Ok so I read the "Differentials or differential covers may have a drain plug added" Does this mean I have to add the drain plug to the oem cover?
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Ok so I read the "Differentials or differential covers may have a drain plug added" Does this mean I have to add the drain plug to the oem cover?
Yeah but with our rear ends I would skip that and pill the cover periodically to inspect the gears and diff.
Clean up the rtv and make sure the cover is straight (new ones are cheap), and get some fiber gaskets. I'm able to pull mine and have zero gasket residue to clean up each time, no leaks.
Good point. I will have to look at fiber gaskets. Thanks.
I got a fresh new diff cover and a stack of gaskets off rockauto for cheap.
I think a new smooth differ cover and a good wire wheel cleaning of the housing will be the trick to get a clean release of the gasket each time, plus about every few race if you pull it to check it shouldn't "set" and harden to where it makes a mess to clean up. I'm liking this a lot better than rtv.
For clarity, you don’t have to add a drain plug to the cover, you can add it to the housing. The GMs have a nice cavity right at the bottom that is perfect for this.
Agreed it's GM biased towards the rearend....of the field.
Had to make a change after the 2016 results in Texas with Fords winning 83% of the podiums, every Toyo race, and every fast lap of the weekend.
2017 got it back in line with 2015's 72% Ford podiums. For 2017 Ford had 75.36% of podiums, every fast lap of weekend, but GM did get a single Toyo win.
2018 so far is right in line (but revisions may need to be reconsidered). Fords have won 73.33% of the podiums, but only 7 out of 8 Toyo races, and they have 3 out of four fast lap of the weekend.
But to keep this on topic are we allowed to run an aftermarket aluminum cover? What if said cover has some bolts to help the carrier bearing in the ultrastrong GM diff? What if the bolts are backed out so they don't provide any support? At least we are allowed to upgraded to the superior Ford 8.8 or Ford 9" with better posi and gearing options. Guess I need to do that swap instead of adding a diff cover with a drain.
That's a negative on the aftermarket cover, this has come up before and gets shot down every time. There's an RCR thread on the national forum about this very topic from a few years back.
lol Brian
Got it! $150 Aftermarket diff cover is illegal but a $4,000 Ford 9" with aluminum center section is legal.....makes perfect sense.
Well scratch part of that. Rules won't allow a GM car to swap to the optimal rearend which is the Ford 8.8 (even though bolt ins are available and cheaper). Guess instead of helping my diff stay cool or possibly allowing us to strengthen a known weak rear end with a $150 cover we should just throw $4k down on a 9". I know the rules are there to try and help us save a little money but guess they also allow you to spend a lot of money.
I remember some about diff cover debate but think that was so long ago that many who argued for or against are gone but really the fact that we have allowed so many other things to happen that an upgraded diff cover doesn't seem like a big deal.
Glad this came up before Nats so I don't get DQ'd for a diff cover. Guess I'm ordering a Ford 9" for my birthday.
To be fair, allowing the Ford 9" was a cost saving measure mostly aimed at allowing A Sedan cars a way into CMC without having to spend big money converting their cars back. It had no realistic effect on those building a CMC car because no one would be dumb enough to add the expense, drag, and weight of a 9" when the stock rear ends were bullet proof on cars with 230 HP, 16" rock hard tires, and 12" brakes...
Richard P.
What is the failure mode for gm rear ends in CMC?
My first one went simply because the ring gear boots were loose, and even then it was fine except for the broken teeth from loose bolts flying around.
I chipped a ring tooth on the second one but I had issues with that build with a loose pinion nut, and later running it all setup wrong and super tight when we took my rear end apart for no reason at all at the track.
I think just a properly setup rear end with a crush sleeve eliminator and heavy oil is all that's needed. I run 85w-140.
That fancy diff cover just adds support to the main caps. I don't believe we're drag racer blowing apart rear end housing are we?
I've had good luck with RCR's if you think it's dumb (plain rotors,broken crankshafts) put in a solid RCR and things may happen. I thought a 8.8 was legal in CMC?
Read extreme ownership by Jocko Willink, I take this approach with my team, before passing blame did you do everything you could to "win" (I'm in sales).
I figure a lot of the GM Ford stuff is just for fun, but if it's a real issue, you have the power to do something about it.
I agree, a 4k ford 9" legal but a cover isn't is BS, but that hasn't been an issue for me so I didn't try to change it.
Mine came with the fancy solid shims and crush sleeve eliminator and hasn't blown up yet. The diff on the other hand seems to unload on right handers.
I'm looking at 4th gens in Texas in general, and I'm seeing all kinds of issues that prevent each particular driver/car combo from running up front. Be it breaking things unexpectedly, reliability, or the driver just not doing enough testing/setup time to win.
I'm not trying to put my fellow 4th gen drivers down, but spend an afternoon observing what the Fox guys are doing vs the 4th gen guys in regards to what they're focused on (or even present) on Fridays before the race, and you may see my point. I feel like the combination of new/fresh talent on the Mustang side, the departure of Proctor/Landrum, and the timing of the rule changes all happening at the same time seems to perpetuate the impression that there is an apparent rule bias against 4th gens.
