TTD/PTD dicussion - Page 10 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


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

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 05-13-2015, 12:40 PM   #181
Supporting Vendor
iTrader: (3)
 
emilio700's Avatar
 
Join Date: May 2005
Posts: 5,146
Total Cats: 1,138
Default

Quote:
Originally Posted by flier129 View Post
That's what I was figuring, thanks for the confirmation!

I had a shower thought this morning......

Rotrex for TTC? I believe a fella down in FL did a rotrex setup and performed pretty well, at least on the east coast.

~13:1 ratio @ 2400lbs = 180ish rwhp(too optimistic?). I'm wondering how many points Greg would give at something like that though.
Probably Josh Feingold, Coraldoc on most forums. I think he has a TTD lap record or two. NA8 with NA8 motor and C30-74 KW based system IIRC.
emilio700 is offline   Reply With Quote
Old 05-13-2015, 12:50 PM   #182
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,007
Total Cats: 0
Default

There was a guy that used to race in PTD with a supercharged NA in the Midwest a few years back and always did fairly well. Not a rotrex I don't think, and I heard he was running something like 4lbs of boost. Not sure what his dyno reclass was for HP.

My understanding is you'd likely get a lower pwr:wt reclass than a similarly powered n/a car because of what Greg calls "torque potential" or something like that. At least that was the reasoning Hustler got when he used to run his turbo car in TT.

It would likely be quite a bit cheaper to run a low boost rotrex setup to get to a good TTD/PTD power level then say an Emilio style full tilt PTD motor, but I don't think it will necessarily be as competitive. I doubt you'd be able to make up for the inherent FI penalty.
Efini~FC3S is offline   Reply With Quote
Old 05-13-2015, 01:14 PM   #183
Junior Member
iTrader: (5)
 
Join Date: Oct 2014
Posts: 468
Total Cats: 23
Default

Sorry for the possible naive question, but wouldn't policing forced induction be difficult if not nearly impossible? You could easily just crank up a few PSI on the EBC and turn it back down if you got protested, could you not?
90civichhb is offline   Reply With Quote
Old 05-13-2015, 01:57 PM   #184
Junior Member
 
Join Date: Mar 2010
Location: Durham, NC
Posts: 392
Total Cats: 19
Default

Not any different than a N/A motor. I can turn the timing up and turn it down.

And I'm pretty sure that the rules are that if you get caught cheating the part now belongs to NASA. Better hide that button/switch well and hope they don't plop a Traqmate in your car/make you show them your tune with your undeclared maps.
FatKao is offline   Reply With Quote
Old 05-14-2015, 11:46 AM   #185
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

Yeah Coraldoc is who I was thinking of.

There's always a catch with NASA classing
flier129 is offline   Reply With Quote
Old 01-17-2016, 07:33 PM   #186
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

Bringing this thread back from the dead!

A buddy of mine made the move to TTD from TTE in his dyno reclassed miata(too much power now lol). He'll be at 151hp @ 2330, assuming he can get that much power. Might be too early to really say, but it's looking like TTD will be a healthy field in the southeast. All I really want to do is go run with some good competition and have fun. Honestly I wouldn't be able to make the switch until 2017 However, this got me thinking about the topic.

My current idea, just add more mods to my current points build and shoot for my 169hp cap! 2410lbs base/14.25 D ratio

Calc currently reads:
NB1 = TTE @ 2410lbs
205 R7s +3
MS3 +3
intake +1
TB +2
square-top +1
cams +6
exhaust +5
LSD +3
Xidas +5
sways +2
front aero +3
rear aero +4

total = +38 (20-39pts is up ONE class)


This would require a zero-points engine build I would think and I have no idea what I'd do with that last point.... rear diffuser maybe?

Would the cams be worth the 6points even with stock 9.5:1 CR? No cams means I could bump up to 225/245s on 10s, but I feel like the 205s would be fine at this power output and a better use of points. I think Emilio/Andrew have said that the oem NB1/2 injectors and pump can handle E85 as-is, correct? Could I actually get anywhere close to 160+ with this setup or is this just a pipe-dream?

And my biggest concern with this idea...... what IF NASA decides to drop points build and go with dyno re-class only ST5/6/7/whatever. I'm afraid this would happen right after I dump money into my own zero-points engine

Thanks for reading my banter All feedback is welcome.
flier129 is offline   Reply With Quote
Old 01-18-2016, 09:47 AM   #187
Junior Member
 
Join Date: Sep 2008
Location: Davie, Florida
Posts: 66
Total Cats: 3
Default

Sounds like an interesting and good plan for a competitive car, but yes, I would be concerned that NASA shifts away from a points-based system. Since you will be waiting a year anyway, let's see what happens to the rules. Eric Powell's Championship winning car is similar in concept.

