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-   -   ST4/TT4 Thread (https://www.miataturbo.net/race-prep-75/st4-tt4-thread-91069/)

aidandj Nov 4, 2016 12:18 PM


Originally Posted by emilio700 (Post 1372062)
We have decided to make a run at 2017 T25 in Vegas, E0 mapped from ST3.

:party:

Want to see this. I love thunderhill.

d k Nov 4, 2016 12:22 PM

Was there any mention of the Mixed Flow Technology like on the 7163?



Originally Posted by Chilicharger665 (Post 1372061)
Speaking of EFR's, they just showed a smaller version at SEMA called the 5951 that is smaller in every way, yet they claim it flows 95% of a 6258. It is 35mm shorter and 35% less interia.


Chilicharger665 Nov 4, 2016 01:06 PM


Originally Posted by d k (Post 1372066)
Was there any mention of the Mixed Flow Technology like on the 7163?


charliehayes22 Nov 5, 2016 07:09 PM


Originally Posted by doward (Post 1371833)
Relocation of suspension mounting points is not permitted in ST4.


That means NO NB subframe/spindles/bumpsteer in 4. Only in 3/2/1

I don't think that's the intention from Greg. You can ask if you please, updating/back dating subframes and suspension pieces are legal. Bumpsteer is also legal.

Relocation in their minds for the rules is getting a torch out and welder. It does not say I cannot follow the update/backdate rule in ST4, I also don't consider bumpsteer relocation if your following this mind set.

Savington Nov 5, 2016 09:50 PM


Originally Posted by charliehayes22 (Post 1372296)
I don't think that's the intention from Greg. You can ask if you please, updating/back dating subframes and suspension pieces are legal. Bumpsteer is also legal.

I was able to read it both ways. It says you can swap subframes, but it also says that ST4 guys can't move pickup points. The NB subframe technically moves the points on an NA. I asked Greg, we'll see what he says.

charliehayes22 Nov 5, 2016 10:12 PM


Originally Posted by Savington (Post 1372314)
I was able to read it both ways. It says you can swap subframes, but it also says that ST4 guys can't move pickup points. The NB subframe technically moves the points on an NA. I asked Greg, we'll see what he says.


I did too. I got the answer that I expected and wanted when I read the rules.

As long as it's factory bolt on its good for ST4.

He also states an answer supporting this on the NASA Forums.

d k Nov 5, 2016 11:00 PM

There was also a clause somewhere that you can backdate/update oem components without a penalty.



Originally Posted by Savington (Post 1372314)
I was able to read it both ways. It says you can swap subframes, but it also says that ST4 guys can't move pickup points. The NB subframe technically moves the points on an NA. I asked Greg, we'll see what he says.


jpreston Dec 14, 2016 05:00 PM

https://www.miataturbo.net/attachmen...ine=1423402060

http://myimages.uk-plc.net/c314612/P...Dry%20Sump.jpg

Dry Sump Kits - Pace Products

Maybe? @Kmiata

emilio700 Dec 14, 2016 05:10 PM

Looks like it might just clear the rack.

KMiata Dec 15, 2016 02:42 PM

I looked at the Pace kit in initially, but I don't think it will clear. Clearance over the rack would be close, but I also don't think there is any room for the big external pump.

So did Greg respond to anyone about if we can use a tubular subframe with all OEM pickup points? I know at least a few customers have asked, so not sure if that has swayed the decision.

edit: nevermind, I checked my emails and I had confirmed that it was a no-go earlier this fall.

engineered2win Jan 5, 2017 09:32 PM


Originally Posted by KMiata (Post 1381524)
I looked at the Pace kit in initially, but I don't think it will clear. Clearance over the rack would be close, but I also don't think there is any room for the big external pump.

So did Greg respond to anyone about if we can use a tubular subframe with all OEM pickup points? I know at least a few customers have asked, so not sure if that has swayed the decision.

edit: nevermind, I checked my emails and I had confirmed that it was a no-go earlier this fall.

I haven't emailed Greg, but my understand is it's not allowed. This would fall under the +0.4 non-production adjustment in TT1-TT3. non-production is not allowed for TT4, and even if it was, isn't worth the penalty unless you really go all out with a tube frame. I know of one LSx Miata that runs TT and has to take non-production for not having the factory unmodified subframes.

Arca_ex Dec 3, 2021 09:44 PM

And back from the dead...

Toyo's look hot with the new 2022 rules but it seems like it's going to be right at the limit or just beyond the reach of the K24Z3 crowd...

I don't know if I can get my comp weight much lower than 2250, and at that weight with 245 Toyo RR, aero, and even no cable throttle credit I'd still have a max of 225whp AVG. With most guys making 205 to 210whp on pump gas, I'm hoping e85 is worth another 10whp, and the underdrive ATi super damper, exhaust collector porting, and velocity stack intake, together hopefully another 5whp? So best case scenario I'll be able to do 225whp all in and no ballast? Not really ideal, I'd prefer to be running heavier. Only thing I can think of left to do is higher compression pistons, punch the block out and send the head out for CNC porting. Other than that what else is left?

Switching to Hoosier R7 is a whopping 31whp difference at that weight...

12.0 base P/W
2250lbs -0.2 penalty
Toyo RR +1.6 credit
245mm Tire Width +0.6 credit

After mod factor it's 10.0 P/W now.

flier129 Dec 5, 2021 09:23 AM


Originally Posted by Arca_ex (Post 1613545)
Switching to Hoosier R7 is a whopping 31whp difference at that weight...

Still worth it! :rofl:

If I ever run ST4/TT4 I'll just be slightly underpowered, but still plan to run R7s. Maybe as time goes on the k24z3 will get some more support to make a tad more power easily?

thebeerbaron Dec 13, 2021 09:44 PM

I finally reviewed the new rules.

I'm a bit surprised that the R7 will be required at the Championships.

Originally Posted by NASA
6.4.1.3 Specification ST4 only (excludes TT4)--The Hoosier R7 and A7 will be the Specified and only permitted tires at the 2022 NASA Championships.

NorCal doesn't usually run at Laguna Seca and has no events there this year. I'm not sure if SoCal will. Someone I spoke with at the 25 made the note that NASA was essentially encouraging racers to join another race group in order to get track time there before the Championships.

With the R7 required for the Championships and making such a big impact on power limits, no wonder they've gone crazy with the rules around ECU maps and switching.


codrus Dec 14, 2021 12:29 PM


Originally Posted by thebeerbaron (Post 1614035)
I'm a bit surprised that the R7 will be required at the Championships.

There was a thread on a NASA forum about the new rules in which they said that the current ST4/TT4 competitors are mostly pretty happy with Hoosier and want to stick with it. They were suggesting that in 2023 it may become a Hoosier spec tire class, and that this was the reason for the special rule at the championship event.

--Ian

thebeerbaron Dec 14, 2021 01:08 PM


Originally Posted by codrus (Post 1614065)
There was a thread on a NASA forum about the new rules in which they said that the current ST4/TT4 competitors are mostly pretty happy with Hoosier and want to stick with it. They were suggesting that in 2023 it may become a Hoosier spec tire class, and that this was the reason for the special rule at the championship event.

--Ian

Very interesting. Shows how little I know about actual ST4 competition, as opposed to just what I imagine in my nutty little world.

So basically the strategy would be - run +18 HP on something like an RS4 until I'm within shouting distance of contingency Hoosiers, then give up those horses and swap to Hoosiers?

Purple crack indeed...

thebeerbaron Dec 14, 2021 01:14 PM

Correction - for 2022 I could run the non-Hoosiers, but in 2023 I'll need to be robbing banks to pay for tires...

I really wish the MK60 was allowed in ST5. I really don't want to give it up, but maybe that's where I'll be in '23.

Arca_ex Dec 15, 2021 01:04 AM

Whoever said they like the Hoosiers for ST4 has to be winning them. Toyo now has better contingency, better prices and better longevity. Everyone at a regional level is going to be running that. Would be dumb to turn it into a spec Hoosier class.

codrus Dec 15, 2021 01:25 AM


Originally Posted by Arca_ex (Post 1614104)
Whoever said they like the Hoosiers for ST4 has to be winning them..

Here's the thread: https://community.drivenasa.com/topi...oday/#comments

--Ian

doward Dec 15, 2021 09:19 PM

Y’all are way out of the loop. Fast and front running ST4 cars are $80-125k builds. It’s essentially a spec E46M3 class. It’s fast and expensive and Hoosiers are absolutely the norm. Hoosiers are the norm in ST5 too btw, and they will still be at the front in 2022.

spoken as a former ST1-4 series director and contestant in 5 different regions over the last 5 years.


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