72 replies to this topic

[pfrichardson]

... are posted:

http://www.scca.com/...t.cfm?cid=44472

[Johnny D]

Recommended Items for 2015

 

The following subjects will be referred to the Board of Directors for approval. Address all comments, both for

and against, to the Club Racing Board. It is the BoD’s policy to withhold voting on a rules change until there

has been input from the membership on the presented rules. Member input is suggested and encouraged.

Please send your comments via the form at www.clubracingboard.com.

 

 

SM

1. #15116 (David Cox) SM Cylinder Head (Runoffs Protests)

The CRB wishes to thank the hundreds of SM drivers and owners who have commented on this difficult

situation. The CRB has been working closely with the SM Group to identify all of the issues that came up as

a result of the Runoffs compliance actions. The CRB has determined that the best course is to use the

regular system to work through this problem.

 

The CRB instructed the SMAC to discuss the issues and prepare a recommendation for the CRB. In turn,

the CRB is recommending (to the BoD) a slight change in the SM rules for 2015. The SM Group (including

Mazda, SCCA and NASA) is currently contracting for dyno testing of various head configurations. When

that testing is complete, they will submit a letter into the CRB system for consideration by the SMAC and the

CRB. At that time, the CRB will take whatever action we feel is appropriate. This may include changes in

weights or restrictor plates, but it may also include a recommendation that no changes be made. No

recommendations will be made to the BoD until the data is complete. The CRB is also monitoring the

availability of cylinder heads and the effect that will have on possible future rule changes. There is a severe

shortage of new cylinder heads in the Mazda system.

 

At this time we are also recommending, to the BoD, that the SM compliance fee, in a form to be determined,

be reinstated and that the SM Group's request be implemented for a traveling Tech squad to be deployed

during the 2015 season at SCCA and NASA events to be determined. This Tech squad should be totally

SM savvy. We are reviewing a possible re-write of portions of the GCR that would give this Tech squad

additional powers to levy penalties that are not currently allowed in the GCR.

 

The SMAC has received over 200 letters from members regarding the Spec Miata cylinder head compliance

issues identified at this year’s Runoffs. The SMAC members reviewed every letter, consolidated results to

determine general consensus, and discussed what actions, if any, need to be taken. Most of the letter

writers advocated keeping the current plunge cut allowance and either clarifying the current specs or adding

an allowance for blending or deburring. Only a very small minority (~5%) advocated eliminating the plunge

cut allowance and returning to “stock” heads.

 

When analyzing the specific issues uncovered at the Runoffs, the SMAC members determined that rules

regarding blending and deburring were clearly defined, properly interpreted, and appropriately

enforced. Some details need to be clarified, but the SMAC believes that the rules are generally fine as

written.

 

Concerning the plunge cut allowance, the SMAC is unanimously opposed to eliminating the allowance

and/or returning to “stock” heads now or in the future.

 

The plunge cut allowance was added years ago to correct for inconsistencies between stock heads that created significant performance differences between motors. Since the plunge cut was allowed, the Spec Miata’s on-track parity has been unequalled among all other highly competitive classes, even classes requiring “sealed” motors.

 

The SMAC also felt that forcing competitors to replace perfectly good 2014-legal heads would place an undue financial hardship on innocent competitors and could significantly impact class subscriptions. In addition, unmodified "stock" heads and

engines are compliant within the current rules as the engine specifications were determined based on

weights and measurements taken on approximately 50 stock engines with allowances for measurement

tolerances.

 

The CRB recommends clarifying the existing rules by adding further definition and measurable

specifications for the plunge cut dimensions and orientation.

 

The specific CRB recommendation to the BoD is as follows:

Change GCR 9.1.7.C.1.f.3: 3. The throat area of the port consists of the 90 degree angle at the very bottom

of the cast steel valve seat as it transitions to the aluminum casting below. It is permitted to plunge cut the

throats in order to correct for core shift that is commonly found in many cylinder heads.

 

The cut must be cylindrical and concentric to the valve guide axial centerline, within a tolerance of .005”, for the entire length

of the cut. The radius tangent to the cylindrical and bottom surfaces shall not exceed 0.375".

 

This cut cannot extend further than the specified number below from the bottom of the ferrous valve seat. There can be no

tooling or machine marks in the head below this point. The area under the seat where the plunge cut ends

and the casting resumes cannot be blended by hand, machined, or chemically processed to create a smooth

transition.

 

The Intersection of the machined surface of the plunge cut to the port casting shall not be altered,

except that the area under the short turn radius may be de-burred, with the de-burring not to exceed 1.5 mm

in width.

 

The 90 degree bend at the bottom of the valve seat and the aluminum directly below it will be

measured with a gauge and must conform to the maximum diameters and depths listed below.

 

 

2. #15634 (Michael Babcock) Camber for SM

Thank you for your request. Add 9.1.7.C.3.p:p. Inner bushing(s) on the front lower control arms may be

replaced with the Mazdaspeed offset bushing (part number 0000-04-5409).

[Bench Racer]

The head rule is open for comment to the CRB.

 

How many 9 illegal 2014 Runoffs heads are now legal?

 

Preliminary Tech Bulletin

 

1. #15837 (Spec Miata Committee) Expand Illegal Engine Coatings List

 

In section 9.1.7.C, change the language as follows:

"The use of any painting, coating, plating, or impregnating substance (e.g.,anti-friction, thermal barrier, oil shedding

coatings, chrome, anodizing, REM, isotropic finishing, etc.) to any internal engine surface, internal transmission or

differential surface, internal or external surfaces of the exhaust manifold or down tube is prohibited."

