Piwoslaw's Peugeot 307sw modding thread
 

I'm finally ready to start a mod thread for Svietlana, our 2005 Peugeot 307sw. I've actually done a few small mods, mostly my driving habits, plus running the tires at 45-50psi (max is 51psi), a grillblock and folding the passenger side mirror outside of the city. My FE gauge is factory installed (is a little off, showing an average of 4.6 l/100km for a tank, when it was closer to 5 l/100km). If the buying a ScanGauge in Europe was as cheap as in the US, I'd already have it. At the moment it's about 60% more expensive here :( Well, soon the USD/EUR exchange rate will be such that it will cost less than the equivalent of 100EUR to buy in the US, thus allowing me to not pay customs and other import taxes.

The grill block was on the inside of the lower opening, the upper slits are harder to cover up, plus one of them is the air intake.http://ecomodder.com/forum/attachmen...3&d=1246610226
When it got warm this year and the A/C started to be in use I decided to uncover the part of the grill in front of the intercooler. This brought coolant temperatures down from 90*C to 80*C, partly because some air gets into the radiator through this opening. The plan is to have a closable exterior grill block with two openings: one for the IC and the other for the radiator, with a wall between them. Both will be closed by default, allowing for shorter warm-up times, the IC part would open when the coolant temps get to 80*C, while the radiator part would be open only when the fan kicks on (first speed is at 95*C, or about 80*C if A/C is on). There will also be a manual override to either. Both parts will have an LED that lights up in the dashboard when open, plus an LED for the fan (maybe different colors for different speeds?). Two things which have kept me from already making this grill block are:
(1) The wiring for the engine cooling system is complicated, I have yet to find where all of the sensors are, let alone which wires to tap into. Also, everything is covered with plastic panels which are hard to take off, impeding fooling around in my spare time.
(2) I'm not too hot with electromechanical gizmos, so if anyone knows how to (and is willing to) help, please add advice here.
The new grill block will also have LED DRLs, shaving 150-200W from the electrical load.

Another mod I'm getting around to is removing the roof rails. This week I almost broke them trying to find out how to get them off, but all is well. It's much easier than I expected, so this changes my plans. Instead of removing them permanently, I can just unscrew them in under 5 minutes, and put them back on if needed. The only problem is finding a way to seal the holes in the roof when they are gone. Since the holes are irregular, and I'm not a materials specialist, I'll probably end up asking some bodyshop for professional ideas. If anyone wants to help, I can post some pics of the workings.

I've been looking for coroplast here in Poland, and it appears that it isn't easy to find anywhere in Europe. It would be nice to do some aeromods though, since next month we're going on vacation to the Fagaras Mountains in Romania, a 1500km drive each way. I'd like to do that distance on one tank. So, I didn't give up and last week I finally found a company that makes 'channeled polypropylene'. If the store wasn't in a far away and hard-to-get-to corner of Warsaw, I'd already have a sheet or two. But having to do a 60km round trip in traffic jams in the middle of a heatwave is enough to make me wait (Transporting a 2x3 meter sheet in a city bus isn't an option). I am using this time to make a cardboard Kammback (yes, I will overuse Kamm's name, even though Groar's uglyback does have a ring to it ;) ) and rear wheelskirts.

First, I needed tools. Since the top of the Kammy should drop at a 11 degree angle, I made a cardboard triangle with an 11deg. angle and taped it to a level ruler.

http://ecomodder.com/forum/attachmen...8&d=1246610724

Since the ruler has two perpendicular level gauges, it can be held flat to check that the sides also have an 11deg inward angle.
Next, I did some math. Knowing that the top and sides were angled inward at 11 degrees, what should be the angles of anything I actually have to construct? Well, the math wasn't that bad, it wasn't anything I didn't do in high school, but I'll give you all a break. (If anyone wants to see it, please let me know and I'll write something up, it might be a good thread/wiki/whatever.) Anyway, the top piece of the Kammback is a trapezoid with a base angle of 79.2 degrees.
http://ecomodder.com/forum/attachmen...4&d=1246610724

