Anybody got Compression Maps for stock turbos

Matt Monson · Post by **Matt Monson** » Wed Nov 19, 2003 9:45 pm

I am interested specifically in the TD04's and TD05's A search brought up nothing...

Matt Monson · Post by **Matt Monson** » Wed Nov 19, 2003 10:00 pm

Nevermind...Look what I just found...

http://not2fast.wryday.com/turbo/maps/all.html#mitsu

Dizzy · Post by **Dizzy** » Wed Nov 19, 2003 11:58 pm

Awesome find, Matt. I've been looking around for something like that.

Post by **Legacy777** » Thu Nov 20, 2003 12:49 am

this page and all the images may be worth saving in case the site goes down in the future.

very good info to have.

vrg3 · Post by **vrg3** » Thu Nov 20, 2003 2:02 am

Done and done. :D

http://www.graphics.cornell.edu/~v/compressormaps/

I thumbnailified it too.

Post by **Legacy777** » Thu Nov 20, 2003 3:06 am

good man!

Brat4by4 · Post by **Brat4by4** » Thu Nov 20, 2003 6:11 pm

So how do you read these things? I believe they show you where certain turbos lose efficiency at a certain boost (& load?)

vrg3 · Post by **vrg3** » Thu Nov 20, 2003 7:35 pm

They tell you about a compressor's efficiency (just the compressor; they say nothing about the turbine).

Generally, the horizontal axis is airflow, measured in either mass per unit time or volume per unit time. If it's volume per unit time it is measured before the compressor inlet.

The vertical axis is the pressure ratio (the pressure after the compressor outlet divided by the pressure before the compressor inlet).

Each of the "islands" is labeled with a percentage, indicating the compressor's efficiency in that area of the pressure ratio vs. airflow curve. You can kind of think of this as if it were like a topo map.

Each of the lines with a number in the tens or hundreds of thousands by it indicates the compressor wheel's rotation speed (usually in RPM) at that area of the graph.\

Does that help?

Matt Monson · Post by **Matt Monson** » Fri Nov 21, 2003 3:11 am

I have saved this as well. My girlfreind and a group of us from Cobb's WRXforum are trying to put together a real extensive database of PN's and compatibilities between years and models of Imprezas and Legacies. Anyone who would be interested in joining read this thread and you'll get the general idea... http://www.wrxforum.com/cgi-bin/ultimat ... 2;t=002928
The project is still totally fledgling and she is still building the site, but some Legacy specailists would be welcome...

As far as the maps are concerned, SCC did an article earlier this year about how to pick the right turbo for your car. I will do the math for the EJ22 and post it up here for all to see. Thanks to Dizzy for planting the seed on this one.

Your warning to me that if I went beyond 13psi or so on the stock turbo that I might be out of the efficiency of it made we want to know for sure. I was thinking that since our cars have the same turbo as the 1st gen WRX's (they do don't they?)

and those cars run a lot more boost than our stock boost, the turbo should be good up to 15 or 16psi. But I need to find out for sure.

I haven't done the math yet, but will in the next day or two. My one question is I am unsure which one of those many Mitsu turbos is actually the same one in our cars. Can anybody help me here?

91White-T · Post by **91White-T** » Fri Nov 21, 2003 4:04 am

I've never seen a flow map for any IHI turbo but I can tell you from personal experience (at least on my setup) that there's almost no power incease after 14 or 15psi. I've had it up to 22psi, and it felt no different than 15.

legacycentral bbs

A forum for 89-94 BC-BF(BJ) Legacy Owners and Fans

Anybody got Compression Maps for stock turbos

Anybody got Compression Maps for stock turbos