My turbo-delsol- aero mods
 

I decided to start another thread to show just aero mods I'm doing as of right now.

http://i147.photobucket.com/albums/r...129091805a.jpg

http://i147.photobucket.com/albums/r...eencoded-3.jpg



I have all the templates made now and the top piece finished.

I'm using clear .060 acrylic sheeting. It has a aluminum frame for attachment.

Next on my list is to cut the side pieces and the bottom.

Future mods will include

full belly pan
outside mirror delete install video cam
front bumper cover mods
rear acrylic sheeting wheel well covers
wiper cover
pizza pan fron hub caps

Looks great! What are those side templates made of? Are you using the acrylic throughout?

Thanks!!!

I'm still going to make some minor changes. The side panels will be clear acrylic sheeting also.

it's turbo and you get 66 MPG? sweet.

Yep, with a personal best of 74 mpg.;)

I'm hoping to squeeze another 20 mpg out of here with the new aero mods.:)

awesome save gas for more mods! I think you're my new hero

aero mods look good... listen to Christ I feel like he knows his stuff. (he'd better with a name like that huh?)

so I guess I am going to read through your posts to find out how much HP you have and learn about how you do this cause I too want a car the saves gas when I want and can hang at a hill climb too.

Thanks Man!!!

I'm thinking about shorting the boat tail by about two feet. The Del Sol design is kicking my arse as far as the way the Qt panels meet the roof. I'm trying to keep the transition smooth from the top of the Qt back. It makes a major bend behind the rear wheel well about 20 degrees and I don't know what to do with it?

The car now make 450whp. It can go from 74mpg to 5mpg by simply pressing the go fast pedal all the way down.LOL

Awesome! In for results, my ghetto kammback fab turned out to be a dud. Back to the drawing board.

450 WHP from the 1.6L ? B16 ? Dyno proven?

Need to see pics / videos asap! Any links to share? Once fully aero-modded you are going to have a real highway monster.

That kam-back is looking good! Any pics of the bare frame? I see your challenge on the side angles. I think a lot of your problems might be aided by just shortening the overall kamm length. That's quite a commitment as you have it now. I think you'd get a large % of the potential gains even if it were 1-2 ft shorter.... no?

Also kind of looks like you need another hard break on the sides. If you keep the angle between panels low enough, separation on the rear piece shouldn't be tooo bad.

I decided to sketch it:
http://i287.photobucket.com/albums/l...delsolkamm.jpg

testing
 

If it's at all possible,I would encourage you to tuft-test the tail before you commit to the design.
Anything above 20-mph ( on a dead calm day ) will tell you what you need.
It's hard to tell from your photos,but it looks like there is a sudden,angular transition at the roof,and reflex at the sides especially below the beltline.
If so,you'll have immediate separated flow ( exactly what you're not looking for ).The flow will reattach on top with some efficiency loss.I'd be suspect to the sides,as there is not as much energy available to sustain flow.
What you've mocked-up holds much promise,and a quick test would soon tell you whether or not to cement your design.

http://farm3.static.flickr.com/2674/...f5522efd_o.jpg

http://farm3.static.flickr.com/2468/...600a52e5_o.jpg

http://farm3.static.flickr.com/2580/...bdc6076e_o.jpg

Looks familiar ;)
Can't wait to see how this comes along !

Did you ever find that MX-3 rear hatch glass that we talked about ?

It made 418whp at Daves Smith's Kellogg Idaho "Dyno Jet" on low boost 28psi on pump premium. On race fuel running 35 psi it should be easily over 450whp.;)

I will have to take some pics of the framework.

I think I need to shorten it also thanks for your drawing:thumbup:

You need to get back on your project. I need another del sol to campare notes with.

I would love to tuft test but as of right now the engine is torn down for inspection. The angle from the roof line down is 11 degrees. It hard to get the angle right.:o I was going to make it only 5degrees but it I'm not to sure on how to make the frame work?

