[pinky49]

Hello to all.
Anyone know how to convert the A/R sizing to cm2 for the exhaust housing?
Thanks for any input, Ed

 

[mooktank]

Impossible!

Someone said there was a thread about it around here but I never saw a good way to convert it. I'm not sure if there is. The cm^2 is like a proprietary thing for Holset which is pretty stupid. There should be some info somewhere I've just never seen it.

 

[pinky49]

Thanks for the reply. I'm still looking though, Ed

 

[LincTex]

Pretty tough.

a 18cm2 housing is pretty close to a Garrett 1.00 A/R housing,
and the 12 cm2 is pretty close to a .69 A/R
and the 9cm2 is pretty close to a .58 A/R

these are just a really vague generalization, though

 

[Dougal]

If we can find out where and how Holsett measure it then conversion is easy.

But remember that A/R is only any use when comparing the same size exhaust wheels as the exhaust velocity at the exhaust wheel tip is the determining factor.

Linctex, what garrett turbo were those housing numbers from?

 

[High Pressure]

Dougal knows the answer!

Dougal.... I think you know the answer! :beer: It is where the exhaust inlet opens into the full volute. The 16cm2 H1C housing has an A/R of 2.34 cm2/cm.. On that turbine housing the radial distance from the center of the housing to the center of the critical area of the volute opening is approximately 6.7cm

http://www.4btswaps.com/forum/showthread.php?t=1362

 

[Dougal]

Dougal.... I think you know the answer! :beer: It is where the exhaust inlet opens into the full volute. The 16cm2 H1C housing has an A/R of 2.34 cm2/cm.. On that turbine housing the radial distance from the center of the housing to the center of the critical area of the volute opening is approximately 6.7cm

http://www.4btswaps.com/forum/showthread.php?t=1362

Excellent.
Garrett measure their A/R in inches, so 2.34cm = 0.92".

If we can confirm (or deny) this, I'll try to sticky it.
Do H1C's have 60mm turbine wheels?

 

[High Pressure]

Excellent.
Garrett measure their A/R in inches, so 2.34cm = 0.92".

If we can confirm (or deny) this, I'll try to sticky it.
Do H1C's have 60mm turbine wheels?

The 60mm exducer (small diameter) is a very common H1C turbine wheel for sure...there are others. That specific exducer size (small diameter) is generally machined with a cast inducer (large diameter) of 70mm for an H1C.

 

[pinky49]

Thanks everybody for all the help. Ed

 

[LincTex]

Linctex, what Garrett turbo were those housing numbers from?

TO4B series, which is approximately the same physical dimensions, with the "O" trim exhaust wheel.

 

[Dougal]

TO4B series, which is approximately the same physical dimensions, with the "O" trim exhaust wheel.

What's the OD of that exhaust wheel?

 

[LincTex]

What's the OD of that exhaust wheel?

http://64.225.76.178/catalog/twheel.html

Major = 2.922" = 74.22 mm
Minor = 2.296" = 58.32 mm