By measuring the base (front), you can use simple trygonometry to find everything you need. The sides are a little harder, those can be done by trial and error once the top is fitted.
So here is Svietlana in her beta-version Kardboard Kammy (the alpha, uhm, didn't exactly work, I don't wanna talk about it, okay?):

http://ecomodder.com/forum/attachmen...6&d=1246610724

(Notice how the rear edge of the sides is an extension of the angle of rear lights. I wasn't aiming for this effect, but only noticed it after taking pictures. I think it has a rather positive influence on the aesthetics of the set-up.)

http://ecomodder.com/forum/attachmen...5&d=1246610724

http://ecomodder.com/forum/attachmen...9&d=1246610752

Like I mentioned earlier, those rails are going to be removed soon. That should really help airflow in the Kammy.

I'd like to coastdown and A-B-A test this set-up, but I had to take down since it rains everyday (for the last 2 months, the cardboard was damp when I pulled it out of the garage). Maybe this weekend, maybe next?

As can also be seen in the view of the rear in the previous post, the Kammback has a flap of cardboard across its width.

http://ecomodder.com/forum/attachmen...3&d=1246612295

This is to keep it from sagging. Unfortunately, I used clear tape which doesn't hold cardboard too well, and this set-up isn't sturdy enough for me to feel good with it while driving. The view in the mirror, however, is OK :)

http://ecomodder.com/forum/attachmen...4&d=1246612295

Hopefully the coroplast version will be stiffer (is 3mm too thin for a 50cm x 110 cm piece?) and won't require the lateral support.


A closer look at the side reveals a bulge in the front of the top piece.

http://ecomodder.com/forum/attachmen...2&d=1246612295

This is from the center stop light. I will have to cut the front a few centimeters shorter because of this, and also to compensate for rubbing against the roof when opening the hatch.

http://ecomodder.com/forum/attachmen...1&d=1246612295

As can be seen, there is a conflict between the Kammy and the radio antena, but removing the latter will result in an even worse conflict with the Wife...

Wheel skirts, alpha version
 

I tried to put a cardboard skirt on one of the rear wheels.

http://ecomodder.com/forum/attachmen...5&d=1246613768

http://ecomodder.com/forum/attachmen...6&d=1246613768

This was just warm-up, with only scotch tape and nothing to space the cardboard from the tire. Instead of a cover for only the wheel well, I decided on skirting the whole section from rear door to end of bumper, Groar style. I'll have to paint it if I want it to look halfway decent.

Nice aerial shot of the kammback. I like that we are the only two ever awake at this hour :)

Kind of hiding behind the bush, isn't she? I agree, that is one of the better pics. Maybe because we don't usually see cars from that angle?
For me it's the middle of the day. For you, well, you never sleep anyway :P

For me is was the beggining of the evening, so everybody wins :)

Very good work Piwo. Have you done much A-B-A testing?

ollie

Not yet :( I haven't even turned the engine on with the mods in place, so I have yet to see other drivers' reactions ;)
I only had a few hours between rainstorms to put up the cardboard and take some pics. This weekend is supposed to be dry, but there are slim chances of being able to find enough time to do test drives. I'd prefer to do them on a Sunday morning, like around 5am, when there is no traffic. I also have to find the best road in the area for testing (no lights, straight and flat). Maybe by next weekend the more stable gamma version will be ready, and then all I'll need is good weather. And a green light from the Wife, since getting up at 4am on Sunday to go for a drive isn't exactly standard practice...

Nice to see some work on your car.
How much will that coroplast cost you (in PLN) and what is it called in PL? Maybe I'll find a shop here in Lodz.
That kammback - weren't you able to make a radius on upper corners to make it fit the roof curvature? Hope it works nicely. I am unfortunate to have pillar mounted rear lights (Punto) so no kamm for me.
Rear wheel sections - maybe you can make inner supporting frame out of aluminium strips, bolted into inner fender?

