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Author Topic:   Weight Percentages
shakin
Administrator
posted January 02, 2000 12:01 AM
What is everyone's preference on weight percentages for any type of a racecar.


Roadhzrd
Member
posted January 02, 2000 12:21 AM
I like 53lw,51cw,58rw on my dirt mod. The reason I'm not afraid to give that info away is every car is usually set up with different springs, shocks, and ride heights... thats what makes this a great sport. So many people racing totally different setups and going just as fast as the other guy.


dirt mod 70
Member
posted January 03, 2000 04:29 PM
WITH % LIKE THESE I WOULD TEND TO BELIEVE THAT THE CAR PUSHES IN THE CENTER OF THE TURN AND DOESNT HAVE AS MUCH SIDE BITE AS POSSIBLE AND IS LOOSE COMING OUT OF THE CORNER? JUST MY OPINION!!
LESS LW LESS CW AND MORE REAR%


jammin
Administrator
posted January 03, 2000 05:20 PM
The less crossweight you have, the less likely you are to push, this can be manipulated with side bite also on entry. But you can run as much rear as you want, as long as the car will enter, and manipulate the crossweight to keep it from pushing in the apex and off.


zippo
unregistered
posted January 07, 2000 06:39 AM           
are you saying that by keeping your left side and right side as close as possible that it will eliminate push in center of corner and coming off corner?


jammin
Administrator
posted January 07, 2000 12:18 PM
Any time you increase the weight on the LR, you increase the crossweight, they go hand in hand. You have to find that delicate balance between tight and driveable. When you find that, you will be going about as fast as you can go on that setup. And, yes, if you can keep the left rear and right rear side as close to 50% weight distribution while in motion (dynamically) in the turn, you will be hooked. So you will have to manipulate your chassis (statically) accordingly to get to that point. At 50% on both rears, your getting maximum traction and driveability. Hope this helps.


fastorange23
Member
posted January 13, 2000 06:08 PM
please help with some basic knowledge. I have heard the term sidebite several times and have some vague idea what it is could someone please help with this?? Also I race a 3200# Street Stock, I can't run weight jacks but I do have hidden adjustable shims so I can make adjustments. Does anyone have any baseline setup ideas? I race A 3/8 med bank track that always goes dry slick by feature time! I have a 355 with great heads and have almost to much HP with it. We also have an 8" rim and 10" tire width rule. Looking for scaling,shocks,and spring ideas. Ballpark of course


jammin
Administrator
posted January 14, 2000 12:37 PM
Sidebite is basically what keeps your car from spinning in the turns once the car's weight is transferred. The main idea about this is that when you increase your sidebite, you can enter and go through the turns harder, simply because your car will set in the turns and wont try to go around on you. You can decrease your leftside weight or increase your rightside weight by simply adding lead high and to the right on your car. This will allow the car to transfer more weight to the outside when in the turns. What you may have to do is tighten the car up after this is done to get a better bite off the corners on the left rear. When you roll more to the right, the car looses the left side weight, thus, left side bite. The front is not as critical, but the left rear is crutial. That is what pushes you out of the turns.

Hope this helps.

fastorange23
Member
posted January 28, 2000 07:41 PM
help with % PLEASE


jammin
Administrator
posted January 31, 2000 04:13 PM
What help do you need fast?


team90
Member
posted February 06, 2000 09:18 AM
How are you getting weight % . I just started racing and don't know what the weight of the car is or the front & raer is not even each corner. I need help?


dirt mod 70
Member
posted February 07, 2000 07:21 PM
team90
you will have to have your car scaled. most race shops will do this for a small fee. ask them as much as you can while your there.scaling your car is a must!!!!!!!!
they will probably have an idea what you should be running and listen to what they have to say about other aspects of your car also!!! ask questions,then listen or write it down


shakin
Administrator
posted February 16, 2000 06:59 AM
Dirt Mod is exactly right team, you have to scale your car, or you dont know where you are at. You need to find this out, so you can basically find out which way you need to go anyway.