I told you that your art work inspired me!!! LOL

OK guys I need your help. I'm thinking of shorting the rear tail by two feet.

As of right now its just a hair under four feet from the rear of the car.

I would also put angles on the rear panel.

Like this
http://i147.photobucket.com/albums/r...mockuprear.jpg

this would give me more width down at the bottom where its needed to decrease the angle I have now.

Thought and opinions please???

Heres another pic of the roof line. You can see it better from this angle. Its very slight in the transition, but mabye it needs to be more level with the roof line???

http://i147.photobucket.com/albums/r...129091806a.jpg

In my old kammback thread, I was told the transition should be 10* to keep attached airflow. After building mine, i ended up with 13*, not sure if that is what affected my negative mpg readings.

Also, I was told by MetroMPG that the transition from the top to the side should be rounded, which i haven't figured out yet. Otherwise (correct me if im wrong MetroMPG) it would create vortices (spelling?) in that area.

BTW: my results: On a 100 mile roundtrip drive with cruise control set to 65mph. Ambient temperature both trips 61*F, filled up at 2:30pm both trips. Using the same gas pump.

without kammback = 45mpg
with kammback = 41mpg

*angry face*:mad:

BTW2: so jealous how shiny your paint is

Oh great... I sure hope I see results. As of right now I have $200.00 in material.:eek:

I can change the roof angle (its adjustable) from 8 degrees to 15 degrees. But when I get the sides and the under-tray part done and in-close it in I won't be able to change the angle anymore.:(

http://i146.photobucket.com/albums/r...er/aerocrx.jpg

Remember this guy?

I don't know why he vanished after doing this but my suspicion is it didn't help fe at all or maybe even hurt it.

Why?

I think he added a bunch of length and a bunch of skin friction (and some weight too) but really didn't reduce the wake area at all.

And in all probability those mods raised Cd in yaw and yes the poor sap doesn't live that far from me so he suffers the x-winds too.

Were I to do such a project I'd mock it up in cheap cardboard or coroplast first, then tuft test. No doubt, even as smart as I think myself to be I'd find that the first version needs changes to make it work. After all has been proven satisfactory... THEN build it "permanently".

I here ya big time. To the point I have a sick feeling in my stomach.:confused::confused::confused:

I'm a performance engine builder and performance EFI tuner. When it comes to aero i can't even make a paper airplane fly right.LMAO

Well if anything I'll have a few bad ass Lexan sheets for sledding.

or use the sheets and build some nice solar panels.

Or maybe he's still in jail after putting that thing on the road. :p
"We don't take kindly ta yer type 'round here"

Well I think the shorter version looks better, as far as that goes. And in a real world situation, it would be safer to drive. As short as the wheelbase is on the Del Sol, if you add that much behind the pivot point, you're going to have to be really careful of not swinging it into other vehicles, and not knocking old ladies off the sidewalk.

I just love watching other people's experiments! I'm still wondering about the template material? Is it paper? Something more substantial? Is it durable enough for mock up road/tuft testing?

I sent the pics to a friend that's one of those aeronautical engineers, so I'm going to see what he thinks.

The template material is made of made of thick paper. I think its used for scrape booking. But to answer your question no it wouldn't survive a tuft test.:(

OK I just finished talking to my aero nerd friend.LOL

Cd's model is what I'm going to copy. I'm going to shorten it up by about two feet to get the length more symmetric and to scale of what "Cd's" pic shows.

This will give me a starting point and then I will tuft test it.

I'm happy again:)

Oh cool ! :)
Glad that could be of use.

You are just mocking up pieces now aren't you ?
The reason that I ask, is that I see that even in your sketches, you have a lot of flat sides and sharp angles.
I'm assuming that you are going to smooth those edges right ?

I'm sure that you know this, but the angles that you have now will result in two huge vortexes ( corkscrews ) of air at the rear of your car.

http://farm3.static.flickr.com/2800/...3d94ffee_o.jpg

The rear of the tail should have rounded edges ( similar to my first illustration ) versus being a boxy shape. The red lines in the picture above show the path that air will take in your current configuration. The black lines are what we are after.
It is basically just a tapering of the shape that proceeds it.

