Testing with Dave at NNJR SCCA

Nationals is only 6 weeks from now and this is the first time this season I've been able to take Bumblestook out for some home region testing with the NNJR SCCA at the Meadowlands. I asked Dave Corsaro  to codrive with me for this event so he could help me quickly dial the car in. Although we had the threat of rain, first heat ran mostly without a hitch in the dry but then the skies suddenly opened up just before our heat.

NNJR SCCA - Meadowlands, NJ - 7-23-2017

Our first two runs were done completely in the wet and it was a pure exercise of car control as Bumblestook wanted to drift more than she wanted to go straight. The course started drying up by my third run but just as Dave was about to go for his first dry-ish lap, the skies opened up again, wetting the dried parts of the course once more. Thankfully though we got a break and it finally did stop raining and a combination of winds and hot conditions allowed us to take our final 2 runs in the dry. 

Dave about to go out for his first lap in wet conditions- 7-23-2017

Dave identified a slight push in the car in our 5th runs and wanted some more front bite so we took out some front compression. I took my final run and the car felt much better. I dropped a good chunk of time and the course was now completely dry (well at least the racing line was). Dave finally got to drive Bumblestook at full speed for the first time and set a good raw time but nicked a cone in the slalom. Unfortunately that was the extent of our testing. The pace was definitely there to compete for the top spots but we ran out of runs. I may try to raise the rear bar a bit at the next event to get just slightly more rotation. It's tricky to tell based on today's data as the conditions were constantly changing. Overall though, I think it was a successful day. Her power delivery with the new tune was smooth, the new alignment seems to be balancing the car well and the handling is ballpark where we need it to be so it's just minor adjustments from here on out. 

NNJR SCCA - 7-23-2017

Extracting Power

Bumblestook was already making good power but it was more towards the top end. In autocross you spend a lot more time in the midrange so the focus has always been to make a fatter, more usable torque curve from around 4000-7000rpm which is why I decided to swap from the PLM header to the Toda Torquie-Kun. In order to make sure Bumblestook would run optimally, I didn't want to take her out without first getting her on the dyno for a retune so I took her over to Evans Tuning today so Jeff could make sure she was running right.

Jeff Evans tuning Bumblestook - Evans Tuning - 7/15/2017

The tank was still full of E85 from Toledo which was ideal. We did a baseline run without making any changes to the old tune and it showed a massive 20+ ft-lb torque drop midrange. This would've been very noticeable (big time bog) if I had tried to run her without retuning. Turns out the VTEC crossover was too low for the way the Toda header flowed so he raised it a little and after a several pulls and adjustments to the fuel map Jeff was able to extract about 10 more ft-lbs of torque and 10-hp in the midrange over the old tune/setup.

Dyno Tune - Evans Tuning - 7/15/2017

It's important to note that comparing dynos over different days and conditions even of the same car isn't really worth doing so the increase is a data point but take it with a grain of salt. I think the important thing to note is that the power did indeed shift more towards the midrange (there's actually a noticeable bump in the graph that wasn't there in the old tune) at the cost of a slight loss of power at the top end. I think that's more than a fair trade off. I will note however that the previous tune was done during the winter and we're retuning in the middle of the summer so in theory the old tune should've produced better numbers to begin with so the fact that we're seeing gains while tuning at much warmer and humid conditions is very promising. We'll be testing her out next Sunday to see how all the changes work out.

Mounting fresh tires - SJF performance - 7/15/2017

I also stopped by SJF Performance so Steve could finally mount the fresh set of tires we'll be using for Nationals on my 2nd set of CCWs. Hopefully I'll be able to scrub these in some time in August before we head out for Lincoln.