I'm curious as to what people have found to be the best shock length for the center shock. Do most use a long shaft or is it better to use a short one. Along with this question is what effect is suppose to happen when using a long shock length versus a short one. I'm mostly interested in the effects it has on flat carpet ovals.

Thanks

RC

Road splat, are you asking about just puttign a longer shaft in the shock and keep the same angle. or are you asking about pod drop, or even asking about moving the shock forward in the car with or without changing shock angle. Just want to confirm your question before I can answer.

Mike, How about all three.

center shock angle is all that matters IMO. the length of the shock shaft has nothing to do with the way the shock works as long as the spring fits correctly and isn't preloaded to much or not enough. Pod drop is more for weight transfer, the more drop the more weight can be transfered. They attachment point to the chassis isn't where the load from the rear pod being compressed is transferd to the chassis, it's a imaginary point in front of the shock mount.

No answer from Proparts on this one

Hi Mike,

Thank you for your response. I was curious about just using a longer shaft and having the mount point further forward on the chassis and keeping the same angle. Was wondering what the effect is suppose to be when compared to using a shorter shaft and having the mount point closer to the t-bar piviot.

What conditions warrant more pod droop? If the rear is chattering would more droop help correct this? I guess along with this question I should ask what is a good starting point for pod droop? I've always set mine at .100 (~2.5mm) That measurement is at the back of the pod using a hudy droop gauge.

I've found a coulpe different things that will require more pod droop. Rough tracks. A longer center shock (IE More pod droop) is needed to keep the tires in the bumps and smooth the car out. Also more pod droop will give you more steering center of the corner.

The more angle the shock is on the shock mount the less weight transfer to the front tires therefor less steering and it also makes the shock spring a little more progressive feeling. The higher the shock is mounted the more weight transfer to the front giving more steering and a more linear feeling on the spring.

EA

This is a dumb question but how do you measure pod droop? I always set the car up with the rear pod flat with a battery in it and change the rear spring to get the car to turn more if needed. I have not used pod droop on purpose to change the handling of the car.

Several mfgs make droop gauges for touring cars,Hudy-Dynamite-Integy-etc. There are two blocks to set the chassis on and a gauge that indicates how much lower the pod(A-arm for TC) is compared to the blocks.

This is a dumb question but how do you measure pod droop? I always set the car up with the rear pod flat with a battery in it and change the rear spring to get the car to turn more if needed. I have not used pod droop on purpose to change the handling of the car.

You can pick the car up and put a straight edge along the bottom of the chassis to the back of the bottom plate and then measure the gap from the straight edge to the very back of the chassis. I know when guys have it written on setup sheets (Like the Salvas Bros) this is how they measure it. Others like KSG setup sheets just measure the center shock length....The longer the Center shock the more droop you will have.

It is one of the biggest adjustments I think you can make on a car!!

EA

This is a dumb question but how do you measure pod droop? I always set the car up with the rear pod flat with a battery in it and change the rear spring to get the car to turn more if needed. I have not used pod droop on purpose to change the handling of the car.

I used to use the straight edge as EA suggested. works really good.
But the Easiest and most consistent way I have found is when you set your car on the scales (assuming the tweak board is level) take a small bubble level (a couple bucks at Lowe's) and put it on the top of the pod and make sure it fits flat on it. As you adjust the center spring or take away or add to the shock length the bubble in the gauge begins to move. Start with a 1/4 bubble (tribute to Dusty Dean, lol) and go from there.

erock that's assuming no chassis rake.

droop - meaning the ability of the rear pod to travel downward

rake - meaning the preload of the rear pod (center shock) to force a droop angle

correct me with my definitions if they are not correct cause I wanted everyone to be on the same page

Brian0525
droop that's how I use it.
rake, reffering to the pod only I would say pod rake.
Chassis rake, front to rear height differeence
Chassis stagger is what I would use to describe left to right rake of the chassis.

Mike, if I dont change my front end shimming or the axle holders, wouldnt using my method work?

Meaning say I always run .080 under the front end and IRS 1.5 's in the rear.
This sets my chassis rake where I want it for a given track. Then I set my pod so the gauge reads level, then put a touch of center spring into it to get the pod where I want it to be. I measure it and its at a 1/4 bubble over the line on the gauge.

