Aerodynamic modifications to a 2007 Camry SE

[woodstock74]

Toyota Highlander, front:


Interesting the Toyota Highlander continues Toyota's philosophy of the inboard hole/holes that I have on my Corolla (a completely different car, large SUV vs small economy car):



Believe just about every Toyota has these (interestingly, the Prius does not) in one form or another.

[Vman455]

Originally Posted by woodstock74

Believe just about every Toyota has these (interestingly, the Prius does not) in one form or another.

Had these. The new Corolla does not, Camry does not, Sienna does not, Prius, etc. (My third gen Prius had them). I was surprised to see them on the TNGA Highlander, which I think is why I took a picture!

The only other car I can think of offhand with the hole is the Chrysler Pacifica.

[freebeard]

Any theory on the function of the inboard slots? That last one isn't so much a slot as an empty frame.

[woodstock74]

Originally Posted by freebeard

Any theory on the function of the inboard slots? That last one isn't so much a slot as an empty frame.

Providing a reliable stream of air for the brakes is as close to an answer as I've determined. Though they seem so ham-fisted. Interesting the current Toyota-crop isn't using them...

[Taylor95]

I am changing the title of this thread to include all the aerodynamic modifications I make to my Camry. This will be much better than having many different threads for all the stuff I want to do. When I get around to doing some tests I will copy results to the first post.

Those holes in the Toyota wheel spats are very peculiar! If they are for brake cooling, I wish mine came with those... the PO warped one of my brake rotors.

The diversity in OE wheel spats tell me that most designs function fine. The other day I saw a Chevy Malibu that had wheel spats larger than the ones I made that span the entire width of the tires.

A future project I have been thinking of is modifying the spoiler on the Camry to be slanted downward slightly and to have a clean separation edge. This will serve to reduce the wake size (something Julian Edgar talked about in his video about the Mirage). This will be coupled with a full undertray and a rear diffuser that will be angled slightly upwards.

[JulianEdgar]

Originally Posted by Taylor95

A future project I have been thinking of is modifying the spoiler on the Camry to be slanted downward slightly and to have a clean separation edge. This will serve to reduce the wake size (something Julian Edgar talked about in his video about the Mirage). This will be coupled with a full undertray and a rear diffuser that will be angled slightly upwards.

The downwards-angled spoiler extension will work in reducing wake size only if there is attached flow ahead of it. (That's certain on a hatchback roof like the Mirage; it's to be expected but not certain on a 2007 Camry.)

Also, the greater the downwards angle of the extension, the more drag created as the attached airflow wraps around this curve. Therefore, the best trade-off between reduced wake size (reducing drag) and attached airflow around the spoiler (increasing drag) can be found only through testing. For example, throttle-stop testing or mileage over a short, flat, repeatable course at the highest speed possible.

The upwards sloping diffuser will again only be effective in reducing wake size if there is a relatively smooth floor ahead of it, basically to the front of the car. In a car of that age, I'd expect that to require an undertray. Again, though, this is easy to test - pitot tube, tufting (if the car is high enough), even pressure testing.

[Taylor95]

Originally Posted by JulianEdgar

Therefore, the best trade-off between reduced wake size (reducing drag) and attached airflow around the spoiler (increasing drag) can be found only through testing. For example, throttle-stop testing or mileage over a short, flat, repeatable course at the highest speed possible.

It would be pretty difficult to test different angles, and probably not something I am going to do because this would require a lot of quality and work to do accurately. I am sure that there is a difference between a 10 degree slope and a 15 degree slope, but not enough to make testing worth it to me.

I will likely slope the spoiler by a conservative 10 degrees, and quantify the change through testing.

[JulianEdgar]

Originally Posted by Taylor95

It would be pretty difficult to test different angles, and probably not something I am going to do because this would require a lot of quality and work to do accurately. I am sure that there is a difference between a 10 degree slope and a 15 degree slope, but not enough to make testing worth it to me.

I will likely slope the spoiler by a conservative 10 degrees, and quantify the change through testing.

I'd never spend money on a spoiler without testing first. Just use plastic sheet and tape to make trial spoilers. Even without throttle stop testing, I could detect (through fuel mileage) changes in drag with different rear spoiler angles on the Roomster shown in the other thread.

(And testing is even more important if it's a lot of work to modify the existing spoiler.)

[aerohead]

Is it a compromise for brake cooling air?

[freebeard]

I can imagine an L-shaped vortex generator directing air to the brake, ...invisibly to the naked eye.