Also, just to clarify my build, its a 1993 NA6 chassis with a 2000 NB engine, using a C15-60 Rotrex supercharger and Megasquirt ECU. I received a 65 pound gift from Greg for this season at my power levels. So, I'll either have to add ballast or further de-tune the car. Last year I was allowed to make 161 rwhp at 2395 lbs in TTD trim, with an adjusted Weight/Power ratio of 14.83. For 2016 I'll be at 15.1:1. I'll have to focus even more on speed through the turns.

When tuned for max power, the car makes about 200 rwhp on a cool day at the dyno. It has been very reliable in both the 185 rwhp TTC tune and 161 rwhp TTD tune. De-powering is via less advance in the top end for TTC and a combination of inlet restrictor and even less advance for TTD.
CoralDoc is offline   Reply With Quote
Old 01-18-2016, 10:00 AM   #188
Junior Member
 
Join Date: May 2012
Location: NYC
Posts: 250
Total Cats: 37
Default

^I become more and more convinced that Greg pulls numbers out of his ***. I got a 15.38lbs/hp reclass for TTD. wtf? And this is for a shitty, stock long block VVT swap making a measly 143whp.

To flier - I wouldn't do a single thing until 2017 rules are announced. Way too much of a chance of a rules and classing total overhaul, but at the least, I'd be shocked if there wasn't at least a minor rules change, screwing over your build plan.
dasting is offline   Reply With Quote
Old 01-18-2016, 10:49 AM   #189
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

Two more solid votes for "Wait, just in case the rules **** you over." Duly noted!


15.4lbs/hp for TTD seems like the standard this year, at least for Miatas . I honestly wouldn't mind doing ST6 with something like "14:1" ratio. I'd do an engine build with whatever combination of CR/cam(s)/etc that would be allow me to do a few things....
1. Make more power than a zero points engine, which would be more fun on and off the track(I go to the mountains often).
2. Possibly could be more reliable than a limited zero points engine.
3. Possibly could be less expensive to make the same/more power than zero points engine.

I'd stay around my fatty 2400+lbs too
flier129 is offline   Reply With Quote
Old 01-18-2016, 01:53 PM   #190
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

Quote:
Originally Posted by flier129 View Post
Two more solid votes for "Wait, just in case the rules **** you over." Duly noted!


15.4lbs/hp for TTD seems like the standard this year, at least for Miatas . I honestly wouldn't mind doing ST6 with something like "14:1" ratio. I'd do an engine build with whatever combination of CR/cam(s)/etc that would be allow me to do a few things....
1. Make more power than a zero points engine, which would be more fun on and off the track(I go to the mountains often).
2. Possibly could be more reliable than a limited zero points engine.
3. Possibly could be less expensive to make the same/more power than zero points engine.

I'd stay around my fatty 2400+lbs too
My guess is that the adjusted power to weight ratios follow the theme from the top. ST5 will probably go in between C/D and ST6 will probably go between D/E. Then ST5 and ST6 will have year/make/model specific mod factors to ding specific cars, which makes ST4 attractive since the Miata won't get a huge mod factor tacked onto it.

I predict:

ST1 = 5.5
ST2 = 8.0
ST3 = 10.0
ST4 = 12.0
ST5 = 14.0
ST6 = 16.0
Arca_ex is offline   Reply With Quote
Old 01-18-2016, 03:15 PM   #191
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

Quote:
Originally Posted by Arca_ex View Post
My guess is that the adjusted power to weight ratios follow the theme from the top. ST5 will probably go in between C/D and ST6 will probably go between D/E. Then ST5 and ST6 will have year/make/model specific mod factors to ding specific cars, which makes ST4 attractive since the Miata won't get a huge mod factor tacked onto it.

I predict:

ST1 = 5.5
ST2 = 8.0
ST3 = 10.0
ST4 = 12.0
ST5 = 14.0
ST6 = 16.0

I can't math..... yeah ST5 @ 14:1 would be fun. Say 165rwhp cap @ 2400lbs ya know, because miata.

I'm not sure I want to go down the FI rabbit hole with this track car just yet. I sure do miss turbo noises and such though. If ST5/6 become a thing I'll give it go when it happens.
flier129 is offline   Reply With Quote
Old 01-18-2016, 03:28 PM   #192
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

Quote:
Originally Posted by flier129 View Post
I can't math..... yeah ST5 @ 14:1 would be fun. Say 165rwhp cap @ 2400lbs ya know, because miata.

