Droop

[Rajflyboy]

https://m.youtube.com/watch?v=2Ew_yweTQNs

[MasterSbilt_Racer]

https://m.youtube.com/watch?v=2Ew_yweTQNs

That was 7 minutes of not really saying anything.

[Rajflyboy]

That was 7 minutes of not really saying anything.I’d say it depends on if you are just a fan or if you know and build race cars. For the fan I think it gives us a basic idea of how this works👍

[lurker]

MasterSbilt_Racer - Serious question. What was Droop before it was Droop?

[Rajflyboy]

Now is it pronounced Drop or Droop ? This guy called it drop

[MasterSbilt_Racer]

MasterSbilt_Racer - Serious question. What was Droop before it was Droop?

I'm not sure I get what you are asking. LM racers say drop. Most road racers say droop. Rebound is also correct.

What I was getting at is the video just told people "do x, y, and z". There is no discussion of reason, what you are trying to avoid, exception to the rules, etc. You are stuck with less drop on that Rocket because it's old. Nothing you can do.

[Rajflyboy]

I'm not sure I get what you are asking. LM racers say drop. Most road racers say droop. Rebound is also correct.What I was getting at is the video just told people "do x, y, and z". There is no discussion of reason, what you are trying to avoid, exception to the rules, etc. You are stuck with less drop on that Rocket because it's old. Nothing you can do.Great points. Thanks.

[Jking24]

Great points. Thanks.Not to further complicate it but it is also commonly referred to as "hike" so hike, droop, lr drop all refer to the same thing just depends what area you are from. I also agree with masters in the sense that that video was all about the problems of yesteryear. I'm not the guy that says you have to have brand new everything to compete but that "tech" info was for cars that are almost 20 years old. Their are exceptions to this rule but generally if your racing with a car that's over 7-10 years old you've got a uphill battle on all fronts that may not be winnable. To put it in perspective xr1's are in year 5 of production and the modern longhorn is closer to 7. And unfortunately we're currently in a era when major design criteria changed. Kinda like the transition from leaf spring to 4bar. Alot of core things in the chassis changed and the older cars have become somewhat obsolete.

[MasterSbilt_Racer]

Not to further complicate it but it is also commonly referred to as "hike" so hike, droop, lr drop all refer to the same thing just depends what area you are from. I also agree with masters in the sense that that video was all about the problems of yesteryear. I'm not the guy that says you have to have brand new everything to compete but that "tech" info was for cars that are almost 20 years old. Their are exceptions to this rule but generally if your racing with a car that's over 7-10 years old you've got a uphill battle on all fronts that may not be winnable. To put it in perspective xr1's are in year 5 of production and the modern longhorn is closer to 7. And unfortunately we're currently in a era when major design criteria changed. Kinda like the transition from leaf spring to 4bar. Alot of core things in the chassis changed and the older cars have become somewhat obsolete.

It's not that hard to fix them, with some know-how though, Jking. We just fixed the easy stuff on our old junk. It works pretty good.

We may get our hands on something modern soon. I'm curious to see if it moves the needle.

[cjsracing]

Isn't the "don't go over 48 degrees" out dated too? I've been told that with zero index we can get above 50 degrees with no issues.

[Rajflyboy]

As far as I’m concerned as a fan ... go ahead and take the left rear tires off the cars... run unlimited droop 😜😁

[MasterSbilt_Racer]

Isn't the "don't go over 48 degrees" out dated too? I've been told that with zero index we can get above 50 degrees with no issues.

Yes. Degrees never mattered. It's about where your instant centers are. Go too far, your car is essentially rigid.

[lurker]

I'm not sure I get what you are asking. LM racers say drop. Most road racers say droop. Rebound is also correct.


Not to further complicate it but it is also commonly referred to as "hike" so hike, droop, lr drop all refer to the same thing just depends what area you are from.


Asked and answered, thank you very much. Left rear tie-down shock on a sprint car would be the same. Yes?

Next question -

In your opinions, why did the “droop” tribulations/rules surface in the DLM world in the last few years? Left rear tie-down shocks have been around forever. Or am I not following something here?

[Josh Bayko]

Nobody really called it droop until Ray Cook came out with first “droop rule”.

[lurker]

Thanks Josh, that’s what I thought.

[MasterSbilt_Racer]

On a lm, they are not tying it down. They are wanting it to come up.

The higher the lr corner comes, the more weight it carries. It also turns the center of the car into a wedge and gets the spoiler higher.

The rules? I think Ray Cooks motivation was that some people had understood the instant center issue and other people were just trying to hike higher and causing their suspension to suffer. Brains ain't fair anymore...

It certainly can't be concern over the extra downforce, because the bodies morph every year to gain downforce, while the people with rule books just ignore it.

It was explained as a safety measure to avoid roll overs. However, you'd have to bring the cars down much more to have any impact on the increase of rollovers seen in the last decade and a half.

[Josh Bayko]

I think the tied down right front is what cause more rollovers than anything. The car is leaned over so hard on that corner that when the RF catches a rut and needs to compress more to absorb the bump and can’t it pitches the whole car. Sometimes when that happens there’s nothing you can do but hold on.

[dirtcrazy4u]

It's absolutely a combination of tying the RF down and LR hike that get the cars in trouble on a heavy, high cushion or bumpy corner track. I for one am surprised that we haven't seen more cars getting over in the corners. I believe what has saved them is as soon as the driver lifts the LR settles quick enough as the shock collapse's.

[lurker]

Thanks everyone for the replies.

[lurker]

It certainly can't be concern over the extra downforce, because the bodies morph every year to gain downforce, while the people with rule books just ignore it.

