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

engineered2win 05-11-2018 08:17 PM


Originally Posted by AlwaysBroken (Post 1478596)
Just run an EBC, set your boost targets at each RPM so that it seeks up and down as desired. You can be totally closed loop for those RPMs on the dyno. The detailed answer is going to depend on what software you're controlling wg duty cycle with. The torque curve will look like something from a chipped diesel VW.

edit- I'm assuming that turbo can hit 20+ psi of boost at 3k rpm and then drop it to zero 500 rpm later. That might be tricky. I have no idea about the 2554 beyond it being really small. As sav basically said above, you're basically going to pick the lowest RPM possible, create a big boost spike, drop it back to zero boost for a few thousand RPM and then go up to whatever your real target is for the rest of the RPM range.

You'll need a really big external wastegate to avoid boost creep.

In unrelated news, how would they catch someone who programs their boost controller to switch to a high boost setting during a race and then switch back to low boost at all other times. You could trigger it with a radio signal or the abs sensor (so it only goes fast when the car is actually moving, etc).

edit2- they use GPS based measurement to see if you're obviously cheating

Well they've always threatened to install a GPS accelerometer on cars they think are cheating. I've never actually heard of it being done, however. Even if they did, it would be quite difficult to conclusively prove someone is cheating.
It's widely known AWD cars are pretty much unrestricted, since most regions don't have AWD dynos at the track. My buddy used to run a fully prepped TTB coyote mustang, which is about the highest hp possible for the class given his portly 3770lb race weight, and would get out dragged on the straights by one particular STI.
FYI, cheating is only accepted if you aren't competitive. Then we just feel bad for you, as in: boy that guy would really suck if he didn't cheat...

x_25 05-12-2018 09:52 AM

That last line is basically what I tell my friends when they are worried about classing a car for events. If you aren't winning/running in the top few, noone is going to give a rats ass at local events.

jacob300zx 05-13-2018 12:00 AM

I still chuckle to myself when I see the cars and the weight/hp the Miata is up against in NASA. Not only have we as a community, but also thanks to shops like 949/TSE/Goodwin, sharpened our spears to the absolute sharpest designs and tech. I also feel that as a whole a group of Miata drivers from any region could take a crack at pro racing. We should all just switch cars for a year to some forgotten platform and school Greg and his Knights of the round table at nationals. Eventually you'll see everyone restricted down to a 185 tire and 200lbs of ballast...drunk rant over

flier129 05-13-2018 12:37 PM


Originally Posted by jacob300zx (Post 1481834)
I still chuckle to myself when I see the cars and the weight/hp the Miata is up against in NASA. Not only have we as a community, but also thanks to shops like 949/TSE/Goodwin, sharpened our spears to the absolute sharpest designs and tech. I also feel that as a whole a group of Miata drivers from any region could take a crack at pro racing. We should all just switch cars for a year to some forgotten platform and school Greg and his Knights of the round table at nationals. Eventually you'll see everyone restricted down to a 185 tire and 200lbs of ballast...drunk rant over

:bowrofl:

I'm with ya, lol.

cabowabo 07-31-2018 12:14 PM

So what are folks doing for power in ST/TT5? Texas has built a strong TT5 field, ST5 field should be growing quite a bit, and I'm thinking about moving that direction even though I'd currently be bringing a dull knife to a gun fight. S2000's are making just shy of 200whp peak, GT86 twins aren't too far behind, and there's a fresh NC ST5 build that hasn't really come out yet. As far as suspension setup I think I'm fine, will only get easier to drive once I get swaybars back. Obviously need aero. The question for me basically comes down to rotrex or rebuild spare bottom end with JDM 10.5:1 pistons and cam it (BP4W). Still a street car at the moment so can't run any lighter than about 2350 (currently 2430lbs TTE*), but truck/trailer is on the horizon, so might be going ST mode.

Not even sure the N/A idea would ever make enough power without running much lighter. With MSM intake cam I'm only making 136whp at the moment, so either I need to learn to tune or just have a weak motor. Little column A, little column B.

doward 07-31-2018 01:23 PM

Pull 200lbs or spend for 40whp.

cabowabo 07-31-2018 01:26 PM


Originally Posted by doward (Post 1494263)
Pull 200lbs or spend for 40whp.

Simple enough. Spend for 40whp is what I'd like to do, but my wallet is saying pull 200lbs.

AA-Ron 07-31-2018 02:22 PM


Originally Posted by doward
Pull 200lbs or spend for 40whp.

Better yet: pull 200lbs and spend for 40whp. Then put 200lbs where your corner weights tell you.

Efini~FC3S 07-31-2018 04:52 PM

For wheel to wheel racing you're going to want the power and torque.

For TT, it could go either way depending on the track.

