[motoworkz]

Originally Posted by Stanimal

The Evo 3 has the TD05H–16G6-7 (7cm^2 nozzle area), inconel turbine wheel and 68mm aluminum compressor. Peak efficiency for this compressor is a high 77%.

This compressor is way pass choke @ 550 CFM. According to the compressor map, at a 2.7 PR (25 psig @ at sea level) this compressor max out at 490 CFM running at rated max speed of 151,274 RPM @ 70% eff. This compressor has max flow between PR 2.0 and 2.4 (14.7 - 20.5 psig), @ 520 CPM but down to a low 60% eff.

The EVO 8 has the TD05HR-16G6-9.8T (9.8cm^2 nozzle area), inconel turbine wheel and 68mm aluminum compressor. Peak efficiency for this compressor is a so so 71%. With this lower efficiency, the compressor will dump a lot of heat in the intake charge and really need the intercooler.

This compressor is near choke @ 550 CFM. According to the compressor map, at 2.7 PR, this compressor max out at 560 CFM running at rated max speed of 150,000 RPM @ a lowly 60% eff. It's making lots of heat at this point. This compressor has max flow between PR 2.4 and 2.7 (20.5 - 25 psig), @ 560 CPM. The eff is very poor at this point (60%).

Also please keep in mind, when you are running the compressor near the choke point, you'll be drawing lot more power from the turbine and producing huge back pressure, which kills HP.

I would never say you couldn't make 400 WHP with the stock turbo, if I recall correctly, a couple of tuners have already done so. However, these guys are great and I think they mod just about everything except the turbo and the bottom end, used race gas and most added alcohol injection.

Personally, if I were to max out the stock turbo on the Evo 8, I would probably stay below 23 psig (2.6 PR) and 490 CFM. At that point, the compressor is still at 68% (only 3% off peak) and 130,000 RPM. With reasonable mods, this should be good for ~350 WHP with the stock intercooler. This is a huge 40+% bump from stock without putting huge stresses on the engine. As a bonus, I might even be able to run 93 oct pump gas.

My idea of reasonable mods:
3" well designed turbo back exhaust
cams
timing gear
computer and dyno tune
MBC
fuel pump
head studs
K&N panel filter

optional:
injectors

And if you play at this power level, you'll need a new clutch shortly.

Not trying to diss on you or anything but I don't under stand what PR is. I think you mean BAR. Please clarify.

Here is a table for the readings of pressure:

Pressure or mechanical stress
Pressure atmosphere (standard)atm≡ 101 325 Pa [8]
atmosphere (technical)at≡ 1 kgf/cm²= 98.0665 ×10−3 Pa [8]
bar bar≡ 105 Pabarye (cgs unit) ≡ 1 dyn/cm²= 0.1
Pacentimetre of mercurycmHg≡ 13 595.1 kg/m³ × 1 cm × g≈ 1.333 22 ×10−3 Pa [8]centimetre of water (4 °C)cmH2O≈ 999.972 kg/m³ × 1 cm × g≈ 98.0638 Pa [8]
foot of mercury (conventional)ftHg≡ 13 595.1 kg/m³ × 1 ft × g≈ 40.636 66 ×10−3 Pa [8]
foot of water (39.2 °F)ftH2O≈ 999.972 kg/m³ × 1 ft × g≈ 2.988 98 ×10−3 Pa [8]
inch of mercury (conventional)inHg≡ 13 595.1 kg/m³ × 1 in × g≈ 3.386 389 ×10−3 Pa [8]
inch of water (39.2 °F)inH2O≈ 999.972 kg/m³ × 1 in × g≈ 249.082 Pa [8]kilogram-force per square millimetrekgf/mm²≡ 1 kgf/mm²= 9.806 65 ×10−6 Pa [8]
kip per square inchksi≡ 1 kipf/sq in≈ 6.894757 ×106 Pa [8]
millimetre of mercurymmHg≡ 13 595.1 kg/m³ × 1 mm × g ≈ 1 torr≈ 133.322 4 Pa [8]
millimetre of water (3.98 °C)mmH2O≈ 999.972 kg/m³ × 1 mm × g = 0.999972 kgf/m²= 9.806 38 Pa
pascal (SI unit)Pa≡ N/m² = kg/(m·s²)= 1 Pa [9]pièze (mts unit)pz≡ 1000 kg/m·s²= 1 ×10−3 Pa
pound per square footpsf≡ 1 lbf/ft²≈ 47.880 25 Pa [8]
poundal per square footpdl/sq ft≡ 1 pdl/sq ft≈ 1.488 164 Pa [8]
pound per square inchpsi≡ 1 lbf/in²≈ 6.894 757 ×10+3 Pa [8]
short ton per square foot ≡ 1 sh tn × g / 1 sq ft≈ 95.760 518 ×10+3 Pa
torrtorr≡ 101 325/760 Pa≈ 133.322 4 Pa [8]