Heave Spring

[Matt49]

Since everybody seems to be sitting around watching it rain, I thought I would go way outside the box here.
I realize many rules packages would not allow for this but wondering if anybody has thought about some type of heave spring system as a substitute for anti-dive being used to maintain nose height under braking. It seems to work for the F1 guys.

[billetbirdcage]

Since everybody seems to be sitting around watching it rain, I thought I would go way outside the box here.
I realize many rules packages would not allow for this but wondering if anybody has thought about some type of heave spring system as a substitute for anti-dive being used to maintain nose height under braking. It seems to work for the F1 guys.

I have but never made or tried anything. There are systems out there that separate roll and dive that I think for sure could be useful, but you probably have a long road ahead of you on sorting it out and packaging it for today's rules. I'm not sure what the actual name of it is, but the one I found interesting and was playing with ideas on was a system that the 2 wheel springs are connected with a 3rd spring between those 2 springs, so roll rate and bump rate could be controlled separate.

[Matt49]

Thanks, billet. I haven't even begun to think about how it would be designed or packaged. Obviously F1 has the benefit of the rockers and the fact that the suspension is symmetrical makes it relatively easy to come up with that design.
If the design challenges and rules restrictions could be overcome, I think the main benefit to something like this is that it would be more tune-able compared to anti-dive and would avoid other side-effects like caster gain, wheelbase deltas, etc.
As our sport becomes more in tune with the realities of the importance of aerodynamics, I'm inspired by a lot of what F1 does and the heave spring really got thinking.
I know I conjure up some goofy stuff but I've found that you stop finding really good ideas very soon after you stop exploring the bad ones.

[Austin34471]

With how little front bias we have, the RF brake being turned off a large number of cars, I am not sure how much current anti-dive we are actually realizing on our cars other than the RF bumpstop.. Plus, if (BIG IF) you could control Heave effectively within the scope of our rules, how beneficial it would actually be? The reason F1 does it is because their aero platforms are so optimized for a certain car attitude ,like, to the milimeter, that it is imperative to control every bit of body manipulation. I feel like the current generation of dirt cars do a pretty good job of sealing the nose all things considered (driving on rough dirt tracks and having the floppiest tires ever made). Any gains made 'sealing the nose-wise' would be in the area of diminishing returns IMO, would hurt compliance, and would make the front of the car heavier lol.
Heave control on rear suspension 0___o?

[Austin34471]

With how little front bias we have, the RF brake being turned off a large number of cars, I am not sure how much current anti-dive we are actually realizing on our cars other than the RF bumpstop.. Plus, if (BIG IF) you could control Heave effectively within the scope of our rules, how beneficial it would actually be? The reason F1 does it is because their aero platforms are so optimized for a certain car attitude ,like, to the milimeter, that it is imperative to control every bit of body manipulation. I feel like the current generation of dirt cars do a pretty good job of sealing the nose all things considered (driving on rough dirt tracks and having the floppiest tires ever made). Any gains made 'sealing the nose-wise' would be in the area of diminishing returns IMO, would hurt compliance, and would make the front of the car heavier lol.
Heave control on rear suspension 0___o?

[Matt49]

Austin34471, the biggest application I would see for it is ease of adjustment. You could throw in spring rubbers if you were concerned about plowing the nose on a heavy track with a cushion. I completely get what you're saying about F1. I actually follow F1 pretty closely. That being said, we are headed that direction. You talk about millimeters...when was the last time you saw a touring DLM car hit the track with a piece of sheet metal with so much as a rock ping in it. These guys have several complete bodies ready to go already wrapped. And I've heard rumors of kevlar being used under the deck to keep the rock marks away since those pieces are obviously harder to swap out.
Every tiny little uption of the air flow is hurting downforce and the dirt late model world is figuring that out little by little.

[billetbirdcage]

There is a huge difference in that mm on an F1 car over a dirt car: Because of the underbelly/panning creates so much down force that one mm can effect 100's of pounds of down force. Look up a wind tunnel for F1 as they have a large belt the car runs on to spin the tires, but they are so rare due to cost because getting that MPH out of the belt and have it maintain that actual ground level and not bow up and lessen the ground clearance (I'm told they have an air hockey table like surface under the belt to pull vacuum to hold the belt down to the surface while it runs) which would severely effect the overall drag and down force and wouldn't be overly repeatable.

Not to undermine the Aero on a LM, but that small or variance on the car to ground on a LM isn't going to have a large % of change on the down force of the car with no under body (as Austin was referring to). While you might be able to use it for Aero stuff, I was looking at it for other things and not so much for Aero.

Disclaimer: NOT AN AERO ENGINEER!

[Austin34471]

Austin34471, the biggest application I would see for it is ease of adjustment. You could throw in spring rubbers if you were concerned about plowing the nose on a heavy track with a cushion. I completely get what you're saying about F1. I actually follow F1 pretty closely. That being said, we are headed that direction. You talk about millimeters...when was the last time you saw a touring DLM car hit the track with a piece of sheet metal with so much as a rock ping in it. These guys have several complete bodies ready to go already wrapped. And I've heard rumors of kevlar being used under the deck to keep the rock marks away since those pieces are obviously harder to swap out.
Every tiny little uption of the air flow is hurting downforce and the dirt late model world is figuring that out little by little.

Bobby pierce wins a few crown jewels a year with half the spoiler missing and his bodies are always hammered flat. lol. Not saying aero isn't extremely important, but i don't think we are anywhere close to the point of rock pings making a even a 1000th of a second difference on a laptime.

[Matt49]

Disclaimer: NOT AN AERO ENGINEER!

I don't think anybody really is. You look at F1 and they have tons of wind tunnel data and CFD at their disposal and they are still constantly making changes to the cars in the most minute ways. It seems more art than science at times. But it is fascinating.

[Kromulous]

I deal with Aero Engineers at work, you do not want any part of that mess. Most of them guys would give a wood pecker a head ache...