reza

Hello,

I could not find any mention of diff braces or diff mounts in the rules here.
Is there any rules against this type Diff Braces and Upgraded PPF for FD in ASP SCCA Solo2?

RX-7 Store Diff Brace
Photo

Dragon Brace
Photo

SCCA Rules for Street Prepared.
http://www.moutons.org/sccasolo/Rules/sp.html

What is wrong with putting images in this forum? broken again huh?

DamonB

Engine torque braces are allowed under statement 14.10 I:


I. bolt-on torque suppression device may be used. A torque suppression device attaches from the engine to the body, frame, or subframe in one location, and controls engine movement at that location along a single axis only. It may serve no other purpose.
Examples of permitted devices:
1) a chain
2) a rod with spherical bearings at each end.
Examples of devices not permitted:
1) one or more solid motor mounts
2) any link which confines movement along more than one axis
3) an engine mounting plate, or one or more plates rigidly bolted between the engine and the frame.
Holes may be drilled to mount a torque suppression device. The installation may not include the welding of any plate(s) to the motor mount(s) or bodywork (7/2002), nor may it include multiple non-parallel links.



Section 14.8 C makes allowance for any suspension bushing material other than metal. It specifically does NOT permit non-stock diff bushings. Quoted:

"Differential mount bushings are not suspension bushings and thus may not be substituted under this allowance, though Section 14.1.C allows certain update/backdate allowances (8/2002)."

Since non-stock diff bushings not allowed then diff braces would also be not allowed. The purpose of the diff bushing is to fix the diff case into place. If they are not going to allow you to anything non-stock to the diff bushings, you can be certain they will not allow a diff brace since its purpose it to do what the diff bushings do.

Once again if the rules don't say you can, then you can't. No mention of diff braces and the fact that non-stock diff bushings are specifically not allowed makes me 100% confident that the diff brace is illegal in SP.

redrotorR1

I've actually had this conversation with a local SEB member. The PPF is not directly supporting the chassis frame, and is not considered a cross-brace or subframe strengthener. Per my discussion with said member, it is legal to substitute any diff brace provided that it bolts to the original attachment points and does not add any lateral reinforcement. However, keep in mind that this is just from one SEB member, and can be overruled by the committee.

From my perspective, it should be a no-brainer. You can change to any aftermarket differential in SP, so an aftermarket brace or mount shouldn't be an issue as long as it does not significantly alter the suspension geometry (thereby giving a possible unfair advantage). I don't see anyone crying foul about a diff brace .... not to mention that the U-haul tow hitch effectively acts like one as well.

DamonB

I still say without a doubt no added differential braces. Read 14.10 N:

Limited slip differentials are permitted. This permits locked differentials, either by design, welding, or mechanical means. Differential cases, internal differential parts, and axle stubs may be machined as required for clearance and installation to the extent that material may only be removed, not added, and the exterior of the case may not be altered in any way. This machining may serve no other purpose

You can do anything you want to the diff itself inside the case, but you can't add anything to the case itself. The PPF may be a loophole, but the aftermarket FD diff braces that tie to the chassis underside and the diff as pictured below are definitely illegal.

redrotorR1

Yes, these mentioned braces are illegal for SP. But, that does not mean NO aftermarket diff braces can be used. Understandably, for the FD, this effectively means that there are no options (at least none to my knowledge). However, my point is that you can replace the diff brace ... as long as you satisfy certain criteria.

It's a dead issue at any rate, Damon. The RX-7 is handcuffed in ASP anyhow ... so I doubt anyone is going to be breaking down the protest shed because of a illegal diff brace on an ASP FD.

DamonB

I still think it odd to make SP cars use stock ecu with no non-stock boost control. I feel electronics are essentially bolt on mods and are in the spirit of the SP rules. Oh well. You know what they say: wish in one hand and crap in the other...

redrotorR1

Therein lies the rub .... the electronics policing is so poor that I question every turbo car that IS competitive in SP classes. How do you really know who's cheating and who's not? And truly ... turbo cars are at a severe disadvantage per SP regulations. I say, screw this "try-to-keep-the-costs-down" train of thought and just let engines be unrestricted in SP. That way, NA guys can also stop paying out the nose for high dollar balanced-and-blueprinted engines that are worth more than the damn car .... and turbo guys can crank up the boost (like they've been dying to do since day 1). But what do I know?

reza

Well with RX-7, as soon as you do Intake, DP, and HF Cat, your boost gonna go up anyway. The problem is controlling it right?

