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Author Topic:   too much rear %?
posted March 09, 2004 05:21 AM
Plan to race at a track that will require us to run at 3400. I scaled the ride last night at 3335, just to see where I was "at" and learned that I was already at 57% rear. If I gotta *** another 70=/- lbs...should I set it behind the seat to avoid gaining excessive rear percentages? Or is there I no such thing as too much? I never had this problem before! That off-season diet did my hot rod some good! Help please!!!!!

posted March 09, 2004 05:30 AM
congratulations on the 57%. I'm not sure if you can get too much rear weight but I would think that you would have to run less cross than you did before to make it in to the corners.

posted March 09, 2004 08:59 AM
actually, with a higher rear %, the car will be looser during pure cornering ...... requiring more cross (at least in the middle) what happens in your entry will have a lot to do with your rear brake bias (do you tend to turn on your left rear?).

in so far as how much rear is enough or too much ..... that has a lot to do with the shape of your track (a track with tighter turns and longer straights may benifit more from a high rear) and how easy (based on your motor and tires) it is to spin your tires on exit.
..... IOW ... if you don't spin your tires at 52 rear, then 57 is 5 percent too much .

Don't lose sight of the fact that your car has the potential for cornering it's fastest when all 4 tires carry an equal amount of the verticle load (assuming you run simalar size tires on all for corners).

having said all that .... congratulations on finding yourself in a position where you can try most any weight distribution (within reason). While it's not critical, you may want to keep an eye on keeping your weight between the axels and as close to the polar center as reasonable.


posted March 09, 2004 11:43 AM
I'm a firm believer that too much rear weight can be detrimental to handling. I was pulling my hair one night after a heat when the car's rear would try to swing out loose on entry then in and around the center it pushed like a dump truck. I knew the track conditions and my set up (scale #s, wheel backspacing, tire sizes, etc.), and they were absolutely not consistent with what I was feeling in the car. Then a crewmember discovered a massive amount of caked mud up under the tail of the car that must have been picked up during hot laps. We estimated that it weighed a good 90 to 110 lbs. You add this much weight to the tail when you've already built in 53 to 54 percent, and I figured I was running about 56 percent or more. That's too much for my car. The car was on the money after we cleared the mud, by the way. Now I've built mud flaps.

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