Originally Posted by Smokem
Spray pattern and pop-off pressures are the same, hone size is different.
That makes perfect sense, but I still don't see what's giving the HO/ETH pistons so much more compression.
Anyone got a visual comparsion?
Also here's what MKoth posted about the ETH/HO once upon a time:
* Electronic Controls: New ECM calibration and fueling algorithms.
* Fuel Pump: Increased fuel flow in the Bosch VP44 injection pump.
* Injectors: Designed to provide increased fuel flow.
o Injector note posted to the TDRoundtable by tgbol:
+ ETH injectors (3946306) flow 600cc at 100bars for 30 seconds
+ ETC injectors (3944828) flow 640cc at the same test.
* Turbocharger: Revised wastegate setting for 26psi at the turbocharger outlet.
o Manifold boost specification is 43.5 inches Hg / 21 psi
* Head: Valve seat inserts for added durability.
* Pistons: New pistons with higher 17:1 compression ratio.
* Flywheel: New flywheel with 330 mm diameter clutch (vs. std. 310 mm).
The HO pump is limited to around 500-550hp max, and will not gain power by using any injector larger then 150-160hp. They also respond to electronics less.