Dynos also read wildly different. GRIDLIFE recently got a mobile dyno for GLTC compliance and people have been reading all over the place below / at / over their home dynos even with all settings the same (Dynojet, Smoothing 5, SAE, etc). And like Emilio said, powerband shaping. When TT6 was still TTE having MS3 allowed me to run E85 for champs and dial in a about 1.5k rpm of flat power. Whether it's flat power or cheesing AVG hp with gearing it gives you more options.

That certainly makes sense, and definitely makes it sound worth it. I've been dragging my feet on getting an aftermarket ECU for a long time...

Curious if anyone has experience with this at a local region... For background, the region has a large and somewhat competitive TT6 field. Last event had 10 TT6 drivers. TT5 is well attended too.

Currently there is a proposal in our local group chat to allow OE-type lips for the drivers not claiming the +0.4 BTM. The basis of the discussion is that it is for aesthetics only, it makes cars with rear wings look better, and there's no performance advantage. My thoughts are the following:
- If it isn't a performance advantage and increases participation then that is a good thing
- if it isn't a performance advantage then why not allow this local exception to be part of the BTM allowances
- it has only been 2 weeks since this was proposed and I'm starting to see the lips drivers are proposing and they have integrated splitters built into them and are not exactly "OE-type".
- I have not seen any verbiage from the TT director that this is allowed nor what the allowance will be.

Participation is king as there's no point is discussing rulesets when there is only 1 driver.

Local gentleman's agreements to rule exceptions never end well. It's always a bunch of people that want a class to be built for their cars instead of building a car for the class. Just stick to the rules as written and there won't be anyone pushing the envelope of trying to turn a "lip" into a splitter like you said. And lips are a performance advantage. Even the R package lip for the Miata had positive aerodynamic results in CFD testing, reduced lift and drag.

Air Dam or Splitter - A Closer Look | Verus Engineering (verus-engineering.com)

Look at how much improvement happens when going from model #2 to the model #3. That's just a little 3 inch vertical lip near the bottom of the stock bumper. Net gain of like 90lbs of downforce at 100mph and also has about 35lbs of drag reduction. It makes you faster in a straight line and in corners, win win.

I also don't think these rogue rule sets are a good idea. Especially in NASA with crossover events. If everyone feels so highly about some rule change, then petition NASA HQ for an official rule change. By default, you can assume Greg G will shoot down any proposals that would benefit a Miata, so you can just assume the free lip won't fly. I miss the aero kit mainly for aesthetics. The NB looks far less wimpy with the lip and side skirts on it.

Do you remember what a shit show the Goodyear SC3R created last year? It's rated as a 100TW tire, but isn't too far off the pace of a R7. And it technically wasn't approved by NASA HQ, so per the rulebook it wasn't allowed, but some regions gave it the ok. And most guys just assumed it was ok because we all knew a bunch of people running them from various regions. Hell, I was close to buying a set last fall had my dad not crashed into my tow vehicle and ended my season. I even know guys on the podium at nationals that ran the tire and nobody said anything. Then it all blew up after the season when the 2022 rules came out. Guys were having a meltdown on the forum.

Looking at the 2023 rules, is my assessment correct that ELBJ's wouldn't count towards the "Replace, modify, or remove control arms, camber arms/links, toe arms/links (Applies only if beyond the allowances of Section 6.1.9.4) -0.5" modifier?

Given:
"One means of aftermarket camber adjustability per wheel by replacement of a single suspension component not requiring modifications to the spindle/knuckle or mounting points (in addition to camber plates) is permitted without a Modification Factor. Also, rear suspension link replacement or modification for toe adjustability is permitted without a Modification Factor. Any
additional non-OEM or modified control arms or links beyond the above shall be assessed a Modification Factor. (Note: Section 6.1.9.6 below still applies)"

ELBJ have always fallen under this section and still do under the 2023 rules.
Non-OEM metallic and/or spherical design replacement suspension bushing modifications on control/camber/toe arms/links, panhard rods, watts links, and torque arms (includes replaced, modified, adjustable, or altered control arm ball joints) = -0.2

The key word in Section 6.1.9.4 is adjustability. See https://community.drivenasa.com/topi...-for-comments/
So, if the part doesn't provide the ability to adjust camber (like an arm that just changes camber but doesn't give adjustability), it would take the Mod Factor for arms.

ELBJ does not allow for adjustment, it just adds camber but no adjustability, so you still have to take the -0.2 mod factor.

Getting into TT6 around June. How have the new rules been going for everyone? Will probably use HPDE4 -> TT $600 Toyo bucks for a set of RR's, then maybe try out the RC1 as Maxxis seems to have better contingency if I don't suck.

The new rules are working well for me. Upgraded to E85 and was able to get the car setup for a 2450#/141HP/Toyo RR configuration. At least for me, I feel that TT6 favors setting the car up for power and BTM aero vs. aero.

