i'm currently running Kumho 712's 205/50/15 (f) and 195/50/15 (r). What are the advantages/disadvantages of this? I've heard this is dangerous? I hear it encourages neutral handling?
I figured i'd get the best answer here.

thanks

 

Good: more oversteer

Bad: more oversteer

 

i'm a noob at suspension tuning. i'm lost right now.

here's my problem. car feels unstable at higher speeds (80 mph on freeway).
i don't know exactly what i want. So i'm going to start experimenting with strut settings and tire pressures.

Here's the setup
88 dx hatch w/b16 swap.
2300 lbs w/driver.
kumho 712's 205/50/15 (f) 195/50/15 (r)
36 psi hot (f) 32 psi hot (r)
ractive coilovers for 92 integra (unsure of spring rates)
kyb agx on all corners (front at 3/rear at 3)
92 integra trailing arms, 91 SiR knuckles, 92 integra mc/bb coming soon.
replacing every bushing in the front w/es bushings on sat.
i need new ta, compensator arm,and rear uca bushings.
89 civic rear lca's and rear shock mounts have es bushings.

I want to decrease oversteer and see if i like it. what must be changed?
please evaluate my setup.

what tire psi/strut settings should i try?

 

Sounds like you're in the process of eliminating some variables. Do that, then come back here if it's not fixed. "unstable" at higher speeds could be as simple as a lot of toe out.

 

unstable at high speeds does definitely sound more like an alignment issue than a staggered wheel issue (unless you've got some balancing issues, which doesn't really relate to the tire size).

as far as decreasing oversteer, in theory you'd want to soften the struts in the back, bump up tire pressures in the rear, decrease ride ht in the rear (if you're raked) but since you've got some general suspension issues, it'll be hard to say what will happen if you do the above without dealing with them.

 

"here's my problem. car feels unstable at higher speeds (80 mph on freeway). "

Sounds like the tires are following the ruts and uneven grooves in the road. Regardless of alignment, although toe-out will emphasize this, higher performance tires in my experience tend to "walk around" more on uneven pavement. This is an extreme example, but I was amazed when I drove a local autocross with V700s on how much more aware I had to be while driving on the street.

IF you're talking about it being unstable in corners, then totally disregard the above.

Ah the never ending compromise of street vs. race.

 

finding out what springrates you have and other missing info like that would be the first thing to do.. for your own knowledge and for people on here to understand the dynamics of your car better..

 

if you are trying to REDUCE oversteer, and your car wanders around on the highway & feels unstable, then it sounds like you've got some alignment issues.