A/R TO cm2 CONVERSION ??

[92 D/UNIT]

Does anybody know what the cm2 is on a exh housing with a 1.28 A/R ? this is a w/g k31 turbo that i picked up cheap and im trying to determine whether the exh housing is too big for a compound setup for the street.
thanks!

[ford69557ci]

if it is the wastegated k31 it is the same turbo that industrial injection uses in their towing twins kit. i have 3 of those laying around off of 60 series detroits. a k31 is also what the compressor side of aurora 5k is but the exhaust housing is different. i would also like to know if the is a way to convert a/r to cm2?

[ford69557ci]

6 cm2 = 0.41 A/R
7 cm2 = 0.49 A/R
8 cm2 = 0.57 A/R
9 cm2 = 0.65 A/R
10 cm2 = 0.73 A/R
11 cm2 = 0.81 A/R
12 cm2 = 0.89 A/R

i dony know how they came up with this but its a start if any math people wanna keep goin with the conversion

[ford69557ci]

looks like for every one cm2 the a/r goes up .08??? thats my take anyway buy i suck at math

[ford69557ci]

6 cm2 = 0.41 A/R
7 cm2 = 0.49 A/R
8 cm2 = 0.57 A/R
9 cm2 = 0.65 A/R
10 cm2 = 0.73 A/R
11 cm2 = 0.81 A/R
12 cm2 = 0.89 A/R
13 cm2 = 0.97 A/R
14 cm2 = 1.05 A/R
15 cm2 = 1.13 A/R
16 cm2 = 1.21 A/R
17 cm2 = 1.29 A/R

im tired of typin a/r and cm2 so someone else continue

[92 D/UNIT]

I saw that on a ricer site but didnt think it was right. do you know if its the same for all turbo brands?
anybody know what the A/R is on the industrial injection k31?

[ford69557ci]

no clue my friends II k31 and the ones off of the 60 series detroit that i have look identical i know the outside if the housing is the same and according to detroit there was only one housing made for the k31 that was wastegated.

[flashgordon]

6 cm2 = 0.41 A/R
7 cm2 = 0.49 A/R
8 cm2 = 0.57 A/R
9 cm2 = 0.65 A/R
10 cm2 = 0.73 A/R
11 cm2 = 0.81 A/R
12 cm2 = 0.89 A/R
13 cm2 = 0.97 A/R
14 cm2 = 1.05 A/R
15 cm2 = 1.13 A/R
16 cm2 = 1.21 A/R
17 cm2 = 1.29 A/R

im tired of typin a/r and cm2 so someone else continue

What is A/R?
the cm2 is a size or measurement.... or space inside a turbo housing?.........is the A/R a flow.......at a set pressure? .....................................................
What do the A/R letters stand for?
just kinda lost here and would like some help to figure it out.
Flash

[92 D/UNIT]

on some turbos there is a exh housing size such as a 12, 14, 16 or18.5. and some turbo manufacturers dont use that type of measurement they use A/R. and i know nothing about A/R.
Here is some reading.
http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html#b
if you understand it, could you explain it too me in white mans terms?

[flashgordon]

on some turbos there is a exh housing size such as a 12, 14, 16 or18.5. and some turbo manufacturers dont use that type of measurement they use A/R. and i know nothing about A/R.
Here is some reading.
http://www.turbobygarrett.com/turbobygarrett/tech_center/turbo_tech102.html#b
if you understand it, could you explain it too me in white mans terms?

WOW Grate read!!!!!!!!
I thing it's a bit over my head put i print it out so i can read it when i have more time............Thanks again for the link.

O and by the way A/R is the Air Radius
EDIT: :bball: HOW ABOUT AREA/ RADIUS

Flash.

[DLittle]

Brain,

Here's some info given to me from CityDiesel. Hope this helps.
jason
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Re: Hot Rod Detroit 60/K31
« Reply #1 on: March 14, 2007, 05:11:00 PM »

--------------------------------------------------------------------------------
The turbo is wastegated at 34 psi

The compressor wheel dimensions are
3.937 / 100 mm back wall
2.795 / 71mm inducer

the turbine housing specs are
24.92 cm

It is a pretty large turbo, but faster spooling than some common turbos used in twins. It will spool faster than an ht3b but will also support slightly less horsepower...

[92 D/UNIT]

thanks Dana, so basically about 25 cm2 exh housing. mine is the garrett version of the k31. do you think it matters? was that for the 1.28 a/r?

[ford69557ci]

the detroit ones i have are wastegated and they say garret on them?

[92 D/UNIT]

yep this came off of a Detroit. same turbo as what you have. do you have any with smaller exh. housings or are they only one size?

[ford69557ci]

the service and parts guys at detroit said that there is only one wastegated housing made for the 60 series. maybe garret makes some others that i am not sure of.