Sunday, April 22, 2012

FSAE Weekend 4/21/2012

I went out with the team to the New York Times printing presses in Flushing this weekend to drive the car around in one of their lots. The facility is huge (I think it takes a solid fifteen minutes of walking to get from one end to the other) and their parking lots are correspondingly big.

It was the first time that we've taken the car out since October, and we've gone through very major changes to many subsystems -- a new intake, a new differential, a cable clutch instead of a hydraulic clutch, and some major frame modifications. We have to prove the car all over again and then make sure that each of our drivers is comfortable driving the car and ready for competition.

The event was very useful -- we found a lot of bugs that need to get fixed over the next two weeks. First and foremost, our charging system is broken -- something that I knew about for months but put off way too much. This limited us to a total of 15-20 minutes of driving with a big lead acid battery hooked up in parallel to our tiny two pound LiPoly battery in a total wasted charge setup. The problem seems to be that the regulator/rectifier that converts the 3-phase 60 VAC output of the generator on the engine gets blown out. We run more electrical systems than the stock motorcycle setup and abuse them more -- an electric water pump, a lot of starter motor abuse, and a lot of driver-facing electronics -- that probably over strain the stock rectifier/regulator. I am going to try to hook up another stock R/R and have it hook into the electrical system on a relay controlled by the ECU on engine RPM because I think that the extra power demands of the starter motor at engine start are the biggest strain on the rectifier.

Other bugs that we found are also significant -- we had to kludge an extension mount for our amazing carbon fiber intake because the frame wasn't designed to fit the intake to begin with, but the extension mount seems to leak a little air -- you can hear the hiss of air leaking when the engine is running and it's not coming from the air filter on the intake. The intake is also cantilevered and the mounting flanges are cracking out of the intake runners because of vibration induced crack propagation. We're going to have to hack in another stiff mount at the top end of the intake to fix the problem.

Our brakes aren't in great shape either. We did an acceleration test and tried to lock all four wheels but only two of four locked up. I don't know much about the brake system so I can't say much about how we're going to fix it.

Anyway, not to be totally negative, here's a picture of the car running:

Also, the car didn't leak any water or oil -- that's something that we've had some big problems with in the past few weeks that would have led to a swift disqualification at the competition. We've learned the hard way that you have to do a very thorough job of cleaning sealing surfaces and then applying sealant to them to avoid leaking problems, even in areas that are not highly pressurized.

No comments:

Post a Comment