Coil Over Threaded Sleaves

M

MMiskoe

New member
A recent post about this subject & a question from an email aquaintence prompted me to ask this.

The GCR does not allow the threaded sleave for a coil over to be permanently attached to a housing (the strut/shock). Can someone tell me what this rule was trying to accomplish? What advantage is there in having the threads integral w/ the shock/strut? Or what is gained by having them be seperate? It is clearly spelled out that coil overs are acceptable as long as the adjuster is not permanently mounted.
 
Originally posted by MMiskoe:
The GCR does not allow the threaded sleave for a coil over to be permanently attached to a housing (the strut/shock). Can someone tell me what this rule was trying to accomplish?
Click to expand...

I'll take a stab at it. You have to remember that the basic IT rules package is 20+ years old. I don't know how old the coilover rule is, but I'd have to guess 10-15 years.

With that in mind, I'd guess that eliminating threaded body coilovers eliminated the most expensive dampers of the day. There were probably few high dollar adjustable dampers that weren't threaded body at the time.

Jump to today (the future when the rule was written)....

Today you can buy a $6,000 set of Koni custom built race dampers (28XX series) that are 100% IT legal. Yet, for less than $1,000 in some cases you can buy threaded body double adjustable coilovers for some cars. Clearly the rule today doesn't eliminate expensive dampers.

The rule that keeps out the mega-dollar dampers is the no remote reservior rule. Yes, there are remote reservior dampers available for reasonable prices, but it opens the door to crazy prices. I know of one Porsche 928 owner who has a set of $15,000 dampers!


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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
And just to toss in the obvious for the benefit of our lurking rules making friends in Topeka...

Furthermore, many of us take perfectly good, reasonably priced, coil over strut tubes and shocks and then spend time and money to machine the threads off and replace them with a slip on coil over tube...this achieves the exact same result with more cost and it technically a complete waste of time.

struttubes.jpg



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Bill Sulouff - Bildon Motorsport
Volkswagen Racing Equipment
## 2003 ITB NYSRRC Champs ##
 
Originally posted by MMiskoe:
A recent post about this subject & a question from an email aquaintence prompted me to ask this.

The GCR does not allow the threaded sleave for a coil over to be permanently attached to a housing (the strut/shock). Can someone tell me what this rule was trying to accomplish? What advantage is there in having the threads integral w/ the shock/strut? Or what is gained by having them be seperate? It is clearly spelled out that coil overs are acceptable as long as the adjuster is not permanently mounted.
Click to expand...


My take (which is similar to George's) is that they were trying to control costs w/ rules. Unfortunately, it's fairly well accepted that the only cost-containment rules that even come close to working are claiming rules, or rules that require spec. parts. And even the spec. parts rules aren't that good, as people will 'parts bin blueprint' things.


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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Bildon, I thought that you didn't have to machine off the threads on the housing, but just install the adjustable unit over it.

I haven't gone done this route yet. My bilstein sports are working just fine, thank you very much.



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Tim Linerud
San Francisco Region SCCA
#95 GP Wabbit (Bent)
http://linerud.myvnc.com/racing/index.html
 
Tim,

If you don't machine the threads off, it's still a threaded-body shock, and therefore, illegal.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Hey, Bill, there's nothing in the rules that says a threaded-body shocks are illegal. The rule states threaded SLEEVES that are permanently attached to the housing are illegal...
 
grega... you want to hit delete now?
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Actually, you are correct in that the wording does say "sleeve"

So are you saying that the threads machined into a strut body are not an attached 'sleeve' and therefore have always been legal?

Let's just hope they whack this rule. It's dumb.
 
I think that you can have a threaded body, and slip a sleeve over it.... Many many IT cars are built that way (not ours).

I think the rule is dumb... but whatever, it has no bearing on our cars.


raymond
 
Raymond,

The way I read your last post (and the posts of others), is that it's ok to use an illegal part, so long as you don't use the nature of that part that makes it illegal (i.e. since you've slipped a sleeve over the permanent threads, it's ok)?

And, in the case of the shocks, if you're interpretation were correct, I sincerly doubt that people would have gone to the time/expense to have the threads machined off of 'perfectly good' shocks.

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MARRS #25 ITB Rabbit GTI (sold) | MARRS #25 HProd Rabbit
SCCA 279608
 
Bill

That is how I think "most" look at the rule... I have not debated with myself about it to much as I think it is irrelevant... you can get a shock/strut built anyway you want if you have the $$$ (The manufacturer I sure would build the same thing with a non-threaded body if you paid them to). I think that if it is cheaper to get it off the assembly line threaded then why not allow it... the threads really do not make it any different if you sleeve it...

Also I don’t think that the rules say anywhere that you cannot use a threaded body shock… do they???? I think they specify that you cannot have a permanently attached adjustable spring perch. I can’t quote it as I do not have the GCR in front of me.


Raymond Blethen

PS: We don’t and probably never will have threaded body shocks…. I know our toughest competition does have threaded body shocks, we wont ever protest them for that. SCCA makes the rules, we all as competitors govern them (unless it is a pro IT event such as the ARRC, then watch out for those stewards
wink.gif
).
 
What the rules say:

5.b.3 - "... Spacers, including threaded units with adjustable spring seats, may be used with coil springs, provided the spacers are not permanently attached to the shock/strut housing."

5.b.5 - "Coil-over struts or shock absorbers, where a threaded sleeve is permanently attached to a housing, are prohibited unless fitted as standard equipment."

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Ony
 
5.b.5 is interesting... I guess one could argue that the threaded body is a threaded body and not a threaded sleeve?

