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.
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| 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.
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| 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.
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| 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.
