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Free spring rule


enginerd
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Now that my racing season is done I'll join in on the 'silly season'.. and there's something I have to get off my chest: a desire to change the free spring rule

 

 

The free spring rule was pushed through the board as some kind of "cost savings" measure, probably by BMW teams who wanted to use H&R race springs for free. I can't remember exactly

 

It has seen a change or two over the years and the end result is that we now have a rule where your springs are free if they are substantially similar to the stock offering (defined in the rulebook).

 

Everyone knows that with small changes in wire diameter, springs can vary widely in stiffness. So these 'substantially similar' springs could have a huge range of performance and function as well as an aftermarket racing spring setup. As such, using custom 'free springs' is held up as a pinnacle of ChampCar building by some members of the TAC and some members. Don't like a VPI increase? That's ok, you weren't optimizing your car in the first place. You can just drop your 40 point coilovers and get equal performance for free for the low low price of several sets of custom springs and a few trips to the track to tune them. Do we really want this huge time and money expense rewarded with the equivalent of 40 free points by not using coilovers? I sure don't. I see that and say 'holy crap I'm not doing that, and I sure hope nobody else does'. 

 

I like a lot of the ChampCar rules which favor ingenuity rather than bolt on parts... bending or cutting a control arm to improve geometry is free while buying an aftermarket control arm gets you dinged for non-OE suspension component. The spring rule however... the custom spring setups require way too much time and money and shouldn't be rewarded with zero points. 

 

I'm fielding input on a petition. The gist would be:

- stock springs in stock form or modified by cutting and/or heating = 0 points

- any non-OE spring even if it's similar in size = 5 pts. per corner

- non-OE spring with adjustable "coilover" perch = 10 pts. per corner

Edited by enginerd
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8 minutes ago, JDChristianson said:

if you are talking springs only and not adjustable coilover then 5pts per corner the way it is now.  Just eliminate the spending on custom springs for 0 points

Thanks for the clarity. I'm not familiar with exactly how it works now. Original post edited.

Edited by enginerd
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1 hour ago, enginerd said:

 

Everyone knows that with small changes in wire diameter, springs can vary widely in stiffness. So these 'substantially similar' springs could have a huge range of performance and function as well as an aftermarket racing spring setup. As such, using custom 'free springs' is held up as a pinnacle of ChampCar building by some members of the TAC and some members. Don't like a VPI increase? That's ok, you weren't optimizing your car in the first place. You can just drop your 40 point coilovers and get equal performance for free for the low low price of several sets of custom springs and a few trips to the track to tune them. Do we really want this huge time and money expense rewarded with the equivalent of 40 free points by not using coilovers? I sure don't. I see that and say 'holy crap I'm not doing that, and I sure hope nobody else does'. 

 

Or you could do some math and hit it pretty close in a couple stages. 

You of all people know that Math is a wonderful thing. 

Calculating the increase in rate change to keep both ends of the car balanced - fun stuff.

Measuring the installed spring height, and then removing it and compressing it in a press with a load cell to check the spring force at ride height, then cutting a stiffer spring you researched with similar ID down to fit that force at the same compressed height - good stuff, and a  lot of fun and rewarding when you see your car handling well after putting so much thought into the work.

My rear springs cost $50-60 per pair vs. my front Eibach coilover springs at $60 each. We're on our 3rd iteration and drivers report the car is pretty decent to drive.

 

 

edit; This same theme is in the NC Miata thread where I almost posted - then I saw this, so i added my thoughts. 

IMO, this is typical suspension development on any racecar and the methodology is the same, just different parts used to save points.

I'm facing a similar dilemma with rear camber arms on my car. I'm paying 20 points for them, but need to free up points. I'll need to reinstall the stock non adjustable arms and elongate mounting holes to change camber. 

Our rules and point system are unique and allow builders to be creative like that.

Trade-off decisions - some may not be easy - but methods of saving points are available...

IMG_1325.JPG.e8cb0a6172a8fe45a11af5448f936322.JPG

Edited by mcoppola
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5 hours ago, enginerd said:

Now that my racing season is done I'll join in on the 'silly season'.. and there's something I have to get off my chest: a desire to change the free spring rule

 

 

The free spring rule was pushed through the board as some kind of "cost savings" measure, probably by BMW teams who wanted to use H&R race springs for free. I can't remember exactly

 

It has seen a change or two over the years and the end result is that we now have a rule where your springs are free if they are substantially similar to the stock offering (defined in the rulebook).

