Reading compressor maps?
 

I thought there use to be a sticky on how to do this? I'm not seeing it and I'm sorry im not digging thru 500 pages that mention the word "compressor map".

Someone help me out here. Anyone have a link or...

http://img98.imageshack.us/img98/1585/untitled15lj.jpg

Someone please explain this to me, I want to know how to calculate for future references not just a # answer. I need to know the max PSI I can run on my hx-35 while staying in the 76% eff range (thats the island thats ideal, correct?)

Explain it like you would to a retard, i can be a little slow.

Sorry, I feel like such a noob. Flame on.

Re: Reading compressor maps?
 

PR is ratio of boost pressure to atmospheric.

It looks like the highest point on the 76% island is at a PR of about 2.35.

2.35 * 14.7 = 34.5 psi

That's just talking about boost pressure, you still have to account for the amount of air being moved.

You don't need to stay in the center island to make good power.

Re: Reading compressor maps?
 

jon do u mind if i hit you up on aim? I dont want to clutter this post w/ back n forth answers. I still have some things to clear up.

Re: Reading compressor maps?
 

I'm not home now so I won't get the messages

Re: Reading compressor maps?
 

www.not2fast.com

Compressor efficiency is over rated. Don't worry about it much. You can see how little compressor efficiency matters using the calc on not2fast and varying the compressor efficiency and pressure. You will see running the lowest pressure possible is way better than running at 60% compressor efficiency.

Re: Reading compressor maps?
 

I think that should be 34.5psi minus atmospheric pressure. I always thought it was pressure absolute listed on compressor maps...

Re: Reading compressor maps?
 

1.0 PR = atmospheric pressure or 14.7psi absolute
2.0 PR = 14.7psi above atmospheric pressure or 29.4psi absolute

So 2.35 PR is 34.5 psi absolute or 19.845 psi gauge.

Re: Reading compressor maps?
 

ok
its easy, i have an ms excel turbo calculator i wrote a while ago to calc this ---- out, and it has heaps of special features and other stuff too. if you want it email me and pm me.

otherwise...

y axis is the pressure ratio generated by the compressor, which jago already said.
x axis is the mass airflow from the compressor, in lbs/min
here's how to convert it.

hope this helps

Re: Reading compressor maps?
 

Have you guys ever come across a Turbo, you get the Compressor map and it says its only good for 1.5 bar boost. but it makes postive power all the way to 2.2 bars.

Is this a Common occurance in the turbo world?

Re: Reading compressor maps?
 

Ok, I was right...Jago had me confused there for a second.