The RMR guys are saying mustangs are getting their butts kicked by Camaros up there.
Yeah the Mustangs have a weight advantage, but they have shit aero and suspension.
Francis has been able to put his car far up there from time to time when it has run right and it (no offense) has the least fanciest gear of the others. Tyler hopped in Sean's car (3rd gen, but still) and was able to put it up there at COTA after working on setup.
My car's been running like a swiss watch and has all of the right parts/numbers to win, but I haven't been put it together as a driver to get it done myself.
At this point performance wise I'm (by choice) weighing 50lbs over post race (I have more than enough extra gas and coolsuit capacity to take it down to zero if needed), and getting closer and closer to 260/310 with the new motor after making tweaks. All that's needed is setup time and a good driver.
We should put Tyler in my car and see how far up he can place vs the big evil Fox mafia.
Also quick show of hands, who is going to DEs, test days, and other racing events outside of the NASA calendar? How many of you guys are changing alignment settings and spring rates between races?
Is your car showing up to the track Friday completely ready to go?
If you're answering no to some of these, go see if the guys in front of you answered less "NOs" than you, maybe fix that too?
Well that did not work.
There it is, what I have been missing. LOL. Now it feels like every other motorsport I have been involved with. Sorry Brian I get the frustration and I don't even have a gm. Not sure why they would shoot down a simple mod like that. Tyler is right file it again. OK carry on.
Pranav-did someone hack your account? You sound exactly like all the GM guys did 8 years ago when the Fords were complaining but none of them did any testing and they all ran the same spring setup. What's cool is now the Fords did what the GM guys did a long time ago. Now you have say 3 Fords at a given event running the fastest lap times which are basically the same lap times but what's so interesting is that those three normally have all totally different suspension setups, spring rates, etc.
Remember just because it's a coilover doesn't mean it's 10 times better than a traditional shock and spring. Same goes for the torque arm which is so weak and flexes. Sure you have aftermarket setups for Fords that put in a torque arm and aftermarket setups on F body's that add a 4 link type of setup.
I'm not complaining or submitting RCR's. I just enjoy sharing the same data that was used way back when to give the Fords an advantage only now the data is totally reversed.
I also enjoy showing how ridiculous some things are like not being able to run an aluminum diff cover for $150 that gives more strength, fluid capacity, and cooling but I can swap in a Ford 9", GM 12 bolt, or Dana...yet I can't swap in the Mustang 8.8.
Pranav-to answer your questions everyone knows between you and Dan the 4th Gen gets more time time testing away from NASA events and on Friday's. I probably do more than the Summer Shootout Winner but not sure why any of that matters.
I know this is all in good fun but you really need to get your facts in line. 8 years ago Jeremiah and I both had cars prepped to the Max of the rules and were testing our brains out trying to get the leg up on the other. What you are thinking of is 12 years ago when we were all brand new to this and virtually none of the Mustangs did true testing and analysis. The rules changes took place after the 2012 season to change the weights of the platforms and get the track widths closer to being equal.
My car has been setup well for a long time now so my lack of Friday practice is a non-issue.
Also, think about getting the most out of your car when you are racing and have 60% of your focus on hitting all your marks, 20% of focus on your car and any potential issues, and 20% focus on everyone else on track. Car prep and mental prep is vital to getting the most out of your performance.
Now flip that focus to 90% hitting your marks, 5% on your car, and 5% on other drivers on track and tell me who you think is going to be faster.
No offense to Marshall but it is the reason he was running slower in his car at the end of his racing career vs 5 years prior. He was spending so much mental energy focusing on a car that had constant problems, that the driving performance suffered.
I think 5 years of staying at the Mustang Ranch at Hallett is rubbing off me.
All I'm saying is I'm just not seeing the "Max Effort" push by the 4th gen drivers that I see the Mustang drivers doing right now, or guys are putting in the Max effort but have incidents/failures that hold them back. I'm guilty just as anyone else in the 4th gen camp.
As far as different setups, it is reversed; most of the 4th gens now are running similar rates while the mustangs are all over the place. Go look under Josh's car and see if you can even see any springs up front.
One of these days we'll keep threads clean.
Isn't it about time for a nation-wide CMC convention to re-think what CMC needs to be going forward? It's completely against the ideals of the old 230hp rules to allow $$$$$ brakes, but not $ diff cover.
I put myself into this camp - my 9.9 effort is equivalent to a 9.0 effort by a trophy queen. I just don't have any processing room left at this point. Some is probably set-up, some is very likely lack of seat time. I think the rules are close though personally I still vacillate between close and not close enough.
