Two Great Days on Thunderhill Raceway

L

Louv

Member
 Das cats, Cali
Just a little eye candy from last weekend. Friday & Saturday were spent with TrackMasters Racing on Thunderhill Raceway in Willows, CA

This was my first time on track with my Z4 Coupe 3.0si. In the past, I've tracked my e24 M6 and e39 M5, both are far heavier and very different experiences.

I was running with Toyo RA1 tires on a set of 4 front tires (you'll note the rear tires are tucked in too far into the rear wheel wells. Why 4 fronts? Because there are no R-Compound tires for the rear tires (255/35R18). This makes swapping front to back (to balance wear) easier too!

The second day it started raining around Noon, so all the afternoon sessions were in the wet. With traction control on, the Z4 was still a great drive (and safe) in the rain. On the front straight, I had her up to about 105 before I needed to brake for turn 1. In the dry, I was regularly getting about 120mph there. My lap times were in the range of 2:17 to 2:20 (in the dry).

More pictures on Flickr
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Oh boy!!! :dance2: , great pics Louv! Looks like you had a blast. So what were your experiences as far as heaviness was concerned? I know when I had that 335 loaner, the extra weight made all the difference in the world. As awesome a car as it was with more power then my Z has, it just couldn't take corners quite as tight - felt high and 'wavy' to me. Thanks for posting :thumbsup:
 
Thunderhill is by far and away my favorite track. Lots of fun either wet or dry. I have events there in 2 different Audis and my old S2000.

:yeah:
 
To give credit where credit is due, the pictures of me driving, were not taken by me (duh!) they were taken by Dito (http://www.gotbluemilk.com) But the other pictures on flickr were taken by me.

The car is definitely lighter (than my M6), and that feels great. But frankly, my M6, in spite of it's extra 500 pounds, can go nearly as fast, partially because it is really set up for the track: Slightly more HP & Torque (3.5L vs. 3.0L), Limited Slip Diff, lowered suspension, chipped, sway bars, etc. Also, I know my M6 much better on track, since I have a lot more seat time there. The Z4 is new to me; I only have 8000 miles on it so far (and 4k of that was freeway between CA and MN).

The front end needs more camber (a solve-able problem) because I was seriously scrubbing the outer edge of the front tires (the right one more so than left one; understandable given that it is a counter-clockwise track).

I ran my first session with traction control fully on, just to get a feel for the car. The car hated it, and "pushed back" at many points on the track. The rest of the sessions I ran in DTC mode, which was worlds better, and the traction control only interrupted on the rare occasion that I did something stupid and graceless.
 
DTC mode is where you press and release the button momentarily, correct?

I think I need to drive in that mode more often :driving: :evil:
 
flyboyaj said:
DTC mode is where you press and release the button momentarily, correct?

I think I need to drive in that mode more often :driving: :evil:
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Yes, that's correct: press and release. And the dash light says "DTC".
If you press and hold, it shuts off the Traction control entirely.
At least I think that's how it works.

Does anyone have a full technical description of what is on & off for the three modes? (On, DTC, off)
I don't want the crappy description in the owner's manual, I already read that and it really didn't help me understand which systems are turned on or off, and what else changes.
 
Louv said:
To give credit where credit is due, the pictures of me driving, were not taken by me (duh!) they were taken by Dito (http://www.gotbluemilk.com) But the other pictures on flickr were taken by me.
Click to expand...

I have one of his CDs from one of my Audi events. He takes great shots and it's nice to go home with a CD of your day :D

Louv said:
The car is definitely lighter (than my M6), and that feels great. But frankly, my M6, in spite of it's extra 500 pounds, can go nearly as fast, partially because it is really set up for the track: Slightly more HP & Torque (3.5L vs. 3.0L), Limited Slip Diff, lowered suspension, chipped, sway bars, etc. Also, I know my M6 much better on track, since I have a lot more seat time there. The Z4 is new to me; I only have 8000 miles on it so far (and 4k of that was freeway between CA and MN).
Click to expand...

Thunderhill is a merciless track when it comes to how well your car handles and what you know about how to use it. The straights are very short so big engine cars that don't handle well are at a severe disadvantage. My last Audi (2005 S4) was a horrible mismatch for that track but my Honda S2000 was 2 days of almost heavenly driving. Those 2 cars were much more closely matched on my home track in Portland. I feel like the Z4 might be a nice one to drive down there but my preference would be to get very well acquainted with how it handles on a track with street tires before trying R compounds.

Louv said:
The front end needs more camber (a solve-able problem) because I was seriously scrubbing the outer edge of the front tires (the right one more so than left one; understandable given that it is a counter-clockwise track).
Click to expand...

I was guessing that about another -0.5 would help the understeer. Understeer is definitely not a welcome trait when it comes to turns like #3 there. For those who have not driven Thunderhill turn 3 is a wide off camber sweeper that is miserable for cars that tend towards understeer and every car that can do a little throttle oversteer will be hanging out on your tail by the end of the turn. You can lose almost a second in that turn with the wrong suspension setup.

Louv said:
I ran my first session with traction control fully on, just to get a feel for the car. The car hated it, and "pushed back" at many points on the track. The rest of the sessions I ran in DTC mode, which was worlds better, and the traction control only interrupted on the rare occasion that I did something stupid and graceless.
Click to expand...

Not surprised to hear that the electronannnies were bothersome. I am more inclined to do the long hold on the button to entirely disengage the system but your comfort zone may vary. In the dry Thill is nice with the hige runoff areas everywhere but in the wet anywhere offtrack is a bog and will result in the call for the tow truck. The bad news is that the first person who has to have the truck called out has to pay for the truck being at the track.
 
Holy crapoly! I just realized that Louv is a NOOB! Welcome to the Z4-Forum, Mate!!!!!!!!!

Awesome pics! Awesome Posts! I just checked out all of your posts. Might I suggest posting in the Newbies section? Introduce yourself and your Zed (with a pic, I know you've already posted pics, to include an awesome one in the Nov Photo Comp, but we all love being able to relate your name to a photo of your Zed in the Noobs section). There you will also get to know many of us a little better!

Again, welcome!

P.S. Oh, and you and AlanL are gonna be like brothers!!! Y'all got lots in common! :D
 
flyboyaj said:
Holy crapoly! I just realized that Louv is a NOOB! Welcome to the Z4-Forum, Mate!!!!!!!!!

Awesome pics! Awesome Posts! I just checked out all of your posts. Might I suggest posting in the Newbies section? Introduce yourself and your Zed (with a pic, I know you've already posted pics, to include an awesome one in the Nov Photo Comp, but we all love being able to relate your name to a photo of your Zed in the Noobs section). There you will also get to know many of us a little better!

Again, welcome!
Click to expand...

Thanks for the welcome... I feel like home here... because I've been lurking since June. I entered a couple of my pics in photo contests (only to be out-classed each time by, admittedly, better photographs. 8)

A tiny bit of background on me:
I'm a BMW addict.
The Z4 Coupe is my 8th BMW.
I still own 5 of them. (and a Tundra to haul gravel and lumber)
I have Zero garage queens. All are dirty. All get driven.
3 have been on racetracks. (Laguna Seca, Infineon, Thunderhill, Willow Springs, and ButtonWillow)
I've driven on the 'Ring (3 Day BMW Club driving school, in a rental 118d )
To earn all the money I spend at BMW parts counters, I help develop consumer electronics. Perhaps you've heard of a few: Macintosh, Newton, WebTV, iPod, Akimbo, and a few recent products for SanDisk and Sirius Satellite radio.
 
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