By the way, the angles on the picture that I did are a little off on the 'ideal' underside angle ( pretty sloppy too), but I was trying to see how short I could make the tail, yet have it look esthetically pleasing.
If you have your car lowered, you may not get that much air under there anyways.

The angles on the sides ( the top view ) should be the 'ideal' angle though.

( I did an overlay of the teardrop template. )

Interestingly enough, the sides of you car already start to taper at just the right angle !
All you have to do is just add to that.

So are you the guy I spoke with about grafting an MX-3 hatch onto the car ?

You would have to do some fiberglass buildup / cutting in some areas, but it looks like it might just fit right in.

Not only would it look professional, but it would be functional as a hatch.

( Note the almost identical angle of the hatch near the C pillar on the two cars )

http://upload.wikimedia.org/wikipedi...t_20080103.jpg

Thanks again for your input!!!

Yeah the pics I have posted are very square to the actual layout. In fact I test fitted a side panel and the way it attaches the whole back will be a cone shape like your black lines of your sketch.

Thanks on the advice of the back panel I will have to come up with a smoother shape instead of the one on my drawing.

Yes that was me I borrowed a hatch off a MX-3 and its way off.

I could make it work but there wouldn't be much left of the original hatch after I got done with it. LOL

Very nice, gives me a though to start my own boat tail. Keep up the good work

Sorry, joining the party late...

That's a rule of thumb for the initial transition. If you taper gradually (ie curve), you can apparently go up to 22* with attached flow (assuming the upstream flow is clean).

Yes. The images Cd made would yield better results than the initial mockup - glad to hear those are being copied. You want an organic shape so pressure recovery is gradual, not hard corners which could trip the flow and cause early separation.

The exception is the very rear surface (what I call the transom - where the tail lights go). You can chop that off clean and have hard corners there.

Thanks, its been a pain but I'm sure when its all done it will be worth it.

Thanks for all the input.:thumbup:

Its about time you joined the party.lol

I need all the help I can get.

pgfpro -

That's too bad, because it looks so good from the side :

http://ecomodder.com/forum/member-cf...mx-3-hatch.jpg

CarloSW2

Just curious about which areas of the hatch were off from the MX-3.
Unless the hatch was too wide, it seems that you could modify the C pillars and the edges of the hatch to meet.
I know that you would have to do some build up or cutting between the two components, but I'm just curious about where they don't match up.

Also, I wanted to add that the corkscrew effect in the picture that I was talking about was mainly due to the angle of the shot. It looked a lot worse than it really is now that I look at it again.

sides
 

It's hard to tell without being right there looking at it but the side I can see has reflex curvature,cupping toward the inside instead of out.
The line should look like that of an ellipse,with almost zero curvature where the tail begins,then gently becoming more and more curved,the further back you go.
I don't have Mair's chart in front of me,but I believe the curvature could possess the 22-degree angle at a length equal to the height of the car ( around 50-inches.1250mm downstream ).
These curves are already cheating the air as much as possible.If you go below the minimums you'll guarantee separation with severely compromised performance.
Remember,Kamm said to follow the path to wherever you want to cut the body off,but you've got to stay on the path.
If you haven't seen the aerodynamic streamlining template,I recommend you do.It will explain the origins of the art and give you good science with which to compare your work.
Really like what you're doing!

This is the template Phil is talking about. (I've learned to listen to him - he's been studying this stuff for a while now.)

http://ecomodder.com/imgs/ideal-teardrop-comparo.jpg

I found this from one of aerohead's old threads over this summer.

Someone wanna take a stab at this? I'm not sure my version is correct.

Yes it was to wide. So as soon as I realized that I would have to replace the glass I gave up.

Thanks though it was a great idea!!!:thumbup: