Street Touring Hatchback (STH) discussion/setup

[xXDavidCXx]

For me, the comfort, surprisingly, came from aligning the bump response, just as Mini7 posted. As I increased the rear spring rate, the ride was better.

Before, on the stock springs, the rear was way behind the front during bump response, resulting in an uncomfortable ride.

I believe this is why many say the OEM suspension is harsh. It's just that the rear is under sprung and behind on bumps.

 

[xXDavidCXx]

Had some complications for this weekend's double event.

Could not get an alignment after swapping rear springs, and corner balance.

Day one I started the shocks at 16 from stiff front, and 8 from stiff rear. Rear bar on soft.

Still understeer in sweepers.

Change the rear bar to hard, though not sure this would make much of a difference because the rear tire is already off the ground.

Small change to rear grip, but front is still not happy.

I spend my worker assignment going over my limited options.

Decided to try full soft front rebound and full stiff rear rebound.

I think this entire time I've had the Ohlins I've run too much front rebound.

The turn-in oversteer and sweeper grip was magical!

Not sure if it's obvious from the video.

Let me know what you think.

In-car view of my fastest competition run.

 

[Mini7]

Had some complications for this weekend's double event.

Could not get an alignment after swapping rear springs, and corner balance.

Day one I started the shocks at 16 from stiff front, and 8 from stiff rear. Rear bar on soft.

Still understeer in sweepers.

Change the rear bar to hard, though not sure this would make much of a difference because the rear tire is already off the ground.

Small change to rear grip, but front is still not happy.

I spend my worker assignment going over my limited options.

Decided to try full soft front rebound and full stiff rear rebound.

I think this entire time I've had the Ohlins I've run too much front rebound.

The turn-in oversteer and sweeper grip was magical!

Not sure if it's obvious from the video.

Let me know what you think.

Interesting. Curious to see what your before alignment is when you get it done.

All you changed was the rear spring rate. What was your ride heights fender to ground: F and R?

 

[xXDavidCXx]

Interesting. Curious to see what your before alignment is when you get it done.

All you changed was the rear spring rate. What was your ride heights fender to ground: F and R?

Fronts are now 425 rears 750.

Fender heights currently with my autocross gear in the trunk

664 | 665
653 | 658

26 1/8 | 26 1/8
25 3/4 | 25 7/8 rear

 

[xXDavidCXx]

Day two in the books. Second place, after holding first place with my first run, until Tim Heaton's last run where he beat me.

The car is good, still could use more camber, but grip is very manageable. It will be nice to keep a steady setup for the rest of the year.

I adjusted the camera view to see my hands on the steering wheel.

 

[bfury5]

I keep cooking my front rotors, so I think I need a softer pad on the Boxster calipers (RS3 ducts are en route too, maybe it'll help). In other news, a clean car is a fast car right?

 

[xXDavidCXx]

Interesting. Curious to see what your before alignment is when you get it done.

All you changed was the rear spring rate. What was your ride heights fender to ground: F and R?

Before alignment was
Front
L Camber -2.0 R Camber -2.3
L toe 0.08 R toe 0.55
Total toe 0.63 (I think this is toe-in)

Rear
L Camber -2.4 R Camber -2.5
L toe 0.10 R toe -0.20
Total toe -0.10 (toe out)

Changed to zero front toe, -2.0 rear camber and -.30 rear total toe out.

That should make the rear more lively.

 

[JackRabbitSLIM]

I keep cooking my front rotors

Isn't this because of the E-diff?

 

[bfury5]

Isn't this because of the E-diff?

Nope, I turned that off for now (planning for a mech LSD over the winter), but I usually saw that cook my tires before it would cook the brakes. The smaller calipers I added moved brake bias forward, I added stronger rear pads to compensate but I'm not sure it was enough. It could also just be the really cheap rockauto rotors I got. Pads and fluid are fine, no detriment to performance so far even when the rotors are toasting.

 

[bfury5]

Before alignment was
Front
L Camber -2.0 R Camber -2.3
L toe 0.08 R toe 0.55
Total toe 0.63 (I think this is toe-in)

Rear
L Camber -2.4 R Camber -2.5
L toe 0.10 R toe -0.20
Total toe -0.10 (toe out)

Changed to zero front toe, -2.0 rear camber and -.30 rear total toe out.

That should make the rear more lively.

That was a lot of toe-in up front, the zero toe should help with understeer. Curious how the rear toe out handles, I want to try it but I think it would be too much for the low-grip asphalt I'm on compared to the concrete out west.

 

[theDoktor]

That was a lot of toe-in up front, the zero toe should help with understeer. Curious how the rear toe out handles, I want to try it but I think it would be too much for the low-grip asphalt I'm on compared to the concrete out west.

I'm with you on the toe-out on the rear, particularly with the asphalt we have to mostly run on here in the east. That will be a handfull to catch. I definitely miss the concrete, but the higher grip levels will mess with what works here set-up wise. I'm doing a Test & Tune Saturday, and rear toe is one of the adjustment items on my list.

 

[bfury5]

I'm with you on the toe-out on the rear, particularly with the asphalt we have to mostly run on here in the east. That will be a handfull to catch. I definitely miss the concrete, but the higher grip levels will mess with what works here set-up wise. I'm doing a Test & Tune Saturday, and rear toe is one of the adjustment items on my list.

Yeah exactly, my car will primarily be setup for asphalt out east as well. There are a lot of things I'd be doing differently if I was running on concrete on the regular. Likely higher springrates in addition to the toe out in the rear.

 

[GTIfan99]

Antigravity 20 cell installed. 3ish lbs with hardware.

 

[Mini7]

Fronts are now 425 rears 750.

Fender heights currently with my autocross gear in the trunk

664 | 665
653 | 658

26 1/8 | 26 1/8
25 3/4 | 25 7/8 rear

I need to check my log. My front height is about the same. I’m higher at the rear. If I adjust the rear any lower the spring starts to spin. So I stopped. I didn’t want he rear spring to unseat at full droop. There should be less spring compression with a stiffer spring so I may get the rear ride height closer to the front By having a little more adjustmen before it unseats.

Going go to a 672lb Swift spring in the rear and keep the 450lb up front. Will get the shocks revalved to gain the rebound adjustability for the track. Most likely request the compression/rebound profiles be more track biased.

 

[xXDavidCXx]

I need to check my log. My front height is about the same. I’m higher at the rear. If I adjust the rear any lower the spring starts to spin. So I stopped. I didn’t want he rear spring to unseat at full droop. There should be less spring compression with a stiffer spring so I may get the rear ride height closer to the front By having a little more adjustmen before it unseats.

Going go to a 672lb Swift spring in the rear and keep the 450lb up front. Will get the shocks revalved to gain the rebound adjustability for the track. Most likely request the compression/rebound profiles be more track biased.

I use hypercoil's helper spring and eibach spring spacer to help keep the spring seated.

At this point, I'm not sure the shocks need a revalve. The fronts have too much rebound, at least for autocrossing, and while I am running the rear shocks at full stiff, I have not verified I need them at full stiff.

Anyway, what does a more track biased comp/reb profile mean to you? Do you have a current dyno of each shock?