AP2 STR Autocross discussion
Joined: Jun 2010
Posts: 1,881
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From: Near Philadelphia
This thread talks about how lowering causes the roll center to be to far down and how to adjust for it.
https://www.s2ki.com/s2000/topic/879...ar-wheel-lift/
Not sure what impact the roll center adjusters have on STR, but, it definately answers when is lowered, to low.
https://www.s2ki.com/s2000/topic/879...ar-wheel-lift/
Not sure what impact the roll center adjusters have on STR, but, it definately answers when is lowered, to low.
Joined: Nov 2003
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From: Atlanta
I think it was a mistake to break this conversation out of the main STR thread. This is as rambling and now it's in a different place whereas it was pretty easy to go into the STR thread and search inside of it. If you can't bother to read a couple hundred pages of thread (skimming works really well) then you probably shouldn't take on building an ST car.
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Originally Posted by glagola1' timestamp='1311292708' post='20803212
Get the 255s. Width is king when it comes to lateral grip and autox is 85% lateral grip.
But, if you can dig up the October 2010 issue of Grassroots Motorsports they have a convincing tire test for the STR Miata that suggests that a narrower tire might not be a disadvantage, perhaps depending on the course. The data is a bit suspect though, as they test a set of 245's on a lighter wheel vs. 255's on a heavier wheel.
I could not find a link to this online but many of you I'm sure have back issues of GRM laying around. The cover looks like this
-Marc
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Agreed. I want to hear/see what AP1 & AP2 owners are doing to advance their builds. There isn't much difference between the generations and many (if not all) of the modifications are applicable to all of the manufacture years. I'll continue to post in the main STR prep thread and I hope AP2 owners will, as well.
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Joined: Jul 2010
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I'm sorry the STR prep thread is to long to be useful.
As for the AP1/AP2 issue, there are to many posts in the STR prep thread where the OEM spring and sway bar rates are relevant and the poster doesn't relate what year S2000 they are posting about.
If I was able to I would update the title of this to STR Tire Discussion, or something like that.
Joined: Jun 2010
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From: Near Philadelphia
Originally Posted by IntegraR0064' timestamp='1311612301' post='20812951
I agree too. Maybe a moderator can merge this into the main str prep thread?
I'm sorry the STR prep thread is to long to be useful.
As for the AP1/AP2 issue, there are to many posts in the STR prep thread where the OEM spring and sway bar rates are relevant and the poster doesn't relate what year S2000 they are posting about.
If I was able to I would update the title of this to STR Tire Discussion, or something like that.
I agree an STR forum would be ideal but having the one rambling thread is definitely better than having multiple rambling threads. And as you saw here, topics bleed together so shifting topics happens quickly.
Joined: Mar 2009
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Originally Posted by bronxbomber252' timestamp='1311480860' post='20809314
After todays event I'm convinced that the 245's are faster on low grip lots (might be that they heat up quicker)... I was almost a full second faster than the people that I am normally within .2 seconds +/-... this on a 45-50 second course. I am getting more even tire wear and temps too...
Jury is still out on grippy surfaces. But I think part of the reason I am getting these results is alignment, my -2.8f/-2.2r camber was heating up the outsides of the 255's much more than the insides, I get better tire temps with the 245's and running more reasonable pressures (low-mid 32-34's psi instead of 38-40psi)
I also like the feel of the car a little better with the 245's but I think I would run 255's at a large concrete course such as nationals because I don't think the 245's would have the heating advantage and I think that on a grippy surface the slight increase in lateral grip would outweigh the better response and transitions.
today seemed to support my observation that the 245 kooks feel like they perform very similarly to the 255 dunlops I had but with better heat resistance and better performance on less grippy lots, yet not as much wet grip.
Jury is still out on grippy surfaces. But I think part of the reason I am getting these results is alignment, my -2.8f/-2.2r camber was heating up the outsides of the 255's much more than the insides, I get better tire temps with the 245's and running more reasonable pressures (low-mid 32-34's psi instead of 38-40psi)
I also like the feel of the car a little better with the 245's but I think I would run 255's at a large concrete course such as nationals because I don't think the 245's would have the heating advantage and I think that on a grippy surface the slight increase in lateral grip would outweigh the better response and transitions.
today seemed to support my observation that the 245 kooks feel like they perform very similarly to the 255 dunlops I had but with better heat resistance and better performance on less grippy lots, yet not as much wet grip.
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