So I run the car with this measurement and say my car is tight so I put a bit more center preload on, now my gauge it reads a full bubble over the line on the gauge. If my car is dialed with that measurement, and I dont change chassis ride height it should work right ?

I know if you changed the ride height by shimming the front or changing your axle carriers, then by all means that would you have have to find a new starting point then go from there.

Erock if your chassis has rake in it, front to back. Then you set the pod to level with the ground (zero bubble). At that point you have pod rake. For tunability and repeatablilty of setup your method works fine, except for tire wear may not be even all day.

Chassis stagger is what I would use to describe left to right rake of the chassis.

In real race car jargon that would be called "chassis tilt".....
So one would say, for example: "I run .050 rake, and .050 tilt".

Dan

Dan, each form of racing, and each part of the country use different terms. It's so easy to get confused between them, I think we need to start explaining our wording better. Just like erock he'll use hookup, If you’re not formlier with that term, the rest of his answer nothing to you.

Dan, each form of racing, and each part of the country use different terms. It's so easy to get confused between them, I think we need to start explaining our wording better. Just like erock he'll use hookup, If you’re not formlier with that term, the rest of his answer nothing to you.

Agreed.
Which is the only reason that I mentioned it.
Tilt is a 'real' def, as far as 'real' cars go..
If you used that def in California, they would know exactly
what you were talking about..
It seems that r/c racing does try to use the same basic
language, but sometimes does go a little astray!
The words have more meaning, the more people use them.
So the more you see/use them, the more they become 'mainstream'.
True... more precise wording to eliminate confusion helps!
You're quite good at setting the explanations straight.
I enjoy your posts.

Dan question for you. When referring to tilt and rake, I assume you use positive meaning rear higher the front, and right side higher then left side, right?

i thought "on tilt" was a poker term used when you take a bad beat, lol

But yeah Mike is right, terminology is key to make sense of people's comments.

Dan, each form of racing, and each part of the country use different terms. It's so easy to get confused between them, I think we need to start explaining our wording better.

I disagree.
With all of the publication of books, videos on motorsports today.

I never went to a race track and found different terminology when it comes to motorsport racing.
It seems that the R/C industry confuses racers with there own terminology.

This is NOT to affend Mike Valentine and don't take this personal.
This is what I notice with a few R/C companies.

I can always tell when a fellow racer had some experience in full car racing when they use the correct terminology. :thumbsup:

Dan question for you. When referring to tilt and rake, I assume you use positive meaning rear higher the front, and right side higher then left side, right?

To be honest with you Mike, in oval racing I've never heard of
it expressed in postive or negative terms... not like camber and caster,
which we do. But your choice leans toward how I would describe it,
if it needed to be specified in those terms.
We would simply say "we run 1-1/2" of rake, and 1-1/2" of tilt.
I don't know of anyone that would ask "which way"?
Not to say that they couldn't...
Just never heard it in any of my circles..

I suspect it's because in oval racing, you would never have the front higher
than the rear, nor would you ever have the left higher than the right.

If you did, you would probly have more of a problem than using
the proper termanology! :drunk:

chassis tilt lol.. is chassis wedge and if the left rear was higher than the right rear the car would be De-wedged

Been doing the real car thing for 20 years. Even in a touring series racing from Canada to Florida and out to Indiana I've never heard a racecar guy say tilt or rake. It's chassis heights plain and simple.

I suspect it's because in oval racing, you would never have the front higher
than the rear


Just about any G bodied, street stock type car needs the RF higher then the RR or you'd never get enough cross weight in it.

I didn't know anyone raced real cars on the west coast.

RPM I don't take these things personaly, and no I don't have any real car racing in my background. But for me using non Real car terms doesn't mean people don't know what the chassis changes do.

Dan I have run the left front higher then the right front many times. I have also ran the front end higher then the rear at one track. In all the cases it was to over come a lack of tire selection. But it did work out in the end with a car that won. But you better believe the next time I went back to that track I had different tires on the car, and it fixed the chassis height issues.

chassis tilt lol.. is chassis wedge and if the left rear was higher than the right rear the car would be De-wedged


Laugh all you want.
I know you've won a lot of races, and you build race cars...
But you can take up the termanology with Steve Smith,
Emanuel Zervakis, and other writers of chassis dynamic books...

Wedge, before you changed the definition, used to mean how much
preload was on the left rear.
Measured by jacking up the car by the rear axle and measuring
how far the right rear came up, before the left rear just leaves the ground...

