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Discussion Starter · #1 ·
I've tried and tried, but I just can't seem to get the rear end of my 02 rex wagon to come around in it's stock form - are y'all having any better luck? Which mod would be best to decrease understeer or even induce a bit of oversteer in my wagon? strut braces/beefier swaybars/front/back?
 

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Rear swaybar would be one of the quickest and cheapest.

Do a search like this one:

http://www.clubwrx.net/forums/searc...id=90637&sortby=lastpost&sortorder=descending

Look around and you'll also find that getting an alignment done with more front negative camber and raising the air pressure in the front tires also help.

Of course springs and adjustable struts or coilovers also help but cost a lot more.

Chris
 

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Discussion Starter · #3 ·
thanks for the reply Chris.

yea, I've done similar searches on this and other forums, and the general concensus seems to be that a beefier rear swaybar is one of the best ways to decrease understeer. But the armchair physicist in me is having a hard time rationalizing why this would be true. Doesn't a beefier rear swaybar lower the rear end in hard cornering? If so, wouldn't this make the rear end stick more, not less, and thus increase understeer, not decrease it?

Maybe I won't really understand this until I get an adjustable rear swaybar on my car and try all the settings for myself...
 

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Discussion Starter · #4 ·
btw, another interesting recommendation to decrease understeer is to run higher tire pressure in the rear vs the front (ie. 30 lbs in front and 35 lbs in back). i'll try this one too.
 

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Quote taken from http://integra.vtec.net/geeser/docs/grm_swaybar.html
When a stiffer anti-roll bar is installed at one end of the car, that end will carry a greater percentage of the total load transferred during cornering. All else being equal, cornering power at the stiffened end will suffer while cornering power at the other end will be enhanced. (The reason for this has to do with the manner in which load transfer affects the torques that are applied about the center of gravity during cornering. This is a subject in itself.) Stiffening the front anti-roll bar will therefore lead towards understeer, while stiffening the rear anti-roll bar will lead towards oversteer.
Here is a good suspension tweak table: http://www.clubsi.com/suspension_tweak_table.shtml
 

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Well, this is kind of a noodle-puzzler.

I've seen the physics before, but don't exactly remember the details.

In general, a stiffer setup will yield more grip. BUT if one end is softer compared to the other it will have more grip. This holds true for springs, dampers (struts) and swaybars. So, you can also take out understeer by adding stiffer springs in the rear or stiffer struts in the rear relative to the front. I haven't done it to my WRX yet, but my preferred method of adjusting a car's balance is adjustable dampers. Then adjust the rear stiffer than the front. On my old CRX, I found the optimal setting for the front (2nd softest) and left it there. Then I'd adjust the rears to adjust balance. Full stiff for dry-weather (radical loose to compensate for the FWD tendency towards understeer) and softer for snow, etc. The nice thing was than on that car (as will be the case with my Rex wagon when I get new struts) I could do the adjustment from inside the cabin - just crawl in the back with the screwdriver on my Swiss Army keychain.

Now here's another noodle-cooker - Re-read my original post. Increase tire pressure in the FRONT, NOT the back! Though the other way around seems more intuitive to me too. This has to do with the tire's optimal pressure and sidewall stiffness. Do a search for more info.

Chris
 

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Discussion Starter · #9 ·
quick follow-up:

This weekend I installed an OEM sedan 20mm rear swaybar on my wagon along with the Kartboy solid rear endlinks and it made a significant difference. My car drifts much more neutrally now - exactly what I wanted. Since I installed the bar and endlinks together, I can't say how much each contributed to the difference, but I'm stoked with the end result.

Thanks for the help guys!

-g
 
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