Blown instead of turbo

[Just puttering]

Could a blower like a vortech be used instead of the turbo?

Is the heat from the exhaust gases heating the intake air or is it from compressing the intake air? I would have thought more from the exhaust heat

I have read some on blowers and using intercoolers, so maybe you run into the same problem of heated intake with the blower also?

Edit- sorry i should have mentioned i was thinking about the aaic compared to needing a awic.

[phil1734]

You could if you wanted to, but it'd be far more expensive and complicated then a AWIC setup.

For starters, the subie supercharger industry is nearly defunct now that they're hardly used in experimental/ultralight aircraft anymore, and as far as I know they were only ever made to retrofit onto older N/A engines. Thus they only ever cranked out boost levels in the mid single digits and wouldn't be appropriate for a direct swap onto a WRX motor that runs 14-17psi.

Secondly, and to answer your other question, the heat comes from compressing the air. When you go to that 14-17psi your temperature increases a lot. 5-7psi not so much, which is why most supercharged cars don't have intercoolers. So even if you got a supercharger that could do ~15psi you'd then need to implement an intercooler on your own and you'd be back to square one.

The 818 does have the additional problem that plagues all mid-engine cars in that the engine bay is a low pressure zone and it's extremely difficult to evacuate the hot air in that area, but it's not the leading cause of high intake temps. Given that the turbo is spun by hot exhaust gases it will run hotter than a super charger for a given boost level, but it's a relatively minor increase compared to what actually compressing the intake charge causes.

[CdnCarNut]

Compressed intake air usually increases volumetric efficiency to >100%. Turbochargers or superchargers both do this. In general, superchargers/blowers offer higher pressure and at lower engine speeds, while turbos have less engine losses. (Think dragster vs F1 car!) The need for cooling the compressed intake air is present for both systems. The heat generated has nothing to do with exhaust -- it is from compressing the air. Simple thermodynamics. Try feeling the outlet pipe of a shop air compressor and you'll quickly feel the effect. Cooling can be with AWIC or AAIC. Both work, but AWIC is smaller and more efficient.

[Kyle @ Forma]

Supercharging a WRX engine totally does work!

^I know this isn't actually relevant, but I still thought it was worth sharing.

Phil and Cdn both nailed it. The only point I could add is that of the few people supercharging WRX engines, the goal is normally to combat turbo lag, so they are used in a twincharged application (like the article above). I've seen numerous supercharged NA Subarus and a few twincharged WRX engines, but can't recall ever seeing a turbo-supercharger conversion.

If heat is your concern, I third the idea of AWIC. We have an 818S with an AWIC and no extra rear ventilation, and have no heat issues (At least, not with outside temperatures in the 80's).

[Sgt.Gator]

There are numerous Legacy EZ30 cars with Raptor superchargers. They also make them for the Imprezza. The Supercharger probably won't work because it sticks too far on the side in the 818. But FYI:
http://raptorsc.com.au/subaru/imprez...y00-myo5-kits/



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