Quote:
Originally Posted by Blacktree
I tend to agree with the above. Like he said, the 2nd gen Prius uses mass airflow rather than speed-density. I also doubt ramming air into the intake will do anything for fuel economy. It could potentially help with power at high speed / full throttle. But if you're trying to hypermile at WOT, you're doing something wrong.  |
I am convinced... it's probably better to trust the Toyota engineers know way more about engine efficiency than I do. Also, I'm a master at doing nothing.
Quote:
Originally Posted by Blacktree
Anyway, it seems like your main goal is to find somewhere to send the hot air exiting the radiator. How about a hood vent? I'm not talking about a louvered race car hood, but rather a smallish vent placed strategically in a low-pressure zone. IIRC the best place to put a vent is right behind that sharp curve at the front of the hood.
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Hahaha! I was actually about to put in a bonnet exhaust a few weeks ago. It's how I accidentally discovered that hood insulation increases mpg. After doing several tests with results I could scarcely believe, I was forced to conclude that it was more efficient to
trap heat in the engine compartment, rather than vent it.
https://www.instagram.com/p/CewAQ08LN2l/
And my main concern was less about exhaust and more about utilizing the top end of the radiator. Once I get done with plastering over the underside of the engine, there will be a 40 sq in exit through the cat channel and two 20 sq in exits near the rear of each wheel (in the low pressure zone). Since I'm targetting a 50 sq in-ish inlet, that's more than enough exhaust venting. The problem in my mind (which may or may not exist in reality) is that it seems like the airflow will favor the bottom half of the radiator, as the path of least resistance.
It also seems like the Toyota engineers felt the same way. The main radiator intake is below the impact bar at the bottom of the radiator, but they deliberately put a small intake above the bar at the top. I assume that's to get airflow saturation near the top. Since I plan on ducting the inlet, I thought that suction near the top would help airflow move that way, and be more efficient use of the radiator.
It looks like I'll just have to do some asymmetric aero on the inlet duct to achieve the same effect. While is a shame... I do so love symmetry.