General Miata Chat A place to talk about anything Miata

my 155mph miata

Thread Tools
 
Search this Thread
 
Old 06-15-2015, 05:49 PM
  #1  
Junior Member
Thread Starter
 
Mazdaspeed_Miata's Avatar
 
Join Date: Jul 2008
Posts: 58
Total Cats: 3
Default my 155mph miata

hey guys,

check out


best regards from Germany!
Mazdaspeed_Miata is offline  
Old 06-15-2015, 07:20 PM
  #2  
mkturbo.com
iTrader: (24)
 
shuiend's Avatar
 
Join Date: May 2006
Location: Charleston SC
Posts: 15,176
Total Cats: 1,680
Default

What transmission and rear end?
shuiend is offline  
Old 06-15-2015, 08:04 PM
  #3  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

Nice. What's the setup?
18psi is offline  
Old 06-15-2015, 09:08 PM
  #4  
Senior Member
iTrader: (1)
 
Schuyler's Avatar
 
Join Date: Apr 2011
Location: Columbia, SC
Posts: 1,332
Total Cats: 87
Default

My money is on 3.9 and a 6 speed.
Schuyler is offline  
Old 06-15-2015, 09:29 PM
  #5  
Elite Member
iTrader: (24)
 
viperormiata's Avatar
 
Join Date: Aug 2008
Location: Key West
Posts: 6,110
Total Cats: 283
Default

****
viperormiata is offline  
Old 06-15-2015, 10:04 PM
  #6  
Junior Member
 
Eipgam's Avatar
 
Join Date: Jun 2014
Location: Purga, Queensland, Australia
Posts: 86
Total Cats: 10
Default

A 6 speed and 3.9 would need 7,750 RPM to reach 254 kmh, acceleration would be 1.63m/sec2. A 4.1 around 8,250 and a 4.3 around 8,400.

A quick aero calc (1,100 kg and Cd of 0.34) shows about 360 RWHP would be required to get to that speed.
Eipgam is offline  
Old 06-15-2015, 10:21 PM
  #7  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,293
Total Cats: 475
Default

Originally Posted by Eipgam
A 6 speed and 3.9 would need 7,750 RPM to reach 254 kmh, acceleration would be 1.63m/sec2. A 4.1 around 8,250 and a 4.3 around 8,400.

A quick aero calc (1,100 kg and Cd of 0.34) shows about 360 RWHP would be required to get to that speed.
I didn't check your math, but my bone stock 99' miata with a crystal mod did 140mph, that's with ~110rwhp. I don't think you need 360whp to go 18mph faster.
patsmx5 is offline  
Old 06-15-2015, 10:25 PM
  #8  
Former Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,099
Default

Definitely don't need 360whp to go 155mph. My 320whp car would pull 3.63s hard into the 7400rpm limiter at ~152mph GPS.

Keep in mind that tire diameter fluctuates dramatically at high speed. 7400rpm with 3.909s and a 6-speed calculates to ~154mph, but if you actually try it, the GPS will say ~146mph.
Savington is offline  
Old 06-15-2015, 11:13 PM
  #9  
Senior Member
iTrader: (1)
 
Schuyler's Avatar
 
Join Date: Apr 2011
Location: Columbia, SC
Posts: 1,332
Total Cats: 87
Default

Originally Posted by Eipgam
A 6 speed and 3.9 would need 7,750 RPM to reach 254 kmh, acceleration would be 1.63m/sec2. A 4.1 around 8,250 and a 4.3 around 8,400.

A quick aero calc (1,100 kg and Cd of 0.34) shows about 360 RWHP would be required to get to that speed.
I can gear out my T25 200whp setup easily in 5th gear with a 4.30 at 7400rpm, at an indicated 142mph (233.36kph) on 195s. While it's a sweet video, it isn't really an indication of mad power.

With 205/50R/15, 6speed, 3.9, and stock 7200rpm rev limiter, you can do 250kph. So, 7538* rpm for 254kph. With a 5speed, it's 7278rpm. So, my new guess with actual maths is 5speed and 3.9.
Schuyler is offline  
Old 06-15-2015, 11:22 PM
  #10  
Elite Member
iTrader: (7)
 
mgeoffriau's Avatar
 
Join Date: Jul 2009
Location: Jackson, MS
Posts: 7,388
Total Cats: 474
Default

Were you on a NASCAR oval track at the time?
mgeoffriau is offline  
Old 06-15-2015, 11:38 PM
  #11  
Junior Member
 
ozbrock's Avatar
 
Join Date: Dec 2010
Location: Clermont, FL
Posts: 262
Total Cats: 39
Default

Originally Posted by Schuyler
I can gear out my T25 200whp setup easily in 5th gear with a 4.30 at 7400rpm, at an indicated 142mph (233.36kph) on 195s. While it's a sweet video, it isn't really an indication of mad power.

With 205/50R/15, 6speed, 3.9, and stock 7200rpm rev limiter, you can do 250kph. So, 7538* rpm for 254kph. With a 5speed, it's 7278rpm. So, my new guess with actual maths is 5speed and 3.9.
He shifts through 6 gears in the video.
ozbrock is offline  
Old 06-16-2015, 12:14 AM
  #12  
Junior Member
 
Eipgam's Avatar
 
Join Date: Jun 2014
Location: Purga, Queensland, Australia
Posts: 86
Total Cats: 10
Default

Originally Posted by Savington
Definitely don't need 360whp to go 155mph.
Agreed, I made some rough assumptions on frontal surface area, Cd, weight, Crr, Fuel energy density, Drivetrain efficiency (95%), Engine efficiency.

From Race Technology Knowledge Base | M / Mazda
94 Miata CD 0.38, frontal area 1.71 sq m, CDa 0.65

Gearing is one thing having the power to overcome aero drag and reach the gear speed is another.

For my car last time I did coast down tests I got Drag coefficients for a given Wing Angle (frontal area of 2.1 sq m):

00 Deg: 0.25293
05 Deg: 0.36337
10 Deg: 0.34050

Plugging my setup into the formula I would need 300 RWHP to get to 155 mph (wing at 00).
Eipgam is offline  
Old 06-16-2015, 12:48 AM
  #13  
Elite Member
iTrader: (2)
 
Arca_ex's Avatar
 
Join Date: Jan 2013
Location: Chandler, AZ
Posts: 1,628
Total Cats: 427
Default

Originally Posted by mgeoffriau
Were you on a NASCAR oval track at the time?
Look at the location in first post. Probably on the Autobahn.
Arca_ex is offline  
Old 06-16-2015, 01:47 AM
  #14  
Junior Member
Thread Starter
 
Mazdaspeed_Miata's Avatar
 
Join Date: Jul 2008
Posts: 58
Total Cats: 3
Default

Hey guys,

some answers:

- transmission is 6speed with 3.6torsen (from a 10th anni edition) (I think this is a great gear ratio step up for the car; gears 1-4 are nearly the same like 5speed with 4.3end)
- setup: 1.6 stock engine, 10psi, GT2560R
- last dyno was 222hp at flywheel, and 190rwhp
- the car was still accelerating, but then a idiot block the left lane, so I had to brake and slow down
- and yes video was filmed on autobahn, so all legal


I meassured 862°C after turbo and 970°C at the collector in the exhaust manifold before turbo at that high speed . All cool I think, what do you think?

Best regards!
Basti

Last edited by Mazdaspeed_Miata; 06-16-2015 at 06:50 AM.
Mazdaspeed_Miata is offline  
Old 06-16-2015, 02:00 AM
  #15  
Elite Member
iTrader: (3)
 
deezums's Avatar
 
Join Date: May 2014
Location: Kansas
Posts: 3,146
Total Cats: 201
Default

3.63 master gear, do want, want bad.

Did you have that imported from somewhere, or is it not oem? Can you find me one lol
deezums is offline  
Old 06-16-2015, 02:50 AM
  #16  
Senior Member
iTrader: (1)
 
NiklasFalk's Avatar
 
Join Date: Jun 2006
Location: Sweden
Posts: 1,391
Total Cats: 63
Default

Originally Posted by deezums
3.63 master gear, do want, want bad.

Did you have that imported from somewhere, or is it not oem? Can you find me one lol
3.6 was delivered on every 6speed in Europe, and Australia, and ... Ebay is your friend
3.9 was used in US/CA and JP (and maybe somwhere else).
NiklasFalk is offline  
Old 06-16-2015, 10:31 AM
  #17  
VladiTuned
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 35,821
Total Cats: 3,481
Default

I've been in a race prepped miata at 156mph, but never in a street car.

How does that feel? That's gotta be scary, my nb's get real floaty past 120
18psi is offline  
Old 06-16-2015, 10:58 AM
  #18  
Elite Member
iTrader: (17)
 
pdexta's Avatar
 
Join Date: Aug 2007
Location: Knoxville, TN
Posts: 2,949
Total Cats: 182
Default

Nice video. That's intense to watch, especially once the speedo is burried in 6th.
pdexta is offline  
Old 06-16-2015, 11:07 AM
  #19  
Junior Member
 
TalkingPie's Avatar
 
Join Date: Oct 2011
Location: Montreal, QC
Posts: 271
Total Cats: 55
Default

Originally Posted by 18psi
I've been in a race prepped miata at 156mph, but never in a street car.

How does that feel? That's gotta be scary, my nb's get real floaty past 120
My feelings exactly. My car doesn't feel like it's in a happy place above 100, to the point that I've only done it a couple of times in 4 years. And I used to hit 120+ on my bikes practically every time I took them out, including the work commute.

OP: Haben Sie aerodynamische Abaenderungen gemacht?
TalkingPie is offline  
Old 06-16-2015, 11:56 AM
  #20  
Junior Member
Thread Starter
 
Mazdaspeed_Miata's Avatar
 
Join Date: Jul 2008
Posts: 58
Total Cats: 3
Default

Well, I won't say that it feels very comfortable past 120mph, but in my own sensation it is still ok. My biggest fears are that I have to do an emergency braking from high speed (because i have no ABS) or that the engine blows away at that speed. The feeling inside of the car without any problems is ok. Only the wind noice gets pretty loud at that speed

Again my question:
I meassured 862°C after turbo and 970°C at the collector in the exhaust manifold before turbo at that high speed . All cool I think, what do you think?

And I have no aerodynamic specs, only the factory airdam at the front.

Here 4 pics of my miata:

<a href="http://www.directupload.net" target="_blank"><img src="http://fs2.directupload.net/images/150616/yqwidcl5.jpg" title="Kostenlos Bilder und Fotos hochladen"></a>
<a href="http://www.directupload.net" target="_blank"><img src="http://fs2.directupload.net/images/150616/ehl9luko.jpg" title="Kostenlos Bilder und Fotos hochladen"></a>
<a href="http://www.directupload.net" target="_blank"><img src="http://fs1.directupload.net/images/150616/owka3uam.jpg" title="Kostenlos Bilder und Fotos hochladen"></a>
<a href="http://www.directupload.net" target="_blank"><img src="http://fs1.directupload.net/images/150616/caqr3hcv.jpg" title="Kostenlos Bilder und Fotos hochladen"></a>
Mazdaspeed_Miata is offline  


Quick Reply: my 155mph miata



All times are GMT -4. The time now is 08:22 AM.