[Ferrino]

I'm looking to add uprated swaybar(s) to my stock suspension setup and am torn between:

i) A set of Che front and rear swaybars.
ii) Just a front Addco with stock rear.

From my notes:

Stock: Front=20mm; Rear=15mm.
Che: Front=22mm; Rear=18mm (2-hole adjustment).
Addco Front = 25mm.

I'm currently running a square 205/50/15 tyre setup and would like to preserve this for convenience (for rotation and because retaining a stagger constrains tyre choice). I was therefore thinking of just beefing up the front swaybar with the Addco (with High and Tight endlinks) and keeping the rears stock. i.e. 25mm front, 15mm rear. I'm under the impression this will help to compensate for the loss of stagger.

I know a lot of the Autocrossers like this arrangement, but I can't tell if this is due to regulations or because they prefer some roll on the driven axle (or for oversteer/understeer balance).

This is mainly for street use at the moment, but with occasional trackdays in the near future.

Thanks for any advice!

 

[il4]

for my experience: need to upgrade rear bar first

 

[SuperWhiteGT4]

I'm looking to add uprated swaybar(s) to my stock suspension setup and am torn between:

i) A set of Che front and rear swaybars.
ii) Just a front Addco with stock rear.

From my notes:

Stock: Front=20mm; Rear=15mm.
Che: Front=22mm; Rear=18mm (2-hole adjustment).
Addco Front = 25mm.

I'm currently running a square 205/50/15 tyre setup and would like to preserve this for convenience (for rotation and because retaining a stagger constrains tyre choice). I was therefore thinking of just beefing up the front swaybar with the Addco (with High and Tight endlinks) and keeping the rears stock. i.e. 25mm front, 15mm rear. I'm under the impression this will help to compensate for the loss of stagger.

I know a lot of the Autocrossers like this arrangement, but I can't tell if this is due to regulations or because they prefer some roll on the driven axle (or for oversteer/understeer balance).

This is mainly for street use at the moment, but with occasional trackdays in the near future.

Thanks for any advice!

In the past, Stock autocross classing dictated that you could only modify the front bar (now it gives you a choice of one). IMO, the more important one for the spyder is the front bar. As odd as it sounds, a front bar increases lateral grip at the back of the car, and functions to keep the back wheels on the ground, almost as a cheap LSD. The opposite is true of the rear bar.

Here's a good read: http://www.stealthtdi.com/SwayBars.html

 

[Ferrino]

for my experience: need to upgrade rear bar first

Interesting, can I ask why you're looking for a stiffer rear? Are you having understeer problems?

 

[pelinors714]

Interesting, can I ask why you're looking for a stiffer rear? Are you having understeer problems?

my exact thoughts too... why the rear first? ive heard so much on this forum that we should upgrade the front sway bars first 0_o..... then again the guy does only have 3 posts.. just sayin

 

[bootz widdafur]

I have an addco front with beefy endlinks and a stock rear sway bar.... i like it

edit: i have not autox'd with this yet though

 

[rcntype]

Hmm i've been thinking about sways as well.

Nice link SWGT4.

Now what about if you have an LSD already. Would upgrading both work better? Would upgrading the front still help even though you have an LSD? Seems so, well for low speed corners if I understood Rocwander's thread on why LSD might not do much in that area.

 

[SuperWhiteGT4]

Hmm i've been thinking about sways as well.

Nice link SWGT4.

Now what about if you have an LSD already. Would upgrading both work better? Would upgrading the front still help even though you have an LSD? Seems so, well for low speed corners if I understood Rocwander's thread on why LSD might not do much in that area.

Depends on what kind of LSD you're upgrading to. The usual suspects for our cars are the OEM, TRD Helical, and OBX, which will all still spin the inside rear under specific circumstances. Clutch types like the Kaaz and Cusco effectively lock the wheels, which won't allow a single wheel to spin, regardless of circumstances.

The main advantage of a big front bar is that it prevents weight transfer, and while it can theoretically reduce front grip, it also greatly increases the rear grip.

 

[Ferrino]

The main advantage of a big front bar is that it prevents weight transfer, and while it can theoretically reduce front grip, it also greatly increases the rear grip.

Exactly, which is why I was thinking of going with the Addco(F):Stock(R) combination to dial back some of the front:rear grip balance induced by a square setup. I think I might give it a go.

 

[rcntype]

Exactly, which is why I was thinking of going with the Addco(F):Stock(R) combination to dial back some of the front:rear grip balance induced by a square setup. I think I might give it a go.

But you know stock grip balance is not optimal interms of performance right? That tire stagger and other things are built in understeer and insurance. I believe squaring the setup brings back the performance lost from the factory.

 

[il4]

Interesting, can I ask why you're looking for a stiffer rear? Are you having understeer problems?

sure
even with wide wheels on the rear axle (235mm AD08)

 

[Ferrino]

sure
even with wide wheels on the rear axle (235mm AD08)

Wouldn't wider rear tyres exacerbate an understeer issue though???

 

[SuperWhiteGT4]

Wouldn't wider rear tyres exacerbate an understeer issue though???

Yes.


I wonder what the rest of his setup looks like.

 

[il4]

Wouldn't wider rear tyres exacerbate an understeer issue though???

ouh, sorry, I mean oversteer

 

[01mrtwo]

Why not whiteline sways?

 

[SuperWhiteGT4]

ouh, sorry, I mean oversteer

If you have oversteer problems, why do you want a rear bar?

 

[il4]

If you have oversteer problems, why do you want a rear bar?

because for control oversteer need to tune rear axle
I have large body roll even though on my car installed apexi N1 coilovers

 

[SuperWhiteGT4]

because for control oversteer need to tune rear axle
I have large body roll even though on my car installed apexi N1 coilovers

You do need to tune the rear axle, but you're thinking about it backwards:

Installing a rear bar will increase your front grip. More front grip + same rear grip = more oversteer. You need a front sway bar. Or more springrate in front, or a combination of the two. You could even remove the rear bar to check the balance.

Here's another good read in case you missed the first one:

http://www.autocross101.com/Sway_Bars_101.html

A softer front bar:
1. Increases front chassis roll.
2. Increases front grip or traction, while decreasing rear grip or traction.
3. Slower steering response.
4. Increases off-power steering at corner entry.

A stiffer front bar:
1. Decreases front chassis roll.
2. Decreases front grip or traction, while increasing rear grip or traction.
3. Faster steering response.
4. Decreases off-power steering at corner entry.

A softer rear bar:
1. Increases rear chassis roll
2. Increases rear grip or traction, while decreasing front grip or traction.
3. Less on-power steering.

A stiffer rear bar:
1. Decreases rear chassis roll.
2. Decreases rear traction, while increasing front grip or traction.
3. Faster steering response in high speed corners and chicanes.
4. Increases on-power steering.

 

[il4]

You do need to tune the rear axle, but you're thinking about it backwards:

Installing a rear bar will increase your front grip. More front grip + same rear grip = more oversteer. You need a front sway bar. Or more springrate in front, or a combination of the two. You could even remove the rear bar to check the balance.

Here's another good read in case you missed the first one:

http://www.autocross101.com/Sway_Bars_101.html

thx for link
with my suspension and tyres set at this moment I just need decrease rear chassis roll
after install I'm necessarily write here about results

 

[Ferrino]

Why not whiteline sways?

Price - they're more than double the cost of the Che swaybars. Build quality aside, with the front Whiteline you simply have 2 stiffness adjustments - effectively 22mm and 23mm.

That said, if anyone has a front Whiteline they'd like to sell, please let me know!