Testing and Tuning (Read: Making Pigs Dance)
I set out with some pretty basic goals for the Test'n'Tune:
1.) Confirm gross car setup (understeer/oversteer and turn in)
2.) Play with damper settings
3.) Check tire pressure and response to heat
4.) Gather seat time
Part 1: Well the car was set up grossly if you ask some people, but overall with the exception of some transitional laziness the setup works. When the BMR Watts link shows up on the doorstep, I don't think I'm going to change anything with regards to height of the rear roll center or dick around with bars. Really it worked out better than I hoped. The new tires didn't change much in the way of setup changes for the car which wasn't that surprising considering how close the RS3V1 and RS3V2 are supposed to be to each other.
Part 2: Damper settings were very straightforward. I started off with no additional damping and worked my way up to where the car transitioned like I wanted it to. Not surprisingly those settings are dang near identical to what I ran last year. One thing I did notice about the tires is that you can definitely feel them moving around more than the 265/40/18's do. I assume this is because of the higher grip levels produced by the tires. This means a little more sloppiness in the transitional response of the car as you wait for the contact patch to move from one side to the other. These are shorter in overall height too which should have reduced that feeling some, but it seems either about the same or worse.
Part 3: Tire pressures. I forgot to fill up the tires before going to the event so they were at 32 PSI all around. Didn't even check them while I ran either. There was substantial delay between runs and the tires had ample time to cool down. Add in a lower overall surface temperature and the tires just never got that hot. At 32 PSI I was getting a little more roll over than I wanted so for the event on Sunday I opted to put 36 PSI into the tires and work down from there.
Part 4: Well, there was about 12-15 runs completed on Saturday. Not as many as I hoped for but they wouldn't let us hot lap our cars because the Modified and Prepared folk have cars that do idling in the line very well. So instead of letting us run as many runs as we wanted we had to wait for a person in charge of the grid to come and allow us to go. At the end of the day this did not produce tons of laps for any competitors at all.
2009 Mustang GT Rear Suspension Autocrossing - YouTube
I was able to get some decent videos of the updated rear suspension and front suspension components for this year and I'm seeing a lot of wheel base changes on and off the gas. I guess the grip levels are compressing those poly bushings pretty hard. Up front, hard braking is still causing the suspension bushings to deflect. Even the poly suspension bushings are deflecting still. Probably less than the rubber bushings would but more than I expected they would.
2009 Mustang GT Front Suspension Video Autocrossing - YouTube
During the Test'n'Tune I also got to meet some novices and give at least one of them some pointers and help them out so they could be ready for the solo event on Sunday. This was a great privilege and I think they had fun! I hope so anyway.
Solo Points #1
On to the good stuff! Sunday was supposed to be about 70º and raining. As Saturday's Test'n'Tune came to a conclusion the weather dipped to less than 50% chance of rain and only in the afternoon. Good news everyone! It was dry. This meant that my Mustang could deliver the powerr! Of course the new wide sticky tires should help with that too! Even more epic was the course designer had just purchased an S197 5.0L and wanted to have a course where he could really open it up. The course was very much so a power course with just a few basic transitional elements and big long straights with sharper corners on them.
Click on the link for more photos from Heat 2 of this event
Some really good cars for the course present too like the above GT3 of Sandboxer Charlie Kim which not only looked great but sounded great too. I'm glad he was able to stick around and run on Sunday as the car looked wicked fast out on course and it was a good course for the car too.
STU only had one other competitor, a BMW 135i, who this was his first event in the car after making huge changes to the car and only casually autocrossed before. The usual competitors didn't show up as one of the regions in Kansas was hosting an event so Mark Hill was out and the other local Evo driven by David Cosseboom is waiting on overnight parts from Japan that didn't come overnight to fix a broken AC Clutch. The WRX driver, Joel, is apparently not autocrossing anymore (he hates us!
) so only one competitor in class.
Run #1:
With knowledge from the test'n'tune the day before it was pretty quick to get the car exactly how I wanted it to be. Tire pressure was set at 36 PSI on each corner and boy was that a mistake. The whole car felt like it was on pin needles. Grip was there but there was no steering feel at all. Of course the tires were cold. Pavement was warmer thanks to running in the last heat of the day and it had been "cleaned" by the drivers before. Drove pretty conservatively to get a clean run in and ended up with a 50.094 which was a pretty respectable time all things considered but I wanted to be much, much faster than that and given how many places on course I was on the brakes way early, there was plenty of time to improve!