BTW - You've stated that DRL will shave 150-200W energy consumption. As far as I know maximum power for headlight bulbs is 55W each so it's going to be 110W max. You still need position lights. However I think that changing other bulbs for LED replacements will give you some nice gain.

In Polish it is called 'polipropylen kanalikowy', comes in sheets of 1600mm x 2000mm or 2000mm x 3000mm, 3mm to 5mm thick, and costs under 20 PLN.
Here is one company I found: Folplex, and here is one which has a store in Lodz: Tuplex. I haven't been to the store yet, so I can't say how good the material is.
With normal lights the dash board lights are also on (5-8 bulbs with 5-20W per bulb), but I'd like to wire the DRLs to be on only with position lights and no cabin lights. I've already replaced two position bulbs, and two flasher bulbs, with LEDs.

EDIT: As of May 4 (or May 20) 2009, Polish DRL law has been changed to comply with European DRL law, so position lights are no longer required with DRLs. This saves even more watts, and allows for much simpler wiring :)

Total destruction :(
 

I had some free time this afternoon and decided I would tape the Kardboard Kammback and wheelskirts on while I drove to check out a road for potential testing. So, the sun is shining, I got everything on (used a whole roll of tape to make sure nothing flies off)), I even painted one of the skirts with some old spray paint I found in the depths of the garage, I put the key in the ignition, and... it starts POURING :( It was short, but intense. A 10 minute downpour (filled and overflowed our 220-liter rainbarrel in under 5 minutes). All I could do was run to the house and take a pic.

http://ecomodder.com/forum/attachmen...2&d=1247141318

What you see in the picture is now called a Sagging Soggyback and a Soggyskirt. Ruined. Totally destroyed. After 10 minutes the sun came out again and I had to pull all of that tape off. Those cardboard templates were supposed to be the stars of next Sunday morning's testing. Now you can squeeze water out of them.

So what's next? I dunno :( I used up my best double cardboard, I don't have enough time or will to fight traffic from one end of the city to the other just to buy a sheet of coroplast, even if I did I won't have enough time to make new skirts and a Kammy before Sunday morning, next weekend is out of the question. And the forecast is more rain for as far as anyone can tell. It's been raining here for the past two months, have I mentioned that enough times yet?

Dang, sorry to hear about that. Perhaps they can still be used as templates for when you get around to making new ones out of whatever material you decide on.

That sucks. I've had my fill of rain this summer too.

You should be able to use them as rough templates for the next version (possibly of cardboard again for testing?) even thought they no longer have any structural stability.

Try a liquor store or something for empty wine/beer cases. They can be assembled into properly sized pieces with duct tape and doubled up for strength.

Piwoslaw -

Rats. I agree with i_am_socket, let 'em dry and try to reuse them as a template.

Maybe you could invest in a tent-shade-thingy to keep your test-mods dry. You could always reuse the shade for something else.

CarloSW2

I threw them into the back of garage, I hope they don't warp too much. Maybe the next batch will be coroplast?
Gee, I could have used the garage, since Dad-in-law took his car to work today, but:
1) Svietlana is so big that she's a pain to get into and out of the garage under the house, so she's only been there twice since we got her,
2) When it started raining, I was on the way out, so the car would have already been outside, anyway.

Eh, a guess it'll have to be coroplast. I'd wouldn't mind fooling around with cardboard, but not with this weather.

Thanx everyone for the kind words, I know "you feel my pain" (to cite an ex-President).

On Friday I finally decided to get that coroplast. I checked out what the company had to offer, and the 2-3mm thick stuff seemed too flimsy. Unfortunately, the only coroplast that was UV-resistant was the 10mm variety, which is overkill for my Kammback. So, the sheet I got is 5mm thick, which turned out to be stronger than I expected :) Does anyone know how to protect it against UV? I plan to spray paint it, so maybe 2 layers would be enough protection? (BTW: Is spray paint a good idea with coroplast?). I googled UV-protection foils, but they seem to be more expensive than the coroplast, so I'm not ready to invest into that option.

