NASA ST5/TT5 - Page 6 - Miata Turbo Forum - Boost cars, acquire cats.

Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

NASA ST5/TT5

Old 09-18-2018, 06:56 PM
  #101  
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,134
Total Cats: 21
Default

HC2 cars should mostly swap over to ST5/TT5 right? Those guys were running 2:39s on shitty Toyos...

I know the car that finished 3rd in HC2 well...I used to race it and helped build it. It had to be de-tuned for HC2. It ran a 2:39.0 on toyos, with the hp turned down, and FWD cars stink at COTA.

In ST5 at 2850lbs that car would have bigger tires, better tires, and 212whp average.

I think I would take that over a 3000+ lb BMW with 208hp...FWD cars aren't that bad...
Efini~FC3S is offline  
Old 09-18-2018, 11:59 PM
  #102  
Junior Member
 
Join Date: Dec 2016
Posts: 70
Total Cats: 5
Default

Originally Posted by Efini~FC3S View Post
HC2 cars should mostly swap over to ST5/TT5 right? Those guys were running 2:39s on shitty Toyos...

I know the car that finished 3rd in HC2 well...I used to race it and helped build it. It had to be de-tuned for HC2. It ran a 2:39.0 on toyos, with the hp turned down, and FWD cars stink at COTA.

In ST5 at 2850lbs that car would have bigger tires, better tires, and 212whp average.

I think I would take that over a 3000+ lb BMW with 208hp...FWD cars aren't that bad...
You worked at Honduh?
engineered2win is offline  
Old 09-19-2018, 12:09 AM
  #103  
Elite Member
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,390
Total Cats: 143
Default

Originally Posted by Efini~FC3S View Post
...FWD cars aren't that bad...
LIES. lies and slander.
flier129 is offline  
Old 09-19-2018, 10:34 AM
  #104  
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,134
Total Cats: 21
Default

Originally Posted by engineered2win View Post
You worked at Honduh?
Hai...in R&D, from 2008-2014.

Drove for both THR and HART
Efini~FC3S is offline  
Old 10-11-2018, 01:12 PM
  #105  
Junior Member
 
Join Date: May 2014
Location: ATX
Posts: 311
Total Cats: 34
Default

Don't want to keep junking up dowards thread, but the time is quickly approaching that I must pull the trigger on ST5 power. Leaning rotrex, but curious how much power I could expect from square top / cams on a BP4W w/ BP5A and VICS mani that currently makes 142whp on e85. Trying to avoid revving to the moon and if I send the head off for work similar to what doward did, well, that adds up to rotrex money real quick. 257mm template is still unlocked at 2400lbs, so that makes life slightly easier. No splitter means about 158whp avg at 2400lbs or 153whp with splitter.

Based on Emilio's stats N/A with headwork, cams, healthy bottom end is good for 180ish on E, but based on my current HP I don't think I can expect anything near that. I'm having a hard time believing square top / cams is going to pickup ~20whp, but have been wrong before. Thoughts? I know rotrex has its own bag of issues and is gutless, but should be able to run some pretty high peak whp. Combined with 6 speed could be a lot of fun, but if I can stay N/A without breaking the bank, I'm all about it.
cabowabo is offline  
Old 10-11-2018, 01:53 PM
  #106  
Senior Member
Thread Starter
 
Join Date: Feb 2007
Location: Aliso Viejo, CA
Posts: 1,046
Total Cats: 315
Default

Your current 142whp is very fast at 2250. I raw timed the IS300 that won ST5 Champs the only time we raced each other. (Yes, I cherish my 2nd place non-win but taking the track record. Don't judge me.)

I view the build options as:

A. 142/2250, 226mm, 205 R7s on 8", +/- splitter, (225RC1 on 9" clears template and gets you a free splitter, or pure P:W bump with the .5 100tw credit now)
B. 159/2400, 257mm, 225 R7s on 9", +/- splitter. (245RC1 on 10" clears template and gets you a free splitter, or pure P:W bump with the .5 100tw credit now)

Either version is allowed an OsGiken for free, which is basically 1 second at any track vs a Torsen, more at some.

I think the "B" build is faster anywhere, and way better nationally vs other platforms, but it requires $$$ in the motor and running heavy. If the car is 100% only for use in NASA, thats the way to go. Any other usage, or HPDE, TT, fun days makes the super lightweight 2250 build really, really fun to drive.

My engine should make enough to cover running at 2450lbs with OE cams(BP5A) and a junkyard block. If not, my options are cams and new lifters, or take the .1P:W penalty and run 2400lbs.
__________________
Dan @ Supermiata
"Button" NASA ST5/TT5 project.
doward is offline  
Old 10-11-2018, 02:21 PM
  #107  
Senior Member
Thread Starter
 
Join Date: Feb 2007
Location: Aliso Viejo, CA
Posts: 1,046
Total Cats: 315
Default

I wrote this for another discussion. Just some general observations.