 

Everyone knows that with small changes in wire diameter, springs can vary widely in stiffness. So these 'substantially similar' springs could have a huge range of performance and function as well as an aftermarket racing spring setup. As such, using custom 'free springs' is held up as a pinnacle of ChampCar building by some members of the TAC and some members. Don't like a VPI increase? That's ok, you weren't optimizing your car in the first place. You can just drop your 40 point coilovers and get equal performance for free for the low low price of several sets of custom springs and a few trips to the track to tune them. Do we really want this huge time and money expense rewarded with the equivalent of 40 free points by not using coilovers? I sure don't. I see that and say 'holy crap I'm not doing that, and I sure hope nobody else does'. 

 

I like a lot of the ChampCar rules which favor ingenuity rather than bolt on parts... bending or cutting a control arm to improve geometry is free while buying an aftermarket control arm gets you dinged for non-OE suspension component. The spring rule however... the custom spring setups require way too much time and money and shouldn't be rewarded with zero points. 

 

I'm fielding input on a petition. The gist would be:

- stock springs in stock form or modified by cutting and/or heating = 0 points

- any non-OE spring even if it's similar in size = 5 pts. per corner

- non-OE spring with adjustable "coilover" perch = 10 pts. per corner

 

I followed exactly the process mcoppola outlined. Purchased cheap OEM replacement springs with the same dimensions of OE and cut to get roughly the spring rates I thought I needed. It took a few iterations to get a good setup. My springs aren't custom. They are cheap rockauto specials.... It was fun. 

 

I'd be pretty frustrated if this rule was reversed. It would have a very large impact on my car. I don't have very many points to play with; 20 points is a lot. After 3 years of development I'd have to rework my suspension again or take laps. 

 

If custom springs are the issue I'd rather see it resolved with paper work during a dispute. ie show the spring you purchased and how it dimensions fit. It definitely isn't clear to me how this is a large issue for the series.  

 

Edited by veris
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When making a petition, I think you will need to have answers for the following (coming from a group that discusses these things)

 

1) You will need a clear database source. If the parts are enforced by geometry you will need to know that for all cars in our series, or have access to it.  will need a list of all the options available for that car as an option. Will also need to determine if the parts for any option the car offered can be used, or not. 

 

2) You will need some information on what performance "stock" parts will provide if we are to factor this into vpi in any way. 

 

3)Will need a pass fail criteria for post race that is enforceable in minutes.

 

4) need to rationalize how this will help the series or parity. 

 

I personally think there is a snowball chance of answering #1, but I could be wrong. I think the series is far better to try and balance big ticket items, (which we often fail miserably at) rather than trying to get parity by hoping we can pin some team into a roll couple distribution trap where their balance limits the car speed in some trackable way. The spring rule also allows us to assume through cutting, spring rubbers or buying springs that you are able to balance your car and get a decent roll gradient and platform. With one less factor to have to equate into value, we can work on making sure other things are balanced. 

 

For the neon I have SDK springs (acr) SDA and SDC (base and touring), "Mopar high rate" "Mopar x rate" and "Mopar xx" rate springs in all my random piles of stuff and cars (we have 3 track cars and parts cars). They all have Mopar emblems on them vary in coil count and all would be cut down 1/3 to 1/4 because of the weight reduction of the car and ride height change. Going to be tough to enforce that at 5pm on a Sunday in 20mins.

 

 

Edited by Black Magic
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I have always hated the current spring rule, ever since it was announced. I submitted a petition to kill it the first year it was in force, but it got voted down.

 

Any rule that incentivizes running stock or stock appearing springs incentivizes cheating. There is no way that tech has a database of the exact specs of every spring that may have come on a car used in the series, and there is no way they are going to be removing springs and measuring them in impound even if they did.

 

The current rule is also quickly becoming a big barrier to entry to the series, nobody would be racing on stock shaped springs in 2021 if they didn’t have to. Even guys with fast street cars end up converting to 2.5-inch springs pretty quickly once they start modifying the cars. Just check the classifieds and see how many cars are offered for sale with 2 sets of suspension, one to run with ChampCar and one that they use everywhere else they race. This is just making it harder for someone to build a car which they can race with ChampCar while wanting to have other options.

