XRS Suspension

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http://www.autozine.org/technical_school/suspension/tech_suspension21.htm#Torsion

La XRS à: Semi-independent torsion beam

[FaisalRollaXRS]

Interesting....

Like the article said "some of the best handling cars in Europe have a Torsion beam"

It is the entire suspension setup that counts i.e. strut braces, springs, coils shocks, tires, rims etc. That is probably why XRS handles so well and pulls 0.85 lateral acceleration on the skidpad, 67 mph slalom speed and outhandles many cars like Mazda 3, Focus ST etc. with multi-link independent suspension setup.

Here is a comparo of Corolla XRS, with Mazda 3 and Focus:

http://www.motortrend.com/roadtests/sedan/112_0507_subcompact_economy_car_comparison/index6.html

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I would prefer multi-link or twin trapezoidal link over a semi independant torsion beam. Toyota were cheap to put such suspension in a car that is competing mazdaspeed/ralliart/civic sir/si ('06)...


Still... i am very impressed to see that the XRS managed 0.85 g in lateral grip... i saw on modernracer that the XRs was doing 0.82 g only...

[FaisalRollaXRS]

Don't forget the biggest plus for torsion beam suspension.... saving weight. You are a dedicated autoXér yourself. This is ONE of the reasons why XRS is much lighter (in some cases by over 220 lbs) than the cars you mentioned. Yet, it handles better than many. Modernrace just regurgitated the early Car and Driver magazine test that was done on a mountain and windy area using GPS, telemetry etc. and unbroken XRS. The 0.82 does not reflect what the car can actually pull on the skidpad. They could only get a 15.8 out of the XRS, which you know is not true since you ran 15.3 yourself. This test is much more reliable since it was done entirely on the Motor Trend testing tracks.

If you pick up the new Car and Driver magazine, they have a head to head comparo of GTi and Si. Si was slower than the GTI (14.9 secs on GTi vs 15.2 on the Si) GTi has a torsion beam and it handles as well as the Si and was the overall winner of the comparo as well.

I would prefer multi-link or twin trapezoidal link over a semi independant torsion beam. Toyota were cheap to put such suspension in a car that is competing mazdaspeed/ralliart/civic sir/si ('06)...


Still... i am very impressed to see that the XRS managed 0.85 g in lateral grip... i saw on modernracer that the XRs was doing 0.82 g only...

[diskace]

saving weight... don't know for this one. Are you sure ?
Also in their article they say this and obviously it is wrong :)

Recommended fuel: Regular

[FaisalRollaXRS]

Yeah I am positive. I read another document on each type of suspensions and their pros and cons. One of the biggest pros of torsion beam is space and weight saving because of it's relatively simple geometry. An independent suspension employs a more complex geomerty, which in turn needs more components that add to the weight of the car as a result. :rolleyes:

saving weight... don't know for this one. Are you sure ?
Also in their article they say this and obviously it is wrong :)

Recommended fuel: Regular

[diskace]

you have the link ?

[FaisalRollaXRS]

I read it a few months ago. I cannot seem to find the same page right now. One place however where I find Torsion beam problematic is when I go over rail tracks or some hard bumps as the back end propagates motion to all of the car thus making suspension busier and uncomfortable.

you have the link ?

[diskace]

if you can get your hand on it, i would really appreciate it.

[BolakXrs]

i don't think that the XRS handle better than the mazda 3... in your link they compare the corolla XRS against all the basic other car... they should have choose the corolla S. If they had took the 3 GT the xrs would be far behind... I enjoy my Xrs but... a mazda 3 handle like no other stock compact.

[FaisalRollaXRS]

Just my own thoughts here...

The Ford Focus ST basically the same as the Mazda 2.3 Sport. ST used in this comparo shares the same engine, transmission and suspension (it was designed by Mazda) as any Mazda 3 model. I hope you know Ford owns a good chunk of Mazda and Mazda 3 and Focus were designed together. I hope you realize that unsprung weight is a big factor in inertia generated during aggressive cornering. That goes in favor of the XRS as well since it is 150 lbs lighter than the comparable Mazda 2.3 sedan and even lighter than the hatchback. The only disadvantage Mazda has is the automatic transmission. Actually, I have been in a twisty race with a hatchback 2.3 Mazda 3 5 speed and I beat it mainly while accelerating out of the apex of the corner because I simply had more power readily available in the right gear as I kept the revs high and less unsprung weight. Although, Mazda 3 cornered with very good poise and balance and maybe a bit less bodyroll than myself, yet the simple fact that it did not have the power to accelerate out as fast as I did.