2009 Mustang GT Autocross - #23 STU - NRSCCA Solo Points #1 - Run 1 - YouTube
Run #2:
Run #2 didn't get recorded because they were launching cars at an 18-20 second pace (which is fast for us!) and we only had about 30 people in a heat. This meant that by the time I got the tire pressure bled down to the 34 PSI front and rear and back in the car, I forgot to turn the GoPro back on until I was in the line and it didn't record. Anyway, the pressure was bled down to 34 PSI and this calmed the car down a lot. Run didn't improve in time as I made a pretty substantial error in the last turn around and killed a bunch of time by being an absolute moron. Run ended up being a 50.432.
Run #3:
For Run #3 I got adventurous and dropped rear pressure down to 32 and kept the fronts at 34. I also decided that the front tires were entirely too hot so I decided to attack them with a water bottle and cool them down some. This ended up working out really well and made for a very fast run. I suspect spraying will just be the norm from now on at events. Everything lined up really well and I ended up pulling in a 49.340 which would be my fastest time of the event and really a solid time overall. Fourth fastest of the ST classes in attendance (beat by three STS cars). I was finally starting to get the hang of the new car setup and was beginning to really enjoy the course too.
2009 Mustang GT Autocross - #23 STU - NRSCCA Solo Points #1 - Run 3 - YouTube
Run #4:
I bled pressures back down to the 34/32 split I had above and decided to water down both front and rear tires. I haven't done a frame by frame but I felt like I was faster into certain areas and slower in other areas on this run. It still felt like a good overall run and the time wasn't bad it just didn't improve upon Run #3's time. It ended up being a 49.485.
2009 Mustang GT Autocross - #23 STU - NRSCCA Solo Points #1 - Run 4 - YouTube
Run #3 put me in first in STU and 20th overall in PAX. The results can be found here:
http://nrscca.com/files/results/863053701Solo-2015-04-12.pdf
and PAX:
http://nrscca.com/files/results/1932338202Solo-2015-04-12-pax.pdf
Lots of "Vehicle Information Not Available" due to a motorsportreg issue and the import into the computer system. This event was plagued by some technical issues but once we got rolling the heats went by pretty quick.
I really "like" those results but by the same token they don't exactly show me much of how the car is doing. I need Mark Hill or some other top level STU drivers to show up at an event to really get a gauge on how things are going with the car. I don't put much faith in PAX numbers but I suppose 20th of 90 is still better "Top%" wise than the previous year's average finish but only barely. In other words, I can't wait for the next event on May 3rd where hopefully there will be some more STU competitors to gauge how the car is doing.
FWIW too, I got lots of comments about the car looking good on course and sounding great. Don't get me wrong, I like a great sounding car, but I'm still interested in placing well against competition. From a performance standpoint I think the car is beyond my current driving level (well it always has been) and there is still some learning to do. Particularly with the brake pads which change character a bit with some heat in them. Odd for a street pad really but the nice thing is with how forgiving the pads are due to the long pedal travel, you can really get on the brakes, still be slowing down fast, but not be in understeer mode due to ABS engagement. I need to do some work on those braking points for sure!
What's next?
Well, generally I tell you how I'm going to continue to throw money at the car but what items are left are well outside what I'm budgeting for this year so I wont be spending any more money on the car except for maintenance stuff. Really all that is left are underdrive pulleys, longtube headers, high flow cats and appropriate mid pipe, lightweight battery and seats. The suspension is basically maxed out so any tweaks there are going to come as tuning changes with spring rate more than wholesale changes in components. I suppose I could see if I can get a hold of some of the new pimp street tires (Bridgestones seem to have a lot of nutswingers going for them but no 285's) but really I'm not sure the RS3V2 is that far off those tires out at Lincoln. I could very well be wrong though.
I've already signed up for Spring Nationals and look forward to competing there and the next event is May 3rd at LAP-N.
As always, questions, comments, concerns, gripes, bitches and complaints are welcome!
