Thunderhill Track Day

**fuggles** · 08-22-2015

Friday 8/21/2015
Track configuration 3 mile east with bypass CCW
Northern California Racing Club

2009 ACR hardcore, stock +A/C & Radio
mild track alignment approximate numbers:
camber 1.8F/1.5R
slight toe out front
slight toe in rear
shocks 6 clicks from firm c/r
approximately 1 inch lower than stock
original michelin pilot sport cups with 3K miles
track splitter
stock rear wing position
2% wedge @ 3357#
plus 10 lbs of bug carcasses from the drive up the night before

It was a beautiful day in Willows, CA. Cool in the morning sessions around 70F. Mid to high 80's in the afternoon. And WOW can this car perform! The amount of grip the car has is staggering. It reminded me a lot of the karts I used to run.

I've driven karts on a few of the tracks in northern California, but this was my first track day in a car. I found there to be many similarities between driving karts and cars on a track. Similarities such as finding the brake point, brake pressure, turn-in, being smooth, carrying speed, and holding yourself in your seat with the steering wheel in the turn. I also found a few significant differences. Like that third pedal. You mean to say I have to brake and downshift? Where is the downshift marker? What gear am I supposed to be in?

I was in the driving school group so the first couple sessions we were following an instructor around at grandma speed trying to find the line and learning how to point-by. In a viper with a 307 diff it's second gear and no shifting. In the last 3 sessions we were on our own driving as fast as we dare. It was at this point that I realized I have much to learn.

I went into this event with eyes wide open. I am not naive. I spent countless hours in a kart at 50 mph headed into a hairpin wondering if I would make it. But this is different. I can't see around the corner. Where is the flagman? When do I downshift? Heal-toe or just drop the clutch? By the way, I suck at heal-toe. Whew. So many decisions. I know. It was my first track day. I need to get comfortable with the car and learn the track. And I can't wait! What fun. I'm already planning the next event.

Speaking of planning, I'm thinking about some adjustments to the suspension and aero. Camber seemed pretty good. Very even heat across the tire. The track at thunderhill seems pretty smooth. It has elevation change but not many bumps and for the most part, berms are flat. However, the car felt like it was hopping and skidding over small bumps.

I have a couple questions for those more knowledgeable.

I'm thinking of softening the compression on the shocks. Good/bad/indifferent? If good, how soft? Is it normal to run compression softer than rebound as a general rule? What about the ratios for front to back? Stiffer in the back?

I'm also thinking of adding more wing. Thunderhill is pretty fast but the 6/7/8 corner slash backstretch may benefit from more wing. I don't know.

Thanks for reading, and I look forward to seeing more vipers at the track. What a blast.

**Rapidrezults** · 08-23-2015

I was there in the White TA. Didn't get a chance to talk to you but your ACR looks beautiful! Glad you had a good time out there, we need more Vipers at the tracks in Northern Cal!

**Redsled** · 08-23-2015

Before you start changing shock settings, worrying about aero settings, the easiest place to start at is tire pressure settings. All of the other changes you think you may need to do will be negated if you don't have tire pressures in check. Luc & Dave run great track days.

**Torquemonster06** · 08-23-2015

It sounds like you had an awesome day out there. As stated above about the tire pressure, you might also want to check the tires themselves. they 6 yrs old.

**fuggles** · 08-23-2015

Originally Posted by Rapidrezults

I was there in the White TA. Didn't get a chance to talk to you but your ACR looks beautiful! Glad you had a good time out there, we need more Vipers at the tracks in Northern Cal!

Thanks! I love the car.

The DS schedule was hectic with the classroom and track sessions. We didn't get much time to move around until late in the day. We walked by when you were packing up. My partner was very excited about the mini. lol.

**fuggles** · 08-23-2015

Originally Posted by Redsled

Before you start changing shock settings, worrying about aero settings, the easiest place to start at is tire pressure settings. All of the other changes you think you may need to do will be negated if you don't have tire pressures in check. Luc & Dave run great track days.

Thanks for the input. I had to lower the pressures after every session! In the end they were still too high. Next time I will start much lower.

Yea those guys at NCRC are on top of it. Even with the two red flags they kept on schedule. Well done to them.

**fuggles** · 08-23-2015

Originally Posted by Torquemonster06

It sounds like you had an awesome day out there. As stated above about the tire pressure, you might also want to check the tires themselves. they 6 yrs old.

It was a blast. Much more to come. Thanks for the heads up. I will definitely keep an eye on them and any deals on new rubber.

Hmm. The site doesn't auto-merge. Sorry bout that.

**Redsled** · 08-23-2015

Originally Posted by fuggles

Thanks for the input. I had to lower the pressures after every session! In the end they were still too high. Next time I will start much lower.

Yea those guys at NCRC are on top of it. Even with the two red flags they kept on schedule. Well done to them.

You should try to make the Buttonwillow event in September. I will be instructing for Luc during that weekend and would be happy to help you out.

**fuggles** · 08-23-2015

Originally Posted by Redsled

You should try to make the Buttonwillow event in September. I will be instructing for Luc during that weekend and would be happy to help you out.

Thanks for the offer. That looks to be a busy weekend with every group running. I'm torn between running at BW or going back to Thunderhill while the memory is fresh.

**Redsled** · 08-23-2015

Originally Posted by fuggles

Thanks for the offer. That looks to be a busy weekend with every group running. I'm torn between running at BW or going back to Thunderhill while the memory is fresh.

Every group is running, but attendance is usually light, especially the afternoons. Hope to see you there.

**Rapidrezults** · 08-24-2015

Originally Posted by fuggles

Thanks! I love the car.

The DS schedule was hectic with the classroom and track sessions. We didn't get much time to move around until late in the day. We walked by when you were packing up. My partner was very excited about the mini. lol.

I figured that. I don't think I saw you once out and about the whole day! Lol. Yeah, my younger brother bought a little mini to learn how to drive stick and get into tracking. He loves that little thing even though I wouldn't be caught dead in one on the street.