AeroMod Me! (1997 Acura CL)

[nbleak21]

Alright, after doing some fine tuning on the VAFC, ive made a record 36mpg tank, and I believe I am about to break that one with this next tank that I'll be filling on Friday (I'm at 36.4 avg according to my torque app)... So I am now ready to dive into the aero mods! Just looking for advice that will help with the biggest gains.

Goals:
-Lighter engine load at cruise speed;
-Longer coast downs.

I cannot do a boat tail because it won't fit in my garage if I do, but any other mods are on the table (other than mirror delete, for safety reasons)

I've done lots of research through this site and have some ideas in mind, but am more interested to hear your thoughts for my particular car's shape rather then just throw on mods.

Current mods: antenna delete, lowered suspension, CAI (though I will likely make it just a short ram in the future for warmer engine bay air)

I am guessing my spoiler doesn't help with aero but it def looks better with one on, though I would not object to taking it off.

What about a plexi Kamm back, would that help?

I could def use some cleaning of the underbelly in terms of airflow...

And a partial grill block is def in the future too (though I may end up glassing a new more aero front bumper if I can find a design that I know will work and still look half decent)

What are your thoughts???

[Sven7]

Kamm back would help. Rear wheel skirts, wheel covers. You can add a little convex mirror on the inside in place of the exterior mirror. Works great.

Also, get a front lip/spoiler to push air around the sides instead of under the car. Then you won't really need to make a belly pan.

[Gealii]

I would do a kamm for sure and plexiglass would work just fine. Depending how far back you bring it if you would either break it into pieces or hinge it at the very top to keep access to the trunk.

The spoiler is probably not hurting anything considering it sits pretty low. The spoilers you have to watch out for are more of the ricer styled ones that increase drag and down force, but down force is not needed at hypermiling speeds

Another thing to consider is smooth wheel covers. I gained about 1mpg consistent tank to tank over having open steel wheels. I can still check fuel pressure and remove the wheels without removing the covers. http://ecomodder.com/forum/showthrea...tml#post330171

[nbleak21]

Thanks for the responses, I've had a hard time finding a good Kamm design thread. Several attempts even netted negative results...

Yes I am planning on wheel covers and possibly skirts for the rear as well.

Just pumped my tires up to 42 psi (max sidewall is 44) up from 30 so we'll see how that helps on the way home today.

[Sven7]

Design the Kammback just like a boat tail, but cut it off at the back of the trunk. You should use all the same angles as a full boat tail would. If you're not sure just do a cardboard mockup with 10-15 degrees on all sides and ABA coastdown test it. (and tuft test too)

If you can get a straight and level photo of the car (or better, a blueprint-I had no luck) then just input it here to overlay the template. That will give you the ideal profile.

[ChazInMT]

I'm not so sure a Kamm would help much without it being meticulously designed and built, and even then you might only get 5-7%. Reason I say that is your roof to rear glass transition area radius is freakin huge, there are papers done on this that show a big rear radius improves Cd a lot.

The rear spoiler is almost certainly helping you some, and very unlikely to be hurting you. It isn't a lot, but If you like it, keep it.

Have you pumped up the pressure on your tires? That's 5% right there if you have them at 30psi currently. Also, blocking any kind of upper front grill area would help for making you more aero and it will also raise the intake temperature since this is generally where the air going to your intake comes from. Forcing the air through the radiator first heats it. (news flash, right?)

Plug that puppies nose!!

[MetroMPG]

Kammback construction (on a sedan) example:

http://ecomodder.com/forum/showthrea...ods-20741.html

[Gealii]

Originally Posted by MetroMPG

Kammback construction (on a sedan) example:

http://ecomodder.com/forum/showthrea...ods-20741.html

would duct tape suffice for holding on a coro kamm? i'm not ready to drill holes in my roof quite yet

[Sven7]

Originally Posted by Gealii

would duct tape suffice for holding on a coro kamm? i'm not ready to drill holes in my roof quite yet

My boat tail's structure is aluminum drilled to the body but its skin seams are duct taped. You just have to manage the rough ends (where you rip it off the roll) so the air doesn't catch them. It helps to cut curves into the ends with a razor. Also, if you're layering, put down the rear-most tape first and work forward.

[RiderofBikes]

tape is more than sufficient!

http://ecomodder.com/forum/showthrea...tml#post320868

My own renditions of a Kamm was/still held onto with duck tape/Clear Packing tape. As I too have not figured another way yet to mount them to my car semi-permanently(still new). But i have tried a few diff ways, and materials. maybe get an idea. Me and Neon above, wound up with similar pivoting kamms, just coinsidence. good luck.