traction on the bars or climbing?

[CageFaraday]

Consider, the tire which is slipping generates more heat.
Also, kicks more mud.

Just food for thought.

^^^This is what I see.^^^ Reckon his LR or RR is doing more work?

We use to see the LR of a DLM wrinkle like a drag car leaving the line(mucho drive), but lately I'm hard pressed to see that anywhere. So in theory I understand 2 solid bars on the LR pushing up/over towards a nearly solid bump rubber on the RF sounds like the ultimate, but if you can't keep the RF pinned to the bump under accel you lose all that dynamic cross the instant it lifts and all you're left with is aero and whatever LR% remains. I'm not an engineer or an educated scientist, all I know is what I observe. JMO

[Matt49]

^^^This is what I see.^^^ Reckon his LR or RR is doing more work?

We use to see the LR of a DLM wrinkle like a drag car leaving the line(mucho drive), but lately I'm hard pressed to see that anywhere. So in theory I understand 2 solid bars on the LR pushing up/over towards a nearly solid bump rubber on the RF sounds like the ultimate, but if you can't keep the RF pinned to the bump under accel you lose all that dynamic cross the instant it lifts and all you're left with is aero and whatever LR% remains. I'm not an engineer or an educated scientist, all I know is what I observe. JMO

Aside from both having 4 tires and an engine, the similarities between a modern dirt late model and a sprint car are pretty much non-existent.
Short of getting on a shaker rig, I don't know of a way to prove to you that a dirt late model has considerable dynamic wedge.
The wrinkling of the tire thing is a different story. The reason that you don't see it as much has to do with the heavy LR components and needing more PSI to maintain contact patch compliance.

[Kromulous]

I seen Bloomquist and Richards going at it during Speed-weeks (East Bay), and they were in the lead for 20 or so laps. All of the sudden they both got so tight on the throttle the car would shove the RF across the track literally 5 or 6 feet. Obviously they went backwards from there, but i never seen a SLM that tight off the corner when they tried to pick up the gas.

So when Matt49 says these cars make unreal dynamic wedge, yep i agree.

Moyer SR is one to watch too, he keeps his car so wedged up he has to literally turn to the left all the way down the straight-a-ways.

[RaceEngineer]

Thrust angle is real and a chain stopping it from increasing doesn't change the anti-squat vehicle dynamics. Add the RF bump stop and we have cars with HUGE amounts of dynamic wedge. And now (due to aero) we are trying to keep the car at the same basic attitude all they way around the track. A lesson learned (on purpose or on accident) from Formula 1 racing. We do this a number of ways (high compression/PSI LR ahead shocks, trail braking, etc.). This holds the dynamic wedge in the car and holds in the rear steer. And this (in my opinion) is why we have to do some things to get side bite back. (NOT so much for the trail brakers because they aren't engine braking the rear tires as much.)It's also worth mentioning that tethering the LF (increasingly popular to help seal the nose for aero) HURTS side bite. So we have to compensate somewhere to get the car to NOT step out the rear up to the center of the corner.

Thrust doesn't exist when the vehicle isn't accelerating. Once the chain is tight, the load is strictly the static load, the load gained from jacking that corner up, and aero load.The more you load the bars, the more you load the chain. No relative motion means net force is zero.

[Matt49]

But thrust DOES exist when the vehicle IS accelerating. DLM cars are RARELY not accelerating when the driver is on the gas.
Stopping the motion with the chain doesn't void the anti-squat loads that were achieved up to that point. It just puts a cap on it. As long as acceleration is happening, weight transfer is happening. If it isn't going into a spring, it's going to the tire. That's the entire point of anti-squat.

[CageFaraday]

But thrust DOES exist when the vehicle IS accelerating. DLM cars are RARELY not accelerating when the driver is on the gas.
Stopping the motion with the chain doesn't void the anti-squat loads that were achieved up to that point. It just puts a cap on it. As long as acceleration is happening, weight transfer is happening. If it isn't going into a spring, it's going to the tire. That's the entire point of anti-squat.

To my knowledge all race cars with (4) tires work in whats known as an, "X". Which means the LR and RF work with each other and the RR and LF work together. This relationship continues dynamically as long as each wheel remains loaded. So, the LR/RF relationship only works as long as both remain loaded, ie through the energy in a compressed spring or by pressing against a bump rubber. Now if the RF rises off that bump then where does any cross weight come from for the LR? Just food for thought.

[RaceEngineer]

But thrust DOES exist when the vehicle IS accelerating. DLM cars are RARELY not accelerating when the driver is on the gas. Stopping the motion with the chain doesn't void the anti-squat loads that were achieved up to that point. It just puts a cap on it. As long as acceleration is happening, weight transfer is happening. If it isn't going into a spring, it's going to the tire. That's the entire point of anti-squat.

If you devised an experiment to measure the thrust, you might be somewhat surprised by the magnitude and duration of the loads.

[95shaw]

^^^This is what I see.^^^ Reckon his LR or RR is doing more work?

We use to see the LR of a DLM wrinkle like a drag car leaving the line(mucho drive), but lately I'm hard pressed to see that anywhere. So in theory I understand 2 solid bars on the LR pushing up/over towards a nearly solid bump rubber on the RF sounds like the ultimate, but if you can't keep the RF pinned to the bump under accel you lose all that dynamic cross the instant it lifts and all you're left with is aero and whatever LR% remains. I'm not an engineer or an educated scientist, all I know is what I observe. JMO

What I see is the RR slipping more than the LR. Other factors, not the least of which is stagger, allows the RR to produce enough traction to overdrive the LR, forcing the front left.

[sidewinder69]

I agree with cage philosophy. Once you get so soft on RF with these stack rates. When you get past the apex of the corner and from there are trying to lift the front end. I believe you are not that engaged in that bump or big bottom spring like everyone thinks. You are more using the soft combined rate of the stack which is nothing so nothing is pushing back to the left rear .

[fast_crew]

What I see is the RR slipping more than the LR. Other factors, not the least of which is stagger, allows the RR to produce enough traction to overdrive the LR, forcing the front left.

The RR and LR are slipping together. Solid axle, car is in yaw, if one is slipping both are slipping. What you see is heat, which is result of friction caused by load. Quick lesson, rub your hands together quickly with very little pressure.....now rub hands together while pushing them towards one another with a but of pressure. Load Trump's speed when dealing with friction, no political pun intended.. LoL

[JLyons]

Agree, and if that Rr is slipping that means the LR should be slipping more. Being that the LR is smaller, it’s just the force on the RR that causes the “smoke” Right?

[MasterSbilt_Racer]

The Rr and Lr are spinning at the same rpm. If you have stagger, the Rr is larger so its surface is moving faster than the Lr.

[JLyons]

The Rr and Lr are spinning at the same rpm. If you have stagger, the Rr is larger so its surface is moving faster than the Lr.

Good looking out lol overthought it for a second lol

[95shaw]

My question is, when the RR goes away, does the car get loose, or tight?

Food for thought.

[RaceEngineer]

My question is, when the RR goes away, does the car get loose, or tight?Food for thought.

Typically, you skate. If you slow down and keep it straight, it will push. Just like if the RR is cold at the race start.