Well about a month ago I put on a 12cm housing, got it used for a good price. It has a waste gate but I just tack welded it closed.

Didn't really notice much more power over the 16cm but the exhaust temps are WAY down. With the 16cm housing and empty truck I would easily see 1000*+ temps(post turbo) and a max of about 26psi boost.

Now with the truck fully loaded(8.5ft camper and pulling a Jeep) pulling a hill will see over 30psi boost(gauge pegs at 30) and 900* for exhaust temp. My water gauge climbs faster then my exhaust temps.

Now I can actually use all the power when towing instead of having to back out of it. Although I'm being pretty carefull not to roast the tranny.

 

Glad to hear it. Makes me feel better about driving blind. Gauges by next month, I promise!

 

The 12cm makes a nice jump in responsiveness, no question.
I'd like to point out a couple things though...
Your pyro is post turbo so you are NOT seeing real temps.
Take your gauge reading and add approx 10*F for every 1 pound of boost, up to roughly 23-24 psi.
After that you should increase the compensation higher.... at 30 psi you will have about 325-350*F over your guage reading.
Be carefull with the 12cm... it had a wastegate for a reason...to prevent high drive pressures and you are now into the high drive pressure zone of the housing.

pastor bob...

 

Yep the 12CM really peped up my 93. gained 10PSI of boost and it really gets up and goes now.
DM01

 

The smaller housings take more heat out of the exhaust gasses. That is where the energy comes from that is used to compress the intake air.

I don't see in your signature whether your pyro is pre or post turbo. It would seem to be post turbo from your numbers, though, as Bushy said, and if it is, he is right! You will have to be careful. 900 degrees post turbo on a 12 is much hotter pre-turbo than it would be on a 16 or 21, so you have to adjust your rule-of thumb safe operating range accordingly.