stagger or square?
02-10-2012, 11:48 AM
#16
Three Wheelin'
Join Date: Jan 2010
Location: Durham Region/GTA East, Canada
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Real world experience is a better judge. To tell you the truth I could never understand how increasing the front or decreasing the rear tire pressure would correct understeer. Yet all the books I read on suspension dynamics and on other sites (tire-rack below) stated the same. Maybe some expert would chirp in and explain. Maybe it's something to do with slip angle as you turn?
Don't think of it as increase/decreasing tire pressures. Picture in your mind contact patch. More pressure less contact patch, less pressure more contact patch.
To anyone else looking at this later, this is NOT a linear relationship. Too little pressure, and you will roll the sidewall, and lose a huge amount of grip, (and would likely crash or at least, go off the road.)
02-10-2012, 02:54 PM
#17
Three Wheelin'
What are you going to do with the car (track, street, mix)? How often do you drive it? What is your frequency of tire purchases?
Unless you are pushing the limits, I would vote square to allow for even tire wear. Because it's an N/A you will not be able to tell the difference if you soften the rear just a little.
On track, oversteer is faster but just a little!! (oversteer that is)
Unless you are pushing the limits, I would vote square to allow for even tire wear. Because it's an N/A you will not be able to tell the difference if you soften the rear just a little.
On track, oversteer is faster but just a little!! (oversteer that is)
02-10-2012, 03:04 PM
#18
Nordschleife Master
Don't think of it as increase/decreasing tire pressures. Picture in your mind contact patch. More pressure less contact patch, less pressure more contact patch.
To anyone else looking at this later, this is NOT a linear relationship. Too little pressure, and you will roll the sidewall, and lose a huge amount of grip, (and would likely crash or at least, go off the road.)
To anyone else looking at this later, this is NOT a linear relationship. Too little pressure, and you will roll the sidewall, and lose a huge amount of grip, (and would likely crash or at least, go off the road.)
02-10-2012, 04:05 PM
#19
Three Wheelin'
Thread Starter
What are you going to do with the car (track, street, mix)? How often do you drive it? What is your frequency of tire purchases?
Unless you are pushing the limits, I would vote square to allow for even tire wear. Because it's an N/A you will not be able to tell the difference if you soften the rear just a little.
On track, oversteer is faster but just a little!! (oversteer that is)
Unless you are pushing the limits, I would vote square to allow for even tire wear. Because it's an N/A you will not be able to tell the difference if you soften the rear just a little.
On track, oversteer is faster but just a little!! (oversteer that is)
02-10-2012, 05:02 PM
#20
Three Wheelin'
At 7 years old, you are flirting with disaster running those at the track. I use some 3 year old RA1's for rains but after this year I will discard as they are just not trustworthy anymore.
I hope you get new rubber before taking it to the track tire mfg's generally don't like you using them after 5 and for abusive use that would be the absolute upper limit.
I hope you get new rubber before taking it to the track tire mfg's generally don't like you using them after 5 and for abusive use that would be the absolute upper limit.
02-10-2012, 06:52 PM
#21
Three Wheelin'
Thread Starter
02-11-2012, 11:15 AM
#22
this a little off current topic but i just fix my stagger on the 924s. When i bought the car it had boxster wheels on it, but some cheap *** didnt want to buy the 7mm spacers for the front to clear the grease caps. instead they put the back wheels in the front making the front a wider stance then the back by about an inch plus the fronts wheel stuck out past the fenders alot.
02-11-2012, 11:25 AM
#23
Pro
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i have staggered rims 7"s and 8"s right now with 205s and 225s. When I eventually change to late offset I'm going to try to avoid some of the trouble sourcing good tires for 16" rims here in NZ by looking for some 17" cup1's.
these rims should be square, yes? is it a good idea to stagger tires on them too or stay square to suit the rims?
If I could keep my fuchs I would have liked to have gone 225's front and 245's rear. If i have to stay square with the 17's I'd go either 225 or 245 all around depending on price.
TIA
these rims should be square, yes? is it a good idea to stagger tires on them too or stay square to suit the rims?