AA-Ron 07-31-2018 10:31 PM

Updating/Backdating question, has anyone running an NA chassis thought about running the 1997 rear subframe and stiffeners?

I have one sitting around but have yet to decide if it's worth the swap.

What's everyone's thoughts?

doward 08-01-2018 02:27 PM

Provisional 2019 rules: https://nasa-assets.s3.amazonaws.com...1--7-31-18.pdf

For 2019 we've already gotten two nerfs.

A arm penalty goes from .7 to .8.
257mm(225 Hoosier) section width allowance goes from 2400lbs to 2450lb.

The consensus ideal 'on paper' heavy car now gets 50lbs added and eats an extra .1 P:W penalty.

cabowabo 08-25-2018 12:22 PM

Anybody measured 225/45 RR on 9? With RC1's running narrow and making it by 1mm (assuming accurate a couple of pages back) I'm guessing it won't make the cut, but wanted to check before I order an RR.

flier129 08-25-2018 06:22 PM


Originally Posted by cabowabo (Post 1498339)
Anybody measured 225/45 RR on 9? With RC1's running narrow and making it by 1mm (assuming accurate a couple of pages back) I'm guessing it won't make the cut, but wanted to check before I order an RR.


Hoosier>the rest

cabowabo 08-25-2018 06:45 PM


Originally Posted by flier129 (Post 1498375)
Hoosier>the rest

No doubt, but RR's are a good bit cheaper and they stepped up their contingency. If I can do well enough to claim tires with RR's (which stay more consistent for more hc's, which allows running more non comp events), then why run hoosier? If 225 fits in 226 template on 9 by some miracle I bet it won't be that much slower than a 205 r7 on 8 anyways, which is why I'm even curious.

cabowabo 09-18-2018 12:53 PM

Bench racing ensues.

So, the ST5 champ ran a best lap of (I believe) 2:37.8 (IS300). One of my friends, who's not quite a hot shoe, ran a 2:38.0 (S2000). Another friend who has pretty much all the TTC records in Texas Region couldn't detune his recent K swap enough, so pulled 200 something lbs of ballast, made a spllitter Friday night, and ran under powered in TT4 putting down a 2:30.8 (S2000). Can pretty safely assume he'd be capable of at least a 2:36 in TT5 trim, his goal was going to be 2:35's, which sounds doable. I'm still planning on taking the plunge into TT5, but other than a small/autocrossy track like Cresson 1.7 I don't think I'm going to be putting up much of a fight to well prepped/driven S2k's. Dropping the splitter and running power seems to be the way to go, but that's a whole new can of worms and money I don't want to really spend getting there.

doward 09-18-2018 01:38 PM

Scott ran a 2:35.447 in Friday qually in his Integra.
Nik Friday qually 1:38.3

Nik rocked that championship race, he was raw-timed in every dry session all weekend, but he's extremely consistent and makes very few mistakes in my experience racing against him. I also raw timed him when he beat me. (Cowboy)Hats off to him.

Sunday Champ race:
Nik 1:38.4
Scott 1:37.5


Benchracing-wise, with the Sedan credit going away for 2019, Nik will need to keep the development train rolling. His car has a lot of glass, no lexan, a stock motor/ECU and only 1 event with adjustable control arms under his belt. It will get way faster.

A FWD strut car has a big advantage still, even with no sedan credit.
The BMW we all fear has not yet been built/campaigned effectively.

cabowabo 09-18-2018 02:08 PM


Originally Posted by doward (Post 1502287)
The BMW we all fear has not yet been built/campaigned effectively.

They did work in ST/TT4, though. Based on that I can't believe the a-arm penalty gets worse for 2019. A top flight bimmer should slaughter, especially on power tracks.

doward 09-18-2018 02:56 PM

Here's the E46 330 that won TT5 with a 1:34.9..

Turns out the BMW we fear was built by a shop with lots of BMW experience, SCR Performance.

https://drive.google.com/drive/folde...p9VcixPmthUQLf

https://cimg7.ibsrv.net/gimg/www.mia...e521a3ce63.jpg


2003 BMW 330i

3015lbs
208 avg whp
Brakes -.2
Sedan +.2
Spliter -.5
14.5 raw
14.0 adjusted.

No arms, no sphericals.

FatKao 09-18-2018 04:51 PM

5.4s faster than Kopitski? I think we're starting to see where the pointy end of ST5 is. He loses sedan next year and the A-arm penalty isn't worth ~2s is it?

Fastest I see in ST5 is a 2:36.1 from a 944.

cabowabo 09-18-2018 04:54 PM

...also, just in case anyone goes further down the bench racing path, don't compare this event against when most CoTA track records were set back in May. Different track limits and conditions by about ~2 seconds using both SM and Kopitski as reference. There were no gators on outside of the corners, so you could track out for days. A 2:34.9 doesn't make a strong case for that a-arm penalty, though, sheesh.


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