How much airflow? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 07-11-2009, 01:39 PM   #1
Junior Member
Thread Starter
 
Join Date: Jan 2009
Location: Ashe County NC
Posts: 217
Total Cats: -1
Default How much airflow?

How much airflow is a .80A/R T25 "SR20" turbo good for? Also what are the siZes of the compressor and turbine wheels? (I know I made a capital "Z" but my "Z" button only works when the shift key is held down... Weird I know..) I have read through the turbo tech pages on the garrett website several times, but its still kinda foggy.. Now, I understand that A/R mean area ratio, and this is referring to the compressor housing correct? Based on that number is it possible to figure out the wheel siZes on my own? Also, Is 16psi reasonable from this turbo, being near the efficiency range I mean... Sorry for the newb questions I'm still getting my feet wet to how all this works..
adamhershner is offline   Reply With Quote
Old 07-11-2009, 02:01 PM   #2
Tour de Franzia
iTrader: (6)
 
hustler's Avatar
 
Join Date: Jun 2006
Location: Republic of Dallas
Posts: 29,114
Total Cats: 351
Default

find the compressor and turbine maps. good luck.
hustler is offline   Reply With Quote
Old 07-11-2009, 02:13 PM   #3
Junior Member
Thread Starter
 
Join Date: Jan 2009
Location: Ashe County NC
Posts: 217
Total Cats: -1
Default

After a half hour of searching I found an old site on google that lists this turbos specs:
.80 A/R compressor housing
60 "trim" compressor wheel
.64 A/R turbine
62 trim turbine
Airflow was said to be 28 lbs/min, does that sound correct? Also is there a way of calculating horsepower based on this airflow number?
adamhershner is offline   Reply With Quote
Old 07-11-2009, 02:29 PM   #4
Senior Member
iTrader: (2)
 
Join Date: Jun 2007
Location: Shalimar, FL
Posts: 965
Total Cats: 7
Default

Isn't the SR20 turbo (idk if there is a difference b/n blacktop and redtop ones) the 2560? I thought Garret's website said something like that.
messiahx is offline   Reply With Quote
Old 07-11-2009, 02:48 PM   #5
Elite Member
iTrader: (7)
 
samnavy's Avatar
 
Join Date: Apr 2006
Location: VIRGINIA BEACH, VA
Posts: 6,020
Total Cats: 175
Default

^No, the regular T25 is a small journal bearing.
On a 1.6 with good management and 3" exhaust, it's good for about 220whp at 16psi, fully spooled by 3k, and that's it. You can squeeze another 10whp or so out of a 1.8. Torque will never be above about 190wtq and it starts to fall of about 5000 rpm.

The T28 is BB, and came on GTiR motors of various models and years and is comparable to a 2560.
samnavy is offline   Reply With Quote
Old 07-11-2009, 03:37 PM   #6
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by hustler View Post
find the compressor and turbine maps. good luck.
ask and you shall recieve.



Braineack is offline   Reply With Quote
Old 07-11-2009, 03:39 PM   #7
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by adamhershner View Post
Also is there a way of calculating horsepower based on this airflow number?

lb/min / AFR / (BSFC/60)


28 / 11.5:1 / .00916 = 265BHP
Braineack is offline   Reply With Quote
Old 07-11-2009, 03:41 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,899
Total Cats: 1,792
Default

Quote:
Originally Posted by samnavy View Post
The T28 is BB, and came on GTiR motors of various models and years and is comparable to a 2560.



this is the difference between the T25 and a T28, the compressor wheel:



the 2560 uses a 60mm compressor wheel.

t28 = t25 + T3
Braineack is offline   Reply With Quote
Old 07-11-2009, 06:19 PM   #9
Junior Member
Thread Starter
 
Join Date: Jan 2009
Location: Ashe County NC
Posts: 217
Total Cats: -1
Default

Wow thanks so much for all the info! When looking at that first map, is it read like a contour map? Like does each line represent a given "Altitude" or pressure? Thanks again all this info is great!
adamhershner is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Underbody Aero Thread (splitters, panels, vortex generators) JimAtFSU General Miata Chat 107 09-19-2012 08:56 AM
Airflow adjustment knobs + airflow adj map ARTech E-Manage 0 07-25-2009 01:23 AM
BEGi Air Scooper - does it impact IC airflow? MazDilla Prefabbed Turbo Kits 14 06-27-2008 10:48 PM
airflow in the NB y8s DIY Turbo Discussion 29 06-28-2007 02:43 AM
E-manage ultimate FAQ smiles Useful Saved Posts 1 07-25-2005 11:34 AM


Thread Tools

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 06:54 PM.