Looking to upgrade a 2001 boxster - 986 Forum - The Community for Porsche Boxster & Cayman Owners

lbrown2009 · 10-02-2009, 08:03 AM

i ordered the underpulley, where can i find one of those ultra light batteries? what kind of labor charge am i looking at to install the underpulley?

stephen wilson · 10-02-2009, 10:31 AM

I agree with your list of benefits of weight reduction ( I race a Formula Ford) , just not the magnitude. I don't have time to try and calculate the increase cornering G's, it's a complex issue, but 100 Lbs. is around 3% less weight & weight transfer. I doubt that equates to a 3% increase in cornering power.

Top speed has little to do with weight, it's dominated by mechanical & aerodynamic drag, and horsepower.

edevlin · 10-02-2009, 11:09 AM

I also do not know how to quantify how much lightening the car changes its performance. But it sure does seem to make it quicker. My 2000 base boxster weighed in at 2780 lbs when new (not 3000 lbs), I have taken at least 100 lbs off of that, so I suspect I am well below 2700 lbs. How do you quantify that weight reduction, I dont know, maybe I have a 2.5% bigger grin when driving

.....

Ed

:dance:

Topless · 10-02-2009, 02:15 PM

Stephen,
Of course you are right. There is no direct correlation between weight and HP because every track is different. I chose 50hp as a wild guess simply based on local lap time comparisons. On a popular 1.8mi track here a keen driver (Grand Am driver Kevin Roush for example) might run 90 sec. in a bone stock 2.5 Box. He then steps in to a 250hp Box S and turns 88.5s. When he comes back to the pits our 2.5 Box has 100lbs removed and he proceeds to run 88.5s in that car. So on this day, at this track with these cars and this driver, 100lbs weight removed was roughly equal to 50hp. Switching over to the Auto Club Speedway in Fontana Kevin will be checking his email down the front straight at 130mph in the 2.5 car as Turbos and Vettes whizz by doing 165.

Feel free to use whatever comparisons you are comfortable with based on your own experience. This is just one crude example of the benefits of weight reduction on our cars. Your mileage may vary.

Here is a link to the 15lb Oddessy 680 battery I am using. If you get the battery also order the mounting cover they have. It is pretty slick:
http://www.odysseybatteries.com/battery/pc680series.htm

stephen wilson · 10-02-2009, 03:02 PM

Topless,
Fair enough. Don't mind me, sometimes I focus too much on minute details!