2000 Dodge Neon aero mods

[2000neon]

I like the idea of the thick weatherstripping, if the kamm stays on that will be a definite consideration.











Here is another update, I have the kamm "done" and started driving and testing it. I am not really fully done it yet, because I still haven't figured out the sealing on the side gaps, so for now I duct taped them down and am just keeping the kamm stationary.

I can honestly say that my initial results are.. meh. I did some quick coastdown testing, unfortunately it was a bit windier than I would have liked, but my schedule doesn't give me many other good oppurtunities for it. The kamm did show some slight improvement. I forgot my notes and don't have my exact figures with me, but it showed about 6% improvement, and a secent amount of error between runs (~3%). So it does seem to show a small gain, but it is difficult to judge exactly what it is.

Without the duct tape, assuming I can get a decent gap filler for the sides, it works great and exactly as I had planned as far as being able to open the trunk.



The pin system I used at the back keeps it really solid, and all I have to do is pull the two small pins and it is ready to open. (If I didn't have it sealed with tape right now).

Here is one of the pins. Just a bolt with a hole drilled through it, a nut on both sides to set the height ant tighten it on, and the pin to slide through the hole.



As for driving impressions, the gaps at the front and sides seem to seal great with just the duct tape. The kamm is very solid, and does not shift, move, flap or even wiggle in the wind which I really like. Visibility out of the rear is still great* (In dry conditions- more on that in a bit). However with the closed in sides it makes a pretty bad blind spot to the right rear of the car. It is bad enough that if the kamm stays on, I will definitely be putting my passenger side mirror back on. So I do have doubts about it, because that alone might negate any gains of the kammback.

[2000neon]

I drove it around yesterday evening and this morning, coming back today I drove a bit in the rain. I found that driving on back roads during testing, and in the rain today led to some interesting observations. I definitely have quite a flow back into and under the kammback. After a little bit of coastdown testing on some country roads, here is the way some of the dirt settled inside of the kamm.



You can see how the dust/ dirt settles on the inside of the aluminum frame. It got a lot worse after a bit more driving but I didn't get a picture of it, this was just driving to my test area. Which to me seems like air is moving into the low pressure zone under the kammback. It also happened while driving in the rain, I got serious mist underneath of it which settled on the bottom half of the back window, about 2/3rd the height of the kamm opening, and at the beginning it actually settled in a semi circular shape matched to the opening at the rear of the kammback. This mist and water under the kamm almost completely killed any rear visibility!

I wonder if/ and how much this forward moving flow under the kamm might be hurting efficiency. Which is where my main question comes from, do you guys think that there is any advantage to blocking off the vertical opening at the rear of the kammback?

The visibility problems to me right now are not worth the small gains that I have seen so far. However, if blocking the opening might help efficiency and stop water mist from flowing in, I might leave it on.

I can usually get about 185 km at the 3/4 tank mark on my fuel level gauge. Today I got almost exactly that again with the kamm on, and part of the drive was cooler temps and in the rain, so it does seem to be showing some improvement in real world driving.

[Weather Spotter]

blocking off the back will help reduce the are from roiling under the Kamback.

Try using a piece of plexiglass and coat it with rain-x

[2000neon]

Thanks, any idea if there may be a significant difference?

[Gealii]

Originally Posted by 2000neon

Thanks, any idea if there may be a significant difference?

I would rain x your furthest back window either your rear window or the plexiglass if you go that way if you were having trouble with the rear window getting covered in the rain

[baldlobo]

do you have a rear window defroster? if so turning it on might help

[2000neon]

I will try to cover the back and see if there is some gain to be had. I do have a window defroster but I try to not use it if I dont have to. just due to the pretty large load on the alternator.

[HyperMileQC]

Great job on the kammback, it fits nice on the car as well. Hope you see some improvements

[2000neon]

Thank you! I really appreciate it, the response I have been getting from people locally hasn't been so positive.

[Smurf]

I agree, the Kamm looks great. Nice smooth gentle curves, doesn't look like a cardboard-n-ducttape type project at all.

Actually, the curving reminds me of a Mazda MX-3: