Re: weight distribution
[Re: fishy340]
#1498906
09/09/13 03:45 PM
09/09/13 03:45 PM
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Joined: Aug 2003
Posts: 43,163 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,163
Bend,OR USA
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I would go run it, my Duster had almost 50% on both ends, 50.3 % front, 49.7 % on the rear with no wheelei bars It would sixty foot in the high 1.30 to low 1.40 on a good track, wheelies where around 6 to 10 inches off the ground for 20 to 40 ft, no big deal I did have the ladder bars in the lowest hole on the front and Koni SPA front shocks, Strange double adjustables on the rear with 4 clicks on extension from soft and 5 or six on compression from full soft As far as the first run be ready to either lift a little on the throttle, not all the way Or use your other foot on the brake to help control the wheelie hieght You can also short shift it you want or need to Way back in the day(mid 1970s) I was told by one of the Chrysler powered Pro Stock racers that they like to see between 54 and 56 % of the cars weight on the rear wheels He said they didn't use a W or stiff sidewall rear tire either back then, revved the motor to 7000+ RPM and let the clutch out
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: weight distribution
[Re: fishy340]
#1498907
09/09/13 04:12 PM
09/09/13 04:12 PM
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Joined: Dec 2009
Posts: 20,640 in a cattle trailer down by th...
Guitar Jones
Paddle faster! I hear banjo music!
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Paddle faster! I hear banjo music!
Joined: Dec 2009
Posts: 20,640
in a cattle trailer down by th...
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Quote:
Ok i got my abody scaled last week and the front total weight of the car equals 53.3%.I never really looked at these post cause my cars pretty much went striaght.Alot more hp in this one and the guy who scaled it..said 1 thing the car will do is go straight.My concern is it going up..lol its got limiters so they'll be real tight to start.So whatta you guys think..good or bad ? Thanks AndyB
Not much info to go on.
"Follow me the wise man said, but he walked behind"
'92 D250 Club Cab CTD, 47RH conversion, pump tweaks, injectors, rear disc and hydroboost conversion. '74 W200 Crew Cab 360, NV4500, D44, D60 and NP205 divorced transfer case. Rear disc and hydroboost coming soon! 2019 1500 Long Horn Crew Cab 4WD, 5.7 Hemi.
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Re: weight distribution
[Re: fishy340]
#1498917
09/10/13 08:42 AM
09/10/13 08:42 AM
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Joined: Jan 2003
Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
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master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
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I found out that going to 53 percent front weight was a positive move for my car, due to the location of the CG.(too high, too little forward ballast). Mine wanted a good hit to the tires to get weight transfer, and once the front is up, the car no longer knows what percent is on the front,cause its all on the back! Sounds kinda dumb and simplistic, but that's what it is. Figure out how hard you can hit the tires and get it out of the gate, and it will fly! With the torque of nitrous, you are probably going to be able to hit the tires as hard as my 528 I would think. The limiters should be set loose is my idea of the right way to go. By starting dead soft on the front suspension, full travel, you can better figure out the back suspension and how much juice to throw at it at the hit. Then when you start seeing it pull the front too high, you can adjust the front to see what it will tolerate in limiting travel or stiffer shock settings to settle it down to your liking. With a little math and a few facts about the car, you could figure out how much torque can possibly be put to the back axles, and that will give you a rough idea of what the car will do. As an example, if you have enough torque to"dead lift" (no spring help) the front of the car, there is no possible way to keep it on the ground IF the tires bite. It made sense to me when I did a little math. Example- Big block with 760 ft lbs torque at 4800 stall plus another 500 ft lbs from a dose of juice would be 1260 x 2.1 converter multiplication or 2646 x trans low gear (1.82?) = 4816 x 3.54 rear ratio = 17,047 ft lbs at the axles, minus 10 percent driveline loss is 15432 ft lbs at the axles. If you have a 30 inch tire, that would be a radius of 15 inch, which reduces the torque -15432/15inch =1022 x 12 inch (for ft lbs)=12274 in torque at the tire surface trying to dead lift that front. At a front weight of 1700 lbs and a wheel base of 108 inches, or 9 feet, you get (9x 1700) a value of 15,300 to dead lift the front of the car. With the help of soft springs to get it moving, and the change of the CG as the front comes up, the car would easily go on the bumper with that 12274 that showed up in the first set of numbers. With only a 1.82 low gear and a soft 3.54 rear gear, it is still a monster because of the torque of the juice. Could you imagine trying to make that car work with a 2.45 low and a 4.56 out back? Thats close to what I was battling, but without the juice. I am looking forward to some full track reports, to see how it goes. This will be a whole lot of fun!
Last edited by gregsdart; 09/10/13 09:25 AM.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
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