Most definitely agree with you on that point.

[Morgs153]

DoD likes to run the Throwback Thursday photo section on their site. Many of those race photos are from the early 2000s. I especially think the cars looked very good around 2000-2005, they looked racy and had some identity. What changed in the rule book since that time in regards to bodies? Not much if anything, correct? Teching bodies is not difficult if you choose to do it.

[lurker]

With all of the Action-Reaction situations you guys are talking about, it sounds like a NASCAR car to me, getting on the bump-stops that is. Rigid, Rigid, Rigid

[billetbirdcage]

DoD likes to run the Throwback Thursday photo section on their site. Many of those race photos are from the early 2000s. I especially think the cars looked very good around 2000-2005, they looked racy and had some identity. What changed in the rule book since that time in regards to bodies? Not much if anything, correct? Teching bodies is not difficult if you choose to do it.

For the most part, nothing changed on the body rules during that time to semi current. The biggest thing was the lack of enforcement on the "deck must be flat for 36 inches from the spoiler forward" (paraphrasing as it was something like that on the dimension). This never really got checked and eventually the cars started dropping the deck behind the driver and making a huge wing out of the back deck. Then began the adding of the huge lip on the left side of the car and lowering the RF corner of the deck to allow even more angle left to right and front to back of the deck. Then it just took off from there.

Those are some of the highlights of a few things, then add in approving noses that manufactures keep developing to out do the other. Take a 1/4" here and there and next then you know we have a modern nose with splitter's and huge left side lips on them.

I'll also add this (just my opinion): Part of the Aero deal got started when the 12" spoilers where added for the spec engines. People saw how big an effect that had on the cars and how much it helped in the slick so they started looking at it a lot more with all cars and ways to increase downforce.

[billetbirdcage]

With all of the Action-Reaction situations you guys are talking about, it sounds like a NASCAR car to me, getting on the bump-stops that is. Rigid, Rigid, Rigid

It really is more of a function of low left side weight, super high Center of Gravity (raised even more when the car hikes up) that causes roll overs. The other part isn't so much from bumpstops but bottoming out or the RF corner of the nose or frame/crossmember hitting the ground and digging in. With the super high COG's and low left % it doesn't take much to dig in and cause the car to go ahead on turn over.

^^No different that sliding a refrigerator on the floor to move it and it catches a crack in the floor and dumps over unexpectedly

[lurker]

Thanks billetbirdcage.

[fastford]

On a lm, they are not tying it down. They are wanting it to come up.

The higher the lr corner comes, the more weight it carries. It also turns the center of the car into a wedge and gets the spoiler higher.

The rules? I think Ray Cooks motivation was that some people had understood the instant center issue and other people were just trying to hike higher and causing their suspension to suffer. Brains ain't fair anymore...

It certainly can't be concern over the extra downforce, because the bodies morph every year to gain downforce, while the people with rule books just ignore it.

It was explained as a safety measure to avoid roll overs. However, you'd have to bring the cars down much more to have any impact on the increase of rollovers seen in the last decade and a half.

i dont think the height of the left rear determines how much weight it carries , the right front determines this more than anything , a car could easily be set up to carry more weight at 1/2 droop than at full droop according to rt frt set up , want turn as good but is possible ....

[MasterSbilt_Racer]

i dont think the height of the left rear determines how much weight it carries , the right front determines this more than anything , a car could easily be set up to carry more weight at 1/2 droop than at full droop according to rt frt set up , want turn as good but is possible ....

When the lr raises, due to lift from the suspension, it removes weight off all the other springs(at least rr, 5th coil, and lf). It's just like spinning that adjuster nut down. It's the very reason when guys started 3 wheeling in the 90s, they got drunk on the forward bite.

This is before you even consider aero load on the rear deck and the longer moment arm it has to apply load to the rear tires.

[Jking24]

When the lr raises, due to lift from the suspension, it removes weight off all the other springs(at least rr, 5th coil, and lf). It's just like spinning that adjuster nut down. It's the very reason when guys started 3 wheeling in the 90s, they got drunk on the forward bite.This is before you even consider aero load on the rear deck and the longer moment arm it has to apply load to the rear tires.To add to that a common misconception is that weight transfers from lr to rf and vice-versa when this is not really the case. Basically you can crank all the static wedge you want into a car and it doesn't create infinite drive.

[MasterSbilt_Racer]

To add to that a common misconception is that weight transfers from lr to rf and vice-versa when this is not really the case. Basically you can crank all the static wedge you want into a car and it doesn't create infinite drive.

When you accelerate off the corner, weight comes off both fronts and goes to both rears. How much moves, and where depends on acceleration, cg location, and relative stiffness of the rear corners. Or starting cg location vs new cg location due to chassis height changes.

You can put enough wedge in to have no drive. 2 tires out pull 1.

[fastford]

jking , at some point it will stop turning left though and that has not changed , and all the weight may not shift from lf rear to rt front , but the majority does and upon entering the turn , the rt front has the most to do with dynamic wedge or weight applied to lft rear.....

[MasterSbilt_Racer]

jking , at some point it will stop turning left though and that has not changed , and all the weight may not shift from lf rear to rt front , but the majority does and upon entering the turn , the rt front has the most to do with dynamic wedge or weight applied to lft rear.....

Rf does have to do with wedge. In my example, leaving all else the same, a higher lr has more load. If it results in more travel on the rf, you are gaining there too.

[dirtcrazy4u]

Corner entry = RF Corner exit = LR

[fastford]

Rf does have to do with wedge. In my example, leaving all else the same, a higher lr has more load. If it results in more travel on the rf, you are gaining there too.

10/4 , i misunderstood what you were saying.....