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-   -   NASA ST5/TT5 (https://www.miataturbo.net/race-prep-75/nasa-st5-tt5-95309/)

doward 11-30-2017 12:43 AM

NASA ST5/TT5
 
Rules: https://nasa-assets.s3.amazonaws.com...--11-29-17.pdf

New for 2018!

14:1 P:W
Adjustment factors for drivetrain layout, suspension design, comp weight.
Limited aero, limited tire.

Could be be a really fun class.
Iíve have more thoughts to add in future posts...

Arca_ex 11-30-2017 12:49 AM

Anybody else find the "coincidence" kind of funny that Greg has a non A-arm TTC car and Miatas well... have A-arms? 0.7 lbs/hp penalty eh...

Also an obvious attempt to lure Supermiata S2 cars back to NASA, with the splitter mod factor making an airdam and spoiler car attractive since they are no hit. Run the numbers and the power to weight is pretty close.

doward 11-30-2017 01:19 AM

My early takeaways:

Miatas take the A arm hit right off the bat. -.7.
Comp weight between 2449 and 2250 is -.5
Conp weight between 2559 and 2450 is -.4

Most of us are looking at a 15.2:1 car in a 14:1 class immediately.
You can run 200lbs heavy to get that .1 back, from 2250 up to 2450. Why bother? It also buys you a wider tire, 225 Hoosiers might be possible.

Airdam and wing is free.
Splitter is -.5

The new section width rule may nerf the 205 Hoosier on 9” wheel that we love so much. Will need to verify this.

Update/backdate and transmission swap allowance give the NB a huge advantage over NA, with much better Brakes/ABS and a free 6spd.
NA only allowed a 6spd with a 4w/6d motor.
Sport Brakes or BBKs are -.2

doward 11-30-2017 01:23 AM

2250 @ 15.2 allows 148 Average WHP. That’s a very healthy, pretty heavily modded(IMO) BP or small rotrex making ~160 peak whp depending on actual powerband.

A heavier Ecotec swap looks pretty attractive too. Motor swap opens the transmission up...

Arca_ex 11-30-2017 01:49 AM

Yeah waiting to see if 205 on 9" wheel is now a goner. I don't even own 8" wide wheels anymore.


That suspension design mod factor though... I guess I kind of get it but 0.7 seems excessive to me. An e36 four door seems like it may be the king as far as chassis goes.

Without that suspension nerf this would be Miatas in that class:


doward 11-30-2017 02:07 AM

Michael Nueman’s in-line 6 swapped E36 TTE champion car is currently for sale. Pull ballast and restrictor plate. Win.

Neversatisfied 11-30-2017 08:25 AM

Reading the rules.... I'm guessing the NB is technically a different "generation" from the NA? That sucks that I can't put sport brakes and an NB front sub-frame under my NA.

My NA is very close to the rule set with a 150WHP VVT 6 speed and Supermiata S2 aero on XIDA's. I lack a cage but was thinking of cage and fire system this winter.

Probably makes more sense to cage an NB and swap my stuff over if going ST5?

Glad I kept my 8" 6ul's

flier129 11-30-2017 09:03 AM

Very curious to find out if the 205 R7s on 9s will be under 226mm as well. I think it's pretty ridiculous measuring section widths, so many variables for it to be slightly different...... I'm surprised there isn't any modifiers around 100tw tire, like the RC1. I'm sure this tire section width will carry down to TT6 in 2019, I'll be super sad if I have to ditch all my 9" wheels.

The difference between a FWD strut sedan and a S2K is YUGGE(ask anybody!). But I'm confused if cars are actually able to run a raw avg weight:power ratio below 14:1? Maybe I should clarify on the forums and get an answer from the guy running a FWD strut sedan in TTC :rofl:

Some bullshit things, but overall a step in the right direction.....less classes.

flier129 11-30-2017 09:32 AM

My initial questions for a miata in ST5/TT5.....