The 5mm coroplast came in 2m x 3m sheets, so I had to cut it up before putting it in the car. I hope I didn't make the pieces too small to use.

I also got a 1m x 2m sheet of 1mm HIPS, for the wheel discs. And here is my second question: Do I need smooth discs on the rear wheels if I plan to cover them with skirts?

Coming home with the plastic I stopped at a boneyard and bought two central lock motors, for 20PLN/4.50EUR/6.30USD each. That's much better than at a different place that wanted 50PLN per motor. Now, I need to find a way to tap into the fan circuit.

I also stopped at a scrap metal yard looking for aluminum bars to act as reinforcements for the wheel skirts, but they had just gotten rid of everything in the morning :( Keep looking.

So that's the update, hopefully I'll start working on the Kammy or the grill block today or tomorrow.

Hope all this work will permit you to beat your record (63.97 mpg) :cool:

Wait, don't beat your record please or you'll beat mine with megane (65.35 mpg) which is 22% lighter than your svietlana (2491 lbs vs 3225) and has 26% better aero (0.31 x 21.4 sq.ft. vs 0.33 x 27.46 sq.ft.) :o

Denis.

Aaaah, I didn't notice that. Now I have a new goal, hehehe ;)

Actually, my goal is the same as your's, Denis: 1600km on 1 tank. That once when I had over 60mpg was only half of a tank, so I say it only half counts. My driving technique has given me a 10%-15% increase in FE, and I am hoping the aeromods will give at least another 10% (so I get the "Hypermiler" in my signiture ;) ).

Sounds good Piwoslaw. It also sounds like you got some good mods coming up. :)

My experience with spray paint on plastic is that it generally doesn't hurt the plastic, and you can tell because it doesn't stick very well, so you get to check the plastic's condition after a while. Ask around. Try modeling shops.

You could buff the plastic surface very gently with some 100-150 grit sandpaper, give it just enough of a texture for the paint to grip mechanically. Once you've got your paint sticking well, you can follow up with more coats to give it a proper shine.

Hallo!

How driving techniques do you using? You have nice consumption.

Good moods. :thumbup:
Keep going. :turtle:

Quick update:
I've been working hard, modding furiously. At the end of last week I removed the roof railing and installed DRL's. The latter required removing what was left of the old grill block, and the new one is still in the works, so the radiator is naked, but the weather is hot, so no problem.
This whole week was spent working on the Kammback, tomorrow I hope to get material for the skirts. This is all taking much longer than I'd planned, and more important things (not excluding the family) are hanging over me like the Sword of Damocles.

No pics now, maybe in a few days I'll find more time.

Krylon has a paint for plastic that I used on my vinyl gutter / side skirts. It bonds quite well; I haven't noticed any scratching in the 8 or so months I've had them on.

Finally!!! :)
 

I've got a few minutes, so here's what I've been up to in the second half of July:

After the last episode of "Rainstorm Aerodynamics - Meet Mr. Soggyback and the Soggyskirts", I finally hunted down a 2x3m piece of coroplast (polypropylene). I cut out the top of the Kammback and both sides and hit a wall with how to smoothly join them. So I had to make another Kammy, this time one piece.

http://ecomodder.com/forum/attachmen...9&d=1249305078

In order to bend it I needed to warm the inside of the bend. The Wife's hairdrier wasn't good enough, so I used a small camping stove. To make sure that the bend is straight I clamped the line between two pairs of wooden boards.

http://ecomodder.com/forum/attachmen...0&d=1249305078

This setup also helped keep the heat close to the bend line and off the rest of the sheet.
Safety Note: Make sure to keep an eye on the wood when warming!!
After a few hours of fooling around I finally got it right:)

http://ecomodder.com/forum/attachmen...3&d=1249305168

http://ecomodder.com/forum/attachmen...2&d=1249305168

http://ecomodder.com/forum/attachmen...1&d=1249305168

Attaching the Kammback
 

The next step wasn't easy either: I had to find a way to attach the Kammy to the hatch with the following (mutually excluding, it would seem) boundry conditions:
- No drilling,
- Strong and stable,
- On/off in under 90 seconds with no/limited tools.

