Monthly Archives: November 2009

End of Season Update

The season is now officially over, with the last October R/R at HPR behind us. What a great season! By completing that last race, I was able to secure the DSR regional championship over Paul Leonard in DSR. At the last race, I set a new best of 1:41.6 at HPR, setting a new track record, and beating Chris Farrell’s old time in the process, which is no mean feat. Naturally he’ll show up and do a :38 next year, but for now I get to be the quickest 😉

Owner’s Manual Supplement

I’ve been adding a bit more to the owner’s manual ‘addendum’ or supplement that I began at the end of last year. If you have experiences or observations to add, please write them up, and I’ll incorporate them into the manual. See the link at the top of the page, just under the title photo.

Recent Activity

The last race left me with a few issues to fix, thought I’d share some info about them here:

  • Chain Tension: Since MAM, and maybe a bit before, I’ve been having trouble keeping the chain tensioned and aligned. I finally broke down and removed the rear differntial from the spar (not a bad job, actually), and the problem was immediately evident: both rear diff bearings were wobbly and shot, so Rilltech repaired them for me, and the car was 100% at the October event.
  • Brake Rotors: The front brake rotors have been getting progressively worse, in that they float OK while cold, but after 3-5 laps, heat up and bind, so that the car vibrates badly on the brakes. I’ve sent them back to Stohr to look at, since my attempts and Rilltech’s attempts at fixing them didn’t seem to do the trick.
  • Fuel Pump Replacement: Even though I had the fuel cell out and apart to look for the (apparent?) fuel leak that toasted my oil temp sensor, after a brief test day at Pueblo (like 10 laps brief), I began having fuel starvation problems. I ripped everything out again, and discovered that the small sock on the fuel pump inlet had come loose, and the inlet was filled with crap. I replaced the main pump (it’s just a standard Walbro 255), as well as the (dead) scavenge pump (with another 255), and kept the seemingly still happy main pump as a spare.

    Winter Projects

Since I got a lot of the car’s reliability woes sorted out during the season, and did a healthy number of upgrades, winter’s to-do list is relatively brief:

  • MXL Gear Display: The MXL has the capability to display the gear, which I haven’t had hooked up until now. David and Ellen at Veracity have sent me a small pigtail that I’ll wire into the Suzuki gear position sensor, and with luck, that should give me 0-6 gear display. I’ve read that it’s fairly dodgy for some folks, but at worst, it should be able to tell me the difference between 5th and 6th gear, so I don’t continually try to go for 7th gear…
  • Rear Wings, Part Deux: I’ve had a Dauntless flap sitting on my shop floor for some time now, waiting installation. It was a prototype/reman/rebuild that Rennie sold me for cheap. Plans seem to change with relative frequency, but I’ll be installing that atop my Dauntless main element (12″ chord), in a Dauntless-style configuration that mimics
    their super-whizzy standard setup, but for a much smaller cost to me. Should be good for 80-90% of the performance they’re getting with the twisted mainplane. More to come on this.

    I weighed the various wing parts that I have. My WF-1 wing (paint, old, etc) is 7.5 pounds. the wing support is 7.2 pounds. The Dauntless flap is 2.8 pounds. The whole Dauntless assembly weighed 25#, so I am hoping that the lighter wings with less “wing support material” may save 6-10# off of the car.

  • Steering Shaft Rebuild: My steering shaft u-joint has developed a healthy amount of free play. This is most noticable when on warmup or cooldown laps, when there is less load on the car, and the tires will dart a bit of their own accord, making the car feel a bit nervous. Stohr is rebuilding this for me, it costs about $200 for them to do. When it is
    back and reinstalled, I’m going to take another stab at installing the 270mm wheel to gain a bit more leverage on the steering wheel, and finally install my button plate from Veracity. It is the very close placement of my bump shifter that seems to be causing the oddity, so I will space the steering wheel back towards me a bit, to give my right-hand that little bit of clearance it needs.
  • Dry Sump, Part Deux: I’m still intrigued by possible horsepower benefits of the dry sump system, as well as the more effective cooling it gave my car, so I intend to have
    my spare motor modified per BRD’s recommendations to get the steady 75psi of oil pressure that is much more comfort-inducing than the 45psi or so I saw at the September national. I’ll run that to start the season, and see how it works, then decide what to do with the other engine.


