Quote:
Originally Posted by Target70
Torqdork: After seeing a properly installed (?) electric s/c participating in a local track day in another run goup, I tend to agree.
The system I saw required two 12V batteries wired in series (heavy, and I didn't have time to figure out the 24V wiring and charging circuit), could only run until the batteries depleted but before that happened an intake air overtemp protection circuit reduced engine output by putting the car into limp home mode after 10-15 minutes.
It would be effective for ¼ mile drags with adequate recharge and cool down between runs, but not so much for track or daily driving.
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It does require two 12v batts, but it also replaces the stock battery with a lightweigt compact battery. The factory battery is 30lbs, the 24v dump pack is about 26lbs, and the compact starter battery at 15lbs. So only about 11lbs more than the stock car, or 23lbs more for the 1.5 dump pack. (which produces about another 10hp/.5psi to redline) due to the additional available current.
I find it unlikely that the ecu increased IAT at all, as it uses the stock air box, and contributes no heat to the intake except the relatively low compression factor. (less than 5psi) between 1.5 and 2psi at redline(depending on your battery setup). More likely the motor controller overheated and went into protection mode, or thermal cutoff. The first is where it will reduce the amount of boost it provides, lowering the demand on the controller untill it cools down a little. The second is where it gets so hot it turns off completely to protect the system from damage, basically converting back into a stock NA car with a slight intake restriction, and a bad tune(as it is now providing more fuel for all the air it is no loner getting). The ESC is just not designed for track use. With enough cooling to the controller, and the soon to come out dual charger it is getting closer. This speeds up battery charging time, and splits the work between the two controllers so that the overheat problem is greatly reduced. But even with these things, the typical track driving style is not a good fit to the systems strengths. The ESC produces little gains at higher rpm's, and major TQ gains at lower rpm's. As you tend to stay in the upper revs on a track, you never get to use the systems greatest strengths. Plus the energy storage system is for more of a short term use. The ESC charges when not engaged at WOT, so a track with lots of long straights, will over tax the system, and not provide enough charge time.
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It's the perfect system for a daily driver IMO. Way more low end torque, more peak HP, better cruising gas mileage, smooth/controlled boost of around 5psi at 2500 rpm tapering to about 1.5psi at redline. I've never come close to running the batteries dead in street use no matter the heat here in the summer - and never had any issues with overheating the system... and there's an add on aux recharger coming soon that will cut recharge time in half - which should resolve most if not all issues of running out of juice even on the track. The overheating issue on the track is still being worked on.
However, based on what I've read about track use, it would probably be fine for that as well, as long as the ambient temp is 80 degrees or below. The overheating has happened occasionally on the track - but it's typically been after 10+ minutes of running hard in 90+ degree weather - at least from the reports in the 100s of pages of thread I've read.