Dave951

I was thinking about compiling the large number of turbo compressor maps I have collected into a nicely organized thread to share with everyone. Data from manufactures such as Garrett, Holset, Mitsubishi, Borg Warner and more.

I did a quick search, and didn't find much but I wanted to ask and see if anyone knew if it has already been done here. If not, I'll be happy to put the compilation together.

blown 944

I have a bunch myself and I have not seen a compilation here.

It would be nice of you to do that.

blown 944

dbl slow computer

porschefig

It would be very nice to have this!

Is it not somewhere on the net already?
(I haven't looked b/c I know if I decide on a turbo I'll want one that much more! No $$$$)

Rogue_Ant

Here is a huge list of maps...

Compressor Maps


-Rogue

Dave951

Rogue_Ant That listing is pretty comprehensive. Looks like somebody beat me to the punch.

Rogue_Ant

Yeah - though nothing wrong with having your own compilation


-Rogue

944obscene

I'm reading up on compressor maps and how to calculate for best flow and efficiency (as per application) and how to calculate for pressure loss over a turbo system. Always been into superchargers. I know those things. Now that I have a turbo car, I'm gonna need to do my homework on turbo's. Always had a loose understanding of them.

INURGRL951

This is ALWAYS a fun topic in other place I have been talking about turboed cars. I always tell people just don't go buying a turbo because you heard it was good. You need to figured out what you wanna do with your car and then you can decide on a turbo.And this is where you need to start with these maps to get the best suited turbo for your car ........sorry I like to ramble at times

333pg333

^^ Put down the MOONSHINE Costas!!

Can someone give a brief precis into reading these maps? How definitive can they be? Are they purely based on a flow rate determined by pressure in and out. So if I am looking at putting Turbo 'X' on my 8v 2.5L and someone else is looking at the same turbo for their 3L 16v, how do we differentiate what is best suited for our needs? Where does the overall VE of the rest of the components come into play?
Thanks for that Link Rogue, it's a great site allowing you to compare up to 8 maps at one time. I just wish I knew what I was reading...

95ONE

complete generalization, but a good start.

Lbs/min = hp. So 40lbs/hr = 400whp. - generalization here and you'll have to decide what equals what depending on your current VE. This motor stock longblock I would use 85% Some maps use CFM, so youll have to do the math on that one. - covered in link a the end.

pressure ratio is easy. It's boost in Bar. 1= atmospheric, 2=1 bar or 14.5psi - just like our boost gauge in the dash.

here's a great write up that you'll have to follow closely, but this is almost as good as it gets. Do the comparisons with him and you'll be a pro in no time. i've spent countless hours deciding on a turbo based on these maps. then in the end, I asked a pro for a more finite final set up.

Read great write up HERE

333pg333

Just had a quick look at that link Bruce and you're right, you have to have your pre beer head on, but from what I can see one of the most difficult parts of the equation to factor in is the VE but I'm also not sure how much variation you're going to get between the eg 85% figure and 93%? I assume there is a more accurate way of calculating this but what do you have to measure? The valve size, cam duration, piston bore/stroke, inlet, throttle body, i/c and pipes?? Does the post turbo exhaust have a bearing on VE?
In the end I too would defer to someone else when speccing a turbo based on what I can see.

RPHARRIS

I'm going to throw out an opinion that probably won't be very popular around here ...or anywhere for that matter: Turbo size is not that critical! There, I said it. I know how to do all the BSFC calculations and I've read that Corky Bell book about 32234523 times and I can confidently say that 90% of people completely over think the issue. The bottom line is that depending on the power level you're aiming for, there are AT LEAST 3-4 options that will all work great. You can use maps to figure out what those options are but that's pretty much it. At some pount you just have to get over the illusion that there is one perfect turbocharger for your goals and you MUST find it.

A couple things you SHOULD look for on a compressor map:
-Are you likely to encounter surge (not a very common issue on our cars)
-Do some rough estimations and calcs and plot your engine's "flow curve" (whatever you want to call it) for the highest, lowest, and one or two other pressure ratios you expect to see. If you live at ridiculous altitude like blown, you might want to factor that in to your calcs.
-I'm already sick of this, just pick one already!

RPHARRIS

Take what I say with a grain of salt, apparently I'm the guy who just had his membership revoked because he forgot to pay the bill!

95ONE

I simplified it by taking into account that at 15psi It made 300 horsepower at the wheels. Meaning it makes right about 150 at the wheels without boost. - best way is to disconnect boost pipe and dyno it. But that can only be done on a map car. you will definately get a better VE picture. Of course the VE is different at different RPM points. you can drive yourself insane chasing this. So generalize as close as you can get. - Hows that for a statement!

I actually used .85 I think.