Left side heavy

[crateracer16]

I was hoping I had the numbers backwards so I just rolled the car back on the scales but sadly I do not. I have everything to bms specs as to the rear end.

[Bubstr]

I'm looking at this tread and wondering, what does the height of your weight change when it comes to dynamic forces? Simply put, Cars move, forces are applied and high weight transferred easier than low weight and low weight is harder to transfer. It's called Polar moments, for any that have had basic Physics. Physical laws don't change.

Someone said you only change weight front to back and side to side is by moving the weight to the other side or end of the car. That may be true sitting still, but what happens when your racing? I think sometimes we get away from the basics. The basics are a triangle of Force, Traction and Center of gravity location, including and especially height. This is true going forward or around a corner. You can have too much or too little of any of these three. The secret is balance. What do you guys think?

For any that would discount weight transfer, tell me how much the front of a Sprint car weighs during one of their wheelies? Or for that matter the left sides of a bicycling Modified? This is a case of too high of a center of gravity for the power and traction. There is your speed secret of the day. Balance of force to traction to center of gravity. It don't matter going forward or around the corner. You have the tools to increase or decrease any of these three to get that balance. If you get that balance right, your fine tuning bells and whistles will work much better.

[setup479point2]

Have you been racing this car this season , on heavy track ? If you have the only thing I can think could be part of your problem is mud in the front crossmember. We have had this with our 06 , shouldn't be more than 15 lbs. though. Also set your bars at the proper length and in neutral , and get brhind car and sight down outside edge of tires , left side should be even front to back. Do you have a bms dealer in your area? If so take it to them. Will be worth whatever it costs.

[let-r-eat]

Agree with Bubstr here. The contact patch must support the movement of weight no matter where it is located on the car.

[MM90]

What are the percentages on your other car that you say are good? With aluminum heads there is no way that you only have 51% rear unless somebody added a ton of bars to the front of the car.

[dirttrackrocker]

We aren't talking about moving weight. We are talking about static weight.

[mod557]

crateracer16 it is tell me your mail box is full and wont let me respond.

mod557

[7uptruckracer]

If its not rims check your control arms sometimes people run aftermarket that might move a wheel out or in, it would have to be packaged with different uppers for camber, but I still think rims may be your answer...

[crateracer16]

Mod557 it's clear now. The other car is 57 rear. 52 left and 49.5 cross on the same scales. I ran the car last night the way it was. No forward bite but the track was so bad we had to crawl through the corners because of the bumps. I do have a dealer close and I think I'll get it to them. I do have a 1" extended rf lower control arm but I also extended the top control arm to match. Thanks

[setup479point2]

If you have the other car sitting beside this one , get out your tape measure and start measuring, wheelbase, engine mid-plate to lower balljount , engine mid plate to center of rearend , outside of tire to engine center both sides , etc. . You should find your problem.

[Bubstr]

We aren't talking about moving weight. We are talking about static weight.

All weight is static in the garage. We don't race in the garage. When you race you have forces applied to that weight. The difference of 2 to 10 inches up or down can make you a hero or a zero on side bite, not to mention forward bite. There is a relationship between roll centers and center of gravity height for side bite and your asymmetrical instant centers and center of gravity height for forward bite. It will determine if you push or are loose. It will not only effect your forward bite but your rear steer. Saying low weight and high weight are the same is like saying all girls are the same. I thought so, till I had a second to compare her with.

[junebug]

All weight is static in the garage. We don't race in the garage. When you race you have forces applied to that weight. The difference of 2 to 10 inches up or down can make you a hero or a zero on side bite, not to mention forward bite. There is a relationship between roll centers and center of gravity height for side bite and your asymmetrical instant centers and center of gravity height for forward bite. It will determine if you push or are loose. It will not only effect your forward bite but your rear steer. Saying low weight and high weight are the same is like saying all girls are the same. I thought so, till I had a second to compare her with.

I agree that all of these things effect the way the car drives on track...but when we setup a car up we have to use static loads for our baseline since 99.9% of the world can't afford a shaker or a pull down rig....itd be way better if we did have these available...but until they are readily available we have to use static loads in the shop...and use the on track feel as our pull down rig to test roll center heights etc

[Bubstr]

Ok would you like a way of measuring this cheaply? Here is a link to A site by Billy Shope, An engineer and one of the original Ramchargers in drag racing. This is called a traction dyno but the same physical laws apply to side forces. Maybe it's something you would like to mess with, maybe not. Billy is an old acquaintance and he said it would work for side forces just as well as front to rear.
http://www.shopeshop.org/contentsDrag.htm

[Egoracing]

Rims Rims Rims.....We use different left and right side backspacing on Asphalt IMCA cars some are designed for 3"s all the way around some 2" on right 4" on left its good for 2% more left so check and see what the car is made for first. and check all your control arms and track widths compare it to the chassis centerline...If you need to scale it one wheel at a time

I was thinking that something may be off with the wheels also, wrong ones on wrong side would really screw up the left %. Also wrong A-arms on the front and rear end wrong for the car or in the wrong location.

[crateracer16]

I was wondering maybe about my front a arms. I have a chevelle stub and the a arms I got take the small (1.9 press diameter I think) ball joint. All the other chevelle a arms I've seen take a bigger ball joint. Is there a good way to tell? They bolted right up and look correct though. Thanks guys

[setup479point2]

Have you gotten your tape and measured anything yet ? Guarantee you measure both cars you'll find your problem.

[crateracer16]

Tomorrow ill measure.will having a 9" in one car and a qc in this one change much? Got stuck with mandatory overtime all week.

[setup479point2]

Tomorrow ill measure.will having a 9" in one car and a qc in this one change much? Got stuck with mandatory overtime all week.

Yes it makes a difference , quickchange is heavier, but, am not sure how much . My guess is 35 lbs.

[Sportmod Rookie]

Why not call BMS? 785-527-5080

[crateracer16]

I've called bms and really didnt get much besides put some weight here and then try. I've been in contact with another ,awesome , guy at close racing supply(who sells bms) and he's sending me some different setup sheets with all the measurements I need.