One last race to write up for the season, the “Brumfield’s Bash” R/R at HPR, at the end of October. Here.

All of us SR and Formula types skipped the Pueblo race, as the surface has gotten AWFUL, and was literally beating our cars apart. I parked my car after just 6 laps of a test day, and Paul did the same, after breaking his header, front splitter, rear diffuser, and camera. Ugh. Hopefully THAT gets fixed.


The season is now in its winding-down stage, with just two events left to go. The car is more sorted-out than ever, so I’m hoping that with a bit of luck,
the next few events will go nice and smoothly. Some miscellany:


On the heels of the MAM race in August were two HPR races separated by just two weeks. One of these was an R/R, the other a N/N:

  • HPR R/R: Quite a weekend this was, running my first laps with the new BRD dry-sump, and getting a chance to run the HPR “West Loop”
    for the first time. Read about it Here.
  • HPR “Last Chance” N/N: So much fun racing with another Stohr, and what a race Sunday’s was – you have to see the video to believe it!


A few small bits if miscellany, that I’ve picked up this year:

  • Chains: every time you have any kind of issue with a chain or sprocket, REPLACE EVERYTHING. Wonked sprockets will kill a new chain, and wonked chains
    will kill your sprockets. Don’t try to save a $15 sprocket to save a $100 chain! Speaking of, Jake, when you’re looking at this a year from now, you replaced your chain for the
    Pueblo October race. 😉
  • Tire Weights: We make our wheels hot enough that normal wheel-weight tape doesn’t hold them on. Neither does duct tape. Neither does gaffer’s tape. The only solution
    I have found, and this mirrors what the tire guys have told me, is the aluminized aircraft tape like Pegasus sells.
  • Car Weights: I finally did a “rigorous” weigh of the car. The car, ready to race, with 5 gallons of fuel, midsection installed (16# per half = 32#), is 350F + 499 R = 849. Add 25 for the nose and 35 for the tail, and you get 909. Subtract off 36# of fuel, and you get 873#. Bodywork total is about 92#.

Black Gold

  • Oiling and Oil Systems: Getting these ’07-08 GSX-R’s reliable has been a theme for the season. On the wet-sump side, it’s been determined that we all need
    to move the oil pickup further forward in order to prevent the pickups from coming uncovered under the hard braking that these cars can manage. The simplest solution has been to turn the pan around 180*, extend the pickup forwards, and create a new baffle. Rilltech has a version where they extend the “box” on the existing pans to avoid having to reverse the pan, and have redesigned the pan for new customers. As well, Jesse Brittsan/BRD and Dustin Wright at Phoenix have come forth with their interpretations of the solution as well. One interesting tidbit is that not only are the pressure dips gone, but steady-state pressure now seems to be in the 70’s, and some folks are reporting lower oil temps, all of which point to less
    aeration of the oil, no doubt a very, very good thing.
  • Oil Systems, Cont’d: Additionally, at the last HPR N/N, I noticed my oil pressure with the dry sump dipping into the 40’s at the race end while running down the straights,
    having switched back to 10-40 oil to avoid the very high low-temperature pressures I was seeing with the 20-50. Hot oil pressure has long been an achilles heel of the dry sump setups, so it appears that BRD hasn’t quite gotten it kicked either. However, Jesse reports to me that they’ve found a key modification to make to the ’07-08 motors that gets the pressure right up into the 70’s, without any major changes, so it may be that solution has been found as well. I’ll have my spare engine modified over the winter to see if the change works for me as well. Eric Vassian and the other West were running the modification at Runoffs 2009, and both reported 75ish psi under all conditions with standard 10-40 oil.

    So, for the short-term, I will have Richard modify my wet sump to finish out the season, then will decide which system to deal with over the winter, since I now have what appears to be two workable solutions for the car.