Saturday, May 27, 2017

All Systems Are Go

After months of various unrelated issues coming up that have prevented me from bringing Bumblestook out, the stars finally aligned and today I was able to take her out on her 2017 debut after all the work done over the winter.

NEPA SCCA Autocross - Poconos Raceway - 5/27/2017
With only two weeks left before we head out to Toledo, time was quickly running out to get her tested. The summary of changes over the winter are:
  • Went to 315/30/18 Hoosiers up front to make it 315 all around (Previously I was running 295/315 staggered)
    • The tires on the front now were my rear tires from Nationals last year so they were covered in OPR from Lincoln
  • Switched from 10mm to 15mm spacers up front for clearance
  • Cut more of the front fender out for clearance and added overfenders
  • Switched to Karcepts front and rear sway bars for increased adjustability
  • New ATS Spec III Type DD diff was installed
  • Replaced passenger side front knuckle, wheel bearings and studs
  • Replaced passenger side axle with the matching spare we used to replace the driver side axle during the ProSolo Finale
  • Added mount for tablet so I can run SoloStorm this year for datalogging
I wanted to test for clearance, scrub the OPR off and break in the new diff as well as get a general feel for the balance of the car with the new setup. NEPA hosted an autocross today at Poconos Raceway. These are typically very fast courses but for some reason, today's course was particularly tight and slow. When we walked the course, many of us thought it was going to be a disaster. The gates were very tight and the elements felt all over the place and visually confusing. I was personally surprised that it drove better than I expected and all the transitions helped me achieve my goal of getting a baseline balance with her new setup.

The new tablet mount worked perfectly for capturing data
My first 3 runs were spent scrubbing off OPR. The fronts weren't hooking up too well with all that clag on the tire so I took the course at about 80% pace and at least get the diff to work. The new ATS diff feels incredible. The engagement is very smooth and I had no problems getting power to the ground. Also this year I'm trying much lower tire pressures so I started the day off with a target 28/25psi. She was feeling a bit pushy so I kept lower the front pressures until they were 25psi even and I really felt she was ready to dance but still leaving a bit of push which I was ok with at the Poconos. If this was at the Meadowlands I would've raised the rear bar to test but I wasn't about to do that on the road course so I'll leave that for next weekend. Also, since I was testing, I took the opportunity to take different S2000 drivers on ride alongs so they could feel what a BSP S2000 really feels like. The reactions were, as expected, priceless. 

Poconos Raceway - 5/27/2017
Unfortunately after our third runs another car had some issues and leaked coolant at the beginning sections of the course so on my final two runs I backed off a bit there to avoid sliding there but I was still able to drop time elsewhere. On my final run, I went solo and put in a good time but the narrow gates and the wider stance put me in cone trouble as all my runs ended up dirty. Overall, I'm super happy with how she performed today. Data showed we pulled a max of 1.6Gs lateral and I didn't even get her to slide yet so there's more. She performed flawlessly, the tires are OPR free and smooth and I had no rubbing anywhere. We've got one more day of testing left before her first big event this year so hopefully I can dial in the suspension a bit more and really make her dance. 

NEPA SCCA Autocross - 5/27/2017

Sunday, May 14, 2017

Alcantara Steering Wheel and Weight Reduction

Probably one of my favorite things with Bumblestook is the Alcantara Mugen steering wheel. It gives excellent feel and grip and just looks great but it's not legal in STR (well not easily made legal at least). What is legal though is replacing your steering wheel as long as the total weight is no lighter than stock. To get the best of both worlds, I went ahead and ordered an Alcantara wrap with red stitching for the S2000 OEM steering wheel from and used their professional installation option. Rather than sending my original wheel in, I opted to just buy a used steering wheel and send that instead so I can keep the original one unmolested.

Alcantara wrapped S2000 OEM steering wheel
with red stitching - 5/10/2017
Alcantara wrapped S2000 OEM steering wheel
with red stitching - 5/10/2017
The ordering process was very smooth. The wrap itself is made in Europe (Poland I believe) and sent to you via regular mail. If you choose to use their professional installation service, you then send the wrap along with the steering wheel to their professional installer in North Carolina where it gets put together and sent back to you. In addition to the Alcantara wrap I also added the option to thicken the steering wheel slightly. The material they use is nice and dense and feel incredible, not spongy at all.