What class do you guys run anyway? ASP? SM2? SS?

I am running ASP in SF region.
I have been trying to get rid of that jerkiness when letting off gas below 5000rpm. I hate that jerk, because it unsettle the car too much specially if you do transition from left to right and slowdown at the same time.

DamonB

Exactly. The boost will increase due to the legal mods but you are not allowed to do anything to the wastegate and its stock controls. In ASP you can legally do intake, downpipe, intercooler and high flow cat but you must run it off the stock ecu (since the stck boost control is performed by the ecu) and can't even change the pills in the wastegate lines! The car could be bone stock but if it has a boost controller it bumps straight into SM.

"Alternate computer control modules may be used whenever an equivalent change to the conventional system is allowed. For example, alternate computer module control of ignition settings or fuel injection is allowed. Direct turbocharger boost control by alternate computer control is not, since there is no equivalent mechanical allowance. "



redrotor runs (Ran? Sell it or kept it?) his FD in SM2 and I run SS.

reza

Hmm....hahaha...i've been illegal in ASP then, I got the home depot boost controller to keep it at 10psi.

Might not hurt to put in the diff braces.

There are two of us with FD in the SFR region in ASP. We kept getting spank by Z06 and Porsche GT2 stock with 335 width tires and 456hp, recently they upgrade exhaust and intake, its probably more than 500hp.

FD in SS is not as bad as in ASP. Depending on course layout, stock FD can still beat Z06 in our region. They usually has GAB shock, upgraded wheel and Hossiers/Kumho.

streldoc

iTrader: (1)

This is essentially a torque arm, and in the SP rules a torque arm may be added or removed.

I'll be mounting mine up this week.

DamonB

Thanks, Eric. Now I see 14.8E:

"Addition or replacement of suspension stabilizers (linkage connecting axle housing or De Dion to the chassis, which controls lateral suspension location) is permitted. Traction bars or torque arms may be added or replaced. "

I hadn't thought of the brace as a torque arm but thats true.

redrotorR1

Ran ... I had a PowerFC, so SM2 was the only choice. But, no mas. Coolant seals gave up on me and it's slowly spewing coolant out the overflow tank. Dumped it for cheap on ebay. Very close to becoming an SS competitor again.

DamonB

SO how is paying for a Z06 going to be cheaper than the money you were putting into the FD? You get a raise or have a rich family member die?

redrotorR1

Haha ... very funny. Actually, ***knock on wood*** [whisper] the stock market is doing pretty good. [/whisper]

Seriously, with the amount of money I spent in repairs, upgrades, and financing .... I was paying more than what financing a used Z06 runs for. AND I wasn't even near done with the car yet!!! If you can't beat 'em .... well, y'know.

reza

A hahaha...we got a Z06 driver here now. How is that car? Are you running in SS? Is it really easy to drive compare to FD?

Alright, so the brace is legal. So which one is better the dragon brace or the kgparts? I have old style racing beat exhaust or N1 Dual.

streldoc

iTrader: (1)

I am not sure the Dragon brace qualifies as a torque arm, so I would stick with the KGparts brace.

The Z06 is easy to drive, but the RX7 is more fun. The Z06 requires more throttle modulations, becuase of instant torque, but the RX7 is as difficult when the 2nd turbo kicks the HP from 250 to 400. The slaloming ability of the RX7 is 2nd only to a miata, but the Z06 is very good despite its large size.

Houdini

iTrader: (3)

Well, you can run a piggy back fuel management system and still allow the stock ECU to do boost management. The only problem is, if you're too open, you'll hit boost cut which would be a pain in autoX. At that point, you either have to restrict flow or fuel to avoid hitting that cut to keep the car driveable. That's if you want to be legal. But like someone said, ASP is not a competitive class for the FD. For now, SM2 is a better bet until someone starts dumping money into some serious project cars. You can do a lot of stuff in SM including any motor swap provided it's by the same manufacturer and you can't modify the firewall(which can a problem for the 3 rotor installs). Oh well...