Cool. Already on MS3 and been using E85 with a flex sensor for a bit, so the power part should be fine. Targeting the same 2450lb, 141HP, Toyo RR, BTM aero w/hood vents setup. Seems you'd have to have MS3 at that weight to be competitive, most will have to add power or lose weight this year. Thoughts on RR vs RC1, or detuning to a flatter power curve and use R7's?

They seem close in performance with a small pace advantage to RC1. With that said, I have contingency dollars from Toyo that will keep me with Toyo for a while. With regards to detuning/RR option, it may be quicker that RR/RC1 on some courses, but certainly seems more expensive in the long run.

side quest from my xT5 post.

I think the 1.6 credit category tires finally have enough of a handicap to win almost anywhere in TT. ST still seems to be Hoosier's domain due to the heat soak and inability to choose when you push/conserve to mange tire heat due to mixed class traffic.
Several folks have been setting TT5 records on the new Maxxis RC1R2 this year.

Constants of the *most* xT6 Miatas:
+.3 mechanical throttle body
-.5 having Aarms
+.4 BTM aero
+0 allowed a control arm for camber adjustability now.

In 6 I think the 205/50/15 R7 on an 8.5" wheel is a niche option that works really really well on Miatas.
This keeps it inside the 226mm template which can earn you the "small tire credit" at >2400lbs.

This would look like:
205 R7 on 8.5"
+.3 "small tire credit" running a 226mm template at >2400lbs.
+0 "not applicable" tire category
+.3 mechanical throttle body
-.5 having Aarms
+.4 BTM aero
2401lbs
127avg whp

What I think is now a very close option B: 225/45/15 "1.6 tire" on 15x9" wheel.
2450lbs
139avg whp
225/45/15 on 15x9"
+.3 "small tire credit" running a 226mm template at >2400lbs.
+1.6 Toyo RR/Maxxis RC1r2
+.3 mechanical throttle body
-.5 having Aarms
+.4 BTM aero

Anecdotally, I find it humorous that ST6 has evolved into a no-aero Supermiata S2 with 100lbs of extra ballast. 139avg whp at 2405lbs.

I've been having some success this year with that setup. I'm currently with a 2454#/141HP setup as I haven't removed my ELBJs yet. The extra power is a huge plus in the straight aways and the car can handle pretty close to the rear aero miatas in the turns. 141HP is easy with bolt ons, E85, and a relatively ok engine.

Wrapped up the TT6 season 2 weeks ago in the Southeast region.

Ran the car in this configuration:
- 2454# min weight
- 141 avg HP (I/H/E and E85)
- Base-trim-model aero
- 225/45 Toyo RRs
- ELBJs

https://cimg6.ibsrv.net/gimg/www.mia...763f301d53.jpg


Essentially the strategy was to make the best hot rod version of a TT6 miata I could. Car seemed to do very well at most tracks (1 track record and 0.1 seconds off a second one) compared to the TT6 miatas I compete against that run rear aero. TT6 in the southeast is quite strong with 7+ entries being a common thing.

Goals for next year:
- Remove ELBJs and increase average HP
- Reduce drag on the car to improve top speed (I’m close to 120mph top speed on several of the SE tracks). I’ve been researching a good hood vent system that doesn’t add a lot of drag and then tape off some of the radiator inlet. I think this would be TT6 legal as I’m not adding anything to the front bumper.E85, Koyo radiator, and some radiator sealing, has been keeping the car cool.

Curious what experience others may have had with reducing drag on a BTM miata?

Remove side mirrors. I used a convex mirror attached to the a pillar. That and a properly positioned rear view obviated a right side mirror. No blind spots. Deleted the quarter windows.
With all the allowed cooling mods, you should be able to actually close up some of the rad opening to reduce drag. Lower ride height reduces frontal area but shouldn't be done at the expense of compliance. Front upper offsets exist which if legal, get most of the camber lost by deleting ELBJ's. Dumb rule IMO.
Run minimal toe. More toe is more tire scrub.

2023 rules update allows a "free" control arm per axle for the purposes of alignment correction.
So, V8R Elite Series front lower control arms (with urethane bushes!) are a "free" allowed mod.

Taping the radiator opening is tricky. If you add 'anything' to the front bumper, its an airdam, and it means giving up BTM.
You can add a mesh grill protector, which is legal and reduces drag. Behind it you can duct the radiator with custom ducting. and tape the actual radiator core if needed, since the OEM grill opening is too big.

Delete the mirrors. Keep the fender liners and belly tray, etc.

Question as I've done some research but looking for some first hand experience. Has anyone just done an airdam and undertray on a NA6 with the 1.6? My reasoning is that airdam has to help, even without rear aero and I doubt I'll get my NA6 close to class maximum horsepower anyway. End game is ST/TT5 with a 1.8 VVT swap, so this would allow me to "start" the aero, granted I do realize it is a -1.0 hit.