 

 

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2 hours ago, turbogrill said:

My lowering springs where $259, and that is the upper end. Not sure there is a cost issue here.

 

Sure it's a pain in the ass to do what @veris did but as long as time != Money...

 

Cost wasn't the issue.  Points and spring availability were issues. I run an odd car. Lots of motor parts, but not much for suspension. 

 

I could also have switched to coil overs and standard 2.5" race springs but that would have cost me 40 points. I only have 75 to play with. 

 

I'm not really sure what the problem with the rule is. It is consistently applied and gives everyone the same options which is what I want to see in a rule book. 

 

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1 hour ago, mhr650 said:

I have always hated the current spring rule, ever since it was announced. I submitted a petition to kill it the first year it was in force, but it got voted down.

 

Any rule that incentivizes running stock or stock appearing springs incentivizes cheating. There is no way that tech has a database of the exact specs of every spring that may have come on a car used in the series, and there is no way they are going to be removing springs and measuring them in impound even if they did.

 

The current rule is also quickly becoming a big barrier to entry to the series, nobody would be racing on stock shaped springs in 2021 if they didn’t have to. Even guys with fast street cars end up converting to 2.5-inch springs pretty quickly once they start modifying the cars. Just check the classifieds and see how many cars are offered for sale with 2 sets of suspension, one to run with ChampCar and one that they use everywhere else they race. This is just making it harder for someone to build a car which they can race with ChampCar while wanting to have other options.

 

 

 

Are you saying springs should be 100% open?

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3 minutes ago, turbogrill said:

 

Are you saying springs should be 100% open?

Yes, no other rule makes sense. I am convinced that eventually this will be the rule, for now we are just wasting time getting there. 

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24 minutes ago, mhr650 said:

Yes, no other rule makes sense. I am convinced that eventually this will be the rule, for now we are just wasting time getting there. 

 

It would be nice if it could get any spring. More options, less cost.

 

I wonder how difficult it is to fit a typical coilover spring into an OEM shock.

 

But could the same argument be had for shocks? And I guess they are free?

 

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1 hour ago, mhr650 said:

Just check the classifieds and see how many cars are offered for sale with 2 sets of suspension, one to run with ChampCar and one that they use everywhere else they race. This is just making it harder for someone to build a car which they can race with ChampCar while wanting to have other options.

 

Being different just to be different?

 

The series can say what they want about attendance but the fall race at Road America 3 years ago had 75 cars take the green flag.

 

5 years ago? 77

 

This year? 44 at the green on Saturday.

 

*Just to add something else, the 2016 winner ran a 2:46.9 best lap. Same as this year.

 

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I know I'm an outlier, but having a car that is the most common circle track chassis in the country has it's benefits when it comes to CC's spring rule.

 

Stock replacement front coils are readily available in 500 to 1400 pound rates in 50 pound increments.

 

Rears are 100 to 400 in 25 pound increments.

 

 

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7 hours ago, mender said:

 

That is really cool. 

 

How do you get the Moog part # by car? I was curious what is showed as options for my platform (neon) since I know the options that came from the factory and can measure old OE springs. Trying to determine if they matched all geometry to OE, or matched the rate with a design using wire diameter they commonly had. 

 

@enginerd If that list does have all the oe options (Moog offers springs to match all oe options for a car) that would really change the chances of a petition working. 

 

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7 hours ago, Bandit said:

I know I'm an outlier, but having a car that is the most common circle track chassis in the country has it's benefits when it comes to CC's spring rule.

 

Stock replacement front coils are readily available in 500 to 1400 pound rates in 50 pound increments.

 

Rears are 100 to 400 in 25 pound increments.

 

 

 

I can use the same springs on the rear of my car for no points. Still hate the rule even though I get half of the benefit.

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11 hours ago, mhr650 said:

I have always hated the current spring rule, ever since it was announced. I submitted a petition to kill it the first year it was in force, but it got voted down.

 

Any rule that incentivizes running stock or stock appearing springs incentivizes cheating. There is no way that tech has a database of the exact specs of every spring that may have come on a car used in the series, and there is no way they are going to be removing springs and measuring them in impound even if they did.