By running a spoiler, wing or airdam, you forfeit the .4 credit for BTM aero. Aero is not free.

A splitter costs another .5 P:W, bringing the 'cost' of balanced aero(wing + splitter) to .9lbs per horsepower.

Adding aero costs more than having oem A-arms, for example.

Running heavy benefits your ratio, thanks to the comp weight adjustment chart. It is easier to add weight, while benefiting your ratio and staying in the lower class. Meaning, you're more likely to be at the pointy end thanks to comp weight adjustment factors if you add the ballast and run 6.
__________________
Dan @ Supermiata
"Button" NASA ST5/TT5 project.
doward is offline  
Old 10-11-2018, 02:52 PM
  #108  
Junior Member
 
Join Date: May 2014
Location: ATX
Posts: 311
Total Cats: 34
Default

Originally Posted by doward View Post
Meaning, you're more likely to be at the pointy end thanks to comp weight adjustment factors if you add the ballast and run 6.
No doubt. My car as it sits needs ~30lbs of ballast (2460lbs) to be optimized on 93 (136whp peak / 131-132avg) for 6. That's the obvious easy button, but I'd be running ST6 by myself vs what's shaping up to be a fairly large ST5 class. Car is only used for NASA and obviously about to be removed from street duty, so I'd like to make it more fun in case I decide to hit the occasional DE anyways. Obviously I can stay right where I'm at, cage the car, start gutting and aero for lightweight ST5 and ballast up for ST6 if the class gets some attention. Just sounds fun to run the car at current weight, mo' powah, aero, and 225 hoosiers.
cabowabo is offline  
Old 10-11-2018, 08:29 PM
  #109  
Newb
 
Join Date: Oct 2018
Location: Houston, Texass
Posts: 2
Total Cats: 0
Default

Originally Posted by cabowabo View Post
No doubt. My car as it sits needs ~30lbs of ballast (2460lbs) to be optimized on 93 (136whp peak / 131-132avg) for 6. That's the obvious easy button, but I'd be running ST6 by myself vs what's shaping up to be a fairly large ST5 class. Car is only used for NASA and obviously about to be removed from street duty, so I'd like to make it more fun in case I decide to hit the occasional DE anyways. Obviously I can stay right where I'm at, cage the car, start gutting and aero for lightweight ST5 and ballast up for ST6 if the class gets some attention. Just sounds fun to run the car at current weight, mo' powah, aero, and 225 hoosiers.
Or take my caged 94 and quickly run out of excuses entirely.
handsoffsam is offline  
Old 10-11-2018, 08:46 PM
  #110  
Junior Member
 
Join Date: May 2014
Location: ATX
Posts: 311
Total Cats: 34
Default

Originally Posted by handsoffsam View Post
Or take my caged 94 and quickly run out of excuses entirely.
That's not off the table, we can chat about it over beers when I come to get the pupper next weekend. If I sell my car and get blue I'd have a hard time not taking it straight back to SM for the huge fields, haha.
cabowabo is offline  
Old 10-15-2018, 03:09 AM
  #111  
Senior Member
iTrader: (1)
 
Join Date: Jan 2013
Location: Chandler, AZ
Posts: 922
Total Cats: 139
Default

Edit: Wrong freaking thread.
Arca_ex is offline  
Old 11-30-2018, 02:47 PM
  #112  
Senior Member
Thread Starter
 
Join Date: Feb 2007
Location: Aliso Viejo, CA
Posts: 1,046
Total Cats: 315
Default

GAH. Stupid "related threads" feature.... Oh well, i'll leave it.


Nothing super sciency or conclusive, just keeping notes here. Confirming some assumptions.

Originally Posted by doward View Post
NASA Arizona, Chuckwalla, Feb 2018.

225 Maxxis RC1
2:03.048 CW
2:05.619 CCW

205 Hoosier R7s
2:00.983 CW
2:01.032 CCW
Car is about 100lbs lighter than it was in February.
Still ST5 legal(14.66 adj) at 2150/144 peak(~140avg). Room for more power, which was the goal.