It came from the days when cars ran leaf springs, and they used to put
hardwood "wedges" in between the leaves, to put more preload on
that corner...
This is how they did it, before you were born.
That is what they called it...
I didn't create the term... just telling you where it came from.

Just about any G bodied, street stock type car needs the RF higher then the RR or you'd never get enough cross weight in it.

Yeah... but you are taking a car, that was never intended to race,
and "compensating" for something that was not built into it..

There aren't many cup cars today, with the right front jacked
up like a streeter... :rolleyes:

sorry dan i just found the term tilt funny

Yeah... but you are taking a car, that was never intended to race,
and "compensating" for something that was not built into it..

There aren't many cup cars today, with the right front jacked
up like a streeter... :rolleyes:

Most Late Model chassis builders today recommend the ride height to be:

LF 3 1/2"
RF 4"
LR 4"
RR 4 1/2"

Watch a cup car and you'll see that the RF rides higher than the LF. Not like a "streeter" but about an inch. More so on flat super speedways and short tracks.

doesnt pod droop put more stress on the t plate ? My car with the center spring with no preload in it the pod is at a droop is that right or wrong its on a pro 3 car.. or is my shock to long?

RPM I don't take these things personaly, and no I don't have any real car racing in my background. But for me using non Real car terms doesn't mean people don't know what the chassis changes do..


Your right Mike.

I didn't want you to feel excluded because you don't have a background in stock car racing. Alot of times people twist the meaning on a form and read into a little differently.

It's like this..
When some says there running about 12.3 oz of weight on the Left Rear
doesn't mean anything unless you know the total weight of the car.

Anyone with some background in racing would say they running 33%
Left Rear weight. :)

r/c car are around 40 to 44 oz!!!! everyone knows that!!!!!

..having a background w/ Full Scale Dirt Late Model racing, and Asphalt Stock Car racing...I can tell you some terms in R/C and Full scale are the same...but others are different.

I attribute that in part to the fact that MOST of the FULL scale guys I know...don't have a clue about 75% or more of the changes a R/C racer will make to his car.

Chassis TILT is NOT the same thing as what we called WEDGE.

What we called WEDGE in Full scale, is what we call 'Tweak' in RC cars. Which was basically how much the RR tire came off the ground before the LR when lifting from the center of the rear end (which we used a jack w/ a piece of Angle Iron for a point to get under the center of the rear end.)

On our asphalt car, we ran the rear frame rail about 7.25 off the ground on the right side, and about 6.50 - 6.75 on the left side, in front of the rear tires.

The front frame rail, just beind the front tires was approx 1" lower. This giving a 1" rake to the chassis, and a .50 - .75 " "Tilt" to the chassis L to R.

We too scaled the car, and those numbers are in an old set up book someplace, but we didn't scale it very often once we found a set up we liked, we'd just check and set the "Wedge" and the frame heights...and we'd be good to go.

A R/C Car has SOOOO much more adjustability, it's almost rediculous. I've recently got a couple old retired, or budget restraint ex-oval racers to try R/C racing...they can NOT believe how much work we go through, and how much adjusting we do...compared the them.

As for the term "TILT" I used that in R/C, but in full size...it was always Chassis Height, and documented at each corner.

I only use it here, to keep it from being confused, because when I said something about chassis TILT somebody thought I meant the rake or front to back measurements...not the side to side.

I don't care WHAT we call it, so long as we can understand what the heck someone else is referring to.

Being a mechanic to nearly 30 years, it's AMAZING to hear what people call things...

[QUOTE=swtour

On our asphalt car, we ran the rear frame rail about 7.25 off the ground on the right side, and about 6.50 - 6.75 on the left side, in front of the rear tires.

The front frame rail, just beind the front tires was approx 1" lower. This giving a 1" rake to the chassis, and a .50 - .75 " "Tilt" to the chassis L to R.

[/QUOTE]

Your asphalt car? Sounds more like dirt. Tube frame or stock? As far as adjustments on a stock car there are just as many or more than an R/C car.

sorry dan i just found the term tilt funny


Yeah, it reminds me of a pinball machine
that you 'body english' too much... :p

Like I said, I didn't invent it, just telling you the "true" definition,
per some respected chassis physics guys..

What would be more effective to obtain proper preload to the pod; either longer shock shaft/ball cup or more spring load using the collar?


