What can I do to improve handling?

There is a bunch of things you can do: rear swaybar, strut brace, body braces, springs, coil overs, etc.

Mine at present has TRD rear swaybar and Tenabe front STB. IMHO with stock 15" there isn't much point to go beyond, unless you plan autocross. As is it is good enough for public roads, while keeping stock height and suspension tuning. It is almost neutral, and with overinflated LRR tires it will do 4-wheel drifts on damp/dusty pavement.

here is the thread with discussions:
http://priuschat.com/forums/gen-iii...-modifications/92408-sway-bars-installed.html

 

I guess that really depends on you... how much you want to spend and how far you want to take the modifications. Below are some threads you could reference. Upsized wheels and tires are always a quick solution to improving handling but is also a bit expensive.
http://priuschat.com/forums/gen-iii...ii-has-anti-roll-bars.html?highlight=sway+bar
http://priuschat.com/forums/gen-iii...-diy-installation-pix.html?highlight=sway+bar
http://priuschat.com/forums/gen-iii...8-sway-bars-installed.html?highlight=sway+bar
http://priuschat.com/forums/gen-iii...ing-springs-installed.html?highlight=sway+bar

 

Most people start with the wheels first.

 

this may be true but IMHO if you only had money to buy one part, it would be rear anti-sway bar. Best improvement for a buck (240$ actually).

Problem with replacing hoops the rims+tires cost $$$$, you loose MPG, and you still have body roll.

 

I agree with the above except I do think upsizing the wheels is a great alternative to a lowering spring install. The difference between my 15s and my 17s is night and day. I've switched them back and forth at least a dozen times over the last 5 years and I'm always amazed at how fast I can take corners when I put the 17s on. Yes I still had body roll but the handling improved immensely. The next best upgrade was lowering springs but that too is pricey and comes with some compromises. The rear sway bar has been touted as one of the best handling mods for cheap and easy but I have yet to do it. I went straight for the new wheels then lowering springs and I am very satisfied with the change in handling. I feel like I'm driving a sports car now.

 

While I didn't upsize my tires I did go to 195/65s and even that small bit made the car feel very different, and I mean that in a good way.

 

I think we are dealing with a law of diminishing effect, where if you install part 1 you get most of the improvement, but when you add next one you get less.

As is (sway bar+STB GenIII) tires are the limit; and I'd bet with if I were to put sticky 17" shoes I'd find it needs additional braces and better springs/shocks.

BUT yesterday on a way from work I had dude on MasdaSpeed3 follow me on winding country road. He did not dare to take corners with the same speed as we but would catch up on straights. That is good enough for me I wasn't really pushing, as there is no run off and the tries grow w/o any shoulder.

 

Driver makes a big difference. Last time I was at Thunderhill Raceway (15 turns in 3 miles) one of the instructors drove a couple of laps in a diesel Dodge pickup and kept up with some beginners in sports cars.

 

I am not really a good driver myself; we had a toyota pickup pass my bike on PCH eep:

Granted I had a bunch of excuses like overloaded bike, fatigue from being on the road for a week and a half for ~500mi a day, pillion who would stand up bike if it is leaned past 50 deg; most importantly being at least 3500mi away from home.

 

195/65 (195/65-15) is the normal size.

 

A little added air, 42/40 psi will also improve handling.

 

Ryan drives a Genii (185/65/15) and I think his point was going tits a wider tire can help.

 

Really?

 

True story.

Guess my phone's preemptive texting turned into sexting...

 

Buy a Ferrari. The Prius is an OK driving economy car, Ferrari is a sportscar.

 

That's realistic.....

Try driving a Prius with handling mods.

 

Suspension tuning!Tanabe 210s installed today.Going for a ride right now! So far so good! Looks nice. Was a little soft before!