suspension tuning...

[Skurj]

STill trying to get a handle on this...

This year I upgraded to 2 way clubsports, and i also have 22mm adj bar up front and OE bar in the rear of 2013 BRZ

The car is one of the quickest locally on fast courses, and I attribute that to the big front bar primarily and the soft rear bar. On the tight courses I get my ass handed to me by twins running OE bars front and rear.

Its just local stuff, and I can't be swapping out sway bars between events. So, I am looking at suggestions or advice in what I can do to loosen the car up for the slower courses.

The front shocks.. currently 2 clicks softer than midpoint on rebound, comp at midpoint of adj range. Rear the reverse at 2 clicks past midpoint stiffer on rebound, again with comp at midpoint.

whiteline 22mm front bar at soft
kw clubsport 2 ways 340/400lb springs
3.5/2.6 fr/rr camber
0/0 toe front and rear

If you could only adjust shocks and you had 1 event of the season left on a tight but bumpy course (6 runs and it looks like it will be wet..)... what would you do?

For next season i will add a bigger rear bar..

[CSG Mike]

Add rear tire pressure. You're sacrificing grip to get it looser, but if it yields better times...

[Skurj]

I tried that, and ended up at 28/30 as it did help, solve the mad push I experience in slower courses, but still a long ways back.

Should add thats on 245/40/17 re71's on 17x9 et 35 rpf1's

all courses asphalt

[CSG Mike]

Add more pressure.

[tony_r]

What phase of the corner does the car push? Entry? Mid? Exit?

[Skurj]

Originally Posted by tony_r

What phase of the corner does the car push? Entry? Mid? Exit?

entry

[tony_r]

Drive easier on entry, turn down front compression, increase rear rebound. Ordered in importance. I would also check available travel in the front at ride height.

[justinco]

Increasing rear rebound damping makes my car turn in better. Add a few clicks and see what it does.

[M0nk3y]

Originally Posted by justinco

Increasing rear rebound damping makes my car turn in better. Add a few clicks and see what it does.

Rear rebound acts as a bell curve. It helps until it doesn't

My first move would be rear rebound to allude to the question that Tony did - you're having issues with turn-in.

[StraightOuttaCanadaEh]

Prime the car for the corner. In F1, you see drivers making a smaller input towards the corner, then the full commitment. It sets up the balance for corner entry. But it's not two separate movements, it's one fluid sort of transition. Hard to explain without gesticulating

[Skurj]

Originally Posted by StraightOuttaCanadaEh

Prime the car for the corner. In F1, you see drivers making a smaller input towards the corner, then the full commitment. It sets up the balance for corner entry. But it's not two separate movements, it's one fluid sort of transition. Hard to explain without gesticulating

I've let one of the local hotshoes drive it, and I've seen him do just that...

[stxbrz]

on very tight turns brake hard and late, ease off the brakes as you near the apex. this is how i kill under steer in auto x and at the track.

[BlueWhelan]

Originally Posted by Skurj

STill trying to get a handle on this...

This year I upgraded to 2 way clubsports, and i also have 22mm adj bar up front and OE bar in the rear of 2013 BRZ

The car is one of the quickest locally on fast courses, and I attribute that to the big front bar primarily and the soft rear bar. On the tight courses I get my ass handed to me by twins running OE bars front and rear.

Its just local stuff, and I can't be swapping out sway bars between events. So, I am looking at suggestions or advice in what I can do to loosen the car up for the slower courses.

The front shocks.. currently 2 clicks softer than midpoint on rebound, comp at midpoint of adj range. Rear the reverse at 2 clicks past midpoint stiffer on rebound, again with comp at midpoint.

whiteline 22mm front bar at soft
kw clubsport 2 ways 340/400lb springs
3.5/2.6 fr/rr camber
0/0 toe front and rear

If you could only adjust shocks and you had 1 event of the season left on a tight but bumpy course (6 runs and it looks like it will be wet..)... what would you do?

For next season i will add a bigger rear bar..

My first suggestion for future events would be to put worse tires on the car (stockers, for example) and run with lower grip levels. The inherent balance of your chassis will become much more apparent, so you'll be able to more effectively analyze where the car is pushing or sliding, and what inputs cause/fix it, etc. Take the time to pay a lot of attention to how the weight is shifting and how the balance changes as a result. It's all about weight management. The better you understand it, the better you'll be able to get the most from your tires.

As @stxbrz suggested, you may not need to change anything aside from your driving style. Try to adjust your inputs so that the front tires are properly loaded as you steer the car.

As far as your next event is concerned, you said it looks like it will be wet, so I would suggest that you soften the dampers at least a few clicks on both ends, but especially in the rear so you can extract more grip from the tires. Yeah it might push more, but if its wet you can always use the loud peddle to make it rotate. The reason I suggest slackening off the dampers is because in the wet, the most important thing is getting the power down. The more power you can put down, the more time you can spend on the throttle propelling yourself to the finish line. The guys/gals that win are the ones that have the highest average throttle % over the course of the lap (without sliding).

In the future, an adjustable rear bar sounds like an appropriate fix.

Looking at this from a different angle however, you could save some money by forgoing the rear bar in the future, and instead try dialing in just a hint of tow-out to the rear, which will help with getting the car to rotate in the tight stuff. Go to a faster course where tow-out may not be preferable, and you can compensate by putting that whiteline sway bar to the stiffer setting and perhaps see some crisper turn-in as a bonus. Not saying that's what you should do, just giving an alternative.



Just my 2 cents. Spend however you like.

[Skurj]

Thanks all, I am lousy at even remembering how the car reacted in a specific turn, i usually come back from the run with a general overall feeling... I've been doing this for about 4 years now between an NB1 for a seasons and then 1 season in a poorly prepped STX BRZ followed by a similarly poorly prepped stock BRZ Lol...
This year I went in with a better prepped STX BRZ though missing all power upgrades and the rear bar. I claimed our regional STX class win for the season, and I think I am top 3 overall, so happy with the result, though that last event (the wet) may have been the clincher as far as overall is concerned...
The wet event turned out to be not so wet but a tighter course, and I did ok, I reduced compression 1 click in the front, and ran 28/32 for pressures and the car was decent, and i was pretty satisfied with my times.

Driving should be my focus for the forseeable future... BUT... I now need to learn a new platform, leaving the twin behind (for now) and running an ND next year in STR.