[wheel]

NONE

[James York]

This proposal is logical and creates the least hardship on the majority of SM racers.  I support this path.

[Steve Scheifler]

At the risk of being seen as ungrateful, if we are doing front bushings why not rears? If nothing is tweaked I can generally get "enough" camber in the rear but mostly because I'm lower than I'd like to be in an effort to get more up front. Just seems like a chance to do them at both ends and be done with it.

[38bfast]

Steve what camber numbers are you shooting for on the rear? At a reasonable ride height we have never had issue hitting camber numbers in the rear. If we do something is defiantly bent. A lot of time it's the subframe bent in the middle under the tank.

[Steve Scheifler]

Been too long, and since I've never had enough in the front, or run too low to get it, I don't really know what I'll need in the rear once the front is better and I can come back up a bit. Maybe it will be OK, but more adjustment just makes sense and potentially save the cost & hassle of a subframe replacement.

[FTodaro]

It is certainly a big step in the right direction, its good to see they are not recommending stock heads. It would be nice to see the size of the Deburr bumped to 2.5MM from the 1.5 to maybe catch a few more heads. but it is a compromise and for that we should be happy.

 

We need to see more on what the process will be for the heads that do not meet the new rule. They admit that we have a head shortage so there will have to be some kind of an accommodation of time and maybe weight for 2015 as there is not enough heads to convert even if we are not going back to a stock head.

 

We need to see how the rest of this plays out but a much better approach than the stock head rule first discussed.

 

Congrats to the class and SCCA/NASA/Mazda for trying to work out a solution that seeks a consensus.

 

On the camber issue in the rear, i have seen a big swing in the amount of rear camber i could get out of cars in  our group. I would be in favor of allowing the new bushings on all 4 corners.

[Johnny D]

Thanks to SMAC and CRB for their hard work and recommendations.

 

"Only a very small minority (~5%) advocated eliminating the plunge

cut allowance and returning to “stock” heads."

 

Can you disclose the other % #'s ??

 

J~

[Caveman-kwebb99]

That other number would seem to be 95% opposed to stock heads which is not at all surprising...

[Tom Hampton]

Finally, some reason.

Thanks to the petition team. Dunno how many letters would have been sent or received without it.

[Bench Racer]

A little help please. Per FasTrack below the bushing is described, inner bushing front lower control arms may be replaced with MazdaSpeed offset bushing. MazdaSpeed describes part number 0000-04-5409 as a Bushing Kit Front Inner, Upper Control arm. Hmmm, does this mean we now may install this bushing kit in the inner upper control arm and pull the upper ball joint inward to gain more negative camber?     We use Cam Bolt NAY9-28-6AZ at the lower control arms. Are the descriptions wrong or are they saying we now have a double dip (cam bolt and eccentric bushing) for the lower inner control arm. I have used eccentric bushings (Delrin) in the front and rear upper inner control arm in an F production car. A bit more of a bitch to adjust, but they do help obtain negative camber.

 

 

2. #15634 (Michael Babcock) Camber for SM

Thank you for your request. Add 9.1.7.C.3.p:p. Inner bushing(s) on the front lower control arms may be

replaced with the Mazdaspeed offset bushing (part number 0000-04-5409).

 

[ChrisA]

^^ Good question? The Miata uses two differently sized bushing in the front lower control arm.

[Jim Drago]

^^ Good question? The Miata uses two differently sized bushing in the front lower control arm.

This will be a four bushing kit for the LOWER control arm. Uses the same eccentric bolts. AFTER(if) this is approved by the BOD, Mazda will have this kit made, this will take 30-60 days. These are not on the shelf at Mazda now, a part number was put in the system in order to get it in the book for 2015. 

 

This is what was recommended to Steve Sanders and what I believe they are pursuing after BOD approval. Whiteline is making a new style, so these may/may not be the final version, Mazda may chose to have them made elsewhere.  But this is what it will look like and what was recommended. 

 

http://www.whiteline...CFRAF7AodsS4AEg

 

Jim

[Charlie Hayes]

Offset bushings are a bad idea.

[Danny Steyn]

Why do you say this Charlie?

[Johnny D]

That other number would seem to be 95% opposed to stock heads which is not at all surprising...

 

Sorry about jumping from the heads subject to bushing and back, but...

 

5% - 100% equals 95%, good job Kyle !!!

 

I guess, I was asking what % wanted 2014 rules or what % where asking for rule creep ?

 

J~

[Bench Racer]

Jim, this is a double negative dip (cam bolt/eccentric bushing) on the lower control arm. Might there be an inclusion in the rule to keep the ecentric bushing orientated??? My experience is they rotate with no anchor. On the MazdaSpeed site the number referes to the upper control arm.

 

Oh, by the way thanks, for all the right reasons.

[Steve Scheifler]

Offset bushings are a bad idea.

Because?

One concern I have is that they are one more thing to slip out of adjustment, and the loads are significant. They are also different from the stock approach in that they directly impact other aspects of suspension geometry by moving the pivot point vertically. That can be good or bad, and you need to pay attention to which way you turn them. The combination of both may be asking for something to slip, but it's worth a try for those struggling to get camber by the rules.

Is NASA on board?