Attention: TDR Forum Junkies 
hehe, the old HY vs HX contravercy
Bob, you traded a HY35/9 for a PDR35/12.....completely different turbos... . especially on the exhaust side.
The HY has a single scroll housing, the HX has a twin scroll housing.
The HY9 flows close to what a HX11 housing would (if one existed) therefore the housing is smaller... . at lower RPM exhaust gas velocity on the exit of the housing is faster..... that is why you get higher cruising boost with the HY over the HX. The Modified HY I have makes 12 psi while cruising at 70 MPH... . the stock HX35/14 I have makes 7 psi at that same speed. cruising EGT is about 50F lower with the modified HY.
since you went to a slightly larger housing, you may see an EGT drop from that, but at peak boost the egt drop you see is mostly from the compressor side modification to the turbo.
lowering EGT by installing a larger turbine housing is just a Band Aid.
but this is an exhaust thread, not a turbo thread.
if you have specific questions, and really want to know something... . e-mail me
Bob, you traded a HY35/9 for a PDR35/12.....completely different turbos... . especially on the exhaust side.
The HY has a single scroll housing, the HX has a twin scroll housing.
The HY9 flows close to what a HX11 housing would (if one existed) therefore the housing is smaller... . at lower RPM exhaust gas velocity on the exit of the housing is faster..... that is why you get higher cruising boost with the HY over the HX. The Modified HY I have makes 12 psi while cruising at 70 MPH... . the stock HX35/14 I have makes 7 psi at that same speed. cruising EGT is about 50F lower with the modified HY.
since you went to a slightly larger housing, you may see an EGT drop from that, but at peak boost the egt drop you see is mostly from the compressor side modification to the turbo.
lowering EGT by installing a larger turbine housing is just a Band Aid.
but this is an exhaust thread, not a turbo thread.
if you have specific questions, and really want to know something... . e-mail me
