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Old 04-03-2012, 10:33 AM
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Buckaroo
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Default Developing a boosted profile

It's all in the boost profile and the motor you choose. The RevTech doesn't like boost profiles at all, the D3, SP, Reedy, and X12's love it.

This is from my friend Harry, and might help you some (some might disagree, but if you can't get a boosted profile to be fast and cool with this method, you need to step up in motor):

Boosted profile from scratch
When I'm starting a profile from scratch, I use the rough kV to figure out where I want my RPM range.

For 17.5 I take 2400 * 7.2 [you can use the battery ending voltage if you think your profile is pretty close, otherwise I use nominal voltage] = 17,280.

You can use this for your end RPM, but I usually knock around 1k RPM off that figure, so call the end RPM 16,000.

For start RPM, I usually set it for the top 60% so 16,000 *.4 [take 40% off] = 6400. Pick something close from the list of calculated Start RPM values.

After that, it's just a matter of fine tuning to preference. If you want more pull off the corner, raise the Start RPM up about 1,000 RPM. If you want to smooth out power deliver on bottom end, lower the Start RPM about 1,000 RPM. Repeat as necessary.

The amount of boost you run is gearing dependent.

I only use Turbo if I'm visibly lacking in straight away speed, and don't think the added speed is going to hurt corner entry at the end of the straights. The most Turbo I'll run is around 10, ramp 1 or 2, with .4 delay [almost always]. I don't remember if I was running any today or not.

EDIT: Forgot to mention, if you feel like you want mid-throttle acceleration snappier, lower the End RPM down 1000 RPM at a time until you're happy. If you feel like mid-throttle acceleration is too aggressive, drop the Boost down in increments of 5.

To me, if you see the car kind of "shifting gears", your profile is likely going to upset the car and make it needlessly hard to drive, and slower. I'd rather see the car accelerate smoothly, but very quickly instead.

FYI: I use 3400 kv as my rough estimate for 13.5, and 4200 kv for 10.5's. Every company's motor is a little different, but the above calculations have served me well when building a boosted profile.
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