Big Blue24
Comp Diesel Sponsor
- Joined
- Jan 5, 2008
- Messages
- 6,310
In my opinion, a spool flange on the bigger down stream turbo will slow down initial spool-up which will translate to slower overall spool up because the tighter the big down stream turbo, the more it affects the smaller manifold turbo. The turbine wheels gets power two ways: 1. extracting heat energy from the exhaust flow, and 2. extracting kinetic energy from the exhaust flow which translates to pressure drop across the turbine. The more restrictive the downstream turbo, the less pressure drop across the turbine wheel of the small manifold charger.
As a single turbo, the HE351 initially spools faster than the HX35 due to the 351's smaller/lighter turbine wheel and 9cm housing. Around 5 psi, the HX35 surpasses the 351, and then around 18-20 psi the HE351 takes over and out paces the HX35 in both spool-up and air flow.
If I had a spare HX35, I'd use it. If I didn't have an extra turbo laying around, I'd get an HE351. If you want maximum power and wastegating potential, get the HE351.
As a single turbo, the HE351 initially spools faster than the HX35 due to the 351's smaller/lighter turbine wheel and 9cm housing. Around 5 psi, the HX35 surpasses the 351, and then around 18-20 psi the HE351 takes over and out paces the HX35 in both spool-up and air flow.
If I had a spare HX35, I'd use it. If I didn't have an extra turbo laying around, I'd get an HE351. If you want maximum power and wastegating potential, get the HE351.