You can say that about me and it doesn't bother me. I struggle whether I should make the investment in the time/cost balance to move up the field a couple of places. OR... keep having a great time with some great folks with a little racing thrown in for good measure.Quote:
Originally Posted by Pranav
Extremely good points in the second paragraph. But I really like this quote from the 39 that sums it up pretty good for me. "You can say that about me and it doesn't bother me. I struggle whether I should make the investment in the time/cost balance to move up the field a couple of places. OR... keep having a great time with some great folks with a little racing thrown in for good measure."
Mosty-I wasn't around 12 years ago as I was still in high school. But yes I'm having fun sharing the same type of data that was used in the past. Sounds like it was 6-8 years ago with what we are talking about when the threads were all about parity. After 2012 the directors took away track width from the 4th gens I think and they specifically threw a bone to the Fords reducing weight by 50 lbs. Of course they used data from you and Procter from one race as well. What has changed on your car since 2012? More power?, Stoptechs?, AST's? etc? Want to test drive my car for a day at Cresson before Nats?
Honestly I think Bryan Curtis showed all of us at Hallett that a well set up 4th gen is as fast as the foxes. He was absolutely favored to win going into the championship race. As I came out early due to old ass foxbody issues I don't know how the race ended like it did...but his car appeared well sorted and fast all weekend...
Bryan choked on the last lap, he had it locked down otherwise.
6.29 Rear axles
6.29.1 Any OEM stock differential housing that was originally offered in an eligible model car is allowed. Updating/Backdating of OEM stock differential housings is allowed.
6.29.2 Both GM and Ford cars may also use a Ford 9”, GM 12 bolt, or Dana 44 rear axle housing, but the housing must maintain both the exact OEM suspension pickup points and OEM rear end geometry as the originally equipped axle assembly.
6.29.3 Any gear ratio equal to or numerically lower than 4.11 that fits the stock/alternate differential case without modification may be used. Differentials may be fully locked (welded) or use any commercially available mechanical limited slip.
6.29.4 Any commercially available replacement type steel or alloy steel axles may be used. Full floater axles are prohibited. Heavy-duty non-”C" Clip style axle ends are allowed and recommended. Competitors should carefully select axle ends. Many of the "C" clip eliminator axle ends are designed for street or drag strip use only and cannot withstand the side loads associated with road racing.
6.29.5 Differentials or differential covers may have a drain plug added.
Can some one explain to my why a aluminum diff. cover in against the rules??
Standard answer. It's not needed. If was made legal, lots of people would think they needed one and lots of money would be wasted. The coolest thing about an aluminum cover is the availability of a drain. As a compromise, they allowed a drain be added to the stock cover.
Richard P.
(The coolest thing about an aluminum cover is the availability of a drain.) not to mention increasing the capacity of the oil, cooling the oil, supporting the bearing caps.
Big brakes were not needed, 260 hp was not needed! But people wanted them so.....the rules are telling us where not to waste our money?
Again, all that crap is overkill and a waste of money (on a 230 hp car with shit tires). At the current state of things, does this need to be revisited? Probably.
NASA, not the CMC management, mandated the S197 Mustang and the LS Camaro. Neither one of them could realistically get to the 230 hp number. Once you've gone there, along with wider and stickier rubber, big brakes actually save money over the old crap that had to be replaced often if you do enough events. Do I like where the whole thing has gotten to? No, and I don't believe many people do. If crap tires were mandated way back when, we wouldn't have needed big brakes and we wouldn't be hurting transmissions, rear ends, etc. at the rate that we are. We are literally tearing the tubs apart on these ancient cars. And we are spending a lot of money doing it. The whole thing doesn't make much sense...
Richard P.
I completely understand this sentiment. It's one of the biggest things mentally I've had to get over transitioning to this series. In my endurance days it was all about finishing the stint to hand the car back off to the next guy to stay in the race... No risks, no dumb decisions, no risky moves.
One of the best things I've done to my car is not put another $4k machine shop built engine back in it. Mentally it's been great knowing that if I pop the explorer engine I'm out way less money. So I'll hit the limiter occasionally trying to make a pass, etc. Never did that on the old one and it blew up fantastically for my trouble... currently considering picking another one up from the junkyard and having it ready to go in the trailer....
In 2015 my car dynoed 70hp low. Turns out I'd lost a rod bearing the last race of the year prior. I forgot how weird the car had felt the last lap or 2 and how I'd just cruised there because we were really spread out by that point. I grabbed a crank off of CL and had it polished, pistons and rods used off of Fleabay, new bearings and gaskets, honed in my garage, all in for about $800. That motor is still in and healthy, has been good and made good numbers. It's getting replaced by an LS. While the rest of the crap is an asspain to hunt down cheap, the motor itself was $220 from the pull and pay for an aluminum LM4. Gotta find another for a spare. 170k and I'm not doing anything to the bottom end. Got a late LS1 cam for free fiddy to pop in there and that's it. I don't believe in machine shop engines for these cars when stock seems to last just fine.
Leave the ls1 cam alone.
An lm4/lm7 as is with some work on intake exhaust restriction is all you need.
If you throw the ls cam in there you may have trouble getting the torque you need after choking the power down to get under the HP limit.