Thanks
Anchor :thumbsup:

ZMain said Your asphalt car? Sounds more like dirt. Tube frame or stock? As far as adjustments on a stock car there are just as many or more than an R/C car.


I don't disagree, but most organized racing I've seen has rules that stops a lot of these adjustments from really being able to be used.

Wheel Base, differing wheel base, motor placement (set-back), tire sizes and types, motor size, and more.

Both the dirt cars and asphalt cars I was involved with, were pre- r/c days for me...and I've been into R/C's for going on 22 years.

Cars were at that time, Stock front clip type chassis' (both on the dirt and asphalt) Cars were Coil Spring cars (No COIL OVERS were allowed) A few guys were running Leaf Springs, most were Coils. Early years were 9" FORD Rear ends, later Quick Changes. Nothing like the tube chassis cars of today, DLM's have come a LONG way. The ASPHALT..DIED out here. Mesa Marin..GONE, Saugus GONE, OILDALE(Bakersfield)...DIRT,

These cars would just about be equal to what I've seen as "Street or Super Street Stocks" now-a-days.

swtour, that makes things clearer for me. I've seen Late Models and even Street Stocks become more adjustable in just the past 16 years. Wrether its R/C or full size, just when you get the most adjustable car another one comes out that has more, and of course we have to get it.

What would be more effective to obtain proper preload to the pod; either longer shock shaft/ball cup or more spring load using the collar?


Thanks
Anchor :thumbsup:

Best to run your rear pod level.
I like to run two shims in the front of the T-plate. :thumbsup:

Yeah... but you are taking a car, that was never intended to race,
and "compensating" for something that was not built into it..

There aren't many cup cars today, with the right front jacked
up like a streeter... :rolleyes:


it's more so compensating for the tires, most street stock cars are still on a street type treaded tire. They still require 53% or more in cross weight. Slicks with late models are in the 50-51% range, the Busch car we ran in the pro Cup series ran as low as 46% and the modifieds I work on now are also in that range. It's just hard to get enough cross weight for street tires without jacking the RF up.

it's more so compensating for the tires, most street stock cars are still on a street type treaded tire. They still require 53% or more in cross weight. Slicks with late models are in the 50-51% range, the Busch car we ran in the pro Cup series ran as low as 46% and the modifieds I work on now are also in that range. It's just hard to get enough cross weight for street tires without jacking the RF up.

Still compensating, no matter the reason.
In your other examples, you should note that the cars are 'designed'
to race...
Even the Busch car has a better front to rear ratio than a streeter...
The motors are set back some, and the clip is lighter.

Streeters are usually very nose heavy.
Busch car is less
Modified is less yet

As you move that weight towards the left center of the car, the need to
exaggerate a chassis shortcoming becomes less.

The streeter will always suffer from being nose heavy, regardless of
tires...

What would be more effective to obtain proper preload to the pod; either longer shock shaft/ball cup or more spring load using the collar?


Thanks
Anchor :thumbsup:

Longer ball cup and pre-load the spring until the collar just touches the spring and go from there.

-E

Anchor you need a combination of both. You can preload your spring all you want to, but if your shock is the wrong length you will never get to the right amount. Or if you make the shock longer and don't change the spring preload it may not be right either. I like running my shock longer then the throw of the spring for flat tracks and shorter then the trow of the spring for banked tracks.

I was right with you untill the last post. :confused: Could you please explain "throw of the spring" :)

Thanks

...I would take that as the spring has "pre-load" with the shock assembled w/ the spring, prior to installation vs. the shaft still having additional extention available.

Maybe someone has a real racing term for it. But I'll try to explain it in my terms. when running any spring it has a fixed free length. When you set preload to zero meaning that you just have the adjustment nut touching the spring or very little preload. Then you can pull the pod back to see how much droop is possible the spring is no longer hitting both the adjuster collar and the spring bucket. Hopefully that makes sense to more then just me. If their another term let me know, like "over travel" maybe.

Mike...I'm assuming you saying that on a flat track you will make the shock length long enough to achvieve the droop but only have the spring just touching the adjustment nut for very little preload. If my assumption is correct, how do you get the pod to run level with the chassis with the battery installed without putting alot of preload on the spring? Or do you not really try to get the pod to run level?

Thanks

RC

The pod should be level, or some droop in it race ready. The post previos was trying to explain my other post, not how to set up the center shock.