I'm not sure I want to go down the FI rabbit hole with this track car just yet. I sure do miss turbo noises and such though. If ST5/6 become a thing I'll give it go when it happens.
But that's the thing. ST5 will have mod factors for Miatas. I mean look at a PTE no star dyno reclassed Miata. The adjusted limit for E class is what, 16.5? And the Miata is sitting at 18.7lbs/hp raw if you were at the exact numbers for the appendix C dyno reclass. So in ST5 a Miata will likely be around 16.2lbs/hp raw and ST6 will be around 18.2lbs/hp raw after adjustments. These are all guesses but I'm likely in the ballpark.

You don't get away from that crap until ST4 where there aren't the same type of model specific penalties. It will be like ST3 but with some additional mod factors to "keep costs down". Kind of like how having a dogbox in ST3 is more of a penalty than it is in ST2.

I'm holding off on this season to see what happens as well. That's what my advice for anyone is at this point. Take the money you would have spent trying to go faster in your class, and wait to see what you need to do once everything gets overhauled.
Arca_ex is offline   Reply With Quote
Old 01-18-2016, 04:56 PM   #193
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

**** I hope your guesses are wrong, a 16.2lbs/hp miata in ST5 would get MURDERED by a GSR Integra or something similar.

Example: This type R that's very mildly prepped walking my 135rwhp miata(we're both on street tires):
skip to 1:35ish
flier129 is offline   Reply With Quote
Old 01-18-2016, 06:34 PM   #194
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

Quote:
Originally Posted by flier129 View Post
**** I hope your guesses are wrong, a 16.2lbs/hp miata in ST5 would get MURDERED by a GSR Integra or something similar.
Looking at dyno reclasses an integra is given about a 1.5lbs/HP advantage over a 94-97 Miata in E class if both cars are base PTE, largely due to the 1.0lbs/HP adjustment from being FWD.
Arca_ex is offline   Reply With Quote
Old 09-12-2016, 01:30 PM   #195
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

This curve is good for TTD...... right?



I'm thinking ST5/TT5 with a variant of the engine setup that made the above. Just day-dreaming here.
flier129 is offline   Reply With Quote
Old 09-13-2016, 03:13 AM   #196
Senior Member
iTrader: (2)
 
Join Date: Oct 2011
Location: SE NM
Posts: 1,419
Total Cats: 41
Default

Quote:
Originally Posted by emilio700 View Post
Probably Josh Feingold, Coraldoc on most forums. I think he has a TTD lap record or two. NA8 with NA8 motor and C30-74 KW based system IIRC.
He has a BP4W and is using a C15-60.
Chilicharger665 is offline   Reply With Quote
Old 09-13-2016, 05:19 AM   #197
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

Quote:
Originally Posted by flier129 View Post
This curve is good for TTD...... right?

I'm thinking ST5/TT5 with a variant of the engine setup that made the above. Just day-dreaming here.
Well, it's less than 3 months until the new season starts for some regions and the ST4 "preview" rules that were promised to be released in July are still not out LOL. Classic NASA.

ST5/ST6 would be 2018 at the soonest, probably 2019...
Arca_ex is offline   Reply With Quote
Old 09-13-2016, 07:31 PM   #198
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

ST4 provisional outline is finally out today. I'm betting C/D/E/F are deleted and replaced with ST5/6 for 2018. That means one less class which is good. The power to weights will probably land somewhere in between of D/E and E/F. I kind of like where it's going actually, and I'm usually one of the most critical of NASA changing **** like this.

nasaforums.com ? View topic - UPDATE ST4/TT4 and other for 2017
Arca_ex is offline   Reply With Quote
Old 09-16-2016, 11:29 AM   #199
Elite Member
Thread Starter
iTrader: (7)
 
Join Date: Jan 2008
Location: Knoxville, TN
Posts: 2,053
Total Cats: 44
Default

Quote:
Originally Posted by Arca_ex View Post
ST4 provisional outline is finally out today. I'm betting C/D/E/F are deleted and replaced with ST5/6 for 2018. That means one less class which is good. The power to weights will probably land somewhere in between of D/E and E/F. I kind of like where it's going actually, and I'm usually one of the most critical of NASA changing **** like this.

nasaforums.com ? View topic - UPDATE ST4/TT4 and other for 2017
I'm not the biggest fan of the weight:tire formula getting talked about in that thread. Why have another weird formula to follow that people have to build around?!
flier129 is offline   Reply With Quote
Old 09-16-2016, 11:31 AM   #200
Senior Member
 
Join Date: Jan 2013
Location: Gilbert, AZ
Posts: 740
Total Cats: 91
Default

No way that actually gets implemented. You know how these threads go, Greg introduces provisional rules, asks for input, final rules pretty much always ignore all input and are almost dead on with provisional rules.
Arca_ex is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
EMB and 360cc injectors Joe Perez E-Manage 12 06-06-2014 11:15 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:29 PM.