chassis gurus!!!
#1425283
04/25/13 11:48 AM
04/25/13 11:48 AM
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Joined: Feb 2007
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maximum entropy
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organ
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my buddy got a nice chassis car, and he's gonna run it for the first time on saturday. he scaled it, and it was heavy on the left rear corner. shouldn't it be the right rear? it's a four link car. idk if he has a roll bar- i assume he does.
for what is the good life if not doing things thoughtfully?
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Re: chassis gurus!!!
[Re: rickseeman]
#1425285
04/25/13 11:55 AM
04/25/13 11:55 AM
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Joined: Feb 2007
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maximum entropy
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organ
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interesting. i thought the left rear gets planted. is that in a leaf spring car only?
for what is the good life if not doing things thoughtfully?
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Re: chassis gurus!!!
[Re: maximum entropy]
#1425286
04/25/13 11:58 AM
04/25/13 11:58 AM
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Joined: Jan 2012
Posts: 2,678 Stuttgart, Arkansas
rickseeman
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Well, a chassis car is normally coilovers. The driver sits on the left. The engine is in the front. So the right rear has the least weight on it.
2011 Drag Pak Challenger
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Re: chassis gurus!!!
[Re: maximum entropy]
#1425287
04/25/13 12:05 PM
04/25/13 12:05 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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I disagree.. but you have to base the weights on how much torque the car has.. any chassis car I have seen wanted the RR a bit heavier as in 10 to 30 lbs... but I would start out at zero and if it goes to the right on the launch I would add weight to the RR by shortening the upper right bar a 1/4 turn at a time
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Re: chassis gurus!!!
[Re: rickseeman]
#1425288
04/25/13 12:06 PM
04/25/13 12:06 PM
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Joined: Jul 2010
Posts: 2,422 Pittsburgh PA
Eric
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top fuel
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Pittsburgh PA
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Generally the right would get the preload making the right side have more weight...BUT...some cars like to be set up neutral and some..like mine.. like negative preload. I set the anti-roll up neutral and make the adjustments with the 4-link. Some people use the anti-roll for preload also.
5.53 @ 125 1/8th on the launch control..more left in her!
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Re: chassis gurus!!!
[Re: Eric]
#1425291
04/25/13 12:10 PM
04/25/13 12:10 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
Generally the right would get the preload making the right side have more weight...BUT...some cars like to be set up neutral and some..like mine.. like negative preload. I set the anti-roll up neutral and make the adjustments with the 4-link. Some people use the anti-roll for preload also.
I keep the anti roll at neutral all the time.. I load it with the upper right bar(or negative if needed)
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Re: chassis gurus!!!
[Re: MR_P_BODY]
#1425292
04/25/13 12:27 PM
04/25/13 12:27 PM
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sounds like there is no set rule- start neutral, and adjust as necessary? neutral with the driver in the car? or without? please pardon my ignorance, but i've raced nothing but leaf spring cars.
for what is the good life if not doing things thoughtfully?
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Re: chassis gurus!!!
[Re: maximum entropy]
#1425293
04/25/13 12:59 PM
04/25/13 12:59 PM
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Joined: Jan 2012
Posts: 2,678 Stuttgart, Arkansas
rickseeman
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Start with neutral with the driver in the car. Fuel. Race air pressure in tires. -2 degrees pinion angle. Ready to make a pass. No preload. Horsepower will dictate if you need preload. Buy Jerry Bickel's book and Rick Jones book. Best money you can spend if you want to learn about chassis cars.
2011 Drag Pak Challenger
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Re: chassis gurus!!!
[Re: maximum entropy]
#1425294
04/25/13 01:03 PM
04/25/13 01:03 PM
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Joined: Jan 2003
Posts: 684 St. Charles, MO.
Slingshot383
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Car needs to be on the scales just like it would be on the starting line, fuel, water, oil, driver (fully suited up), air pressure in the tires set. Set everything neutral and square (distances, front to back, and left. front to .r rear, and r. front to left rear) for the start, and adjust from there.
1994 Undercover Chassis 125" altered
stack injected big block, soon blown and injected
Member of The Torque and Recoil Club
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Re: chassis gurus!!!
[Re: maximum entropy]
#1425295
04/25/13 02:46 PM
04/25/13 02:46 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
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Quote:
sounds like there is no set rule- start neutral, and adjust as necessary? neutral with the driver in the car? or without? please pardon my ignorance, but i've raced nothing but leaf spring cars.
No there is no set rule as to pre load... that is determined on which way the car goes on launch... and that means at the line to maybe 50-60 ft out... really anything beyond that can be alignment or brakes or other factors.. like Erics car likes a touch of negative pre load, my car likes about 10# of +pre load.. so you get the idea.. and once you take the play out of the bar (upper right) it doesnt usually take much unless something is wrong... all this is based on the zero of the car at race weight... Note... if you go to square up the car like slingshot said make sure what the front end is.. my car has 3/4" of stagger built into the front end(right tire is set back 3/4" to give me a longer roll out) and a lot of chassis shops do the same thing
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Re: chassis gurus!!!
[Re: Slingshot383]
#1425296
04/25/13 03:03 PM
04/25/13 03:03 PM
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Joined: Jan 2012
Posts: 2,678 Stuttgart, Arkansas
rickseeman
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Hopefully the car will go straight the way it is already set up. My car is 150 lbs heavier on the left front than the right rear. Do I care? No. All I care about is if it goes straight when I let go of the button. And it does. I have some buddies that think you are supposed to put it on scales and crank the preload into it until it has the same weight on the rear wheels. I don't know why. There are experts somewhere who could take your wheel weights and horsepower and set the car preload before you go to the track but they don't live next door to you, so you have to learn this yourself. Set your 4-link heim joints up where the left hand thread joints are in the front. You didn't say how much horsepower you have, lets say you have 800. If you set it up with no preload it will probably drift to the right after the launch. Put a half a flat of preload in it and make another hit. Keep working it until it goes straight, then life will be good.
2011 Drag Pak Challenger
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Re: chassis gurus!!!
[Re: rickseeman]
#1425298
04/25/13 06:58 PM
04/25/13 06:58 PM
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Joined: Mar 2008
Posts: 1,596 BX, CT, FL.
B1KILLER
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pro stock
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Quote:
Hopefully the car will go straight the way it is already set up. My car is 150 lbs heavier on the left front than the right rear. Do I care? No. All I care about is if it goes straight when I let go of the button. And it does. I have some buddies that think you are supposed to put it on scales and crank the preload into it until it has the same weight on the rear wheels. I don't know why. There are experts somewhere who could take your wheel weights and horsepower and set the car preload before you go to the track but they don't live next door to you, so you have to learn this yourself. Set your 4-link heim joints up where the left hand thread joints are in the front. You didn't say how much horsepower you have, lets say you have 800. If you set it up with no preload it will probably drift to the right after the launch. Put a half a flat of preload in it and make another hit. Keep working it until it goes straight, then life will be good.
That would work for me
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