staggered or square for the track?
- Thread starter Danng
- Start date
Re: staggered or square for the track?
In general and with these sorts of cars, because of ability to get on the throttle a little quicker coming off corners, you're still going to drop some time by going with more tire in the rear, even if it increases the perception of understeer through the earlier parts of the corner. Actual US does not increase because it is only stronger at higher cornering speeds vs the original square setup.. ie. the US tendency is more easily picked up in a staggered set up when it is overdriven. Depending on the type of car, course and stint length, a little steady state US can be a good thing as well.
Above refers to adding tire without adapting set up or line. The gains are not insignificant. If you change the line and throttle on points you pick up a little more. You can gain in braking depending on how aggressive stock bias and EBD is. If you go further and adapt the rest of the setup to match, then you gain the most from the stagger.
There are many factors that affect how much you can gain get from adding tire to one end of a specific model (zero and negative gain situations are extremely rare), but based on the little I know about the typical track-applied street BMWs, there definitely are gains.
In general and with these sorts of cars, because of ability to get on the throttle a little quicker coming off corners, you're still going to drop some time by going with more tire in the rear, even if it increases the perception of understeer through the earlier parts of the corner. Actual US does not increase because it is only stronger at higher cornering speeds vs the original square setup.. ie. the US tendency is more easily picked up in a staggered set up when it is overdriven. Depending on the type of car, course and stint length, a little steady state US can be a good thing as well.
Above refers to adding tire without adapting set up or line. The gains are not insignificant. If you change the line and throttle on points you pick up a little more. You can gain in braking depending on how aggressive stock bias and EBD is. If you go further and adapt the rest of the setup to match, then you gain the most from the stagger.
There are many factors that affect how much you can gain get from adding tire to one end of a specific model (zero and negative gain situations are extremely rare), but based on the little I know about the typical track-applied street BMWs, there definitely are gains.
Re: staggered or square for the track?
I'd reco staggered set up in general for RWD cars...
The difference in front n rear tire sizes , for BMW car as example, shouldnt exceed 30mm in width..
If u stick with 30mm which is wot mostly the M-cars are shod with, then dial a bit more aggressive cambers in the front and slightly toe out...the impact is amazing.
I'd reco staggered set up in general for RWD cars...
The difference in front n rear tire sizes , for BMW car as example, shouldnt exceed 30mm in width..
If u stick with 30mm which is wot mostly the M-cars are shod with, then dial a bit more aggressive cambers in the front and slightly toe out...the impact is amazing.
great info and advise.
Rastaman
Well-Known Member
Re: staggered or square for the track?
I'm all for staggered .... coincidentally tripleM and i were talking abt this subject during our last meet up as i saw that in US beemer forums...seems a lot of trackies especially M3 seem to like square set up. I agree it does help correct understeer but u can correct US via other means as well as mentioned by Jack..camber, sway bar and coilover setting ! which i think is a whole lot better than having square ...think heavier tyres ! unsprung weight ...ouch !
And bro Dan, there is no massive understeer !! Shaun has said it man..it comes when u overdrive, brake too late, etc ..sure to understeer ! cheers and enjoy ! just take it easier on brakes n throttle input pt and be smooth !
I'm all for staggered .... coincidentally tripleM and i were talking abt this subject during our last meet up as i saw that in US beemer forums...seems a lot of trackies especially M3 seem to like square set up. I agree it does help correct understeer but u can correct US via other means as well as mentioned by Jack..camber, sway bar and coilover setting ! which i think is a whole lot better than having square ...think heavier tyres ! unsprung weight ...ouch !
And bro Dan, there is no massive understeer !! Shaun has said it man..it comes when u overdrive, brake too late, etc ..sure to understeer ! cheers and enjoy ! just take it easier on brakes n throttle input pt and be smooth !
PerverTT
Well-Known Member
Re: staggered or square for the track?
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 …
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 …
Rastaman
Well-Known Member
Re: staggered or square for the track?
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 !!
Shaun;328488 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 !!
Re: staggered or square for the track?
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.
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.
PerverTT;328492 said:
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:
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.
Re: staggered or square for the track?
Re the square set up done in US M3 forum...
The only compelling reason I know is not because they want to run square but it is the fact that the tire that they run for track day for eg, mostly comes in 265 ( as used in the rear, eg Mich PS Cup ) and we know this brand got sizes 235 , 265 and nothing in between which is the most common set up from BMW factory...
So the next best option for them is 265 all round and mind you, they dont run 9.5J all round either, but front is 9J and rear is 9.5J (typical stock width)..both of which can be nicely shod with 265 anyway.
Now the good news is......Mich PS CUP has recently launched 245/35/19!.......yeeha, and I am getting it for my front set up ( was 235 before )
Steady ah.....
Re the square set up done in US M3 forum...
The only compelling reason I know is not because they want to run square but it is the fact that the tire that they run for track day for eg, mostly comes in 265 ( as used in the rear, eg Mich PS Cup ) and we know this brand got sizes 235 , 265 and nothing in between which is the most common set up from BMW factory...
So the next best option for them is 265 all round and mind you, they dont run 9.5J all round either, but front is 9J and rear is 9.5J (typical stock width)..both of which can be nicely shod with 265 anyway.
