Lupa's Debut Event - Tuning Suspension

After months of installing parts and getting her ready, it was time for Lupa's first autocross in full STR trim. Although I had adapted a lot of Bumblestook's settings over to Lupa to try and mimic her balance, I knew it would take time to get her the way we wanted since we had no actual starting point to compare against. We were also on fresh RE71s that hadn't been fully scuffed in so their performance was going to be reduced. Still, it was time to focus on the important thing at hand which was to try and get the balance to a good starting point.

Lupa ready to run - NNJR SCCA - 8-30-2015

I took the first run as a general systems check to make sure there were no issues with the car. There was no rubbing and we were going over the undulations with ease. We were good to push hard now to find the limits. I immediately noticed a very large amount of understeer that needed to get dialed out ASAP. We softened the front shocks and Hez took it out for a run and it was a bit better but still pushy. We also started off running 33/29psi but started to decrease this delta to find the balance and gain traction. I brought my pyrometer but the battery ran out so we were adjusting pressures blindly here unfortunately.

We increased rear compression and added more rebound all around to try and find that perfect balance between being critically damped and keeping the weight where we needed it to be in the transitions and powering out of sweepers. The goal wasn't necessarily to get the fastest time as it was to push the car to explore the limits and make all the necessary adjustments to dial out any observed weaknesses. Every run Lupa was feeling more and more balanced and the setup was moving in the direction we wanted. On the final run, which Hez took, it was important to drive for time rather than for tuning so he drove it normally and set our baseline. We were only a few tenths off the fast STR cars at the end the the day. This is very promising. You can see the difference in how the car behaves in the video of our fastest runs. My time was set on my third run and Hez was on his last run. You can see how much less effort it takes to drive her fast in that last run. He looks like he's on an early morning Tofu delivery run despite clocking in a respectable time.

Our Fastest Runs - NNJR SCCA Autocross - 8/30/2015

I'm highly encouraged by Lupa's performance. She unfortunately still exhibits push under power coming out of the tighter turn arounds and could be faster in the transitions with quicker weight transfer. We also ended the event running as low as 27psi all around. That was just a bandaid to try and balance her out but I don't think this is ideal as I'm sacrificing some of that sharpness in steering. There's also too much rear toe preventing her from rotating under power the way I want. The RE71s also seems to not roll much under load so I think we can afford to reduce some of the rear camber and salvage some straight line speed.

Below are the changes I plan on making before her next event. I think she's going to be up there competing for the top spot very soon.


Sway Bars:
Front: 6/6 full stiff (current 5/6)
Rear: 3/7 stiffness (current 1/7)

Alignment:
Front: -3.1, a hair of toe out (current -3.1, 0 toe ....well actually unknown since it shifted due to tranny installation)
Rear: -2.2, 1/16" (0.06) total toe in (current -2.4, 0.18 toe in)

Pressures: 
Probably try 29/27 but bringing a pyrometer to make proper adjustments.

Also, big thanks to Kamil at Clean Cut Vinyls for making my awesome car/class magnetic numbers and other decals.

NESTR - Decals by Clean Cut Vinyls - 8-30-2015

Magnetic numbers by Clean Cut Vinyls - 8-30-2015