CMC Rules Clarification

[Tony G]

We had a couple of items that came up in question.

I discussed the following with Jeff Trask.

 

#1)Rule 8.32.1 Differentials

 

The 9" Factory Ford Diff's will be allowed if a car is purchased (like my A/S car was),so that you are not forced to take out good parts and replace with the same good parts.Location,pick up points,and OEM geomtry must stay the same as the rules are worded.

I would NOT run out and try to put one of these in place of your 8.8,as this will potentially slow you down due to its larger size.The 8.8 has proven to work very well.

 

 

Rule #8.32.2 Differentials

 

The wording is a little conflicting on what a torque sensing diff really is.

So here is a clarification:

NO electronic traction control,or any type of electronic,sensored device will be legal.

You may run the Detroit locker,Auburn,Torsen,Power Trax,Stock traction-lok limited slip,welded rear,Eaton,Tractech,Powertrax,etc.

These are all controlled by torque(your throttle),but not electronically.Some of the above work well and some don't.

Basically..no High dollar devices here.

 

Thanks,

Tony Guaglione

CMC Chief Director

[Neil B.]

I think the rule needs to include specs on rear track width. I don't think the rule should allow a track any wider than the stock SN95 car. Adding your proposed rule change also opens up the old discussion about putting 9-inch ends on an 8.8 and getting rid of the c-clips. It also opens up the possibility of running really trick rearends like the Dan Press Gold Trac. What about the Camaros? Does this rule apply? Right now they're stuck with the Dana 44s. Making it cheaper to convert an AS car makes it more expensive for everyone else.

[Neil B.]

And how do you enforce stock geometry when both upper and lower control arm mounting points must be custom fabricated on a 9-inch?

[Richard Pryor1548534703]

Neil, et al...there's one way to keep out the goldtrac and the quaiffe and other trick differentials (which they don't make for the Camaro anyway) and that's to put a price cap on diff components to keep out the high end stuff, or else just make a list such as Tony has that is allowed. I've used most of the above and haven't found any real advantage except the Auburns really go away after a few races in the Camaros, even the race prep auburns, and so cost more. The detroit locker we use in the Dana 44 in the Firebird hasn't worn out in years of racing. Keep everything as cheap as possible.

[NickS]

For the mounting points on the rear ends, we should be able to come up with a set of measurements that locate where the stock pickup points are located on a stock 8.8 and add in some fugdge factor for production tolerances and list those in the rules section. It should be pretty straight forwared for any new car coming along with a 9" in it to be measured in inpound.

 

- N

 

[ This Message was edited by: Nick Steel on 2002-04-09 15:21 ]

[Neil B.]

Sounds like a tech nightmare to me. Tony, how did you convert from a full-floating setup to the stock 4-link witout pulling the diff, putting it in a jig, taking very precise measurements, cutting up a stock 8.8 to get the upper brackets, etc., etc., etc. I'm all for anything that increases car count, but I bet it's cheaper to put in a stock 8.8 and sell the 9-inch. And what about those modified K-members up front?

[Tony G]

WOW,you must think I have a trick car..Thanks.

But the reality is that my 9" comes stock with pick up points already attached by Currie so it is a true bolt in ,it was and still is a stock four link factory Mustang set up..and as a matter of fact it is running STOCK rear control arms top and bottom...nothing trick.The only thing I had to do was remove the torque arm,which I did.

My K member is also bone stock,as are my front control arms and it has NO K member brace.

So what this means is that I could go and buy some nice control arms like everyone else,a nice K member brace,some other cool stuff,or just forget it and leave it bone stock.Think I'll leave it the way it is,I love factory STOCK parts!..

Tony

[Neil B.]

Fair enough. I never looked under your car, so I'm speculating without knowing. My opinion on this is that allowing this diff violates the intent of the series and allows for liberal interpretation of what is legal. What's keeping someone from installing a 9-inch with an killer limited slip, improved pinion angle, better track, and the ability to change gear ratios in minutes? I'm not saying someone would, but the rules would allow it.

[Tony G]

Nick,Don,Jeff,Ben,And I are working on the limits which will be the same as the 8.8.

Including track width,no gear changing at the track,pick up points to be stock as mentioned.

Relax,we will do this right for everyone.

Nick is working on the tech side of all the rear ends that we can run right now including the Dana 44 that is also legal.

[Neil B.]

I'm very relaxed, we had the fastest Mustang at the track. And it was legal.

[WillE]

Traction control is built into the 4th gen camaro, via timing retard if slip occurs. I am to understand that the computer must not be modified, yet to remove this I'd have to modify my tune.

 

Dont want to be out of turn, but wanted to add that in.

[NickS]

Traction Control (TCS) on the 4th gen cars uses the ABS sensors in the rear to determine whether the rear wheels are slipping.

 

According to 8.35.8 - ABS has to be disabled. If you disable ABS in the 4th gen, that shoudl take out TCS as well w/o modifying the computer. And, if for some strange reason it doesn't take out TCS, I bet that cutting the leads to the wheel speed sensors for the rear wheels will disable TCS.

[WillE]

Ahh, ok - gotcha. Yes, need to figure out how to remove that.