Even against the Focus, this is what they said

"The Toyota, however, would likely run away from the Focus and the Mazda3 on a track or a mountain two-lane whatever tires they wore. When the road and crowds open up sufficiently to rev this engine, the chassis is more than capable of putting the power down deftly. Supple damping helps keep the contact patches pressed to the pavement, and a firm brake pedal suffered no noticeable fade with repeated hard use. At any point on the mountain road, the Toyota could maintain a four- to five-mph advantage over the rest of the pack. If your commute is from Mount Crumpet to Whoville, this is the only car to consider.""
:)


i don't think that the XRS handle better than the mazda 3... in your link they compare the corolla XRS against all the basic other car... they should have choose the corolla S. If they had took the 3 GT the xrs would be far behind... I enjoy my Xrs but... a mazda 3 handle like no other stock compact.

[BolakXrs]

I drove both (2.3 GT and XRS)when I was looking for a car and I can tell you that its not at all because of the handling that I choose my XRS. It was more for the engine style. I enjoy a smaller engine with more HP and less gaz consumation. With my trd spring and my 17" wheels the car is handling well. But stock with the 16" wheels... Against the 3 GT with the 17" wheel? I'm sure that on a track like mecaglisse, both stock xrs and gt sedan, I will do a better time with the 3. I don't know for the other car like the focus(even if its the same car the engine has less hp than mazda as I saw on your web site). It's my opinion. I respect yours.

[FaisalRollaXRS]

Yeah cool. :) Focus ST and Mazda 3 share exactly the same suspension setup too. I do agree that the XRS Michelins although very sticky and with good lateral grip in corner, are too skinny. I could only imagine how much better it would be with say, 205mm or even 215mm. Once my stock Michelins wear out (right now I have winters on), I am going to get much wider tires for a wider track.

I drove both (2.3 GT and XRS)when I was looking for a car and I can tell you that its not at all because of the handling that I choose my XRS. It was more for the engine style. I enjoy a smaller engine with more HP and less gaz consumation. With my trd spring and my 17" wheels the car is handling well. But stock with the 16" wheels... Against the 3 GT with the 17" wheel? I'm sure that on a track like mecaglisse, both stock xrs and gt sedan, I will do a better time with the 3. I don't know for the other car like the focus(even if its the same car the engine has less hp than mazda as I saw on your web site). It's my opinion. I respect yours.

[diskace]

BolakXRS is right, according to specs, the 4-door saloon mazda3 sport is showing impressive numbers. According to mr again, this little car gives a 200 ft skidpad of 0.86 g wich is better than a stock XRS.

However, i would be very impressed to see that the mazda3 employ 195/55/R16 tires ;) and can get out with a 0.86 g lateral grip.

[BolakXrs]

However, i would be very impressed to see that the mazda3 employ 195/55/R16 tires ;) and can get out with a 0.86 g lateral grip.

It would be great to see it. It would probably change a lot!

[FaisalRollaXRS]

Remember XRS has a engine speed sensitive power steering, which in turn means that steering is very loose at slow speeds and the stiffness and tightness of the steering progressively increases with engine rpm. You can do this test at an empty road by steering and quickly revving up at the sametime, you actually can "feel" the steering getting heavier. That is why when you corner while keeping the revs very high, you will feel the steering response to be much much sharper than say taking a lazy turn while applying brakes.

An interesting story here:

When I put my winter tires on, Toyota did not have their alignment and wheel balancing guy in that day. They basically handed over the car back without aligning and balancing the wheels after putting the winter tires on. As a result, the steering felt loose, turning radius increased big time. I was just so surprised that the steering had become floaty and without the road feel. First I blamed the winter tires for it. I was extremely turned off since the steering felt nothing like the way it was before.

At the beginning of the month, I went to the dealership and inquired about it and told them to fix it. They did the wheel alignment on the front two wheels and tightened it up. Now the steering is back to the very tight and connected feel with the road and wheels and with great feedback from the road.

Case in point, have your alignment checked every 4-5 months since it makes a massive difference in handling and precision in the corners. ;)