If I could keep my fuchs I would have liked to have gone 225's front and 245's rear. If i have to stay square with the 17's I'd go either 225 or 245 all around depending on price.
TIA
What is your motivation for switching to late offset?
02-11-2012, 03:08 PM
#24
Three Wheelin'
Thread Starter
968 parts car
02-11-2012, 09:14 PM
#26
Nordschleife Master
02-12-2012, 11:10 AM
#28
Racer
Join Date: Nov 2007
Location: Waterloo, Ontario, Canada, eh
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The series 1 944 came with 7x15 and 215/60s all around, and was a very balanced car at the track. I had the experience of driving a series one, then driving a 951 at Mosport. I could definately feel the 200# difference between turns 9 and 10 (just before the last corner going back onto the pit straight).
The 951 had 7s and 8s x 16. I bought a 951 in 86 and swapped the 7s for 8s and ran 225/50 and 245/45s. So the wheels were square, but not the tires. I did a couple track events a year. Then I started on the modification spiral, cup sway bars, cup suspension, camber plates, big reds and floating rotors, chips and shims, Hajny roll bar, 8.5 and 10 x 17s with 255/40 and 275/40. Then the front sway bar bracket broke and I crashed at the glen. So now I'm making 335/30s and 285/30s x 18 fit. Contact patch? I'm sure I can adjust that. Eventually. I have an IR temperature sensor (or two) that I use to monitor brake pad temp, or tire temp.
Regards,
doug
86 951 (http://www.pcaucr.org/visuals/photos...egory&catid=61)
01 E320 (W210) 4matic Wagon (http://www.benzworld.org/forums/w210...body-do-2.html)
00 540i-6 (http://forums.bimmerforums.com/forum...hp?albumid=976)
94 855 turbo Wagon (sold in 09)
85 535i-5 (sold in 07)
76 300D (sold in 92)
83 944 (sold in 86)
I apparently only buy cars designated by numbers
The 951 had 7s and 8s x 16. I bought a 951 in 86 and swapped the 7s for 8s and ran 225/50 and 245/45s. So the wheels were square, but not the tires. I did a couple track events a year. Then I started on the modification spiral, cup sway bars, cup suspension, camber plates, big reds and floating rotors, chips and shims, Hajny roll bar, 8.5 and 10 x 17s with 255/40 and 275/40. Then the front sway bar bracket broke and I crashed at the glen. So now I'm making 335/30s and 285/30s x 18 fit. Contact patch? I'm sure I can adjust that. Eventually. I have an IR temperature sensor (or two) that I use to monitor brake pad temp, or tire temp.
Regards,
doug
86 951 (http://www.pcaucr.org/visuals/photos...egory&catid=61)
01 E320 (W210) 4matic Wagon (http://www.benzworld.org/forums/w210...body-do-2.html)
00 540i-6 (http://forums.bimmerforums.com/forum...hp?albumid=976)
94 855 turbo Wagon (sold in 09)
85 535i-5 (sold in 07)
76 300D (sold in 92)
83 944 (sold in 86)
I apparently only buy cars designated by numbers
02-12-2012, 11:59 AM
#29
Square preferred especially for tight tracks.
02-12-2012, 05:10 PM
#30
I actually prefer staggered.
I've taught performance car control skills for 20 years. Going wider in the rear does not "increase" under steer, it just makes the rear stick more making you notice the understeer because the back is not wanting to come around as easy. So you might simply have an understeer situation because you are pushing beyond a spot where you would have had oversteer. (typically going faster than you would have otherwise)
I much prefer the look of staggered and I want every corner of the car to stick as much as possible. No reason to give up potential grip in the rear.
I've taught performance car control skills for 20 years. Going wider in the rear does not "increase" under steer, it just makes the rear stick more making you notice the understeer because the back is not wanting to come around as easy. So you might simply have an understeer situation because you are pushing beyond a spot where you would have had oversteer. (typically going faster than you would have otherwise)
I much prefer the look of staggered and I want every corner of the car to stick as much as possible. No reason to give up potential grip in the rear.