My understading is that the Automatic models had open rears.
The 6 speed models had LSDs.
Greg agrees with that so I went from 42 to 39 points
which means that I am in TTD and not TTC!!

 

Gearing inside the rear diff is free. Changing the diff itself is points though...

And since the auto is on a different spec line we get to run the stock MT one for free. If the spec lines weren't separated between manual and auto it would depend on which transmission is the optional extra.

Where are you guys getting your 4.77s and 5.12s from, and what should one expect to pay for them?

 

you can get either through Mazda Motorsports

 

As far as the 4:77 ratio it's a lot cheaper if you get the series II diff and bolt it right up.
I picked up mine for $750 shipped!

Thanks for the feedback guys

I am not adding modification points for the diff.

 

this is true. there are three suspensions for the 04-08 Rx8.

the normal suspension, which is ONLY found in the US on the AT models, open diff, and 16" wheels.

the sport suspension, which is found on ALL the 6 speed manual cars, and the AT's with 18" wheels. its limited slip, etc.

the special tuned suspension is the shinka, with the bilsteins, etc

outside of the US the normal suspension is found on other models

 

The only difference between the Series II and Series I rear differential (besides the ratio) is that the Series II has a diff cover with a little bit more extensive cooling fins. Since adding transmission or differential cooling is not a point mods you can put in the series II differential with no penalty.

 

it all works out the same in the end, but the differences in the differential case are what you were getting at I was specifying the differential itself which is also what the rule specifically addresses.

 

Another fun TT weekend for NASA TX, thanks to kbrewmr2 and crew!

 

2:03.812 for the stock RX8 R3 (well, Conti DWs for tires but stock everything else) vs 1:58.985 for etzilon's machine. Post the video - looked fun

I'm not sure where I can find 5 seconds in free mods couple tenths in getting spot on min weight, maybe half a second in alignment, another half a second in brakes maybe (running stock fluid & stock pads), not sure how much a 5.12 or higher gear would help. Don't have video of the car to see if anyone can spot if I'm leaving much on the table...

 

Oh chucks... ok

This is the 1:58.985 lap -
I've watched already about 300 times. There might be 0.5 secs left on the table; I'm my worst critic.

I'm going to have to find you on my videos, kbrewmr2.

 

NOLA (i.e. New Orleans)... check.

Although the car wasn't feeling well (failing coil, dirty e-shaft sensor), it was still a blast. I wish I had more sessions to figure out the track.

NOLA Motorsports Park is a very nice facility with a fun/fast track.

 

Has anyone dealt with Mazdaspeed's RX8 Lower Control Arm Bushings (used to add neg camber) and how they translate to NASA PT/TT points?

They seem to fall under E.9, however, adding camber via camber plates (for those cars that can use them) is a free mod.

 

If they are Delrin they would be a free mod. But I think they are an all metal bushing, correct? If so then you have to take points.

 

The only description I could find was: This is an aluminum bearing housing with a spherical bearing installed offset to add negative camber to the front of the RX8.

So, yes, metal bushings.

Given that I don't think you get more than camber out of these bushings, it's rather annoying to have to use points for it (as opposed to falling under I.e.1)

 

Using spherical bearings instead of bushings you have to take points for. If you can't get enough camber just lower your car more, I can get over -3.0 negative camber in the front with stock bushings and stock adjustment methods.

 

NEED.MORE.CAMBER.

So, no spherical bearings for me at least while at TTD. I get -2.2 but gotta reduce my caster to gain more neg camber.

 

Really?

The LEAST amount of negative camber I can get is -2.4. I can't even get to -2.2 LOL.

 

What!? Front camber? What did you bend :-) ?

 

Nothing. The car is just really low, ride height has a lot to do with static camber measurements.

 

The Mazdaspeed Lower Control Arm Bushing is offset so that you can get more negative camber.

 

So, E.9 states:
Replace or modify control arms (other than plates, shims, slots, or eccentric bolts/bushings for simple camber/caster adjustment only) or RWD/AWD rear trailing arms (may have spherical/metallic joint for the connection to the spindle/knuckle) +4

Since the bushings we are referring to are "eccentric bolts/bushings for simple camber/caster adjustment only", shouldn't it fall under the free mod, just like camber plates do?

 

If they are a metal spherical bushing you must take points. The ones they describe in E.9 don't provide an advantage to suspension geometry and are purely for alignment purposes, replacing one of our bushings with a spherical one will provide an advantage in both suspension geometry and alignment.

E.23:
Metallic and/or spherical-design replacement suspension bushings +3 (except for pillow ball camber plate joints, sway bar end links already assessed points in E.7) above, control arm spindle/knuckle joints already assessed points in E.9) above, and panhard rod, Watts links, or torque arms already assessed in E.19), E.20), E.21), E.22) above.)

 

It has a spherical bearing

There are several ways to get there without spherical bearings

Running min caster is actually a good thing .... he's also using OE type springs rather than coilovers so the issue is twofold; soft springs and no height adjusters


.

 

What do you guys consider minimum caster? Minimum as it as low as it can get or a minimum recommended (say, 4 degrees)?

Yup. I can't adjust height but the Tokico springs I have lowered the car approx 1.25". Based on the many comments on this forum, that seems to be a good place to maintain suspension geometry (it could actually be a bit higher).

 

He's running a lot lower to have that much camber

Minimum i.e. the lowest possible equal settings. On mine its below 4