Chike's official 2007 AutoX Blog thread (D-Stock)

[Chiketkd]

Figured I'd start a thread where members of the SVXWN can keep up with my autoX progress this season in my D-Stock '06 WRX TR. Feel free to post questions & comments but I won't always be able to respond right away as my time has become extremely limited. Due to the upcoming birth of my second child (June 14th due date), I will not be making the trip to Topeka this year, however, I'm currently registered in D-Stock for the June 24-25th National Pro Solo in Washington D.C.

Winter Reading
As I had some time on my hands this winter, I decided to read a few autoX books. By far the best one I read and would recommend is Secrets of Solo Racing by Henry A. Watts:




Winter Development
The basic set-up I ran with last season included:

• Whiteline adjustable 27/29mm Front Swaybar (set on the 29mm setting)
• 4 wheel alignment (-1.1 front, factory setting of -1.2 rear)
• Heavy 22lb Prodrive P7 wheels with 235/40/17 Toyo RA-1's
• CG Lock (seat belt tensioner)

This set-up lead me to trophy in DS at the '06 Subaru Challenge (5th) as well as to win the DS class for the season with my Blue Ridge SCCA Region.

Over the Winter I corresponded with several National champions and top national drivers (including Brian Garfield, Jonathan Roberts, Ian Stewart, Keith Casey, Max Hayter & Scott Hoffman), and using their input/suggestions I began making changes to my set-up...

[Chiketkd]

2007 Set-up

My complete set-up for 2007 currently stands as follows:

• STI Performance panel filter
• 2.5" highflow Prodrive axleback muffler section
• Whiteline adj. 27/29mm front swaybar
• Alignment (-1.4 camber front, factory -1.2 rear)
• CG Lock (seat belt tensioner)
• Pair of 3mm spacers for my front wheels only
• 17x7 18lb +55et Subaru SPT wheels
• 225/45/17 Kumho Victoracers

The 2.5" stainless steel Prodrive axleback shaves 7.5lbs from the stock system, and dynos have shown an increase of 3-4whp and 5-6 wtq.



As stock '06+ WRXs are making 200-205 whp on Mustang dynos, it is estimated that true stock power output is ~255hp at the crank (factory rated at 230hp). With the Prodrive axleback and STI panel filter, I'd estimate my car is making somewhere around 260hp at the crank (~210whp).

The brand new 17x7 Subaru SPT wheels I bought use my stock factory offset (+55et) and weigh 18lbs a piece (3lbs lighter than my stock wheels).



I got some used 225/45/17 Kumho Victoracers and they're now mounted & balanced and ready to go:





245/40/17 Hoosier A6's will go on later this Spring prior to my National Pro Solo in June!

In regards to my alignment, as I can't legally adjust rear camber from the factory setting (rear camber bolts are unadjustable), I had the technician crank in as much front camber as possible w/o any cross-camber. The most he could get was -1.4 degrees per side. I had my toe set to 0.0 all around and didn't want to add rear toe-out per the following comments by Brian Priebe in the May '06 issue of Sports Car:



Based on his comments, I'm trying to focus on adding as much front grip as possible, to make the rear-end easier to slide on course in a predictable manner. Through my new front-end alignment, 3mm spacers upfront and adjusting tire pressures front & rear, I should be able to accomplish this...

[Chiketkd]

Corner Scales

In February, I went to my Solo Chairman's house to weigh my '06 WRX TR on the corner scales he recently purchased from C-DOC. After receiving them in the mail, he sent them out to a specialist to have them calibrated within 1/10th of a lb. His 2001 Corvette Z06 weighs 3,150lbs exactly on these scales with a full tank of gas.

He built a ramp system out of wood for the scales, and after adjusting it for my car's wheelbase and width, I drove her into place.

We then measured my car's weight w/o driver and w/ driver. My car had an indicated 1/3 tank of gas which I confirmed later by driving to a Shell Gas Station immediately after leaving his house and filling up with 10.13 gallons of gas - so 5.8 gals were in my car at the time of the weigh in (15.9 gal tank). I also performed the required SCCA weight reduction and removed my spare tire and all-season rubber mats.

Results were as follows:

w/o Driver

LF 919lbs RF 932lbs
LR 636lbs RR 569lbs

Total weight: 3,056lbs (Front 61%, Rear 39%)
Left-side: 1,555lbs; Right-side: 1,501lbs (Left 50.9%, Right 49.1%)


w/ Driver (170lb driver w/ seat-belt on AND both of my hands on steering wheel)

LF 990lbs RF 951lbs
LR 691lbs RR 594lbs

Total weight: 3,226lbs (Front 60%, Rear 40%)
Left-side: 1,681lbs; Right-side: 1,545lbs (Left 52.1%, Right 47.9%)

These measurements were done on my factory wheels with heavy 225/45/17 RE070 tires. My racing 17x7 SPT wheels with 225/45/17 Victoracers will be roughly 8lbs lighter per corner.

A few pics:






I'm extremely happy with these results as my racing weight (with racing wheels & tires) will be over 30lbs lighter i.e. 3,025lbs w/o driver and 3,195lbs w/ driver.

[Chiketkd]

2007 March Schedule:

My schedule for the month of March currently sits as follows -

3/10 BRR-SCCA Test & Tune Verona, VA
3/11 BRR-SCCA Event #1 Verona, VA
3/17 Philly SCCA Winter Series Event #3 Ripken Stadium, MD
3/25 WDCR-SCCA Test & Tune Fedex Stadium, MD

I'm the course designer for the 3/10 Test & Tune with my BRR-SCCA club, and this was the course I designed for the event:

[Chiketkd]

Instruction:

Over the Xmas holidays, I signed up for a Phase 1 Evolution School in Danville, VA on April 14th. The 1 day school, that includes lunch, ran me $220.00. From all accounts by previous attendees, it's worth every penny.

My confirmed instructors are Sam Strano & Mike Johnson with two others to be determined (possibilities are Tim Aro, Jinx Jordan, Dave Newman, GH Sharp and Rob Falkner). As my instructors will be driving my car that day, I'll be gathering their input on how my new set-up is handling...

Evolution School webpage

From their website:

Phase 1 - Skill Building

The "original" Evolution program as developed by the McKamey Autocross School. This first step in the Evolution is where all students start, regardless of experience. Daylong course builds upon students existing skills, while introducing new ideas to improve one’s times. Students both ride and drive with Evolution trained national caliber drivers to learn where they are fast and where they need to improve. Small student teacher ratio of 6:1 insures quality instruction time. Computerized timing provides segment times, which can be compared at various times during the day. Do to some factors such as, weather, segment times may not be available and are beyond our control.

Combined with race proven skills, concepts, and techniques this course will improve the performance of all drivers on both road and track. Even experienced driver’s benefit from the Phase 1 course as a refresher for those things they’ve forgotten over the years or perhaps never learned. No matter what type of car you drive the Phase 1 skills will improve your overall driving abilities.

[SVXRide]

Chike,
How about the cross weights? This is what will affect your polar moment the most.
-Bill

[Chiketkd]

Originally Posted by SVXRide

Chike,
How about the cross weights? This is what will affect your polar moment the most.
-Bill

Bill,

I have the print-outs it at home - will dig up and post tonight.