Left side heavy

[crateracer16]

06 bms 4 bar chevelle front clip. 700rf 650lf 175lr,spring behind. 150rr. No weight on car. Stuck at 56.1 left side % and only 51.6% rear. Cross and bite is good. Ride heights are also good. How can I pull some of the left off and get it to the rear and not mess up my bite. Thanks.

[dirttrackrocker]

The only way to add rear % is to physically add weight to the car

[racinjj]

You will have to physically move weight on your car to change left to right and front to rear weight. When you are done with that you will have to readjust your screw jacks and coil over eliminators to get your bite and cross weight back. That seems very heavy on the left, is that with the driver, how heavy is the driver, how heavy is the car.

Sounds like you will need to stick weight in the right rear of the car. Also, what wheel offsets are you using?

[crateracer16]

That's without driver but with 75lbs in the seat because I weigh 285 and my setup sheets are for a 210lb driver. The car without driver is 2112lbs with about 15 gals of fuel. 2" offset on rf and lf and lr and 3" on rr.

[MM90]

I would make sure your cables aren't crossed on the scales you are using. How big is the fuel cell? What engine are you running? If you don't have a problem with your scales then you need to add some lead to the rear and right side of the car.

[crateracer16]

Cables are good. Rolled my other car on them right after this one and she came out perfect. Fuel cell is a 32gal rectangle. Engine is a 418sbc with alum heads.

[dirttrackrocker]

Fill it with fuel and start hanging weight on the RR

[setup479point2]

No way a bms is that percent , even with the weight in the seat . With my 285 lb. driver in the seat we don't have that much left . The rear is way off also. Try another set of scales , and definitely call bms.

[junebug]

No way a bms is that percent , even with the weight in the seat . With my 285 lb. driver in the seat we don't have that much left . The rear is way off also. Try another set of scales , and definitely call bms.

something is definitely way outta wack...ive never seen any modified even capable of getting close to those numbers

[racin6mod]

check the springs we had a couple springs throw the set up off once and maybe a shock or something binding up.

[setup479point2]

check the springs we had a couple springs throw the set up off once and maybe a shock or something binding up. This will not change left or rear percent , it will cause problems with scaling. You can't change left or rear percent without physically moving weight location.

[crateracer16]

Put the car on another set of scales and same numbers. Can't move the cell. The cage it's in isn't designed to slide. The battery is already on the right side. How much should I hang to get the rear % up? Are talking 50lbs or more?

[junebug]

Put the car on another set of scales and same numbers. Can't move the cell. The cage it's in isn't designed to slide. The battery is already on the right side. How much should I hang to get the rear % up? Are talking 50lbs or more?

hmmm that's really crazy numbers....i would check alignment of the rearend...maybe it is shoved way to the right...other than that im not sure how you'd ever get over 55% at most left side

[crateracer16]

Ya. I'm pulling my hair out over this thing. I tried 2 different sets of shocks and springs just o make make sure nothing was bent and no change. I can get the left down to about 55% but then I have low cross numbers.

[setup479point2]

We have an 06 bms , with recommended fuel in car and 20 lb weight , no driver it's over 56 percent rear. To get 51 percent in one of these you'd have to have moved the engine forward about a foot , and I don't even think that would do it. Left percent could be rear to far to right as suggested above. Again call BMS , they will gladly help. Also left and rear percent have nothing to do with cross , you can get any cross with any left and rear.

[jared1624]

you can try putting 1/2" wheel spacers in the lr and lf, it will take left side % out. prob not enough. scale with shocks unhooked, pull out an axle. Something is def going on, prob something simple that you are just over looking. good luck

[junebug]

Ya. I'm pulling my hair out over this thing. I tried 2 different sets of shocks and springs just o make make sure nothing was bent and no change. I can get the left down to about 55% but then I have low cross numbers.

what'd u change to drop the left side down to 55%...? no matter what the left side is u can get ur cross back up just by turning weight jacks....the left% and rear% are all that cannot be change by weight jacks

[powerslide]

are you sure you have the correct rearend housing and the rearend centered per BMS specs?

[7uptruckracer]

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

[JustAddDirt]

I am wondering if he has the numbers backwards.
wander if the left side is 51, and rear is the 56. that sounds more like it to me.
wander if the wrong buttons were selected on the scales.
If not I would say it needs 2" offsets on the left, and 4" on the right. that would help a bit, but it is a band-aid to the real problem.

[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.

[racing_kid]

with the bms we have we get horrible support from bms, im guesing you have to buy A brand new bms to get any kind of good support.
sorry to change the topic but whats a good way to get ahold of the guys at close racing supply ?

[crateracer16]

Call Joel smith at (814) 225-3250. He is an awesome guy!!!

[rubbinsracin]

i live within a hour of BMS and alot of guys are going away from them, partially from the troubles the owner got into and now that this other kid runs it it has gone down hill as far as support....lots of guys around us that used to be huge BMS guys are now going to JET Mods...and man are they fast

[crateracer16]

Ya I called bms directly and I played hell just getting someone on the phone. But call Joel at close racing and he will spend all day on the phone helping you. He knows all the different years and thier different characteristics.

[emod03]

if u have a bms work with joel he has helped me aton over the last 7 yrs... knows alot and isnt afraid to help out. great guys to work with.

[racing_kid]

i talked to him last night, man it was nice finally getting a hold of someone who cared. thanks for the link

[crateracer16]

Got the car setup a lot better now. Moved some stuff like Joel said and she was on a rail last night. Thanks fellas.

[powerslide]

So after 3 pages you arent going to tell us what you had wrong on the car?!?!?

[crateracer16]

Can't give away secrets. J/k. Rear end was to about 2" too far to the left. The biggest problem was a birdcage was bound up bad. It was a brand new bearing cage and somehow came messed up from the factory. I had to put about 45lbs of weight on rr. They also said it was ok to be down around 54% rear percent.

[powerslide]

Can't give away secrets. J/k. Rear end was to about 2" too far to the left. The biggest problem was a birdcage was bound up bad. It was a brand new bearing cage and somehow came messed up from the factory. I had to put about 45lbs of weight on rr. They also said it was ok to be down around 54% rear percent.

Thank you it may help a fellow racer down the road. We knew something was bad off based on your numbers.

[crateracer16]

Sorry. Said two things at once. It was out right and I moved it left. The cage was getting stuck foward when i jacked the car up, so it pushed it back into the spring when I set the car back down. I started having too much wedge and thats how infound the cage. I changed cages and I had more rf wheel weight and less left side. Then I moved the rear end over 2" and added the 45lbs to the rr and then it brought it down to where I needed it.