
GTIR T28 79 Trim Turbine Exducer/Inducer Calcs...

Originally Posted by
Kleensleeper
^That might be an interesting combo.

Originally Posted by
fro20
Oh, and I wish you could tell me the major of the gtir t-wheel, I have 3 trbos in my garage and am thinking of building a frankenstein, have all the specs less the gtir, and no Micrometer handy.
I guess I can go to the shop and mike it.
Here we go... I dont know if the way i did it is the best... but there leaves a tiny room for error, but nontheless. This is for a GTIR T28 Turbine Wheel... since I couldn't find diameter specs anywhere...
I used a zip tie and a ruler to measure instead of the string... because the string didn't exactly make a circular patter around the turbine blade... I marked where the circumference stopped, and found the radius that way. This is what I found...
http://www.sr20forum.com/forced-induction-performance-parts/164299-gtir-t28-turbo-kit.html#post1609555

Originally Posted by
andatronPrice includes shipping so its effectively free! Usually take around a week to get to ya. Yes i have these every now and then, but if you are after one at a later date it is better to commit to it and let me know in advance so i have time to source the parts. thanks
No the GTI-R t28 is not a ball bearing, however it is the largest of the factory t28's.
Specs Are:
Compressor: Inducer 47.1mm Exducer 60mm A/R .60
Turbine : Inducer 53mm Exducer 47mm Trim 79 A/R .86
cheers
But I went ahead and still posted my calculations to check it... it was a little off from what he posted, but I'd just assume what he posted since his numbers were probably from the factory or a remanufacturer or something.
Here's what I calculated...
[b]Circumference Calculated = 170.5(+/- 0.5mm)[/b]
Circumference = 2*Pi*r or Pi*d
D = 170.5mm/(3.14159265)
[COLOR="DarkRed"]D = 54.27mm = Turbine Inducer[/COLOR]
[b]T28 Turbine Trim = 79[/b]
Turbine Trim = [(Exducer^2)/(Inducer^2)]*100
0.79 = (Exducer^2)/(54.27^2)
(Exducer^2) = (2,945.23)*(0.79)
Exducer = SQRT[2326.73]
[COLOR="DarkRed"]Turbine Exducer = 48.24mm[/COLOR]
[b]Double Check Trim (Because sometimes I don't remember PEMDAS
[/b]
Turbine Trim = [(48.24^2)/(54.27^2)]*100
Turbine Trim = 79.01.... yep
Thank God for Google Calculator!!!!

Pictures are worth 1000 words... enjoy!
1. Measured my oh so ghetto fabulous way

2. Another Angle...

3. Marked w/ a Sharpie... which leaves for about a 0.5mm error... I marked it right in the middle of where the zip tie intersected.