 

The current rule is also quickly becoming a big barrier to entry to the series, nobody would be racing on stock shaped springs in 2021 if they didn’t have to. Even guys with fast street cars end up converting to 2.5-inch springs pretty quickly once they start modifying the cars. Just check the classifieds and see how many cars are offered for sale with 2 sets of suspension, one to run with ChampCar and one that they use everywhere else they race. This is just making it harder for someone to build a car which they can race with ChampCar while wanting to have other options.

 

 

 

This!!!!!

 

Back when i was building the e30, the standard Billy/H&R setup was unavailable for almost 9 months I think it was, so i just went ahead and did the coil over conversion. The kit cost exactly the same as the billy/H&R combo, and now there are a multitude of spring options where the spring costs are cheap.

 

Moreover the penalty for single adjust shocks is silly. It's well established that there are teams having things re-valved for zero points and maybe have a few diff sets for different track profiles. So this penalty is completely ineffective w.r.t. it's intent...

 

I feel like part of the dance with rule systems like this is being aware of what's available in the market, the effects on cost as commoditization/supply come into play and aligning the rule to both take advantage of and not be damaged by those market drivers.....

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5 hours ago, Black Magic said:

 

That is really cool. 

 

How do you get the Moog part # by car? I was curious what is showed as options for my platform (neon) since I know the options that came from the factory and can measure old OE springs. Trying to determine if they matched all geometry to OE, or matched the rate with a design using wire diameter they commonly had. 

 

@enginerd If that list does have all the oe options (Moog offers springs to match all oe options for a car) that would really change the chances of a petition working. 

 

I have an older (up to the mid '90s?) Moog spring catalog that cross-references the part numbers by application, I'm pretty sure they must have that somewhere on their site. 

 

I used that to find the V6 Pinto front springs that fit in the front spring pockets of the Fiero and produced the desired spring rate. 

 

Edit: here you go:

https://drivcat.com/digipubZ/MOOG-Coil-Springs-F2925/MOOG_CoilSprings_F2925.pdf

 

I'll check my old catalog, it also sorted the springs by size (inside diameter, end style, wire size, free height, etc) and listed each spring numerically with applications (in other words, which cars to look for at the scrapyard). My secret weapon for "stock spring" racing classes.

 

Edit again: I just finished playing on those sites, they do the searching for you! Click on the spring part number and the applications for that spring show up. You can then insert the spring number to get all the dimensions and then compare them to other springs, etc. Should have everything you need on those two sites, and lots easier than the manual search method I used decades ago!

 

Stock Neon spring: 81460

Enter that part number to get dimensions. 5.59" id.

Enter 5.59" in spring diameter, erase 81460 from the part number box. Four springs with the 5.59 diameter show up.

81460 has 138 rate and 0.56 wire size. 7504 has 182 rate and 0.59 wire size, same installed height.

Click on 7504 to get application: '98 - 2001 Intrepid. 32% higher rate in a "stock" spring with the right ends, etc.

 

Either order Moog springs or go to the junkyard and grab a couple sets to play with.

Edited by mender
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30 minutes ago, mender said:

I have an older (up to the mid '90s?) Moog spring catalog that cross-references the part numbers by application, I'm pretty sure they must have that somewhere on their site. 

 

I used that to find the V6 Pinto front springs that fit in the front spring pockets of the Fiero and produced the desired spring rate. 

 

Edit: here you go:

https://drivcat.com/digipubZ/MOOG-Coil-Springs-F2925/MOOG_CoilSprings_F2925.pdf

 

I'll check my old catalog, it also sorted the springs by size (outside diameter, end style, wire size, free height, etc) and listed each spring numerically with applications (in other words, which cars to look for at the scrapyard). My secret weapon for "stock spring" racing classes.

 

Edit again: I just finished playing on those sites, they do the searching for you! Click on the spring part number and the applications for that spring show up. You can then insert the spring number to get all the dimensions and then compare them to other springs, etc. Should have everything you need on those two sites, and lots easier than the manual search method I used decades ago!

 

Neat catalog. But I checked and in the Mazda section it has no listings for any version of the Miata, any version of RX7 or RX8. It has no BMW listings at all. How is that supposed to help tech in a series where those cars, which are not listed make up the majority of the entries at any race?

 

 

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