Ironically, I noticed the car being a bit loose after the second run so before the 3rd, I backed off 2 psi in the rear.
2 psi lower than the beginning of the day. I started at 42f, 41r. Backed off to 42f, 39r
[quote=“Zong,post:243,topic:27647"”]
2 psi lower than the beginning of the day. I started at 42f, 41r. Backed off to 42f, 39r
[/quote]
Yeah, lowering rear tire pressure will make it even more loose.
[quote=“fairgentleman Z,post:124,topic:27647"”]
Nah all that does is reduce the contact patch, be brave, less tire pressure in the rear = lower cornering stiffness in the rear:
Cf*a - Cr*b > 0 = oversteer Cf*a - Cr*b = 0 = nuetral steer Cf*a - Cr*b < 0 = understeerFor FWD car a is small…
For example a FWD car with 63/37 weight dist a would = 37 and b = 63. Therefore to approach neutral steer the cornering stiffness of the rear should be lower (achieved by running a lower tire pressure).
It’s just that overpressurizing the rear is prefered as it is much easier to control.
[/quote]
I hope that people read this, learn from your unfortunate mistake, and understand tire pressures more. Lowering pressure in the rear does not increase grip by increasing the contact patch, it makes the sidewalls softer = oversteer.
Think of it this way:
two flat tires up front = big push
two flat tires out back = big rotation
i thought it was a good time…alot of nice cars and cool people there :tup:
[quote=“Zong,post:238,topic:27647"”]
Apologies to the course-workers who I put in danger and also for holding up the race.
I was on a new setup and got too comfortable in the first 2 runs and wanted to push harder. I came into the last slalom quite fast and the back end broke loose, pointing my nose directly at the curb and some course workers behind it @ maybe 30 mph. I had a moment to decide either to hit it head-on and jump the curb or to pull it sideways, so I pulled it sideways hoping I wouldn’t go over the curb and so the back corner of the car would take most of the impact. Some people told me afterwards that there were a few others who had close calls at that location as well.
Thanks for everyone that helped push my car off the course, and the help afterwards:
esp. Jarrod, Jim T, Paul, soloIIscoob, Jim P, FuzzyDevin, Carnut, Nick, the safety stewards.
[/quote]
I worked that slalom for one of my shifts, and saw several people get squirrely in there, but it was earlier in the day so people were still pretty cautious. At the end of the day, I’m glad no one got hurt!
This is so true… I can’t tell you how many times I’ve heard people tell Novices to lower their tire pressure to get a larger contact patch. Lower pressures mean mushy turn ins and a higher slip angle
[quote=“Zong,post:238,topic:27647"”]
Apologies to the course-workers who I put in danger and also for holding up the race.
I was on a new setup and got too comfortable in the first 2 runs and wanted to push harder. I came into the last slalom quite fast and the back end broke loose, pointing my nose directly at the curb and some course workers behind it @ maybe 30 mph. I had a moment to decide either to hit it head-on and jump the curb or to pull it sideways, so I pulled it sideways hoping I wouldn’t go over the curb and so the back corner of the car would take most of the impact. Some people told me afterwards that there were a few others who had close calls at that location as well.
Thanks for everyone that helped push my car off the course, and the help afterwards:
esp. Jarrod, Jim T, Paul, soloIIscoob, Jim P, FuzzyDevin, Carnut, Nick, the safety stewards.
[/quote]
No prob Zong, anything to help a friend out.
Zong for the damage I saw on ur car I can say this: Lat links, strut tower, drive axel, maybe swaybar endlink definitely the rim need replacing and trunk was not lining up properly… a little bent perhaps.
Just make sure Northtown takes care of you. Ask Trap what happend to his Sti over the winter and how northtown did a half ass job. Just make sure your happy with the work.
Zong if you need anything let me know.
:headbang:for still wining your class…asshole
[quote=“jrod0187,post:247,topic:27647"”]
No prob Zong, anything to help a friend out.
Zong for the damage I saw on ur car I can say this: Lat links, strut tower, drive axel, maybe swaybar endlink definitely the rim need replacing and trunk was not lining up properly… a little bent perhaps.
Just make sure Northtown takes care of you. Ask Trap what happend to his Sti over the winter and how northtown did a half ass job. Just make sure your happy with the work.
Zong if you need anything let me know.
:headbang:for still wining your class…asshole
[/quote]
Rob can tell you a thing or 2 about them as well. Do not take your car back until you are 100% satisfied.
[quote=“RobHimself,post:249,topic:27647"”]
Rob can tell you a thing or 2 about them as well. Do not take your car back until you are 100% satisfied.
[/quote]
Yea i totally for got about that whole hood incident, yea i can attest too but the workmanship was fine… just the fact that they were careless scratching my paint on the other side.
[quote=“fairgentleman Z,post:244,topic:27647"”]
Yeah, lowering rear tire pressure will make it even more loose.
I hope that people read this, learn from your unfortunate mistake, and understand tire pressures more. Lowering pressure in the rear does not increase grip by increasing the contact patch, it makes the sidewalls softer = oversteer.
Think of it this way:
two flat tires up front = big push
two flat tires out back = big rotation
[/quote]
I respectfully disagree.
There is an optimum point of traction in relation to pressure. Going above OR below that pressure point will reduce the available traction at that end of the car. The traction/pressure curve is more gradual on the soft side, and more abrupt on the hard side. It’s very unlikely that going from 41 to 39PSI caused the spin.
I’m not sure what type of tires were being used in this case, but assuming that they were decent street tires with reasonably firm sidewalls the range of goodness on the back of a WRX should be anywhere between 30 and 45 PSI. On both my WRX and my first EVO, running on good streets (Azenis|Advans), when running at Valeo (bumpy surface) that didn’t like high pressures, I would have to run down into the 25PSI range on the rear to get decent rotation.
Didn’t want to jump in on this, but I’d hate for someone with less experience to be afraid of adjusting their pressures for fear of spinning off into a curb.
George M (AS 91)
Speaking of pictures, I know quite a few were taken early on. Don’t suppose they were posted anywhere?
im lazy.VERY fun event…so nice to be back out racing again finally. Pauls car is set up beautifully. The car easily had FTD times in it with a solid clean run which I could not pull off in 5 runs. Props to Canadian SM guys coming out and bringing some fierce competition, looking very foward to seeing them in future events.
Next event I should hopefully have my quickness back up and running.
[quote=“99_civic_si,post:254,topic:27647"”]
Next event I should hopefully have OUR quickness back up and running.
[/quote]
Fixed.
And Zong - make sure you talk to Mike Keller at Northtown, I hear he is a Suby tech there now. He’ll make sure you get taken care of. If you don’t know him, just ask for him and tell him you are with us.
[quote=“Mrs. Karus,post:253,topic:27647"”]
i’ll get some up in a bit… 
im lazy.
[/quote]
so that was u taking the pictures i thought u looked familiar.
and just for the record my face feels like its on fucking fire today!!!
[quote=“Tunerfreak,post:256,topic:27647"”]
and just for the record my face feels like its on fucking fire today!!!
[/quote]
My arms are toasted and so is my face, i think alot of people forgot to wear sunscreen. I didnt forget to do it, i was too lazy to grab it walking out the door
ATTENTION!!!
Please don’t mention names, details or post any more pics of a certain someone’s car being involved in any “incidents” yesterday. Please help a bother out.
Oh, and FTD was Alan Smith with a 43.844, and PAX was Dale Kunze with a pax of 36.404. Results will be up shortly.