zredbaron Posted May 3, 2007 Share Posted May 3, 2007 been searching the forum for awhile now, really surprised this one didn't come up! i just got a set of kuhmo v710s for my sm2 240z....just wondering what tire pressure these dot slicks like with our z cars. the size? 225/50R16 all around. i have a simple setup: tokico 5-way struts with 200fr/225rear springs. thick sways, strut braces. no camber plates yet. my kuhmo ecsta mx street tires liked to be around 37.5 for the front and 35.5-36.0 for the rear. same exact size... 225/50R16s. any recommendations would be appreciated! thanks. also, the kuhmo street tires i ran didnt like to be cooled with water between runs...the hotter the better. do these behave that way too, or do they like to be cooled? thanks again. -mark Quote Link to comment Share on other sites More sharing options...
johnc Posted May 3, 2007 Share Posted May 3, 2007 Without camber plates you'll have to watch for rollover. Look for the treadwear indicator triangles on the side of the tread. Adjust air pressure until the scuffing just meets the top of the triangles. Start high (35 psi cold) and work down. On my 3200 lb 350Z with 1 degree of negative camber I run 29psi cold front and 27psi cold rear and ajusted hot pressures to 30F and 28R. Back when I ran 710s on the 240Z and had lots of camber, I run 24psi cold front and rear and adjusted hot to 26 all around. Quote Link to comment Share on other sites More sharing options...
zredbaron Posted May 3, 2007 Author Share Posted May 3, 2007 good to know, i'll start high and chalk the sidewall. in your opinion, do you think the pressure just above where rollover occurs will be best for me, or is it possible i may find the tires hook up better at a higher pressure than that even? obviously some experimentation is in order...just curious... thanks, john. Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 4, 2007 Share Posted May 4, 2007 For open track/HPDE use, I start out at 28 psi cold. I don't do any autox, so that's FWIW. 2700# car, neg 2.5 camber F&R. John Quote Link to comment Share on other sites More sharing options...
evildky Posted May 4, 2007 Share Posted May 4, 2007 I ran 28 front and 32 rear on my 225/50 15's, with koni' classics and st springs, it's gonna be unique to you, also if oyu have a digital thermometer, you want the tems across the tire surface to be as equal as possible, if the center is higher than the sides then it's over inflated, if it's hotter on the outsides than the center you need more air Quote Link to comment Share on other sites More sharing options...
johnc Posted May 4, 2007 Share Posted May 4, 2007 The lower the tire pressurs, the more the V710s grip, assuming good temps across the tread and no rollover. Quote Link to comment Share on other sites More sharing options...
Clifton Posted May 4, 2007 Share Posted May 4, 2007 I haven't run V710, just V700's and RA1's, not quite the same I know but closer than a street tire. I run 3* camber up front with 40 psi cold just to keep the temps close to even . Rear, about 1.5-2* and 35 psi and the outsides are hot. I would think with stock camber you would need to run higher pressure, I know I would on my car. I would invest in a pyromoter. I do know if you run a soft tire that loads one part of the tire hard (lack of camber), you will know at the end of the day by looking at it. Quote Link to comment Share on other sites More sharing options...
zredbaron Posted May 11, 2007 Author Share Posted May 11, 2007 Thanks for the inputs. I took the car out for a test drive last night (35 psi all around), and well, god-*damn* those tires hold well! I couldn't believe the snap i could demand (1st gear full throttle from a decel... holy hell that's some grip!)...didn't ever lose traction from torque... Wow. So yeah, basically I think it's going to take some seat time before I can even notice my tires responding to different pressures. I think my first event or two I'll still just be in awe of the difference. The only thing I'll be able to measure is rollover. Hopefully I'll get a temp probe soon, too. Thanks again for the numbers. Ballpark good. Quote Link to comment Share on other sites More sharing options...
evildky Posted May 12, 2007 Share Posted May 12, 2007 I suspect your ideal time is gonna be south of 30 psi, I settled my 315/35 17 rears in at 19 psi, and my 295/40 17 fronts in at 21psi, honestly the car doesn't have enough weight to take full use of tires this wide, strait line traction is still an issue, thinking of softer rear springs and maybe even adding weights to the spare tire well Quote Link to comment Share on other sites More sharing options...
zredbaron Posted May 14, 2007 Author Share Posted May 14, 2007 figured i'd follow through with my weekend. well, i started high, 37.5 front and 35.0 rear, working lower and lower all day. i never went so low that i noticed a decrease in performance, only an increase. i got down to 29.5 fr and 27.0 rear. really liked that. i'll try lower next time. and man, dot slicks are freakin' SWEET! haha! i was told after my third run that i was lifting my inside tire when powering out of a tight turn... that's one pic i *HAVE* to have! looks like i got 4th best raw time, bested by a gutted sti, a Z06, and an s2000. sigh... i really want that pic! but hey, in other news, on my way back from the race, my truck (trailer in tow) decided it wanted to get all squirrelly at 75mph... kuhmo truck tire! (turns out it was damaged, not a defect. the rim ripped the sidewall from the tread due to the weight of the trailer) images of my trailer and z flipping into a ditch flashed before my eyes... oh hell no!!!! managed to get it calmed down... not something I ever want to experience again! Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 14, 2007 Share Posted May 14, 2007 Great you had a good weekend. Keep looking for the sweet spot. I've started the V700's as low as 24 for a time trial. They hurt the edges a little and heated up quickly, but for about 3 laps they flew. John Quote Link to comment Share on other sites More sharing options...
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