Old square sedan kammback

[tvbd56]

I would imagine your vision is blocked partially by the aluminum, as long as you're comfortable and safe with it that's what counts It looks amazing!

[renault_megane_dci]

Originally Posted by Joris

So, 2 AM and I have the results from the coast-down test. There is a hill nearby and I used both sides of it. B is with kammback, A is without. Started with the kammback because that was easier. Then took it off, did some runs and then some more runs with the kammback on. Starting speed was 100 KM/H. And roadsigns where used as speedtraps. No wind as far as I could feel.

Route North.
B1; 100 - 95 - 81
B2; 100 - 97 - 82

A1; 100 - 92 - 80
A2; 100 - 93 - 80

B1; 100 - 98 - 82
B2; 100 - 96 - 82


Route South
B1; 101 - 61 - 50
B2; 100 - 59 - 48

A1; 100 - 58 - 45
A2; 100 - 58 - 45

B1; 100 - 60 - 50
B2; 100 - 60 - 49
B2; 100 - 60 - 49


It looks like the kammback is doing it's job. The road wasn't really sutable for faster testing, but that would have been better I think.

Next thing is tuft-testing, but that will have to wait until after the 2000 mile trip.

I'll dig out a conversion to turn those in % improvement cos someone nice made it for me in my bike thread

[Joris]

Originally Posted by tvbd56

I would imagine your vision is blocked partially by the aluminum, as long as you're comfortable and safe with it that's what counts It looks amazing!

You're right, it is blocking the rear view. I can see about 20-30 meter behind the car. Best would be an open view to the back, but that is not possible. So I will have to do with it. Parking is no problem this way.

But, I sometimes have to drive a van for work. And those vans also don't have a rear window. So I am a bit used to not using the rear view mirror.

@ Renault_Megane_DCI

That would be great!

Do you know if driving in France with something like this on my car will get me pulled over? Are you allowed to have shiny aluminium sheets on your car there?

[RedDevil]

You probably don't need a full size rear window, a half size would give you a clear view straight back from the center rear view mirror.

Maybe you can use what's left of your acrylic kammback.
I've cut my acrylic upper grill block (not fitted yet) with a Dremel (like) mini tool and its small disc blade cutter. The acrylic will melt (and stink! Do it outside) but not shatter.

You need a lot of patience though and a steady hand.
I shattered the little disc just before finishing the cut and was too lazy to replace it and continue. Well it is too hot now for a full grill block anyway...

[MetroMPG]

Originally Posted by Joris

So, 2 AM and I have the results from the coast-down test.

Thanks for posting your testing efforts.

[MetroMPG]

Originally Posted by Sven7

Fantastic. I vote we put this on the front page.

Added to home page after testing!

[renault_megane_dci]

Originally Posted by Joris

Do you know if driving in France with something like this on my car will get me pulled over? Are you allowed to have shiny aluminium sheets on your car there?

It is my personnal opinion that it looks factory enough to help you through scutinity.
That and the fact law enforcement might fear to have a chat with a foreigner.

I would add a paint stripping and a brand marking to help with this scenario.

But you know, **** happens ...

If you get pulled over, stick to dutch

[renault_megane_dci]

http://ecomodder.com/forum/showthrea...t-21853-2.html

Originally Posted by renault_megane_dci

Today was coast down test day.

We rode to the "quiet back road" my colleague mentionned.
It was rather windy ...
So I went for a ride, trying to pass his parked car at 100 Km per hour, pulling the clutch and then cheking the speed at a distance, namely a sign on the side.

With the kammback : two attempt showed 62 ish Km per hour

Without the kammback, the bike was easier to maintain at speed (probably more throttle, maybe less wind) and I got a consistant 60 ish Km per hour.

Then I fitted the kammback back but we didn't do more attempts.

All in all : waste of gas ...

I don't know the distance from point A to point B either just the tiny difference in speed

Can I work out something out of it ?

Originally Posted by janvos39

The kinetic energy at 100 km/hr is 0.5*m*v*v and that is with a bike+rider of for instance 250 kg 0.5*250*27.77*27.77=96450 in both tests
This kinetic energy at 60 km/hr is 0.5*250*16.66*16.66=34722
So without the tail enengy consummed by air and roll resistance is 96450-34722=61728

Now with the tail. Energy left at 62 is 0.5-250*17.22*17.22=37076
So energy consummed in this case is 59374. (so approx. 4% less)

[Joris]

Wil do some maths tonight, thank you!

Today I swapped the fuel filter, differential oil and made some last additions to the kammback to make it a real 'Kammback'.





Should be good now! I have decided that I won't paint it, but maybe put on some graphics.

Thanks for putting me on the homepage, really pleased with that!

[whatmaycome14]

Impressive and inspiring!