225 Maxxis RC1 (Stickers)
2:01.9 CCW

205 Hoosier R7 (same set I raced on in 2016, TT'd on in Feb 18, probably 20+ cycles)
2:03.07 CCW


So, sticker RC1 in the same "real" size(both tires are 224-226mm wide) are faster than cycled R7. Duh?
Weather, track conditions, cycle count, weight reduction and 4whp worked out to be worth about 3.7 seconds on 225/45 RC1s.
__________________
Dan @ Supermiata
"Button" NASA ST5/TT5 project.
doward is offline  
Old 12-01-2018, 08:02 AM
  #113  
Senior Member
iTrader: (1)
 
Join Date: Feb 2015
Posts: 855
Total Cats: 112
Default

That's some great data on RC1 vs. R7. I'm hoping a 245 RC1 will narrow the gap slightly, doubt it'll make it up entirely.
Bronson M is offline  
Old 12-01-2018, 09:17 PM
  #114  
Senior Member
Thread Starter
 
Join Date: Feb 2007
Location: Aliso Viejo, CA
Posts: 1,046
Total Cats: 315
Default

Originally Posted by Bronson M View Post
That's some great data on RC1 vs. R7. I'm hoping a 245 RC1 will narrow the gap slightly, doubt it'll make it up entirely.

dont get too excited.
10 cycle R7s(the same ones, 8 months ago) were 2 seconds faster than rC1.
Sticker/low count R7s are 3+ seconds faster.

Its just that r7s fall off a cliff somewhere around cycle 12-15.
__________________
Dan @ Supermiata
"Button" NASA ST5/TT5 project.
doward is offline  
Old 12-01-2018, 09:38 PM
  #115  
Senior Member
iTrader: (1)
 
Join Date: Feb 2015
Posts: 855
Total Cats: 112
Default

I'm under no allusions that even a non-existent 295 rc1 would hold a candle to fresh 205 R7's. I can get 8-10 cycle SM7 take offs for 200$ ish a set. I can get 6-10 more cycles out of them till they cord. I'll give up 1-3 seconds a lap and run the 245 RC1 just so I don't have to swap tires like a madman. Seems like 30 heat cycles for 600$ is what I could expect out of the RC1 and puts the costs in the same ball park.

Last edited by Bronson M; 12-02-2018 at 08:29 AM.
Bronson M is offline  
Old 12-04-2018, 12:44 PM
  #116  
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,134
Total Cats: 21
Default

Originally Posted by doward View Post
Its just that r7s fall off a cliff somewhere around cycle 12-15.
Do you "break-in" and cure your R7s per Hoosiers instructions/recommendations?
Efini~FC3S is offline  
Old 12-04-2018, 03:01 PM
  #117  
Senior Member
Thread Starter
 
Join Date: Feb 2007
Location: Aliso Viejo, CA
Posts: 1,046
Total Cats: 315
Default

Originally Posted by Efini~FC3S View Post


Do you "break-in" and cure your R7s per Hoosiers instructions/recommendations?
Yea.

They still have a finite life span. I can stretch them out to 18-20HC when I'm only running R7s for an extended run of races/events, but when I switch back and forth between several different tires, old R7s feel like crap. They get really razor edgy and when they start sliding, you're gonna be slidin for a while. They also take forever to warm up when they're cycled and worn. They run so cool at full tread depth, that when they're worn down halfway, they're hard to bring up without weaving(which is becoming no bueno with many orgs) or waiting for 2 laps.



__________________
Dan @ Supermiata
"Button" NASA ST5/TT5 project.
doward is offline  
Old 12-04-2018, 06:27 PM
  #118  
Junior Member
 
Join Date: Oct 2010
Location: LI, NY
Posts: 95
Total Cats: 10
Default

Originally Posted by doward View Post
Yea.

They still have a finite life span. I can stretch them out to 18-20HC when I'm only running R7s for an extended run of races/events, but when I switch back and forth between several different tires, old R7s feel like crap. They get really razor edgy and when they start sliding, you're gonna be slidin for a while. They also take forever to warm up when they're cycled and worn. They run so cool at full tread depth, that when they're worn down halfway, they're hard to bring up without weaving(which is becoming no bueno with many orgs) or waiting for 2 laps.
Kinda off topic to ST5 and the tires but why are racing organizations having issues with weaving on outlap to bring up to temp before start off race?
BMWidmer is offline  
Old 12-04-2018, 08:52 PM
  #119  
Junior Member
 
Join Date: Mar 2010
Posts: 486
Total Cats: 24
Default

Because dipshits don't watch for the yellow flags to drop then weave into a car going 50mph faster who is watching for the flags.
FatKao is offline  
Old 01-06-2019, 08:29 AM
  #120  
Senior Member
iTrader: (1)
 
Join Date: Jan 2013
Location: Chandler, AZ
Posts: 922
Total Cats: 139
Default

Thinking about running ST5 for a little bit while getting other parts together... leaning towards the 2450/158 build with airdam/splitter/wing and 225 R7's.

I saw that a 245 RC1 on a 10" wheel fits the 257mm template? Anyone know if a 225 R7 on a 10" wheel also fits? I figure if a 205 RC1 can fit on a 9" wheel then a 225 R7 will definitely work on a 10" as far as ease of use goes for being able to have all one wheel size...
Arca_ex is offline  

Thread Tools
Search this Thread

Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.