After about six 4km bike rides to the local sewing supply store I did the following set up:
The top of the Kammback has slits for a 4cm wide band which loops around both ends of an 5mm aluminum bar.

http://ecomodder.com/forum/attachmen...4&d=1249305551

The bar sits against the hatch's hinges.

http://ecomodder.com/forum/attachmen...6&d=1249305551

The band is not elastic, so I needed something to be able to adjust its length/tension.

http://ecomodder.com/forum/attachmen...5&d=1249305551

The bottom corners of the Kammy have elastic line inside the canals which loop around a rubber stop on the inside of the hatch.

http://ecomodder.com/forum/attachmen...7&d=1249305551

http://ecomodder.com/forum/attachmen...8&d=1249305551

In the near future I will add an extra set of 4mm bands in the center for more stability (and to cover up the red plastic of the stop light). I will also add elastic line at the upper outside corners, but I'm not yet sure where that can be anchored. I'll also glue an extra piece of coroplast to the underside to make the whole thing more rigid.

Rear skirt braces
 

Now for the skirts. A visit to the local scrap metal yard got me (at the cost of 1 beer) a 2m profile of 2mm aluminum.

http://ecomodder.com/forum/attachmen...9&d=1249306135

I quickly cut the sides off.

http://ecomodder.com/forum/attachmen...0&d=1249306135

Safety Note: Notice the gloves and earplugs (I still had the glasses on).

I used the 2cm-wide sides for the horizontal reinforcement bars and cut up the center for the mounting tabs. The front of the reinforcement bar, and the two top pieces, hang on plastic pins which hold the plastic liner in place.

http://ecomodder.com/forum/attachmen...1&d=1249306135

The rear tab sqeezes the inward-facing lip, like Darin did here. The first tab, unfortunately, didn't have anything to hang on to, so I bent it, drilled and threaded a hole, stuck it under the plastic liner and put a screw in. Yes, I had to make a 4mm hole in the plastic liner. Sorry CarloSW2, I know I just lost your approval ;)

http://ecomodder.com/forum/attachmen...2&d=1249306135

The rear of the reinforcement bar could be attached to one of three holes under the bumper. Instead of the hole just behind the wheel, I picked the middle one, since that allowed me to taper the bottom of the skirt. I'll build on this when the time comes for a belly pan under the rear.

http://ecomodder.com/forum/attachmen...3&d=1249306161

Rear skirts
 

A close inspection of the rear wheel well suggested something thinner than 5mm coroplast would be ideal for the skirt itself, so I got two 50x100cm sheets of 0.6mm aluminum. As in Darin's rear skirt thread, I first made a template out of newspaper, then cardboard, and finally aluminum. (BTW: Darin used one sheet of newspaper, I needed 3 taped together to span the wheel well. Does this mean a 15" wheel well is soooo much bigger than a 13", or are newspapers in Nova Scotia larger than in Poland?) As I found out, each template should be larger than the previous. I did this, but the aluminum on the first skirt was barely enough. The reason I needed something thin is that my wheel well's rear is the plastic bumper with a 'lip' that juts inward, while the front is the frame with no 'lip', so I tucked the aluminum sheet inside the well in the front and let it out in the back. This is probably the best way to go as far as being immune to wind.

http://ecomodder.com/forum/attachmen...4&d=1249306718

The finished skirt is secured to the reinforcement bar with four 4mm screws, and the whole setup comes off together using only a screwdriver in about a minute. Putting it back on takes a little longer, but isn't too bad (we'll see how bad it is in the snow, hehehe). Both skirts together weigh less than 1.5kg.

