It is really a topic too long to cover in a forum post but I'll ask this. if the front of the car can't keep up with one rear tire on the ground how will making the front work even harder by keeping 2 rear tires on the ground give you more ultimate grip?

 

If you worry too much about tri-podding and attacking that directly, you'll end up sacrificing front grip and net a slower car. If you attack front grip as is the bigger issue on most Evo's (understeer), you'll end up with a car that will lift the rear but only just (A good thing according to Grice which I agree with)

 

I have a set of cusco 3 way fsb brackets for sale used for less than half of this season. 50 shipped. We are parting out our stu evo 9. Imho most of you are running too low of spring rates, and need to run a front sway or have a way to stiffen it up.

 

I'll take those FSB brackets...

PM me your PayPal.

 

I never really see people running the swift bars, I imagine it is because they are not adjustable but I really like their approach and level of R and D. They do not rate their bars by the thickness but rather by the amount of stiffness increase from stock which makes more sense to me.

I am currently setup with re valved bilsteins and swift spec R springs and like most I want Sway bars but not the front because it's labor intensive.

Here's what i was considering let me know your thoughts: Swift rsb (+120% stiffness) with the cusco fsb brackets which will make the front 116% stiffness of stock... So it will be kind of like the OEM balance with the volume turned up (still larger up front)

http://www.frsport.com/Rear-Sway-Bar...Fa5r7AodwGgA5A

http://www.frsport.com/Adjustable-Fr...X_p_22792.html

 

Thanks for chiming in guys. As I mentioned I really have no clue other than pure speculation. I am not a ME so what I know comes from personal experience as well as feedback from others.

With that being said, it sounds like I should approach this in a different manor. Instead of saying what can I do to get my car to not tripod, I should say what can I do to maximize front end grip?

If the options that I laid out, what would be my best course of action? I'm well aware that there is not a one size fits all solution, but what would be the best (simplest/ cheapest) progression?

 

Since the OP mentioned me I'll chime in here

I am OK with upgrading both bars I just don't like slapping only a large rear bar on the car. The reasoning behind this (as one poster mentioned) is balance. The EVO by design has near perfect inherent balance from the factory, it's so good that it makes you question how nose heavy it actually is! People who say the car has too much understeer are simply people who don't know how to correctly brake... it is a driver problem.

That's why the stock balance should be maintained so you either do no bars and leave them stock or both. In either case you keep the intended balance.

 

I couldn't disagree more. That statement is way to much of a global characteristic. In general the evo stock has good rotation and is great in transitions, but steady state has nothing to do with braking. In steady state the evo understeers. The front will run out of grip before the rear, that's just physics. More weight, more roll moment, less camber gain, same tire.


The goal is to get the car to just push that limit higher and not ruin the transition capability.


I do agree though the factory did a proper job of balancing spring rates and sway bars. Both individually and as a combination, the math works out well. Staying similar to that but just more is a good thing, you just need to know how it works out by checking the math. Then driving and tweaking to your liking.

 

what are the stock spring rates?

 

You make some good observations but there are different types of understeer, there is gross unadjustable understeer (bad) and then there is mild manageable understeer and this is very very good and extremely fast. Faster than the neutral car over a whole lap (not to mention several in a row where the advantage grows).

You "strongly disagree" because you think a proper set up car should be neutral in steady state correct?

They are not, that will make the car too loose and slow on corner entry and in transitions (like you hinted at) and also make them too pitch sensitive mid-corner to be effective in traffic.

The driver kills the understeer (to the point of mild oversteer rotation) by carrying in light brake as deep into the corner as necessary to transition into the acceleration phase without understeer developing. Why should the driver do it rather than just set the car up to do it in the first place? One word; adjustability, a loose car to start will just gets looser as the laps pile on and mild understeer car can continuously be balanced to neutral by the driver compensating for wear without slowing corner entry or transition speed like the driver of the ever loosening car will have too.

Sometimes the corner is so long you might not be able to link the trail brake to the acceleration phase and yes you will sit there for a moment with the dreaded understeer but the corner has to be over 180 degrees for that to happen (and they are very rare). Meanwhile the car set up to be neutral in steady state has it's moment to shine there but is loosing time at every other corner (so it is overall slower). That is why the mild understeer is faster as long as the driver has the skill set to manage it.

This argument pops back up from time to time, I have told this tail my entire professional life and always get push back... from people who think it is the suspensions job to balance the car when it is actually the drivers.

As you stated there is a little wiggle room in set-up for driver style but that window is surprisingly narrow before it starts affecting lap time negatively.

