StanB

I need to know the compressor A/R. I was told it came off a 6 cylinder Nissan truck. The noob that pulled the turbo left off the flange that connects to the intake pipe, and the flange that connects to the input side of the intercooler. The number might have been stamped on or inside one of the flanges. The exhaust/turbine side A/R is .65.

Thanks in advance for all the help/information.

ThingyNess

That's kind of an odd little guy - dont' see too many with 3-bolt compressor inlet flanges. If it's a Garrett and you have the Garrett part number from the CHRA, i might be able to help you out.

Alternatively of course, if you have the turbo in hand, you could just measure the A/R yourself with a set of calipers and a telescoping bore gauge (not that everyone has those handy)

StanB

There is no name of the maker or a part number stamped on it. If no one is able to identify it for me, I will have to take it to a machine shop to get the A/R measured.

Thanks for the suggestion.

HMT-Admin

What do you plan on putting it on?

StanB

My D16Z6. I wanted to try it and see the outcome. Right now I'm running a Garrett A/R-.60/.48.

HMT-Admin

it will work pretty similar to the turbo you have now

ThingyNess

If the machine shop is going to charge you anything at all to figure it out, i'd just do it yourself. A set of plastic vernier calipers can be had for $0.99, and a telescoping bore gauge isn't too terribly expensive, and is a nice tool to have kicking around. If you REALLY want to get ghetto, you can just take a toothpick or something and break it until it just fits in the diameter of the compressor outlet scroll at the point where you want to measure (A/R is constant throughout the scroll), and then take it out and measure it with your calipers.

Take that diameter (in inches), divide it by two to get the radius - square the radius and multiply by 3.1415 to get the cross-sectional area.

Then divide the A you just measured by the R - which is the distance from the center of the compressor wheel to the middle of the part of the scroll you just measured. You won't be able to get this exactly accurate, but within 5%, which should be enough anyway.

Voila, you now have your A/R, and it cost you $0.99 and a wooden toothpick.

The trim / size of the compressor wheel is generally much more important than the A/R of the compressor cover anyway - you'd be better off taking off the compressor cover and measuring the inducer and exducer of the wheel, along with the height and using that to estimate flow.

Generally you can match that pretty close to an off the shelf garrett or mitsubishi wheel which we already have flow maps for.

StanB

Ok. Thanks for the info.

StanB

ThingyNess, based on your suggestion, I'll take it to school and use one of the telescoping guages. I'll then use an outside micrometer to get the diameter reading. After that I just have to do is follow your instructions. Thank you