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Author Topic:   Starting point
Eljojo
Member
posted January 13, 2002 09:27 AM
How about a place to start with a chassis set up for a metric? Minimum weight is 3100, but should I run heavy to get desired percentage? Where should I start with cross weight? What rear percentage would I need? How much left %? I've redone my ride and moved weight higher...should any lead be mounted behind the axe? All the way to the bumper? I've seen lead mounted in some strange (I thought) places...where do you think it should go? Please...your input is greatly appreciated!


Eljojo
Member
posted January 15, 2002 07:53 PM
And while you're all bustin yerazz to reply to this topic----------how about ride heights? LOL--c'mon guys--help me out a little


champ
Member
posted January 16, 2002 09:43 AM
My theories....put your weight as close to, but in front of, the rear axle as you can. I had my battery mounted on the floor on the driver side where the back seat was. I have moved it forward some right where a rear passenger would put their feet. I built a neat little cage for it...coming off the roll cage. Now I have room a little farther back for my "real" weight. I built another neat little hold down also using the backside of my roll cage. My theory is...keep the weight off the body of the car and more on the frame. Since the roll cage is attached to the frame and it's all near the rear and on the driver side, I think it's good placement. I don't know if you have your body mounts removed but I don't. any weight I put on the body makes body-roll even worse. The only downfall to this that I have suffered thus far is, it's a little harder to get to the battery. The neat brackets I made make it easy to add and remove weight by loosening 2 nuts and lockwashers. MAKE SURE everything is locked, pinned, welded, anchored and double reinforced. If you have a really violent crash, all the heavy stuff is right there with you. Don't want any of that landing in your lap or crackin yer skull.
The other thing I've heard is it's ok to have weight in the trunk but I've heard it can effect the momentum of the rear end when you swing into or out of the turn....all that weight that far back wants to keep on moving when you're ready for it to stop.
Front and rear percentages and ride height are beyond me. I feel more comfortable "eyeballing"(feeling it on the track) my car and what it does.
Hope this helps.


WesternAuto17
Member
posted January 16, 2002 11:50 AM
Keep the weight out of the trunk if possible. The theory is that the weight will act like a lever as you go thru the turn -- the farther away it is from the rear wheels, the harder it will pull the rear end loose. My old car drove a hundred times better after I removed the weight from behind the axle.

Now I'm building a new car and I'm going to add weight as far down and to the left as possible b/c I don't like body roll. Some people like that and add weight high on the cage to make the car roll. My opinion is to not go overweight just to get the percentages correct. You shouldn't have to do that anyway, but I don't know what your car is like.

Look into the old posts, there are about a million on baseline set-up info. That's why no one's really responding.

Eljojo
Member
posted January 17, 2002 08:02 PM
Well hey I really do appreciate you two taking a minute to respond. Thanks!


wkramer
Member
posted January 19, 2002 05:46 PM
how about some info. like track size , banking, any rules that pertain to your set-up


jwalsh9499
Member
posted January 20, 2002 12:43 AM
I followed an earlier suggtestion and did a "search" Looked to me like 52% was the desired cross, but I never did find anything conclusive about rear% and left side %. Is there such a thing as too much?


blanep
Member
posted January 20, 2002 08:11 PM
None of my knowledge is from experience, only from reading everything I can get my hands on for the past 10-12 years in anticipation of finally getting a car. (I just finished cataloging every applicable article from the last 11 years worth of issues I have of Circle Track Mag and Stock Car Racing Mag.)
Everything I have ever seen seems to shoot for a baseline of roughly 53% left and 53% rear and 48-49% cross. And as for adding weight to be able to get in the neighborhood of those percentages, I would differ from westernauto17 by saying yes. Weight is the greatest influence on the car during corner entry, springs and shocks the greatest influence on the car during turn and exit. If you don't have the weight correct getting into the corner then nothing else (springs and shocks) will ever work to their greatest potential. Being light is no good to ya if if you can't keep up going into, through and out of the turns IMHO.
Again, take what I say with a grain of salt since this will be my first season, just telling you what others have written from their experiences. Also, every car and driver are gonna want something a lil bit different so just get yourself a baseline and go from there. Who knows, your car on your track may come alive by being light and having wacked out percentages. No two cars or tracks are alike.


owracer
Member
posted January 21, 2002 08:29 PM
What percentages you will need will vary with track conditions. On a track that stays tacky-48-49% cross,52-53% left & rear. On a dry slick track that is more like cornering on asphalt-51-52% cross,53-54% left & rear. How much body roll you need also varies with track conditions and even the type of tire you run. A harder tire and or track needs more body roll to generate side bite. You can locate lead in many different places to achieve the desired effects of the weight transfer that you want. I have put weight any where from the rear bumper to the center of the car. I try to keep the bulk of my weight at the rear axle. The correct spring and shocks also play a big role in this also. I suggest a 1200 rf, 1000 lf, 250 rr, 350 lr. Shocks also vary with track conditions, but to keep it simple, use a easy up on the rf,heavy on the lf, and mediums on the rear. AFCO p/n in order-1022,1021,1030. These are good general set ups that should have you right in the ball park.


uforacing51
Member
posted February 02, 2002 12:32 AM
I had a fellow that has 14 track championchips at 3 different tracks over 25 years, set up our car last year and he put all the weight behind the rear end. but the percentages came out ok. Is this wrong. warning: the car may be bent from accident when it was a street car. this may be throwing off the scaling. I think this car is on its way out however. She wants to have a baby and I am almost thru with school and want to get back into a modified.


Machinah
Member
posted February 03, 2002 06:22 AM
Since conditions at your track(s) are unknown, I will offer my opinion about the best general rules of thumb to follow. 1... The stiffer that you can make your chassis, the better. There is more than one way to do this, depending on your track's rules. When welding in your roll cage, don't just weld to the frame, weld it where it pierces the body, and weld in reinforcing plates and gussets if possible. Weld in as many center to front and center to back reinforcing braces as your money and rules will allow. Weld in cross-frame, under body braces if the rules allow. 2... After your frame is as stiff as its going to get, if you can get enough practice in, set your front suspension without any weight added. 3... When you have all other things adjusted, then add your weight to adjust your handling. 4... Lastly experiment with tire pressures. Weight and tire pressure should always be left for last because these two are generally employed to correct components that either can't be emplimented due to rule restrictions, or they are employed to correct already incorrectly adjusted exsisting components.


tobyone00
Member
posted February 03, 2002 09:48 PM
quote:
Originally posted by Eljojo:
How about a place to start with a chassis set up for a metric? Minimum weight is 3100, but should I run heavy to get desired percentage? Where should I start with cross weight? What rear percentage would I need? How much left %? I've redone my ride and moved weight higher...should any lead be mounted behind the axe? All the way to the bumper? I've seen lead mounted in some strange (I thought) places...where do you think it should go? Please...your input is greatly appreciated!

We run 3200 lb metric monte on 3/8 dirt,we put half the weight above rear end and half behind rear to raise% have 55%L-55% cross and 57%rear car works exellent,run 4-5 inches stagger for heat and when track dries out 2-3 inches stagger we run for springs 1200-rf 1000-lf 250-rr 300-lr won many features this way hope this helps

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