Airbag disconnected, steering wheel ready to be removed
To swap steering wheels, you disconnect the battery so the airbags don't go off. Remove the covers on each side of the steering wheel. Using a Torx T30 bit, remove the bolts holding the airbag in place and pull it away from the wheel and then disconnect the cables connecting the airbag and the cruise control switch. Using a 14mm socket, loosen the center bolt but don't remove it all the way. Tug on the wheel firmly towards you free the wheel from the hub then remove the bolt all the way. Reverse this process to install the new wheel.

Alcantara wrapped OEM steering wheel installed - 5/14/2017
Since I had to disconnect the battery to install the steering wheel, I figured now would also be a good time to replace the OEM sized battery with a lightweight one. I opted to get a Deka ext14 which is a 12lb battery. This is a solid 14lb reduction in weight from the OEM sized 26lb battery. In order to install it, I got 8" J-hooks since the battery is smaller and replaced the steel OEM battery tie down with an aluminum one for extra weight savings and a cleaner install. Also, since you have to install automotive battery terminals on the Deka in order to use it in a car, I hardwired the battery tender quick connect so it'll be much easier for me to hook Lupa up to the battery tender without using alligator clips.

Deka ext14 battery installed - 5/14/2017
Deka ext14 battery installed - 5/14/2017
Lupa is mostly done with her 2017 modifications. I'm just waiting on one more part that's currently on it's way from Japan :D

Saturday, May 6, 2017

Less Pressure, More Winning

Last week I got the opportunity to codrive Rad's STR S2000 because I somehow misplaced my trailer lock keys and wasn't able to bring Bumblestook to the NNJR SCCA event. I always like to find the silver lining in bad situations and driving Rad's car woke me up. For starters, I had a lot of fun which is probably the most important thing but it also made me rethink Lupa's setup.

Philly SCCA Autocross - Warminster, PA
I really liked the way Rad's car handled and put power down. On balance it was on par with Bumblestook but with less grip all around of course but the balance was comparable. Lupa's slightly down on power but I'm addressing that shortly with some parts from Japan. When we ran last week, Rad remembered that during the Test-n-Tune event on the BFG Rival S 1.5 they found running lower tire pressures to work best and only after we lowered it to that level did the car feel on point. I still run Bridgestone RE-71Rs but because I haven't really been running Lupa much, I hadn't been doing any tire pressure testing. I wanted to see what the sweet spot would be for Lupa. With the itch to try a few things, I made the trek out to Warminster today to do some testing. The day started out with some potential with the sun breaking through the clouds but before my heat started, it started raining making the surface really slick.

Of course it had to rain - 5/6/2017
On my first run, I started with my usual pressures of 29/27 but with the wet conditions, testing was really moot. I was sliding all over the place and even some throttle with the wheel cranked would cause the rear to kick out. By the third run, the rain had stopped and we were in drying conditions. I found by my fourth run that running 27/25 worked really well. Lupa was rotating really well and I was able to get on the power earlier. This would've been a good day to have a codriver as the cool temps made it hard to keep the heat in the tires but Warminster has always scared me a bit especially in bad weather conditions. I've definitely seen my fair share of unwanted excursions into the grass there so I opted to run solo for this event.

I got one run in the dry. It was my last run and Feinberg, who ran in the first heat, mostly in the dry, was in the lead. Looking at the data, I was able to identify corners where I suspected that in the now dry conditions, I'd be able to just lift instead of brake. This mostly worked except towards the finish where I overshot one of the corners making me late for the last set of offsets. Even with mistakes and some fairly conservative driving in areas by the grass, I was able to drop a good chunk of time to take the lead. There was definitely a lot more pace that could've been extracted under more stable conditions but overall, I'm just happy things are coming together nicely and the nut behind the wheel is starting to find some improvement again.

Philly SCCA- Warminster, PA - 5/6/2017