Tech. info.

[Robs89LXi]

1. Does anyone know what the air flow rate is for an A20A3 cylinder head? (Flow vs. RPM would be nice).

2. Does anyone have turbo compressor maps plotted for a stock A20A3?

3. Does anyone have a dyno chart for a stock A20A3?

[AccordEpicenter]

1. I think its 130cfm intake, 90 exhaust... idk i think sean knows.
2. WTF are you talking about?
3. not really sure

[smufguy]

2. Compressor maps is exactly as it is called. They are mapped for just the compressors not for the block they are mated to. The motor it is mated to has nothing do with the compressor charectaristics.

3. not an actual dyno, but a dyno sheet none the less.

http://img62.exs.cx/img62/5766/engine4.jpg

[Robs89LXi]

2. Compressor maps is exactly as it is called. They are mapped for just the compressors not for the block they are mated to. The motor it is mated to has nothing do with the compressor charectaristics.

3. not an actual dyno, but a dyno sheet none the less.

http://img62.exs.cx/img62/5766/engine4.jpg

LOL. Gee, thanks for explaining that to me, Praveen. No, Sherlock, I mean has anyone plotted our engine requirement at different rpm ranges ONTO a compressor map. You know, taking into account such things as displacement, rpms, air-flow requirements, temp., volumetric efficiency etc. How are you going to decide on a turbo, if you don't know where your engine falls on the compressor maps?
Thanks for the dyno sheet too, but for some reason, I don't see the yellow line that is supposed to be the A20A3. If it was just lost when you posted it for some reason, please PM it to me. Thanks.

[smufguy]

lol, i was just messign around ROb. Well, no one except sean and Elijah who have turbo has dynoed it. Sean for some reason is against presenting his dyno sheet no matter how many members ask him, despite how many times. Elijah dynoed his car, so ask him. I dont think jason did it yet and Rob-t will join there soon.

[Robs89LXi]

Okay, question is though, can't you plot N/A figures for an engine on a compressor chart to see where they fall? How else would you use a compressor map to determine what size turbo you need? Wouldn't that be kind of "after the fact" otherwise?

[smufguy]

Okay, question is though, can't you plot N/A figures for an engine on a compressor chart to see where they fall? How else would you use a compressor map to determine what size turbo you need? Wouldn't that be kind of "after the fact" otherwise?

okay i quite dont get what ur talking about, but u cannot plot NA figures on a compressor chart. The compressor chart has Pressure raito on the Y axis and corrected air flow on the X-axis. The graphs inside mark the area of turbo efficiency in relation to TURBO rpm. The engine rpm or engine corralation is not on the compressor chart.

If im not mistaken, the turbo size for a given engine is chosen by the ar ratio. Like for example. Jason runs a smaller turbo than Rob-t cause Rob-Ts motor has more work done to it but Jason's motor is stock and so is Elijahas. Turbo sizing mainly concetrates on what displacement ur engine is and how much u can push and where u wanna make the power. LIke the Drag motors use bigger turbos not caring for low end power since they run on high rpm. Street guys use smaller turbos since they want low end power. U can also use bigger turbo with nitrous to help spool up if you badly need. So saying how to choose a turbo has a lot of opinions on it basically. Its each of his own liking.


On the original A20 Graph i showed u, the second white line u see, is actually the A20A3 motor. THe long white graph is the B20.

A20A dyno sheet (not stock, sorry)

http://openloopmotorsports.com/dyno2.jpg

Compressor Chart.

http://cherrypicker.tripod.com/sitebuildercontent/sitebuilderpictures/t3-60-cm.jpg

[smufguy]

here is something i came across. http://www.ztechz.net/id7.html

http://majesticturbo.com/images/info.gif

i hope these kinda give u an idea and what you asked is a pretty common thinking but no one really asked. I am glad u asked, cause it made me look more into it.

[Robs89LXi]

here is something i came across. http://www.ztechz.net/id7.html

http://majesticturbo.com/images/info.gif

i hope these kinda give u an idea and what you asked is a pretty common thinking but no one really asked. I am glad u asked, cause it made me look more into it.

Okay, but look at that site you showed above. That is exactly what this guy did; plot a graph onto the compressor chart to see when/where he would be obtaining boost. With the example he gave, that turbo would start building boost at around 3K rpm and pull to redline.

We should be able to plot our engine needs against different charts as well to see what is optimum for us. I plotted some on an Excel spreadsheet, using info from http://www.turbofast.com.au/javacalc.html and others. These are all rough figures though, as they certainly don't consider all the parameters, but they should give a pretty good estimate. How do I post an Excel spreadsheet?

[Robs89LXi]

Oops. Let's try this again.

[Robs89LXi]

Also, look here:
http://www.gnttype.org/techarea/turbo/turboflow.html

[smufguy]

Oops. Let's try this again.

Rob i got a excel file that i have that plots it. Do u have an email i can email it to? This file basically plots the engine output in relation to certain given Turbos. u can also edit it ( i dont know how) to fit more turbos in.

[Robs89LXi]

You've been PM'ed.