http://ecomodder.com/forum/attachmen...5&d=1249306718

http://ecomodder.com/forum/attachmen...6&d=1249306718

http://ecomodder.com/forum/attachmen...7&d=1249306718

DRL's and roof rails
 

As I mentioned earlier, I installed LED DRL's. They use 5.5W each and they save about 200W compared to using headlights (2x55W), position lights (4x5W) and cockpit lights (8x5W-20W). The DRL's are slightly crooked. This is because they are pushed from behind by a plastic wall which isolates the radiator from the rest of the engine bay. I'll cut a bit out next time I'm in there.

http://ecomodder.com/forum/attachmen...8&d=1249307144

I also removed the roof rails. Unfortunately, a lot of cars today have roof rails standard, not optional, so there are no covers ready for the holes in the roof. I carved covers out of coroplast and screwed them in with shorter screws. Replacing the covers back with the rails takes less than 5 minutes (this was one of the WAC - Wife Approval Conditions).

http://ecomodder.com/forum/attachmen...9&d=1249307144

http://ecomodder.com/forum/attachmen...0&d=1249307144

(Those covers look better in the pictures than in real life, eh :( ) Hopefully the lack of rails on the roof will improve airflow down the Kammback. Each rail weighs about 1.5kg. That's not much, but since it's coming off the roof it will slightly lower the center of gravity.

I've been driving for 2 weeks without the grill block and the coolant temp is just under 80*C. The fan doesn't turn on when the A/C is on. Temperature was around 90*C with the full block, and just over 80*C with the intercooler unblocked. With A/C, the fan would kick in to keep the temp around 80*C. Since the upcoming trip will be at full load, in the mountains and in hot weather, I've decided to keep the grill unblocked. After we return I'll start working on the dual-openable version.

Here's a picture of the Kammback from the inside of the car:

http://ecomodder.com/forum/attachmen...1&d=1249307361

I hoped that I could make both skirts on Saturday, then I could go testing at 4am on Sunday, but the job actually spilled over Sunday and I finally finished on Monday. Hopefully next weekend will be nice and get some testing before our trip.

I've already had a drive with the Kammy on Friday and I could notice the difference in two ways. First, when I would need to decelerate I would put it into neutral only to notice that I was decelerating at a slower pace, so I'd have to use the brakes. Second, I'm so used to P&G that I more or less know when to put it back into gear and accelerate again. With the Kammback, when P&G-ing between 50kph and 70 kph I would get into gear when I though I was down to 50kph, only to find that I was still at above 55kph! Today I will do 50-60km with the wheel skirts so the glide will be even longer :D

PS. I already have 1200km since fill-up and another 100-200km in the tank. And this was done without any mods :) Maybe a 1600km tank is within reach? What about 2000km?

BTW Am I the only person who sees a similarity in shape between a Kammback:

http://ecomodder.com/forum/attachmen...2&d=1249307361

and an old-fashioned nun's cornet?

http://ecomodder.com/forum/attachmen...3&d=1249307361

Looks good from here! :)

:thumbup:, very :cool:

Denis.

Hi Piwoslaw.

Top notch work on the kammback. I like the way the lines flow and the way they compliment the tail lights. You also did well to have the centre brake light coming over the kammback. Very nice!
Re: your roof rail inserts. You could get some stainless countersunk allen bolts to hold the inserts in. They'd be flush and look better too.
The wheel skirts look awesome. The boattailing on them is fantastic and should join seamlessly with the belly pan. Have you tried removing the rear wheel with them on?

ollie

Damned irresponisible rubberneckers!!
 

Update
On Monday afternoon I went into town. Rubberneck galore!!!! At least three drivers took pictures with their phones while driving, one van stayed in the lane next to me for four kilometers, blocking everyone behind, with the passenger yelling at me "What is this supposed to be?" All of this at 80km/h. Whenever I stopped at a red, the cars in the neighboring lanes wouldn't pull up right next to me, but slightly behind. I was kind of expecting this, but I thought drivers would be at least slightly more responsible. I'm putting this in my signiture:
That monday excursion really stressed me out. I'm not a shy person, but I don't like being in the center of attention either. Especially if this attention can be potential hazard :( When I got to my destination I was really tensed up and had to walk around a park for 30 minutes to calm down.
After that I picked up the Wife and told her about my trip, and she says "Aw, come on. You've been reading that forum of your's too much and you're seeing things. Noone really cares." As she was saying this I was waiting at an intersection for a city bus to roll by. Just as she finished, the bus suddenly stopped in the middle of the intersection, the driver stared at Svietlana for 5-6 seconds, and continued on. Wife: "I take that back. Sorry."
Maybe it's good I didn't do a full boattail or the Air Force would escort me to the nearest landing strip. That's what you get for being the only rear-skirted and Kammbacked car within thousands of kilometers.

