Compressor Maps - Skool me like I'm Stooopid - 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 11-05-2012, 02:35 PM   #1
Senior Member
Thread Starter
iTrader: (4)
 
mr_hyde's Avatar
 
Join Date: Jul 2009
Location: Seattle
Posts: 799
Total Cats: 25
Default Compressor Maps - Skool me like I'm Stooopid

I know a map doesn't tell the whole story but I want to understand more about what part of the story they do tell. Here are two turbos that are somewhat comparable on the butt dyno - the 2560 and Mazdaspeed IHI with the 15g wheel upgrade.

The pressure numbers listed up the side are atmospheres (BAR), correct? On these charts, 1 Bar is what we inhale and 2 Bars is ~14.7psi on the boost gauge, correct? Bigger turbos flow more (x-axis) and allow higher pressure (y-axis) at the possible expense of spool/lag time, correct?

How would you expect these two turbos to perform in the real world (all other things equal) and do you think flow is more important than pressure or vice versa? Is a good balance the better way to look at it?

It's cold and wet here and since I can't drive the car and haven't found the motivation to dig into the winter projects, I thought a little book work might be helpful. Informed opinions much appreciated - thanks!



Attached Thumbnails
Compressor Maps - Skool me like I'm Stooopid-garrett_gt25_turbocharger_gt2560r_compressor_map_60_trim_330_hp_honeywell_450x600_turbocharger_s.jpg   Compressor Maps - Skool me like I'm Stooopid-td04_15g_raw.sized.jpg  
mr_hyde is offline   Reply With Quote
Old 11-05-2012, 02:36 PM   #2
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,877
Total Cats: 1,790
Default

Braineack is online now   Reply With Quote
Old 11-05-2012, 03:27 PM   #3
Senior Member
Thread Starter
iTrader: (4)
 
mr_hyde's Avatar
 
Join Date: Jul 2009
Location: Seattle
Posts: 799
Total Cats: 25
Default



I read through them once and understood what I was reading (I think). Now, I need to go through about 5 more times and pencil out some actual calculations to see if I can put this in the mythical 'applied knowledge' category.

I haven't searched yet but does anyone know the basic VE for our engines (BP4W head)? I appreciate there are dozens of variables so perhaps just a ballpark range? Very interesting - thanks for the links Brain!
mr_hyde is offline   Reply With Quote
Old 11-05-2012, 03:33 PM   #4
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,051
Total Cats: 7
Default

Compressor maps won't show any spool or lag characteristics, that's what turbine maps are for (well sort of).

Compressor maps will show you exactly what it says, how much air the turbo can flow at any given pressure ratio (the y-axis, not BAR) and how efficiently it does it and at what wheel speed. You can use this information and some specifics of your engine to guesstimate if you will have problems with surge and if the compressor can meet your goals.

Oh and the answer to your question is EFR6258. It's compressor map makes these look like a joke, oh and it will spool much faster.
Efini~FC3S is offline   Reply With Quote
Old 11-05-2012, 03:35 PM   #5
Senior Member
iTrader: (14)
 
Join Date: Oct 2006
Location: Las Cruces, NM
Posts: 1,404
Total Cats: 263
Default

Good read. Props!

6258 map:


Taken from this page of all EFR maps:
http://www.turbos.com/efr-compressor...and-specs.html
99mx5 is offline   Reply With Quote
Old 11-05-2012, 04:21 PM   #6
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Heres a pretty nifty spreadsheet to help you understand how a certain compressor will work with your engine. Right now its setup for a 2.5 liter subaru so you'll need to change the displacement and the VE numbers. The 15t compressor is in the spreadsheet.
Leafy is offline   Reply With Quote
Old 11-05-2012, 05:15 PM   #7
Senior Member
Thread Starter
iTrader: (4)
 
mr_hyde's Avatar
 
Join Date: Jul 2009
Location: Seattle
Posts: 799
Total Cats: 25
Default

Quote:
Originally Posted by Efini~FC3S View Post
Oh and the answer to your question is EFR6258. It's compressor map makes these look like a joke, oh and it will spool much faster.
True - that is on the list for... someday. I could have rephrased the question to be 'what's the best without spending a penny of additional budget?'

Leafy, I didn't see the spreadsheet attached. Do you have a link?
mr_hyde is offline   Reply With Quote
Old 11-05-2012, 05:41 PM   #8
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

I gues it cant do xls and I didnt notice it failing. I dont have time now maybe tomorrow.
Leafy is offline   Reply With Quote
Old 11-10-2012, 08:56 AM   #9
Junior Member
 
Join Date: Jun 2012
Posts: 68
Total Cats: 0
Default

Here is my spreadsheet for the 1.8L.
https://docs.google.com/spreadsheet/...ya3p6MGc#gid=0
TheGrim is offline   Reply With Quote
Old 11-10-2012, 11:36 AM   #10
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Finally got around to posting the one I use. Credit goes to a whole litany of people on rom raider forums. I've only just made the most recent update, and that was really just combining tow sheets.

https://dl.dropbox.com/u/18163809/co...ap_combine.xls
Leafy is offline   Reply With Quote
Old 11-10-2012, 12:03 PM   #11
Junior Member
 
Join Date: Jun 2012
Posts: 68
Total Cats: 0
Default

Your VE is much higher than mine. Is this a more accurate representation? If so I will update mine as well.
TheGrim is offline   Reply With Quote
Old 11-10-2012, 12:16 PM   #12
Elite Member
iTrader: (2)
 
triple88a's Avatar
 
Join Date: Apr 2006
Location: Chicago, IL
Posts: 9,131
Total Cats: 598
Default

Quote:
Originally Posted by Techsalvager View Post
For reading turbine maps is the pressure part from the exhaust manifold pressure?
/thread
triple88a is offline   Reply With Quote
Old 11-10-2012, 12:23 PM   #13
Junior Member
 
Join Date: Jun 2012
Posts: 68
Total Cats: 0
Default

Ugh...I haven't been here in months, yet I still remember the garbage that Tech spewed...
TheGrim is offline   Reply With Quote
Old 11-11-2012, 11:37 AM   #14
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Quote:
Originally Posted by TheGrim View Post
Your VE is much higher than mine. Is this a more accurate representation? If so I will update mine as well.
No, thats all subaru numbers in there.
Leafy is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
Someone help me with AE ihiryu MEGAsquirt 33 10-08-2015 05:56 PM
"Chimney Ethanol" E100 MiataGarage Engine Performance 5 09-30-2015 12:04 AM
In need of base map for stock 1997 brandonbkd MEGAsquirt 0 09-29-2015 12:52 AM
Missing/knock at idle, can someone point me in the right direction? Mikel MEGAsquirt 4 09-28-2015 05:46 PM


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 10:16 AM.