Dyno Day

I scheduled an appointment with Evans Tuning a month or so ago to get Bumblestook back on the dyno just to make sure she was still running right. The earliest weekend appointment I could get was today which worked out great since we've got a few weeks of downtime to get her sorted before the final countdown to Nationals. She's been running rock solid (knock on wood) for the past 2 years without issue but it was worth having Jeff put her through her paces while carefully monitoring all engine parameters. The dyno is the best and correct way to do that. The battery quick connect SJF Performance installed fixed the ground issue but on occasion we'd still hear and feel a kind of burbling sound at part throttle and sometimes even at the full throttle and she would behave like she was momentarily fuel starving. This would mostly happen in the slaloms and we knew were losing power and when this happened.

Jeff Evans getting ready to dyno Bumblestook
Evans Tuning - 6/25/2016

On the dyno she seemed to pull ok with the same power as before so at least we don't have any power loss but he did notice something weird when holding part throttle at higher revs, the TPS voltage would jitter a little (about 0.5%) but this was actually enough to trigger the ECU to act like the engine was just starting up and then would momentarily run rich. We probably would have not easily seen this by just looking at a datalog after the fact so it was really good that Jeff was trying to zero in on this problem while looking at everything on the ECU in real time. Jeff tweaked some of the TPS voltage sensitivity parameters in the ECU and Bumblestook immediately responded positively. The momentary rich condition is now gone and she revs smoothly through the entire power band both at part and full throttle. Unfortunately our next local event to do some final testing won't happen until August but at least the mystery "burble" issue has been addressed so expect some more pace out of Bumblestook the next time you see her out there.

Radial trailer tires - SJF Performance - 6/25/2016

Radial trailer tires - SJF Performance - 6/25/2016

I just replaced my trailer wheels and tires before Nationals last year but after doing some more research I decided to change them yet again. I switched from bias-ply to radial trailer tires. The radials have slightly less load capacity but still well within my requirements but more importantly they are rated up to 81mph unlike the bias ply tires which are rated to 65mph. This will help greatly in Iowa when I-80 speed limits are 80mph and the last thing I want to worry about is blowing out a trailer tire. We generally try to stay below this limit but it's always good to have that extra cushion just in case. All four wheels/tires were replaced and I also got two new ones as spares. The trailer's going to be at SJF Performance for a while so he can make some nice little modifications to the trailer for me and put a fresh coat of paint and get rid of some of the rust that's started to form. The countdown to Nats has started.