Raymond "Interested after actually looking at the rule" Blethen
 
This discussion cracks me up. I've personally spoken with several manufactures of suspension systems used by numerous SCCA IT racers and also looked at many, many suspension systems on existing IT cars. As long as the sleeve is not attached, it is legal. And this was a very recent inquiry - just last year.

5.b.3 - "... Spacers, including threaded units with adjustable spring seats, may be used with coil springs, provided the spacers are not permanently attached to the shock/strut housing."

5.b.5 - "Coil-over struts or shock absorbers, where a threaded sleeve is permanently attached to a housing, are prohibited unless fitted as standard equipment."

Even I didn't find this rule confusing.

Bill - I think you're stretching with your comment about "it's ok to use an illegal part, so long as you don't use the nature of that part that makes it illegal (i.e. since you've slipped a sleeve over the permanent threads, it's ok)?" I'm not sure how you interpreted Raymond's post that way, and honestly don't even want an explanation. Not trying to be harsh, but at the same time don't think we need to go down that road...

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Dave Gran
NER #13 ITA
'87 Honda Prelude
 
The rule was written before "real" threaded-body shocks and struts were available for production based cars.

This is a dum rool, too and I look forward to a change. That said, the problem will not go away as long as the GCR and ITCS are edited incrementally and changes are driven by member requests.

K
 
Here's whats really stupid. This was done to 'control costs' and be in the spirit of minimal modifications that most folks could do.. Funny, cutting apart struts, rewelding, shortening, adding the sleeves, removing stock perches etc... was done to control cost??? Yet for many years, you couldn't remove passenger seats, and still can't do something like move the battery!

The rules for IT are nuts. Allow expensive mods, disallow cheap or free mods that would make the cars more enjoyable. I think its just to not threaten the other classes (GT and Prod).

As usual, Cal club was really onto something some years ago with their rx7 and corolla classes where you could basically gut to your hearts content, but the rest was basically stock - lower load on components, more fun, better racing!
 
Bildon, I'm not really trying to "say" anything except 'open your mind'. We see what we want to see (or what we've been told to see) rather than what's there...

Kirk really nailed it: the rule is one that was authored in the days when NO ONE except maybe Formula One and Champ Cars had threaded-body shocks. IT rules derived from the minds of people who had no choices for their street cars other than Bilstein, Tokico, or Monroe Formula GP replacement shocks, and maybe Neuspeed springs if you were lucky. Most of the time folks trimmed off a coil or two to lower the car. 1984, people: the year of the SSB Rabbit GTi and the emergence of the non-turbo SSB Dodge Shelby Charger. The Pinto was less than a decade old, and we were still hearing remnants of disco on the radio now and then. Threaded body shocks, threaded sleeves, and even racing coilover springs were UNHEARD OF in 1984.

But, times change: I can go in the back of Sports Compact Car and order up a set of coilover sleeves, adjustable gas-pressurized shocks, and springs in my choice of anodized colors for about what I would have spent on a set of Bilsteins 20 years ago.

While times change, SCCA rarely does. Datsun Z-cars are still popular amd competitive, an old 50's British car can still win the Runoffs, and IT rules are still saddled with 20 year old regs.

But, if I were a young open-minded chap with no preconveived SCCA biases, and I was reading ITCS 5.b.5, I would go out and buy me a set of threaded-body shocks and drop them in with a set of Eibach springs. People would scream and holler at me, I'd get protested and possibly excluded if I couldn't argue my case well, and then I'd quit and go run COMSCC, EMRA, NASA, and/or a host of other organizations...

We think we "know" what the spirit of the rules are, but that ain't what they say. There's nothing in the rules that make threaded-body shocks illegal, only our preconceived notions do.

GregA
 
Originally posted by grega:
We think we "know" what the spirit of the rules are, but that ain't what they say. There's nothing in the rules that make threaded-body shocks illegal, only our preconceived notions do.
Click to expand...

Greg, I couldn't agree with you more here.

The one other thing I will say (as I have many times) is that the spirit of the rules is meaningless once they are written. What matters is the letter of the law. The disclaimer here is that if we get a little too clever, we could find the rules changed for the next year to remove a loophole we may find. But the only concern for the spirit of the rules should be in writing rules, not interpreting them. IMHO of course.



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George Roffe
Houston, TX
84 944 ITS car under construction
92 ITS Sentra SE-R occasionally borrowed
http://www.nissport.com
 
So Greg, to really beat the dead horse, in an attempt to make sure I get your angle, you are saying that a set of shocks with threaded bodies are perfectly legal as long as the threads aren't used to adjust a perch that mounts a spring? The spring is mounted elsewhere in this situation.

BUT, IF the spring sits on a perch that adjusts up and down those threads, (AKA a 'coil over') it's outa here! Right??

Yup, a rule whose time has come.....and gone. They'll get rid of it, it just takes time. Have you guys seen the pile of letters they get from the Prod guys!?! And they have to pay attention to those guys! Arrrggg!

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Guys... I've hinted at it before, but the poor dead horse is still getting the crap smacked out of it!
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RELAX... Watch for the upcoming Fastrack issue (hopefully, might be the following one...), and then have someone standing by with smelling salts to revive you because you might just see something in there that makes sense and kills this conversation...
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Kirk had it exactly right... You guys need to understand that these rules were put in place MANY years ago, and they have worked fine for MANY, MANY years... The reason why some of these things persist is because of the protectionist attitude that many have had toward this class... Well, it's time to modernize and we are working on doing that.

The spirit shall remain, but some of these anoyances will hopefully be revised...

Keep this spirited banter alive, and be ready to write in when asked for official membership input. It's up to all of us to show the BoD and CRB what it is we want...

Stay tuned!


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Darin E. Jordan
SCCA #273080, OR/NW Regions
Renton, WA
ITS '97 240SX
DJ_AV1.jpg
 
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