K so here is the data regarding temperature readings with the down pipe on the stock exhaust system and downpipe, and the Powervalve downpipe with thermal wrap.
Apparatus - Laser thermometer taking readings at 400mm.
We measured two sets of criteria for both options.
First data model is of the stock car driven over a short course to get it to full temperature.
a - Down pipe exiting the turbo temperature - 374.7 deg C
b - Turbo inlet temperature - 63.8 deg C
Then after the car has been stood on tickover for 5 minutes
a - Down pipe exiting the turbo temperature - 248.6 deg c
b - Turbo inlet temperature 62.8 deg C
Second data model is of the Powervalve system with wrapped downpipe car driven over a short course to get it to full temperature.
a) Down pipe exiting the turbo temperature - 295.7
b - Turbo inlet temperature - 61.0
Then after the car has been stood on tickover for 5 minutes
a - Down pipe exiting the turbo temperature - 208.6 deg C
b - Turbo inlet temperature 62 deg c
Overall temperature drop with the thermal wrapped 76mm downpipe at turbo outlet after being driven 52 deg C
Overall temperature drop with the thermal wrapped 76mm downpipe at turbo inlet after being driven 2.8 deg C
Overall temperature drop with the thermal wrapped 76mm downpipe at turbo outlet after 5 minutes ticking over 40 deg C
Overall temperature drop with the thermal wrapped 76mm downpipe at turbo inlet after 5 minutes ticking 0.8 deg C
So that's a big drop in outlet temperature and a small drop in inlet temperature - bearing in mind however, that the intercooler has yet to do it's job at this stage.
A point to note is that this is radiated heat and not actual surface heat - nonetheless the internal down pipe temperature is massively hotter with the wrap which makes for a lower physical mass that must be pushed through the system and thereby releasing kinetic energy which translates directly into crank power.
Ceramic coating will always achieve better results as the internal and external surfaces can be treated.
however be prepared for a hefty bill.
cheers
Nige