What are the performance effects of a light weight front bumper?

[Luis]

I have always heard that 76 Firebird Formulas are nose heavy. I have also heard great things about moving the battery to the trunk. I have recently purchased a nice looking fiberglass front bumper from Classic Ind. and was curious if the light weight bumper would have a similar effect as moving the battery to the trunk. The original weighs anywhere from 75 to 95lbs., while the fiberglass only weighs about 8 lbs. My suspension consists of GW upper and lower arms, GW subframe connecters, Koni shocks, approx. 550 lbs.front springs, stock rear leafs, H.O. 1 3/8th front swaybar and 7/8th rear swaybar, solid GW body bushings, 255/50/17 Nittos. I have never driven this car to its limits, so I am curious to hear about what potential my set up has around the driving course from more experienced drivers. Overall, my Formula is fun to drive on the streets, slightly stiff, responsive and it sets quickly(good weight transfer, I guess. I would appreciate any suggestions. Thanks. Take it easy on me guys this is my first post.

[David Pozzi]

It should help a lot. Battery relocation helps double because you subtract weight up front & add it to the rear. Your front bumper is just a front weight loss, but a very significant one. On an autocross course it could mean a faster time by .3 to .5 seconds. But that's just a guess.

[Norm Peterson]

Nearly all of the older US domestic V8 RWD cars are nose-heavy.

Less weight anywhere = better acceleration (tire traction permitting).

Less weight up at the very front = slightly quicker turn-in as well as slightly higher lateral g.

I like David's guess.


No matter how hard you drive on the street, even just a moderately hard autocross run will be harder still, and you'll be a lot busier. On the street it is natural to leave some (or a lot of) performance on the table, because at least in the back of your mind is the idea that things like curbs, trees, utility poles and ditches tend to hurt stuff if you hit them.


Norm