Rep Power: 0

Well, I just got a set of Falken Ziex 512s in 195/60/14 installed on my stock steelies, and I pretty much like them. They definitely are a lot stickier than the stock Firestones, and seem like they'll do better in the rain too. However, they may be good street/occasional drag tires, but they are definitely NOT an autocross tire. Driving them through a really windy (and fun) road, I really noticed the soft sidewalls, which actually seem softer than stock, although the increased traction helps to compenstate for them. I'm overall pretty satisfied, but I would like to know from some of the autocross/tire experts here, what's an optimal pressure to run these tires at? They came installed set at 37 psi on the fronts and 35 on the rears, I drove it and it feels like it needs to be adjusted...

Also, what suspension parts would decrease body roll or otherwise help to compensate for a softer sidewall? I'm not into autocrossing, but I do like to drive aggressively through the curves. Oh, and I'm jealous of everyone who has a one finger wheel gap. I have a one hand gap, haha.

 
Rep Power: 453

they should be set at the same PSI as recommended by the factory which is 30 front and 30 rear. I keep mine set at about 31 PSI on the front and rear. But yea 37 seems to high. That is a good way to kill the tires. As for the body roll, some good springs, definetly some high performance shocks, and a good upper strut bar, preferebly neuspeed, and a good front and rear sway bar. As for the sidewall, there isnt much you can do. I have the 512's too and I love them.

 
Rep Power: 339

37 is too high. I wouldnt go above 35... somewhere between 30-35 should be good.
I also agree, the 512's are NOT for racing. I feel they are good all around tires but if youre planning to go to track should have gotten the Azenis.
Ahhh.. to reduce body roll. did you get a thicker sway bar for the front and rear (or both)?

 
Rep Power: 283

I ran my stock firestones at 35psi also to make up for the soft sidewalls. If you want a softer ride, go 30psi, decent street handling go 35psi. Autocross levels are more like 40-45psi, not good for daily use. When I bought new tires I went with potenzas because I wanted stiffer sidewalls, and I wasn't disappointed. I still run them around 33psi though, worlds better than those firestones.

To reduce body roll you're going to have to go to stiffer springs or bigger swaybars. If you do swaybars, the front is going to make a bigger difference, but then you'll get major understeer so you'll want to upgrade the rear as well. I have an 03' and went from 16mm/12mm to 25.4mm/19mm, using the 01' civic ex stock swaybar and the rsx 19mm rear stock bar.

 
Rep Power: 381

Reducing body roll isnt going to make the tires more responsive....

 
Rep Power: 0

I have the same question as you, except I will be running falken ze 512's 195/60/15...
I kept my stock tires at 30 psi, so what do I keep the falkens at??

 
Rep Power: 0

15 should stay at 30.....IMO.

however, for my 215/45/R17...should i follow the rule of thumb? +2 psi ever 1" increase of diameter?

so, is 34PSI should be the number for my new tires?

 
Rep Power: 0

34??? wow, isn't that a bit low for daily use? Maybe you mean for track or race use? If you don't keep your tires pumped up very high, you can see the sidewall crunch up. I don't even want to know what happens when you hit a small pot hole with that low of pressure.

 
Rep Power: 453

34 is about normal. the car says 30 PSI front and rear. I keep mine in between those two numbers.