I just recently got some new rims so I could fit wider better tires on my car. This improved handling some but still not as much as I would like. I used to own a Civic with about every suspension mod available for it and it handled awesome and I would like to get my xA a little bit closer to that even though I know the suspension design isn't as good as the Civics was.

So what are the main proven mods I can do to improve the handling. I hear good things about the Progress rear "anti-sway bar" even though I don't really understand what it does since a true sway bar connects to the body and suspension and this just seems to reinforce the rear torsion beam which is already a giant metal piece, I don't get how a little bar is going to improve it much.

Also the TRD underbrace I hear things about, what is this exactly?

 

Lower your xA. Lower center of gravity, reduce body roll and cleans up the wheel gap.

 

Springs, spring/strut/shock, or coilover package... depending on your budget. I dropped my xB using the DF210's from Tanabe, with 215/40/17 Cooper Zeon ZPT tires and it handles a LOT better than stock, with a heck of a lot less lean. It's a blast, especially in the curvies.

 

I already have my car lowered on Teins.

 

Oh, then sway bar, shocks, underbrace.

 

Hotchkis sway bars, then shocks/struts, then TRD rear brace & GTSpec front brace - in that order.

David -

 

Progress Tech rear axle stiffner, better known as a "sway bar".

 

With regards to the Progress rear bar, the jury is still out! Not enough real life testing has been done. Also, installing a rear bar by itself is just lame. Just because it's an easy mod to make, does not mean it's the right thing to do. The key is BALANCE, and it should be done by addressing the front bar first, then the rear.

 

Huh!?!

The Hotchkis bar is soooooooooooooothin, I can bend it in half and I have zero grip in my right hand.

Scions are FWD cars and don't require the front ends to be so stiff it doesn't flex. If the front end gets so stiff and has no flex then the front tires have NO GRIP!

I had the Hotchkis bar, and was no happy, the Progress bar works.

Do a search on my posts where handling is concerned.

Do a search on handling for FWD cars, they are not the same as rear wheels drive cars.

You want the tire THAT GRIP, in constant contact w/ the ground. Too much sway bar up front and your inner tire looses grip.

 

On front wheel drive cars, front anti-sway bars actually contribute to understeer.

 

Huh!?!

So, according to you, being the expert that you are, Hotchkis got it all wrong. Aren't you the same person who said that installing a Blitz supercharger would net zero horsepower because the horsepower would all get absorbed by it's clutch/pulley? Please!!!!!!!!!!!!!

What you're suggesting simply flies in the face of basic physics! I'll acknowlege that there ARE times when a rear bar alone is appropriate, but only in cases where there is an extreme amount of understeer already built in. As a rule of thumb the area of greatest mass should always be ones first concern when addressing handling. I am not advocating a front bar alone, but a balanced approach like Hotchkis. I am also saying that simply installing a rear bar MAY not be the right thing to do, FIRST! As far as the thickness of a bar is concerned, just a 1 1/2mm difference in a bar can cause a 50% difference in it's stiffness, a 2 1/2mm differnce can jump its stiffness up to 85% more, so don't discount the effectiveness of the Hotchkis. Furthermore, by advocating just a change in the rear with a substantially heavier bar, you can possibly change the vehicles driving characteristics so radically that it becomes unpredictable for an unexperienced driver. It is much better to make changes in small "engineered" amounts and test, test, test. Front wheel drive cars are not necessarily different from their RWD relatives in a sustained turn.

 

Personally I think it would be better if they made a smaller bar for the front and 22mm for the rear. My Civic had like an 18mm front (stock) and 22mm rear and it had very neutral handling. The xA has a massive front sway bar, it would be good if someone made a smaller one because these cars understeer pretty bad.

 

Tein SS coils, Progess sway bars, front and rear struts, and a light weight rim with 35 size tires. Rota makes some really nice light weight rims. Then, stiffen the frame with some frame braces and you'll be good to go.

 

That may be what Hotchkis did with their hollow front sway bar. If the wall thickness of the Hotchkis front bar is less than 0.111", its actually less stiff than stock. I don't know how thick their front sway tube wall is though........

The compromise you must accept with a super stiff rear sway bar is an even poorer ride (the rear wheels do not travel as much relative to each other).

Anyhow, as many have said before, the Progress bar works well. I've got it and whole heartedly recommended it. I've also got Tein S-techs. The Tein springs being significantly stiffer in the rear also act like a "rear sway" as well. This Tein/Progress combination may push you into slight oversteer without any other corrections.

What I have found to be a pretty neutral combo is to add rear wheel spacers (I've got 20mm in rear, 5 mm in front and they really improve the look/stance of the car). I've also got a front strut bar which contributes very little. The large rear spacers add back understeer.

The end result for me is that the car corners hard and very controllably with all four wheels sliding (very neutral). I can't wait to get Koni's to dampen those stiff rear Teins, then the handling should be sweet. Good luck.

 

handling???

Wider rubber and negitive camber...

Negitive camber can be acheived with lowering the car which also lowers the center of gravity as stated before... But, if you have 0 camber... your not going to handle that well... -2 ~ -4 negitive camber is what you find on track cars...

My personal cars camber is -4 front -2.5 rear... mmmmmmm

 

-4 is alot in the front f every day driving ... -4 for the track is great ... for street driving just go -2 in the front and atleast -2 in the rear ... also besides camber adjustments a rear sway bar is good but shocks that you can adjust the damper rate on is better ... If you looking for top handling you should look into getting adjustable shocks ... bay adjusting the damper on the shocks you can controll the rebound and compression of the shocks which will help you on difference surfaces ... I know the FULL Tein Coilover Suspension you can get the EDFC (Electronic Damper Force Controll) and adjust the damper rate from inside the car so you can tune all 4 corners while you are going!

 

Front sway bar if anything will be more important IMHO on a single beam rear axle...

There really is no use for a rear sway bar with the single rear axle...

Best cornering... If you go with a TEIN Super Street with Pillow Ball upper mounts so you can use the EDFC... Tune the front to a stiffer setting and put the rear at around 3-4 before the softest setting... That paired with Negitive camber up front just slightly more then the rear and a good front sway bar / strut tower bar and you got a very good handling car in the twisties!

The above are my opinoins... If you choose, you may ignore them

 

You would figure this with a beam axle design, but, the echo beam axle seems to be quite flexible in torsion. Sort of a "semi-independent" design. Trust me, a rear "beam stiffener" goes a long way to correct roll and understeer with this car. Of course the ride suffers a bit.

A front sway is important, but, the Scion has a very substantial stock front sway which may not worth the trouble to mess with. Considering that many people also add a front strut bar, and rear wheel spacers (for looks), the car has the potential to be a "poster child" for understeer (front too stiff, rear too soft). An easy way to combat this understeer is the rear sway and stiff rear springs.

 

jomo is right squirrel is right these cars are soo prone to understeer it's rediculous. and yes a rear axle stiffener "sway bar' does alot for these cars. go and ride with someone with and without the progress bar insane difference.