Left-Rear Weight

[ReignMan23]

Hopefully someone smarter than me could shed some light here. I always thought the lighter the better but it seems that thinking is changing. What is the deal w/adding weight directly to the left rear? How is this helping the cars? At what lengths are guys willing to go to put weight on the left rear? Are there any rules preventing the addition of left-rear weight? Is this beneficial for a tacky and a slick track? Any information would be greatly appreciated. Thanks

[dalemcfan]

You'll prob get more help if you post this in the Tech section than here.

[Ryan21mid]

the unified rules council just this past week released rules pretty well preventing any additional weight being added to the left rear. All it does is simply put more weight on the left rear tire without effecting body roll imo. Helps plant the tire and give the car more drive in the slick. It'd tighten the car up drastically in the mud.

[tb1545]

When i first heard people doing this 2 years ago, it didnt make much sense to me, sure the weight might help hold that down in smooth ideal situations, but what i dont understand is track surfaces arent smooth, therefore if you hit a bump in the track surface, the suspension now has to try to control more weight before putting it back down to the ground.
I look at it like the medicine ball quick catch and throw workouts people do. When you throw and catch a 20lb medicine ball it takes longer to catch, control and in return throw back than a 5 lb medicine ball does. Maybe the mechanical leverage of the LR is so much that any loss of control doesnt matter.
I always thought it was one of those things people were doing to screw with people while they were making speed up somewhere else.

[Centeroff]

Reignman, adding left rear weight will change the balance and cross of the car dramatically. You normally do not just add a ton of weight to the LR of the car. We call LR weight "bite" so if you load the lr your always gonna add weight to the rf as well because loading the lr can cause a push. Most of these new cars are sooo LR and RF balance dependent. You also have to decide where to bolt the weight on the LR of the car because that's where weight transfer comes into play. The higher on the frame that the weight is added the more transfer and roll you will create. I could talk LR weight for days. You can watch certain cars on the track and almost watch the car teeter totter off the LR and RF. Bloomquist and Macdowell are two that come to mind. I know the basics but you will have to listen to someone like Shane Macdowell to really get accurate with it. The 116 of weaver looks like he may run higher cross in his cars also. It's all about balance and being able to keep the RF tire on the car for 100 laps.

[MasterSbilt_Racer]

the unified rules council just this past week released rules pretty well preventing any additional weight being added to the left rear. All it does is simply put more weight on the left rear tire without effecting body roll imo. Helps plant the tire and give the car more drive in the slick. It'd tighten the car up drastically in the mud.

They stopped well short of preventing added weight. They mostly prevented added rotating weight. And, only if checked.

There are quite a few things going on with it. Don't forget, the tire is a spring itself.

[ReignMan23]

Dalemcfan, I didn't even know there was a tech section, I will have to cross-post and see what I get there, thanks for the info. Thank you Ryan, TB, and Centeroff, good info! I have been researching and found a company called Strange Oval, they sell heavier and lighter axels, i'm guessing heavy for tacky tracks, and the lighter axels for when the track slicks off. Are guys really going to be switching axels pending if it's dry or tacky? Seems expensive if this is what guys are doing.

[MasterSbilt_Racer]

When i first heard people doing this 2 years ago, it didnt make much sense to me, sure the weight might help hold that down in smooth ideal situations, but what i dont understand is track surfaces arent smooth, therefore if you hit a bump in the track surface, the suspension now has to try to control more weight before putting it back down to the ground.
I look at it like the medicine ball quick catch and throw workouts people do. When you throw and catch a 20lb medicine ball it takes longer to catch, control and in return throw back than a 5 lb medicine ball does. Maybe the mechanical leverage of the LR is so much that any loss of control doesnt matter.
I always thought it was one of those things people were doing to screw with people while they were making speed up somewhere else.

You got the actors in the wrong place. The uneven track surface is the guy trying to throw the medicine ball. The medicine ball is the rear assembly, and the tire is the guys arms.

[MI Dirt Fan]

So there's weight on the LR during the entire weight transfer in the corner. Seems like a bottom side setup. Maybe reduce wheel spin converting it to traction

[flagone]

The key is unsprung weight. Not weight mounted to the frame.

[MasterSbilt_Racer]

The key is unsprung weight. Not weight mounted to the frame.

Correct. Some pieces were left untouched by the rules. I guess too many folks already selling a part?

[MI Dirt Fan]

No weight can be mounted to the axle tubes?

[billetbirdcage]

No weight can be mounted to the axle tubes?

You can't clamp a weight to the tube (cheap and can be done safe), but you can conveniently buy some heavy products from certain people to put on the rearend. Who would have thought, that's the way they went with the rules.

[MI Dirt Fan]

That's what I thought. That's why I can't figure out why Keyser's sells clamps to mount weight to the axle tubes.

[MasterSbilt_Racer]

That's what I thought. That's why I can't figure out why Keyser's sells clamps to mount weight to the axle tubes.

They have had those for over a year. And not everyone has adopted those rules.