no plate and gutted afc to plate and tuned afc?
#31
The turbo takes pressure across the exhaust turbine to spin it. This is drive pressure. The HX35 turbo has 1:1 drive pressures up to a boost of around 32-35 psi. This means that the boost air pressure is equal or just a little less than the drive pressure on the exhaust side.
Once you get to the 40+ psi boost mark on the HX35, the drive pressure goes up exponentially and you have to drive it with near 50-55 psi. Net effect is zero to the engine as you have all this boost but its going nowhere because the exhaust pressure left in the cylinders is 10-15 psi higher than the boost air. Hot air charge ups EGT's and peak firing pressures causing head gasket problems and other more fatal wear to the piston crowns.
Getting a bigger turbo allows the drive pressure to stay in the 1:1 range and keep the air flowing through the engine more efficiently. Lower EGT's, Higher HP and better overall wear to the engine.
To sum it up, the difference between 35 psi and 40 psi on the HX is nothing more than hot air.
Once you get to the 40+ psi boost mark on the HX35, the drive pressure goes up exponentially and you have to drive it with near 50-55 psi. Net effect is zero to the engine as you have all this boost but its going nowhere because the exhaust pressure left in the cylinders is 10-15 psi higher than the boost air. Hot air charge ups EGT's and peak firing pressures causing head gasket problems and other more fatal wear to the piston crowns.
Getting a bigger turbo allows the drive pressure to stay in the 1:1 range and keep the air flowing through the engine more efficiently. Lower EGT's, Higher HP and better overall wear to the engine.
To sum it up, the difference between 35 psi and 40 psi on the HX is nothing more than hot air.
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tyrel_44 (01-13-2009)
#32
#33
#34
you can but its just a matter of time before the headgasket blows i ran mine with out rings and studs for almost 8 months at 50psi with no problems, then one day i blew a headgasket which gave me an excuse to get the head port and polished, o-ringed, oversided valves, hd valve springs and studs, now i dont have to worry, my budy is running a sps62 at 50spi for 2 years and as stock gasket, depends on the milage, i had 315,000 when mine went he dont even have 180,000 yet
The following users liked this post:
tyrel_44 (01-13-2009)
#35