I am not saying driving the car understeering is faster. I am saying a car set-up with mild understeer steady-state but balanced neutral by the driver is faster.

Make sense?

 

Exactly. My car tripods depending on how much speed I'm carrying. I'm on MR Bilsteins, GTWorx springs, Tein camber plates, stock swaybars, with 255/40-17 ZII tires. I use it to my advantage to get the rear to rotate along with braking and rocking the car.

I have a bunch of stuff waiting to go on the car to try to reduce understeer. Whiteline RCA, rear bump steer kit, anti-lift/caster bushings, another bushing in the rear (forget which), restacking the diff clutch plates, and better brakes (for upsetting the chassis at turn in). All of this is to try to maximize grip on the "cheap" suspension I'm running before switching to an expensive, high spring rate, coilover setup. I'm thinking of adding Whiteline 26mm front and 24mm rear bars to this list. I want to try the Swifts I just don't like the pricetag. Anyone have a comparison between Whiteline and Swift sways? Also, I'll search, but does anyone know off the top of their head what the GTWorx spring rates are?

Chronohunter - Seems like you're talking about track days. Do you have any opinions on setup for Auto-X? Either way it looks like I need to be on the brakes more and take the time to learn left foot braking. Also, my car has some nasty power understeer, any thoughts on that?

 

Autocross is similar but you can be more aggressive since the average speed is so low. You are correct in your point that you will need to be on the brakes more. The slower the corner the further in you have to trail the brake in to counter the understeer. You shouldn't have power understeer, I have never seen an EVO do it actually... if it was trail braked in correctly. Usually the power understeer comes from over slowing the entry then the drivers has no option but to start accelerating (before they are unwinding the wheel) then they create mid-corner to exit understeer (that sometimes will power over into oversteer by the exit).

The solution is more entry speed and carry that light brake in deep which will have the rear out a couple of degrees which will allow you to slightly reduce steering, just as the car has pointed at the apex you can get back on the power and since the car is a tick tail out it will stay neutral to the exit. Much easier said than done but EVO's are awesome at this due to... well everything (great geometry, AWD and really clever ABS that knows when to stay out of it).

The difference between understeer and oversteer on entry can come down to a couple of pounds of brake pressure difference, it is that subtle and you just have to develop a feel for it over time.

 

Paul
So glad you chimed in.
I don't like to bug you any more than I desperately attempt to, but am glad you clarified the technical position you held with respect to sway bars.
I will upgrade both, so that the car retains the balance you speak of.
And I do agree, especially for novice driver, that Evo has that near perfect balance that allow driver to pitch it in, or enter sheepishly with mild understeer, all adjustable depending on corner entry.
I feel that your Setup I am enjoying on the 8 is actually more-immediate in transitioning to mild understeer or oversteer, sharper, quicker adjustable, compared to the TME that is little slower being still on stock suspension. And I like that immediacy.

Paul,
Would you use Robi adjustable 26mm front bar, or Whiteline non-adjustable: any preference?

thanks in advance
Ivica

 

Thanks Ivica, I would go with a matched set and have them both be adjustable if at all possible, that will give a more usable range to fiddle with. I would start with both in the middle position then carefully work through the range of both bars hopefully with some subjective and objective measurements. I would also include tire temps, you will see more temp differential from side to side now (positive in Auto-X where you struggle for temp, negative on a road course where you struggle to not overheat them). You will also see less shoulder temp due to the better roll control so you might have to reduce camber to re-optimize the tire.

Oh and remember you can do one side at a time on bar adjustments (they both don't need to be in the same position so three holes gives you 6 different stiffness levels) and don't forget to set the pre-load each time (remember a few lbs of force can change balance), we don't want to introduce anything that can mess with the results.

Have fun

 

My suspension setup:
stock sway bars
Weir 12 plate diff rebuilt to 1.5-way by TRE
Bilstein PSS9 coilovers (~8kg/mm front and rear)
285/30/18 Yokohama AD08 tires
-3.2 camber front, -1.8 rear
5.4 caster up front
0 toe all around


My limited experience:

AutoXing, I always have understeer on corner entry. This is due to my driving too hard into the corner and mistiming the braking.

On the track, I have never felt understeer as I ease my way into corners for my first couple laps. If I need to tighten the corner up, I add more trail breaking to the corner. On corner exit (post apex and pushing towards the outside of the track), the car feels very neutral. I have gotten a lot of oversteer on exit if I have to tighten it up mid corner or if I get on the gas too hard, too early.

I am sure this will all change when going to R-comps and a higher rate spring. I was considering going to larger, adjustable sway bars to run a lower spring rate.