Now the good news is......Mich PS CUP has recently launched 245/35/19!.......yeeha, and I am getting it for my front set up ( was 235 before )
Steady ah.....
Re: staggered or square for the track?
Sorry Ed
No 18 for 245...just the usual 235
Tire Specs for Michelin Pilot Sport Cup=
Sorry Ed
No 18 for 245...just the usual 235
Tire Specs for Michelin Pilot Sport Cup=
fasterthanferrari
Well-Known Member
Re: staggered or square for the track?
So 265 front and 285 rear (more tire in the back and less difference btw them to minimize US) is better than 265 all around...is that too much, if there ever was such thing as too much tire?
So 265 front and 285 rear (more tire in the back and less difference btw them to minimize US) is better than 265 all around...is that too much, if there ever was such thing as too much tire?
Re: staggered or square for the track?
Strictly in terms of tire patch influence on total grip and overall balance, there's no such thing as an too much tire. You can always do something with more tire especially with heavy, no/low downforce cars.
If you talk about extreme cases of really low powered cars driving some big open courses or ones with a lot of tight radius turns that are more about rotating the car than laterally accelerating it (point and shoot).. then performance wise there are limits of how heavy wheel combined wheel and tire are, and how much extra drag you have to deal with from the tire and aero.
I mean you could come up with a fairly long list of performance exceptions to the rule, but in total they'll make up some 0.00X% of everything that's run in real life. The practical limitations are almost always the first limits encountered. Things like like packaging (mechanical, aero), cost, safety (limiting speed), etc.
Strictly in terms of tire patch influence on total grip and overall balance, there's no such thing as an too much tire. You can always do something with more tire especially with heavy, no/low downforce cars.
If you talk about extreme cases of really low powered cars driving some big open courses or ones with a lot of tight radius turns that are more about rotating the car than laterally accelerating it (point and shoot).. then performance wise there are limits of how heavy wheel combined wheel and tire are, and how much extra drag you have to deal with from the tire and aero.
I mean you could come up with a fairly long list of performance exceptions to the rule, but in total they'll make up some 0.00X% of everything that's run in real life. The practical limitations are almost always the first limits encountered. Things like like packaging (mechanical, aero), cost, safety (limiting speed), etc.
PerverTT
Well-Known Member
Re: staggered or square for the track?
Shaun - I should know better than pick an argument with you about a technical issue, but surely, for any car, there must come a point where the minuses of extra unsprung weight, extra rotational inertia, extra rolling resistance, etc outweigh the benefits of extra grip afforded by a wider tyre?
And that's setting aside issues normally associated with wider tyres such as diminished steering feel for the fronts, understeering tendencies for the rears, rubbing against wheel arches (fenders to Americans), hydro-planing tendencies, etc etc.
Surely there is legitimate use for the term "over tyred?"
Shaun - I should know better than pick an argument with you about a technical issue, but surely, for any car, there must come a point where the minuses of extra unsprung weight, extra rotational inertia, extra rolling resistance, etc outweigh the benefits of extra grip afforded by a wider tyre?
And that's setting aside issues normally associated with wider tyres such as diminished steering feel for the fronts, understeering tendencies for the rears, rubbing against wheel arches (fenders to Americans), hydro-planing tendencies, etc etc.
Surely there is legitimate use for the term "over tyred?"
Re: staggered or square for the track?
Perv, yes the performance limit varies depending on car, but for nearly all cars (as explained in last post), the limit is performance limit is still far off, and in any case you run into practical limits much earlier than performance limits.
So performance wise, given average weight and power of the cars we deal with on the street, and given the available tire sizes (like the range mentioned on this thread), there is no such thing as over tired.
The very real practical limits are a function of a huge mix of factors, and vary for every individual or team. You could discuss it, even with specifics, forever and still not come to a conclusion, so it's up to the indivudals and teams to do that themselves.
Perv, yes the performance limit varies depending on car, but for nearly all cars (as explained in last post), the limit is performance limit is still far off, and in any case you run into practical limits much earlier than performance limits.
So performance wise, given average weight and power of the cars we deal with on the street, and given the available tire sizes (like the range mentioned on this thread), there is no such thing as over tired.
The very real practical limits are a function of a huge mix of factors, and vary for every individual or team. You could discuss it, even with specifics, forever and still not come to a conclusion, so it's up to the indivudals and teams to do that themselves.
Racebred
Core Group Members
Re: staggered or square for the track?
i've tracked really quite a bit on BMW 3 series. my preference is square, upsized or not. it gives a better well-balanced feel. upon turn-in, and at mid-corner, the centre-of-rotation feels a lot more near the centre of the car rather than skewed a bit with fatter rears. i don't know which gives better timing. but when it comes to feel, it feels less understeery. which = more fun.
i've tracked really quite a bit on BMW 3 series. my preference is square, upsized or not. it gives a better well-balanced feel. upon turn-in, and at mid-corner, the centre-of-rotation feels a lot more near the centre of the car rather than skewed a bit with fatter rears. i don't know which gives better timing. but when it comes to feel, it feels less understeery. which = more fun.