1. Is it worth the -0.5 for a front splitter or would it be faster to run just air-dam and rear wing(funky balance?)
2. Let's say 15.2:1 @ 2251lbs for bench-racing purposes here, what's the best way to make avg 148rwhp and what's the most practical?
3. Would a 6spd with a 4.3 be better over a 5spd with a 4.77?

Noble819 11-30-2017 11:15 AM

Yes very curious about the new "Nasa Section Width" and which tire/wheel combos will work for under 226mm and 266mm for ST5 and ST4.

FatKao 11-30-2017 11:23 AM


Originally Posted by flier129 (Post 1454320)
Some bullshit things, but overall a step in the right direction.....less classes.

Now it's time to tell GTS and HC to get fucked.

flier129 11-30-2017 11:31 AM


Originally Posted by FatKao (Post 1454341)
Now it's time to tell GTS and HC to get fucked.

GTS definitely, it's so similar to ST it's silly. HC has some healthy numbers though and is semi-spec.

doward 11-30-2017 11:40 AM

Just measured a worn 205 R7 on a 9" 6UL.
I get something close enough to 226, that I'll be taking a brand new mounted tire with me to have measured by the official NASA jig at the first event. I would recommend you all do the same. Your air pressure will make a difference.

I am 100% confident this rule is specifically targetted at those using 205 Hoosiers on 9" wheels. The number is too close. lol

flier129 11-30-2017 11:41 AM


Originally Posted by doward (Post 1454345)
Just measured a worn 205 R7 on a 9" 6UL.
I get something close enough to 226, that I'll be taking a brand new mounted tire with me to have measured by the official NASA jig at the first event. I would recommend you all do the same. Your air pressure will make a difference.

I am 100% confident this rule is specifically targetted at those using 205 Hoosiers on 9" wheels. The number is too close. lol

https://media.giphy.com/media/12XMGIWtrHBl5e/giphy.gif

Noble819 11-30-2017 12:00 PM

Would you mind measuring a 245 Hoosier on a 10" 6UL to see if it fits under the 266mm rule?

Arca_ex 11-30-2017 12:52 PM


Originally Posted by FatKao (Post 1454341)
Now it's time to tell GTS and HC to get fucked.

QFT.


Originally Posted by doward (Post 1454345)
I am 100% confident this rule is specifically targetted at those using 205 Hoosiers on 9" wheels. The number is too close. lol

I was going to make the same guess, at this point it's par for the course.

boileralum 11-30-2017 01:56 PM

So am I reading between the lines correctly that the guy who wrote the rules wrote them to specifically handicap the cars which will be running against him? Eff that guy.

Savington 11-30-2017 02:08 PM


Originally Posted by Noble819 (Post 1454350)
Would you mind measuring a 245 Hoosier on a 10" 6UL to see if it fits under the 266mm rule?

It is really close but it appears to fit. 15x10 6UL, sticker 245/40 R7s, 25psi, they measure 266mm at ~31mm of depth. The sidewalls angle in, so they will measure <266mm at 30mm depth. Adding pressure will decrease measured width, wearing the tire will decrease it (but you can have tech measure a new tire if you are protested).

doward 11-30-2017 02:10 PM


Originally Posted by boileralum (Post 1454371)
So am I reading between the lines correctly that the guy who wrote the rules wrote them to specifically handicap the cars which will be running against him? Eff that guy.

Mostly us poking in jest. Greg was not alone in this and has expressed much dismay with some of the 'committee's decisions. Some of the coincidences are striking though. :p

flier129 11-30-2017 02:12 PM


Originally Posted by boileralum (Post 1454371)
So am I reading between the lines correctly that the guy who wrote the rules wrote them to specifically handicap the cars which will be running against him? Eff that guy.

As much hate there is for that guy, this isn't 100% true. There's more than one guy who decides on the rules. Greg is the guy who delivers the rules and undoubtedly has sway of the route of certain sections.

I think I'm going to crunch the numbers on a whammy n/a build vs TSE kit for 5. Turbo obviously having a big advantage of easily bumping to ST4 or even ST3 by removing ballast and add duh boooost. Wheels/tires swap between 5 and 4 could be tricky, though.


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