cost has been cited a lot in terms of against - does cost tend to be the reason that the SEB denies certain rule changes? installing an LSD is about as expensive as a new set of tires, if that, depending on the route you choose. I don't necessarily see STU as the low cost class (i've seen some of the suspension setups people run ) but more like the 'focus on handling' class.

the SOLO rules say the category is meant for affordable sports cars with common engine and suspension modifications - but they can't exactly cite that as a rule not to let AWD cars upgrade one of their LSDs, since they allow 2WD cars to

 

It breaks down something like this...

Reasons this is potentially bad:
-It will be a must have mod and probably expensive (think OSG $$, I'm sure a lot of folks would go that route). Especially when you factor in that the diff is not just a "bolt on and go faster" thing at the pointy end, and might require tweaking
-It might screw up STX
-It makes it even harder for the E36s in STU

Reasons this is potentially not that bad:
-Not all aftermarket rear diffs are expensive
-STR has this allowance and that class is massively popular

Reasons this is potentially good:
-Non-cars-to-have, like 07+ STis and 09+ WRXs, can narrow the gap substantially
-Cars who are breaking rear diffs can fix them more "once and for all"
-Cars should be a little more fun

From a practical standpoint, I think you would have a hard time convincing the 2WD folks in STX that this won't be a nightmare, because well, turbo AWD cars kick puppies and club baby seals and can run 50 psi on the stock turbo and and and Realistically I think it puts the WRX back in the mix a bit but not overly so, given how WRXs haven't even been winning at *Pros* let alone tour events / Nationals. But STX is really healthy so there is always going to be resistance to change, witness the uproar about the twins in STX.

For STU there would be some support for it, especially from the above mentioned cars, but the NASIOC folks seemed to come down on the side of "too expensive" which is a perfectly reasonable position.

Shrug. Whichever, IMHO.

 

like i stated above though, i really don't get the too expensive thing.. it's not that much, and it would be the same cost as what other ST 2WD cars spend in LSDs..

I also don't *necessarily* think it's a must have mod, but pretty close if there ever was one. the car would probably be faster holding all other things constant, but it's more about changing the behavior of the car to me. here's a good article: http://grassrootsmotorsports.com/art...hats-the-diff/ - check out the mean times between the stock and the Kaaz (though the driver had a bad lap in the Kaaz). I would imagine the Kaaz is more or less equivalent to TRE's rear diff service.

I think adding rear diffs for WRXs in STX would help close the gap, but definitely not suddenly turn them into a dominant force in that class. If anything, things would just be more competitive. Same goes for STU, except in terms of the diversity of cars that are "competitive."

 

There is no way to see the proposal unless you are the one that wrote the letter. The reasoning behind this is that many letters need to stay confidential.

 

thanks for everyone's input. i did go ahead and submit a letter, though, as people have said, the fear of turbo + awd make things there a touchy subject. just as a refresher, this is a rule for a single differential modification allowance, and the idea switched to either front or rear, rather than front, center, or rear. i learned a lot through the process though, which I'm glad about.

i thought the pushback from the subie community was odd, especially given WRXs setup and how they do in STX. 02-07s have viscous rears, which pretty much lose all effectiveness over time and actually do need to be rebuilt anyway, and 08+'s have open diffs in the rear to begin with. this mod doesnt suddenly thrust WRXs into being the dominant car of that class either - but I do see it as being able to allow them to at least break back into the top 15, which they've not done since 2009 (5th, 6th, 7th). I see it as putting them back into that level.

overall, from what i've seen, cost was cited as the biggest reason against the mod, followed by a disruption in class balance. i think cost can be thrown out from a ruling standpoint, since RWD cars have the same allowance. in terms of cost for drivers, it's about the same cost as a good set of tires, and will probably actually improve front tire wear significantly lol. for STX, i think this is actually good for the balance of the class, for reasons cited above.
for STU, i think it just brings a few other AWD cars back into play. i doubt the "balance" of this class would be upset. for rwd cars, i think last year's nationals result does bring an interesting thought to light - perhaps intelligent course design can be used shift the balance of rwd and awd cars more effectively rather than penalizing ALL awd cars just because of the evo/sti's success.

anyway all this talk is really moot since there are strong doubts this will make it anywhere in the committee. i didnt mean to rustle as many feathers, i just thought there were some legitimate reasons for this to be considered.

good luck to everyone running this year

 

Good luck but I really don't see this going through. As Geoff has suggested, I would support AWD cars in STX and STU being able to add a diff to one end that is open. It may help equalize some of the cars in a class. Front diff for 03-04 EVO 8s in STU and 02-05 WRXs and STX. But I wouldn't support swapping diffs for AWD cars that already have 3 working diffs.

Primarily, you have to think about how this is going to shake up the "apple cart" for cars in all ST* classes. Eg: In STS diffs (except viscous) are specifically disallowed because it could give the 1.8L Miatas an upper hand on the 1.6L Miatas essentially making them obsolete and thus hurting participation. The SCCA tends not to rock the cart for classes that usually have a high participation level.

 

who knows, maybe some parts of it will be passed. I limited the discussion to STX and STU for the letter - I think the implications for STX are very good - WRXs have not been up there nationally for some time, and 08+ have open diffs in front and rear. could be just what they need to get a little more into the top ten mix.

For STU, like you mentioned that really depends on the car, but then that would complicate the ruling a bit. I like the simplicity of 'one aftermarket diff for cars in stu', whether that is front or rear.. ie Lancer Ralliarts competing against Evo X's with AYC, that's not exactly fair - though the Ralliart has '3 working diffs'.

Anyway yeah, kind of just beating a dead horse now. Up to SEB, and like everyone has already said, it probably will not go through.

 

Kinda curious, have you heard anything?

 

i'm aware that the STAC has reviewed it, made their personal recommendation, but it's yet to be reviewed by the SEB.

I'm not sure what's going to happen, but I had an interesting discussion with someone on nasioc about rwd w/ rear diff vs awd car with open diffs. he was arguing that awd, open diffs or not, almost always have the advantage in a corner because it can get power to an axle that the rwd car cannot (obviously). he brought up a scenario where both cars lift their rear wheels under braking - in this case, an open diff car would not get any power down to the ground, but an awd car would still have power going to two wheels (he mistakenly said one in front and one in back, but its both front wheels).

however, when you consider the scenario with the rwd car has diffs, which is the current state, the rwd car will get power down via it's diff, and can then proceed to power out of the corner. for an awd car with open diffs, the car essentially becomes fwd, with all the rear power going to the lifted rear wheel, center diff shuffling (some) power to the front wheels, which has an open diff anyway - i think the advantage here is for rwd. obviously all powertrains have pros and cons, just something that is food for thought.

i have no idea what kind of recommendation, for or against, the STAC made, nor will I ever know, and i'm not sure what the SEB will say. from what everyone's told me, chances are slim to none. sucks, if mitsu just gave US evos AYC we wouldn't have to think about this problem

 

Hope no one was holding their breath:

#10334 Differential Allowance Proposal

The STAC believes the current restrictions on limited slip differentials for AWD vehicles are appropriate.

Interestingly enough, I found this near the end of the article as well:

#10297 AWD Differential Comments
Thank you for your input.

Someone else in favor of the diffs? Or perhaps one of the Subie folk crying no?

 

However::::

I noticed something interesting - in the new "Street" proposed class -

This section was specifically crossed out - thoughts??