just have a hard time getting excited about the idea.

I'm not sure if you can draw that conclusion. There are many people who track heavily and don't autocross who run square setup.

Originally Posted by Hujan

After reading the above and thinking about it, I am really leaning toward going with the staggered setup. Perhaps the most important thing for me is maintaining confidence in my car. Nothing would kill my enthusiasm faster than losing confidence in the car, be it the breaks or the handling. I am thus perhaps willing to give up the more neutral handling and ability to rotate tires of the square setup for the increased confidence of the staggered one.

Run whatever (staggered or squared) you want. Judging by your line of question, I gather you're just starting to get into tracking and, in such case, either way will make a very little difference, if any noticeably.

I've run 70 track days with both staggered (in the beginning, mainly because I was using OE wheels) and eventually squared, and squared doesn't exhibit less handling that us non-pro's can detect.

One thing to consider is, the wear rate on front tires at the track is substantially higher than that of rear tires (opposite of what happens on the streets). I would estimate at nearly 3-to-2 ratio - i.e. 3 sets of fronts for 2 sets of rears. Given that, being able to rotate the tires has a substantial economic advantage. Get into heavy amounts of tracking and you'll find out pretty quickly how the tire expenses become one of the biggest on-going expenses. Another thing to deduce from this wear rate is that the fronts do much more work than the rears. So, wouldn't we want as much meat on the front as possible?

[okusa]

Originally Posted by OC3

Another thing to deduce from this wear rate is that the fronts do much more work than the rears. So, wouldn't we want as much meat on the front as possible?

THIS! Which is the essence of the running square preference, especially when running 295 square TDs.

[jphughan]

Originally Posted by aus

Staggard is probably better for ultimate balance, but staggard just makes so much more sense.

??? I assume one of those "staggard"s was meant to be a "square"?

[jphughan]

Originally Posted by The HACK

My philosophy. Don't reduce grip in favor of achieving a balanced handling.

Say, if the only way to go full squared means you'll have to run skinnier tires in the rear due to clearance issues, then it makes no sense to run squared, since it's easier for the driver to adapt to the difference in grip between the front and the back.

This has to be weighed against the cost of maxing out tire sizes. Keep in mind that fatter tires also add unsprung, rotating weight -- the worst possible kind. That is a net LOSS in overall performance in every situation that isn't traction limited, so it's overly simplistic to say that you should maximize grip. The C7 Vette has skinnier tires than the C6 for this exact reason.

And frankly, unless the OP is competing, if it turns out that square feels better or more fun even if staggered is faster, then there's a case to be made for square. HPDEs are about having fun, not setting records. And if square turns out to instill more driver confidence, then square could be faster for most people even if an absolute pro would be faster on staggered.

[FogCityM3]

Have never run square so can't really speak to that, but run a staggered setup, but with an aggressive offset in the front 19 x 9 ET 20 (stock ZCP is ET31) and less aggressive in rear (19 x 10 ET 20 vs ZCP ET25). That 11mm difference in front felt like it dialed out 60%-70% of the understeer and car feels much better on track, so something to consider in terms of widening the actual track of the car without increasing tire size.

[jphughan]

Originally Posted by FogCityM3

Have never run square so can't really speak to that, but run a staggered setup, but with an aggressive offset in the front 19 x 9 ET 20 (stock ZCP is ET31) and less aggressive in rear (19 x 10 ET 20 vs ZCP ET25). That 11mm difference in front felt like it dialed out 60%-70% of the understeer and car feels much better on track, so something to consider in terms of widening the actual track of the car without increasing tire size.

^ This.

[Kunman]

hmmm i am thinking of running 255/40r17 squared next season for the track, the savings are huge over a 275/17 or 18inch setup, think 250 - 350 in savings.

And before people say 255 is too narrow, the c64 507 which is 250kg heavier then the M3 and much much more powerful uses 235f/255r tires.

[Groundpilot]

Originally Posted by jphughan

This has to be weighed against the cost of maxing out tire sizes. Keep in mind that fatter tires also add unsprung, rotating weight -- the worst possible kind. That is a net LOSS in overall performance in every situation that isn't traction limited, so it's overly simplistic to say that you should maximize grip. The C7 Vette has skinnier tires than the C6 for this exact reason.

And frankly, unless the OP is competing, if it turns out that square feels better or more fun even if staggered is faster, then there's a case to be made for square. HPDEs are about having fun, not setting records. And if square turns out to instill more driver confidence, then square could be faster for most people even if an absolute pro would be faster on staggered.

HPDE events are for fun, i agree, its not a competition, but for most drivers, including myself, its more fun when you are faster than other cars, and if staggered set up is faster, and what is more important safer, then why would anyone chose square set up over staggered, unless ability to rotate tires and save $$ is a priority.

[bkrM3]

Originally Posted by OC3

One thing to consider is, the wear rate on front tires at the track is substantially higher than that of rear tires (opposite of what happens on the streets). I would estimate at nearly 3-to-2 ratio - i.e. 3 sets of fronts for 2 sets of rears. Given that, being able to rotate the tires has a substantial economic advantage. Get into heavy amounts of tracking and you'll find out pretty quickly how the tire expenses become one of the biggest on-going expenses. Another thing to deduce from this wear rate is that the fronts do much more work than the rears. So, wouldn't we want as much meat on the front as possible?

+1 to this. I've tracked staggered setups on my previous 335 and my current M3 and have now switched to square (apex arc-8 18x10 - 265/35/18 Yokohama AD08). I have to say that I prefer the handling characteristics of the square setup, but it's hard to say whether it's the tire size or the tire itself (or some combination of the two) that makes it feel better to me. FWIW, my car has ground control camber plates with stock EDC suspension (-2.5 front, -2.0 rear) and is definitely still prone to understeer, albeit less than with the stock staggered PSSes.

Even if a square setup offered absolutely NO handling advantage over staggered, I would STILL do it so I could move tires around to even out wear and prolong the life of the set. Whether you track a lot or you don't, if you're not a professional I think this aspect of the square setup alone should be enough to sway you in that direction.

[jphughan]

Originally Posted by Groundpilot

HPDE events are for fun, i agree, its not a competition, but for most drivers, including myself, its more fun when you are faster than other cars, and if staggered set up is faster, and what is more important safer, then why would anyone chose square set up over staggered, unless ability to rotate tires and save $$ is a priority.

A Z06 is faster than a Cayman S, but even when owners of both have them purely as dedicated track cars, some people choose the Cayman over the Vette because they prefer the way it feels and find it more fun/rewarding/whatever. And if they ALSO find it more controllable, THEY might actually be faster in a Cayman because they'll feel more confident pushing it harder. Going fast isn't always the most fun. One of my favorite rides I've ever caught was in an Elise, which was worth at least as many smiles per mile as my ride in an instructor's MP4-12C. And I've heard plenty of people say that a GT-R just isn't fun after the initial shock wears off, but since I've never been in one, I can't speak from personal experience.

The ability to rotate tires (and running smaller tires in the rear) also saves cash, and less cash spent on tires means more to spend on track days.