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Adding an LSD unit to a stock, OEM differential

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1 hour ago, wvumtnbkr said:

If I hear it clicking coming off the track, I would protest.

 

The mentality of "if you can get away with, you should do it" is the mentality of a 4 year old.

 

Why not just put a VQ30 valve cover on it?

I completely agree.  But I sympathize for cars that dont come with options for diffs.  BTW, Torsens dont click.

 

I would suggest this is a similar situation to the Radiators.  Anything over what, $300(?) is more points?  Its so hard to enforce a diff, how to you clarify the rule IF you want to allow A/M diffs?  OR is it kept to must being an OEM option from the list?

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31 minutes ago, Black Magic said:

 

If you hear it clicking, they aren't doing the "bought a diff" game right....

 

Without crazy amounts of teardown, i think from a practical standpoint it is hard to enforce. 

 

It's hard to prove arson, should we stop enforcing that also? There are a lot of rules that are hard to enforce and we have to rely on our better natures to do the right thing. The 2 fallacies we constantly fall back on are "if its hard to enforce, make it free" and "my situation is unique and deserves a rules fix". As written, the rule clearly states that a diff swap from a car on the list has a fixed value of 25 points,  a reasonable person could then assume that anything else would have a value assigned by tech which may or may not be 25 points. 

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Might as well allow stroked engines in the series...  Cause hard to enforce....

 

The majority of cars have an option for an LSD in this series.  RWD can just swap out for a different RWD diff for 25 pts.  Front drive gets a little more difficult, but I would think it is not impossible with some effort.  (says the guy with an engine and trans swap).

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I think for fwd the options are hard to source for some makes, not others. Just depends. They also respond well to welded diffs, which would be my suggestion to most teams. 

 

How many arson convictions have you seen? Sure we keep it illegal to feel good, but i was just trying to be practical, not emotional. Stroked motors are not where i would cheat, if i wanted a real benefit. Cams are a better conversation point, and since i haven't seen anyone measure a lobe i think there are bigger fish to fry than engine stroke, compression ratio or even diffs. Hell we had a guy put the wrong motor spec in.....

 

I would suggest a fixed price for non oe differential, non adjustable. Sure you can shim a torsen, but if we see guys pulling cases apart mid test day we can address it. 

 

Or go with the current enforcement, which from a practical standpoint is open diff rule that fits in a stock housing.

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24 minutes ago, Eman911 said:

It's hard to prove arson, should we stop enforcing that also? There are a lot of rules that are hard to enforce and we have to rely on our better natures to do the right thing. The 2 fallacies we constantly fall back on are "if its hard to enforce, make it free" and "my situation is unique and deserves a rules fix". As written, the rule clearly states that a diff swap from a car on the list has a fixed value of 25 points,  a reasonable person could then assume that anything else would have a value assigned by tech which may or may not be 25 points. 

^^^This^^^

Original question: If I put an aftermarket diff in a stock housing is that 25 pts?

 

Answer: It probably is at least 25 pts, but you might want to talk to someone other than the peanut gallery to get the straight poop (which is presumably the most correct poop).

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18 minutes ago, wvumtnbkr said:

Might as well allow stroked engines in the series...  Cause hard to enforce....

I'll keep my mouth shut on that topic.

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3 hours ago, Eman911 said:

 

...a reasonable person could then assume that anything else would have a value assigned by tech which may or may not be 25 points. 

 

No assumption is required here.  4.4.1 and 4.4.2 clearly says that points will be assigned (to claimed changes, so this does rely on people passing 4th grade).

 

4.4.1. ALL non-stock components, parts, assemblies, or systems MUST be declared to Tech Inspection, noted in the vehicle Log Book, and declared and accounted for in the total points of the vehicle.

4.4.2. There is NO SUCH THING as a free part, every part of a vehicle has a value. Parts not covered elsewhere in the rules will be assigned a point value by ChampCar Tech.

 

 

In this case (regardless of what anyone wants to define 'diff' as), a PART (with significant performance gain) within the stock rear-end housing has changed and needs to be declared and points assigned.

 

Basically, while actual points are unknown without input from Tech, the fact that putting in an aftermarket LSD unit into a stock housing/gear-set will have points assigned is should be clear. 

 

 

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18 hours ago, NigelStu said:

Basically, while actual points are unknown without input from Tech, the fact that putting in an aftermarket LSD unit into a stock housing/gear-set will have points assigned is should be clear. 

 

 

Yes, that part SHOULD BE clear.

The part that is unclear is: How many points is it to install a LSD unit, then?

Just like so many other rules that get debated to no end on the Forum - no clarity.

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18 minutes ago, mcoppola said:

Yes, that part SHOULD BE clear.

The part that is unclear is: How many points is it to install a LSD unit, then?

Just like so many other rules that get debated to no end on the Forum - no clarity.

 

I think it kind of depends on how much you spend.  For example a Hurst short throw for the T5 is $120... or I just googled this snazzy unit for $2,400: https://www.bremershifters.com/product-page/bremer-sequential-shifter

 

For JUST a freaking shifter that supposedly converts your regular trans from H pattern to sequential.  Note: no idea if it works as they pre-sale.

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27 minutes ago, Ron_e said:

Note: no idea if it works as they pre-sale.

Buy one and let us know.

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IMO, the only situation where this discussion is really relevant is if the diff/transaxle in question was never offered with an LSD from the factory.  If that's the case, then I feel adding one should be covered by 25pts, even aftermarket.  Why start another area where one team gets charged 30pts, while another with a similar situation in a different region gets dinged 50pts.  I don't care about clarity as much as I care about consistency.  As of the OEvsAM, in many cases buying an aftermarket LSD can be significantly cheaper than sourcing a used OE unit.

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52 minutes ago, zack_280 said:

Buy one and let us know.

 

Not likely, no, never.

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Put a heavier spring in the diff, effectively locking it. Free.

 

Detroit Locker? Dunno how many points. 25? Didn't an early Stang come with one?

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Lift the drive wheels and spin them by hand works pretty good for identify open vs LSD.

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9 minutes ago, Mashley Adison said:

The short track test is to jack up one wheel and start it up, place the crew chief in front of car , let out clutch.

Nice!

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I love the public spectacle aspect of both of those suggestions.

 

Unfortunately from a technical standpoint, the limited slip differentials worth racing would pass both of those tests...

 

 

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