10 replies to this topic

[dirtstudent2]

H.) Approved shock locations are as follows:

 

I.)One (1) shock will be permitted at each front wheel

 

J.) One (1) shock will be permitted at the right rear wheel

 

K.) Two (2) shocks will be permitted at the left rear wheel. When using only one (1) shock at the left rear wheel, the shock must be mounted behind the rear axle tube. When two (2) shocks are used at the left rear wheel, one (1) shock must be mounted behind the rear axle tube and the second shock must be mounted on top of or forward of the rear axle tube.

 

L.) One (1) shock will be permitted mid-ship at the front of the lift arm assembly.

 

M.)One (1) braking shock will be permitted. The shock must be mounted within three (3) inches of the center line of the rear axle center section. This shock must be mounted horizontally.

 

It adds up to 6 shocks being permitted on a Late model.

 

I have two questions.

 

If two shocks are permitted on the left rear, why do I read using a shock to dampen left rear corner lock down to be illegal, as in a Rumley device?  Or is a Rumley device or use of a shock, assuming I'm thinking correctly about it's use, not ok?  Sprints have been trying to control solid lock down of the left rear corner for years with shock rubbers etc..  I also think Lates are pretty much only down hard on the left rear at turn in after the end of acceleration is there some place else on the track where a Rumley device would come into play.  My second thought about where it might be useful is under acceleration or at a constant speed after turn entry.  But I generally don't see a late model being able to put the left rear hard down on the left rear corner at that time.  I say that because if there's grip then being harder on the RR for acceleration would keep the left rear being locked down and if there less grip and you need to bring in the left rear more, then there's just not enough grip all around to lock the left down.  Thinking more on it I guess banking would also come into play, with higher banking and where your going to be able to run the banking, making it more likely to get down harder onto the left rear.  I guess though if it helps putting it down on the left rear at turn in, it would help or at least extend the time you can remain down on the left rear and that would be the real advantage.  Heck I don't know I'm not into lates, so I'm throwing my feeble mind out there asking on here.   

 

My second question is what is a braking shock, where is it mounted.  I looked on the net for info, got too lazy to keep at it trying to find info on it and came here to ask. 

[jo73]

DS2. you counted wrong. 7 shocks. 4 corners, xtra LR, 5, lift arm, 6, and braking 7. And your question is what the hell is a braking shock ? Only thing I could come up with is to control the rear axle from rolling past a certain degree of angle.

[BaconBits]

Late models and sprint cars are nothing alike. Not even a little bit. Trying to equate their setups is incredibly stupid.

 

The Rumley device was about keeping the car on the bars (and the spoiler in the air) even when off the gas and on the brakes. Modern late model setups are the way they are to take advantage of the aerodynamics a late model brings. It's all about keeping the nose sealed off against the track and the spoiler in the air. It's also the reason you're starting to hear guys talk about aero push in dirt late models.

Edited by BaconBits, 26 August 2016 - 08:16 PM.

[dirtstudent2]

"Modern late model setups are the way they are to take advantage of the aerodynamics a late model brings."

 

Thank you.  I read your reply while at Lernerville tonight and it allowed me to watch cars come around three and four in terms of how they appeared to present their body work to the air.  Actually I've been looking at late models for a long time as if the total car was a so to speak 'wing'.  Your reply made it a bit more fun watching the race.

 

I just learned about the Rumley effect today reading on the net.  What I read said it was a way to control the application of the LR when the LR suspension was maxed out.  I took maxed out to equate to locked down solid.  I think my reading also said it was a way to add some additional coushion to the LR even though the LR was maxed out, with the purpose being to prevent instant total loading of weight at the LR.  Generally speaking any time you lock down any corner it's instant maximum weight and that corner is "very" likely to let go.  The ONLY time I see lates down hard on the LR is at turn in when they momentarily get off the bars.  I at times see lates seem to "not" get off the bars at turn in, is that what your saying the Rumley effect allows to happen.  Instead of my thinking it coushions when the car comes down off the bars, it is actually used to keep the car up on the bars.  I can see how keeping the car up on the bars could relate to keeping maximum weight on the LR, simply because the LR is extended.  Because of what you wrote I do now see two different way to apply maximum or towards maximum weight on the LR.  Thanks, I'm going to have to do some more reading and thinking on this.

 

I'm going to have to do some more reading tomorrow on it.  What I read was about cushioning to prevent instantly maxing out or locking down the LR when it's put down after acceleration.  What your explaining to me is it's a way to keep the car on the bars.  If I think of it that way it's the extension of the LR suspension along with rear steer, that requires a shock cushion at the LR.   There's what the cars and their suspension do and there's how what they do is used.  When I do see a car stay up on the bars after the straight and into the corner, it not only relates to sprint cars but to every other kind of car.  It's about the cars ability and the drivers ability to carry speed not deeper into the corner but on to and around the corner.  I suspect the same as a sprint, when a late is able to stay up on the bars into and around entry into the corner, there's a tendency to then push when they want to get on to final acceleration and down the straight.  The farther a driver can carry speed around and into the turn off the straight, the more likely it also is to tend to push when wanting to head onto the next straight.