RX7M5GUY

iTrader: (2)

[Quote By Streldoc]
The Z06 is easy to drive, but the RX7 is more fun. The Z06 requires more throttle modulations, becuase of instant torque, but the RX7 is as difficult when the 2nd turbo kicks the HP from 250 to 400. The slaloming ability of the RX7 is 2nd only to a miata, but the Z06 is very good despite its large size. [/B][/QUOTE]

This is OT but I am always interested in Streldoc's comments comparing SS class competitors, especially since I have a '93 RX7 set up for the SS class and I have just acquired an '04 Z06 which I am considering setting up also. I only run local club events.

So Dr. Strelnieks, any advice whether I should spend the $3K to get started on the Z06 or should I spend it on the RX7, moving up to a faster class.
(The Z06 is my daily driver; the 7 only comes out for autocrosses)

If I an correctly informed, I understand that you have your previous SS class 7 set up for SM2. I would love to hear the details of it and its construction and competitiveness vs the SM2 vettes. Can you share that? (Maybe I missed an earlier post on it)

Regards, Philip

streldoc

iTrader: (1)

Just was looking at the 2004 SCCA rule book, and there is now an added section saying torque arms are only allowed on live axle suspensions. Therefore, this arm is now not legal in SP or SM2. :-(

redrotorR1

If it can fall under the catch-all allowance for subframe connectors, I think it could be SM2 legal.

Subframe connectors are allowed, but each connector must be attached individually without any lateral components attaching the two longitudinal frame rails. Subframe connectors may be bolted or welded.


OT, I noticed Andy McKee is now running the formerly Tri-Point ASP RX-7 in SM2. He took down Scotty White at the San Bernadino Pro. Maybe I shouldn't have sold the RX-7 ......... nah.

-Don

DamonB

Subframe connectors do not attach to drivetrain parts...

bond007

From what I remember reading in the Solo GCR, you could eliminate fuel cut from the stock ECU (since you can chip the car in SP) and have the boost go high to wherever it goes. You then have the piggyback handle the fuel/timing for the higher boost level. There is a solution, it is just not conventional or perfect, which is why everyone seems to complain that the car is "handcuffed" in ASP.

Besides, folks should spend more time behind the seat and complain less about rules because someone with more seat time in a stock Miata can beat someone with less seat time in a stock FD. I was the stockish FD and I have been the experienced C-stock Miata driver.



Eh. What do I know. After realizing that to be competitive nationally in autocross (from watching what some of the nationally competitive locals do) you have to basically buy the car du-jour or rebuild your car from the ground up, I decided if I was going to autocross, it would be for fun, because racing at ANY level begs the question:
"How fast do you want to go and how badly do you want to win that trophy?"

Answer:
"How much do you and can you spend..."

Regards,
--Ashraf (jaded autocrosser, much happier "run-what-you brung and learn" track day enthusiast)

AMRX7

No, you can't. The stock boost cut system must remain active. The rules are quite clear.

You can legally achieve 11.5-12psi of boost through creep, but that is it. Even if you explicity control the boost to that level through an alternate computer, it is still illegal.

Many people run regionally in ASP and are illegal, though typically at that level it's not a big deal.

-Andy

bond007

My mistake, Andy. I didn't have a GCR in front of me and I haven't read through the particuilars in a while.

It is explicitly prohibited to remove the device that instigates fuel cut per section 15.10 part C.

All things being equal is the idea behind classing. If you can't win because of one restriction, find another one you aren't hampered by and exploit it...

And even if you want to be uber-competitive in Super Stock, you would need to rebuild the entire suspension from head to tail -- not a cheap proposition considering you would want to put in the best shocks you could find and get them fitted custom...as I alluded to earlier, if you want to win at autocross, sometimes you have to pick the better car.

Regards,
--Ashraf