Green Grand Prix modding thread

[mpg_numbers_guy]

Where are your wheel covers?

[Gasoline Fumes]

Originally Posted by Vman455

Earlier this spring, I noticed on an Insight that Honda had added some devices under the rear bumper cover when they refreshed it for 2012...I found them in a parts catalog--they're called "rear air splitters"--and ordered a pair. The Prius' bumper cover is slightly too short, but the locating pin at the end of the splitter still fits in a hole I drilled in the cover, so the whole thing is stable.

The 2nd gen Prius had boat tails behind the rear tires.

[Vman455]

Originally Posted by mpg_numbers_guy

Where are your wheel covers?

I removed them last spring in the first stages of the weight-reduction kick; all told, the pans were ~10 lbs. I might do something lightweight in the future.

Originally Posted by Gasoline Fumes

The 2nd gen Prius had boat tails behind the rear tires.

Yep, and the 3rd gen continued that with a slightly modified design:



The Insight doesn't have the raised diffuser like the Prius, so it's just a flat surface without the inside shaping like the Prius:



But I think the splitter should function the same, adding surface area for the airflow behind the tire to attach to. I inset it like on the Insight rather than making it flush with the outside of the bumper cover since there's probably a reason the engineers did that despite having all that real estate available.

[hat_man]

Were the rear wheel "boat tails" a removable piece or were they molded into the rear bumper/body panel?

[Gasoline Fumes]

Originally Posted by hat_man

Were the rear wheel "boat tails" a removable piece or were they molded into the rear bumper/body panel?

On the 2nd gen? It's removable.

[hat_man]

Was at the salvage yard yesterday and didn't notice them on any Prius. I wonder if those could be adapted for use on other cars?

[Vman455]

Update:

I haven't had much time to work on the car, what with being back in school. But I wanted to get at least something done before this year's GGP. So, I thought I would try some air curtain ducts. I have the internal ducts from a Hyundai Ioniq, but rather than retrofit them I used them as a model for some (much easier to fabricate) external ducts. The Hyundai ducts are about the same size as these, ~30mm inlet, ~20mm outlet, ~150mm tall, and angled downward toward the outlet (that was a surprise). So, these are too.

Cardboard template:


Ducts in aluminum. I'm happy with how they turned out, considering I: a) have no experience working with aluminum, just tin and lead pipes (and some zinc repair); b) have no mandrels or brake.


On the car:






I don't know why the Ioniq's ducts are angled downwards, but I'm just copying for now. I'll take a close look at other air curtain ducts at the Chicago Auto Show next month to see if other manufacturers do the same.