3x Racing
Member
posted April 06, 2000 01:05 AM
to help fastorange alittle, here's a good baseline.
on a 3/8 mile track that gets drys****, try this as a BASELINE....
52.5% left
56% rear
49% cross
try to accomplish this with around 200lbs. of FRONT bite, (lf weighing 200lbs. more than rf)
1/2" to 1 1/2" of rear tire stagger
and about 80lbs. of rear bite (lr 80lbs. heavier than rr).
springs will depend on car type, standard, metric, leaf springs, coil rear......
start with a 1200lb. lf and 1400lb. rf (add 200 lbs. to both for metric cars)
leafs- a 250# lr & 225# rr.
coils- 225# lr & 200# rr.
depending on banking you may need to adjust your rear %. (the less bank the more rear %)
if the car is ass-happy (sliding around in rear) add a % or two to the rear, or add a % to cross (50-50), the higher your cross, the tighter the car will be throughout the corner. I like to stay at 48.6% cross no matter what track and adjust my rear % and front springs. try to keep the front springs 200lbs. apart to help exiting the corner. I fhte car picks up a push coming off, try stiffening the lf spring, or add 1/2" of stagger. hope this gets you close, let me know if i can help any further.
studiodesigns@worldnet.att.net
p.s. the car will be alittle tight getting in with the above #'s so adjust your brakes accordingly.


fastorange23
Member
posted April 07, 2000 06:33 PM
just curious on your spring selection for the metric chassis,which is what I run. I run at Thunder Hill in Mayetta,KS somewhat high bank for the area and I have never run over a 1250 on the LF and 1000 on RF also I have always run 275 LR and A 250 RR,our cars must weigh 3400#s and can run good racing shocks. I am not disagreeing with you just trying to learn/understand these chassis!!Thanks for all your Info it is greatly appreciated!!!!!!!!!!!!!!!!


3x Racing
Member
posted April 07, 2000 06:47 PM
does your car push going in?
here's why im so high on spring rates.
a metric car uses longer lower control arms than a standard car (at least from the spring pocket to the ball joint it's longer).
What this does is give the spindle more leverage to compress the spring than does a standard a-arm. I ran a camaro (standard frame) on a HIGH (38 degree) banked 1/3 mile and had a 1300# lf and a 1500# rf springs and still had the car loose.
If you have a slight or momentary push on entry, whats probably causing it is the lowers are bottoming out on the frame and making you think the spring is too hard when in fact its not hard enough.
What type of car is it? make & model.


fastorange23
Member
posted April 09, 2000 09:38 AM
82 buick regal
quote:
Originally posted by 3x Racing:
does your car push going in?
here's why im so high on spring rates.
a metric car uses longer lower control arms than a standard car (at least from the spring pocket to the ball joint it's longer).
What this does is give the spindle more leverage to compress the spring than does a standard a-arm. I ran a camaro (standard frame) on a HIGH (38 degree) banked 1/3 mile and had a 1300# lf and a 1500# rf springs and still had the car loose.
If you have a slight or momentary push on entry, whats probably causing it is the lowers are bottoming out on the frame and making you think the spring is too hard when in fact its not hard enough.
What type of car is it? make & model.



3x Racing
Member
posted April 09, 2000 07:16 PM
ok, with a regal, you could get away with the softer springs if you like em. just make sure the rear springs are soft also, maybe a 225lr and 175-200rr. Make sure you have about 55% rear,may have to adjust depending on banking, 57% would be better for flat tracks. stay around 49% cross and only 53% left. depending on the banking, start with 75# of lr bite and adjust from there (tight in and off, lower the amount of bite, loose in and off raise it). Use the travel indicators on the shocks to tell you travel. you dont want more than 3 1/2" on the rf on a high bank track. also check for coil bind on the rr in the center of the corner. ( i use alittle clay for this).

[This message has been edited by 3x Racing (edited 04-09-2000).]

3x Racing
Member
posted April 10, 2000 05:00 PM
There is no 'proper' travel on any car, just a baseline of what we know has worked before. Your car may need more or less and your driving style is going to effect this as well. On our camaro, we couldn't get enough rr travel because the shock would bottom out. High bank tracks require a ton of rr travel and i don't think you can get through a race without bottoming it out at least once.


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