Anyway, down to business. It's hard to tell whether the mods made a big difference since I was too stressed out and had to pay a lot of attention to what was going around me and not get hit, plus there was a moderate wind that day. But, on the way home, there is a long (1-1.5km) downslope going from the city center to the river, and normally if I start at 80km/h I barely slow down. With the mods my speed was constant, maybe with a slight tendency to increase:)

BTW, the Monday trip was to take the Wife to her driver's licence exam. She passed:)

Today I went to get the oil filter and oil changed (to 5W30, previously either 5W30 or 5W40, I don't know). As I left home the computer signalled that I have fuel for only 95km left in the tank (I've already done 1250km). I did 10km and when I got back the comp estimated that I now have fuel for 100km. Now, how's that for hypermiling?!

If all goes well, this Sunday I'll do coastdown and cruise control testing, A-B-A style. Anything in particular that I should pay attention to? Any last minute suggestions?

I guess I'm lucky that the designers made the rear lights the way they did. Absolutely ideal for a Kammy:) The center brake will probably be covered up with extra bands. I did think about cutting out a hole and putting in a plexi window so the center brake would be visible.
I've make new roof rail covers from aluminum scraps. Looks slightly better. I think I will go with the countersunk screws. The gap between tire and reinforcement bar inside the skirt is about the width of a finger, so no way to get the wheel off without pulling the skirt. Fortunately, it comes off in about a minute, so no problem. Putting it back on is trickier and can take up to 5 minutes.

Re: the centre light. You could just apply some heat gun to the kamm back and bend that part of it down. It would leave the rest of the kammback to do it's job while you had visible brake lights.
You also mentioned the similarity to a nuns cornet. Might i suggest the name "Nunnback" for your creation? It's up to you, but it cracked me up on the way to work! I definitely got about 30km out of it!
In any case it seems you got some decent improvement in drag reduction as per your last post. Kudos to you!!! I bought ecomodding material about two months ago and still have to do something with it!!!

ollie

Nunnback!!
 

Nunnback, I love it!! Unfortunately, it doesn't translate into Polish at all :( But I may just call it a 'Kornet'. I like how you used the double 'n', as in 'Kamm'. I'm still ROTFLOL :D Nothing like a good laugh to start the morning. Thanks, Ollie :)

After I glue the reinforcement to the Nunnback, I'm thinking about painting the underside flat black, to reduce glare, etc. Is this a good idea? I've painted the outside with 2-3 layers of spraypaint. The color is supposed to be identical with the car's paint job, but it's not as shiny. The reason for painting is not only looks, but also UV protection, since the polypropylene coroplast I used isn't UV-resistant. Any guesses as to how long it'll last and how to protect it?

Piwoslaw -

Just another :thumbup:. The instant-off design is great. It's soooo clean! I'm gonna try your coroplast-heat-bending method with a heat-gun.

CarloSW2

Painting the underside would keep glare to a minimum. The "Kornet" name is probably more respectful too. I just wanted to throw it out there!

ollie

What a night...
 

Oh, what a night. On saturday evening we met with some friends at a club. Beer (I didn't drink), singing sailors' songs, shouting, dancing, partying. Got home as the eastern horizon was getting light. I put the Wife to bed, crawled into the car and went coastdown testing. I had a paraphrased version of the Beach Boys' Surfin' Safari in my head:
"Let's go coastin' down
Everybody's learning how
Come on and coast down with me
(come on and coast down with...)"