 

Thank you, I figure your correct but I'm still going to study up on if the Rumley effect is to add a cushion when locking down the LR or comes into play allowing a late to stay up on the bars at turn entry.  I got to watch Bloomer and Davenport go at it at Attica entering one and through two last year.  I attributed how they managed the corners to prepping tires because of how I saw their side walls working.  Now i'm not so sure because of reading about the Rumley effect.  Sure wish I could instantly go back now and watch the same race, in the light of what you presented.  thanks

 

[jo73]

if aero is going to become a issue in a dirt track race car they need to make changes. I have heard sprint car guys say I lost the front end because the air was taken off the nose wing. Bullcrap. Take them off, make them smaller, remove the side panels on the front wings, do something. and yes SLM need a change to. get these big nose's off them with the sides that push the air up over the car. 2 LR shocks, stupid. braking shock, hey let's spend more money. All this is doing is driving more guys away from the sport. aero in a dirt car, give me a break, drive the dam thing. I my opinion shocks have taken over dirt track racing. anyone can buy a SLM, sprint car or modified. but if you don't have a dam good shock specialist you better hope on luck a lot. ever look into the trailers anymore, shock dyno's, and racks of shocks hanging there. tires are another bullcrap issue, pic a spec RR and 2 LR and same for the fronts. it's been a proven fact, the more rules you make the more the costly it becomes to race. If you make it basic and simple where all your competitors are on the same as your car it then becomes who is the better wheel man.

[dirtstudent2]

Why did this kind of car go away?  Who made the decision the would no longer be allowed to race?

 

It's one thing to talk about how they got to far out of line or too fast.  Someone had to say they will not be allowed anymore, who was it?  Probably track owners because their the only one who say what will and what will not race.  I'd bet at the same time they stopped from racing, by someone and who was it, pay out was reduced.

 

 

 https://www.google.c...jiqyAbNdqEkmPM:

[BUTTBEAK]

Brake shock is axle wrap dampener, used to tighten entry..(almost) No one runs one anymore, with all the motion in modern cars on the hook, it usually makes cars too inconsistent on entry and tends to decrease forward bite(mounting angle changes too drastically). Sometimes in the old days guy's would run 2, and move them l-r to adjust axle loading on decel."Modern" shock packages use more rebound in the 5th coil shock to do the same with more consistent results.

 

You would see them mounted horizontally above the rear end center. Some ran to front and some toward rear on different manufacturers chassis. It's functionally impossible to mount one 3" from the center line of the rear axle!

 

See axle dampeners @ bottom of page for visual.

http://www.speedwaym...-Link-Swing-Arm

 

Aero can be a weapon!

Edited by BUTTBEAK, 06 September 2016 - 02:28 PM.

[dirtstudent2]

I've been trying to read about and understand the rumley effect.  I don't know enough about late models to understand it.  

 

The closest I got to maybe understanding it's purpose is to think it allows for the amount of grip at a rear tire, to change chassis adjustments.  Rather then setting up a car by making a guess on how much grip will be available, available grip with it can change actual chassis adjustments.  yeah I said up front I don't know enough about it    

[MBRLLC]

Brake shock is axle wrap dampener, used to tighten entry..(almost) No one runs one anymore, with all the motion in modern cars on the hook, it usually makes cars too inconsistent on entry and tends to decrease forward bite(mounting angle changes too drastically). Sometimes in the old days guy's would run 2, and move them l-r to adjust axle loading and decel."Modern" shock packages use more rebound in the 5th coil shock to do the same with more consistent results.
 
You would see them mounted horizontally above the rear end center. Some ran to front and some toward rear on different manufacturers chassis. It's functionally impossible to mount one 3" from the center line of the rear axle!
 
See axle dampeners @ bottom of page for visual.
http://www.speedwaym...-Link-Swing-Arm
 
Aero can be a weapon!

Tell that to Bloomquist. He runs one all the time.

[RocketChassis#1]

Why did this kind of car go away?  Who made the decision the would no longer be allowed to race?

 

It's one thing to talk about how they got to far out of line or too fast.  Someone had to say they will not be allowed anymore, who was it?  Probably track owners because their the only one who say what will and what will not race.  I'd bet at the same time they stopped from racing, by someone and who was it, pay out was reduced.

 

 

 https://www.google.c...jiqyAbNdqEkmPM:

They went away locally after the 1984 season. Some will say the Jim Dunn wreck was the cause, but car counts went down and engine costs went up and up. W.PA was one of the last areas to allow the "wedge" cars. The All Star Late models ran the big spill boards and roofless after the went to the downsized cars in 1985, and Marion Center ran a outlaw type Late Model after that for a while also. When they went to the smaller bodies car counts went back up. Aero has always been a factor in short track racing, I recall back in the late 1960's Moose Myers and Joy fair showing up with big spoilers on the back of their cars at Heidelberg, and both were fast. 

[BUTTBEAK]

Tell that to Bloomquist. He runs one all the time.

Like I said,ALMOST. And I misread the axle center, center line deal.

 

Do you work on his car?