At 04:30 I was filled up and ready to start. Since the car was already "dressed up", this was the 'A' of 'A-B-A'. So 'B' is the standard car, as the factory made it (only tire pressure was 50psi instead of 36psi), while 'A' has:

• removed roof rails
• lower grille opening totally covered
• Kammback
• rear wheel skirts
• folded passenger side mirror

The air temperature during the 3 hours of testing was between 8-11*C (recorded every 15-45min.), humidity around 70%, pressure reduced to sea level about 1020 hPa. No wind. I estimate the car with me and a full tank, but without rear seats, weighs about 1550kg.The test track was a 4 lane (w/ median) road going east from the Warsaw city limit. Elevation about 100m. Unfortunately, central Poland is supposed to be as flat as a pancake, but pancakes have lumps, and this pancake was made on a crooked frying pan. As I found out during testing, the road slightly slopes down towards the west (river basin), giving a 20% difference between E and W runs :( The test track has a 2km stretch between urban zones, with a speed limit of 100 km/h. At each end is a turnaround, a few hundred meters further intersections with lights. Since this is one of the most important transport routes, there are a lot of cars, trucks and busses. Sunday morning at 5am would be the best (and only) time to try to do tests here. Unfortunately, towards the end of testing there was more and more traffic, so I only did the bare minimum. On the last few passes I would have to wait up to 30 seconds to turn around, and then wait on the side for a hole in traffic to allow me to not get in the way, and vice versa. On a few occasions a passing car or truck may have effected the trial :(

First I did the 'A' coastdown with a webcam aimed at the GPS.
http://ecomodder.com/forum/attachmen...5&d=1249901691
Instead of fooling around with recording each run separately, I left it on while turning around. Six passes (3 in each direction) took about 17-18 minutes. I have yet to go through the data for coast downs, so I'll post that later.

After coasting I did cruise control. I set the CC to the right speed using the GPS instead of the speedometer. I did two passes at 70 km/h (one in each direction) and four passes at 100 km/h. I'd turn the CC on earlier so that it stablizes and reset the fuel gauge at the beginning of the 2km test track. I know that my built in gauge is a little low compared to at-the-pump calculations (about 0.5 l/100km), but until I get a SGII this is the best I have.

Next I took off all of the mods, put the roof rails on, opened the side mirror and did coast downs and CC for 'B' data, then put everything back on and did another round of CC testing. By now it was 07:00 and too much traffic for coastdowns. Because of traffic and time constraints I had to resign from testing each mod individually :(

Note The first 100km/h pass is missing b/c I had trouble setting the CC.

Here is the raw CC data in l/100km:
Speed(km/h) W E
A:

Speed(km/h)	W	E
100	---	4.6
100	4.2	4.3
70	2.4	3.1

B:

Speed(km/h)	W	E
100	4.2	4.9
100	4.0	4.8
70	2.7	3.3

A:

Speed(km/h)	W	E
100	3.6	4.4
100	3.6	4.6
70	2.6	3.1

Average@100km/h	W	E	Both
A	3.8	4.5	4.15
B	4.1	4.85	4.5

Average@70km/h	W	E	Both
A	2.5	3.1	2.8
B	2.7	3.3	3.0

So removing the roof rails, folding one mirror, adding a grille block, Kammback and rear skirts improved FE by just under 7% @70km/h and under 8% @100km/h. This is less than I was hoping for (at least 10%). Maybe I'd get better numbers if the test track was flatter, with less traffic, and if the fuel instrumentation was more reliable. I also would have liked to make more passes, but traffic was increasing with every minute.

I didn't use my LED DRL's in the test, since when I started the test it was too dark for them and I decided to keep the normal lights for the whole test.

During the runs I had the radio off, but when taking off/putting on mods I listened to music.

On the way home I filled up again. I used 6.5 liters of diesel, the total distance was 130-140km between 04:00 and 07:30. On the way home, the night finally caught up with me, I started feeling sleepy, but it wasn't bad enough to effect my driving.