Custom Chevelle Air Dam Help

[71beast]

Hi everyone, long time follower of the forum, and have gotten tones of ideas and help from other posts, but I finally have a question that I hope someone here can help me with. Long story short, I have a 1971 chevelle that I have slowly been making her handle as well as she should for having the amount of power she made, but I've noticed that even though she's been lowered there is still a ton of air that enters from under the front and causes front end lift. I can't stand it. So, I've been looking at making my own air dam, that is functional and looks good, so that it's not really out of place looking. In my quest to find info and see what people do I came across Iwan Customs (http://iwancustoms.com/), but it's only for 69 chevelles, and I've sent them like 3 messages to see if they could make it so that it can fit a 7, but I get no response.

I figure to block air from going under the car or being directed into the radiator, a la spoilers by randy, it needs to mount to the bumper, not farther back. I'm also going to add one of the undercover innovations radiator block out panel to direct the air in, and prevent it from lifting up on the hood. Before I start to make my own over the winter, any idea if anyone has something similar or know of anyone that could make one without costing an arm and a leg.

Btw, here's what it looks like:
83820
If I need to make one I'm going to have to figure out how to make a mold correctly and then order some carbon fiber or fiberglass to make it, as my original plan was to do it out of metal, but didn't like that idea in the end. Any good places to look for working with either material? I found a few books I might pickup, but could use as much info/help as possible.

Sorry for writing so much and babbling. But I want to say thanks in advance for any suggestions and help.

[71beast]

Anyone? Bueller?

[astroracer]

Any side shots? How far is the car lowered? It still looks pretty tall in the front pic so that is why I am asking...

[71beast]

I think they have some on their site. I'll look and post any. I'll post some pics of my car besides the one in as my avatar. My car is fairly low, about 4-5", in fact I have a low profile jack to get under the frame, because a normal jack won't fit. The problem is the 71 Chevelle's front bumper is higher than that, but not sure of the measurement, can try taking some on mine.

[71beast]

So here are some more pictures of the Iwan Spoiler.

84377

84378

Here are a few of my Chevelle. I figure that I would have the spoiler wrap around a little and attach to the bottom of the fender, where the fender brace is attached.

84379

84380

84381

84382

[badbu68]

It looks like on that 69 they took a camaro air dam and added to the sides. The camaro repro air dams are cheap enough to play with.

[jlcustomz]

As far as fiberglass materials, I usually get from either a production fiberglass product shop or some boat supply places.I have both in my area & the resin itself is much cheaper & fresher than from a body shop or hardware stores. There are many different methods to make something from fiberglass. When making a mold , more time spent on the mold quality can mean less bodywork time on the final part, but for 1 part only I won't spend the time to go for a perfect mold. For the shape you're posting, you could make a decent form from wood to make a mold from. you will also need to figure how to mount, this area could be made separately.

Also ,there is the fleece fabrication method. You start out streatching out fleece over a frame to shape wanted,wet it with resin, lay fiberglass matt & resin over it for strength & then have to completely bodywork into shape. This is done for speakerbox & interior work all the time.

google powerblock tv. Trucks show did a fleece modified bumper on the ranger project. Musclecar show did a ford lift off fiberglass hood, making a top notch mold off modifying the old hood.

I could make a spoiler like you want hammerforming & tig welding aluminum sheet, but glass is easier for most to work with.

F

[71beast]

I think I actually recorded that episode from powerblock, but I'll check it out. I just bought some books on working with composite like carbon fiber and fiberglass, but its good to find out where you can get good materials for a cheap. Thanks F for the offer, I think maybe I'll give fiberglass or carbon fiber first.

I just wonder how affective this is going to be, or if there would be a better design that looks as good, really don't want to ruin the look of the car. So I want to make sure that the air is directed around the car, and blocked it from going underneath the car, while being able look good, be sorta non invasive like the Camaro spoiler. I'm really tired of having the front feel like its barely on the ground at high speeds, I just need to make sure that if I make this, put all the time in I can stop some of the front end lift.

All I've really seen on Chevelle's look like an afterthought or ones that I think try to make the car look more modern like the roadster shops 70 Chevelle. Although, I feel like the roadster shops is close to what I'm looking for, but can't figure out if my problem is that since it's body colored that's why I don't like it and think its more modern looking, but if it were black would be do what I'm trying to.

84386

84387

No Disrespect to either of these cars, they are real badass, just not what I'm going for.

I figure I want it to mount it under the bumper to the bumper bolts, and have a wrap up and tie in under the fender braces. Here's how theirs mounts to the bumper:

84385

Any suggestions on some designs that aerodynamically work, and look good for this body style?

[jlcustomz]

the last 2 pics are just sheetmetal, Idon't like the first at all, the 2nd isn't bad. I think your first pic is a good design choice. One option for this or other designs is a small set of adjuster bars, I guess you may call them.
Another option could be to cut a few pcs of 1/4" aluminum or even 3/8 to 1/2" plastic. this option could be bolted together with small (#10) stainless allen head cap screws. Take a close look at the diamond plate spoiler I made as a temporary replacement for a smooth air dam I destroyed. While the overall shape is not what you want, a small bolt in center section similar to this one could be an option worth considering making from smooth sheet aluminum. the outside edges could slip behind & bolt to the centers.
Just giving easier options. PS, not sure how that F got at the end of my last post??? , Joe.
https://static1.pt-content.com/images/pt/2012/10/DSC00074_zps7047bfd4-1.jpg (http://s1094.photobucket.com/user/jlcustomz1/media/DSC00074_zps7047bfd4.jpg.html)

[71beast]

Oh man joe that looks really good, and that's an interesting way to do it that I didn't think of. Since it looks like in going to be making it myself, I'm trying to get a good design going that's functional and looks good, so I've been reading a lot about aero, even picked up a book on race car aero, hopefully it will help.i want to make sure that it doesn't look out of place too, ya know what I mean? I know it's going to be black and smooth when it's done, got to figure out the height, shape, and make it look like it came from the factory. So much work, so little time. Lol

[csouth]

You definitely need to get the angle of the spoiler close to Roadster Shop or whats pictured above by JLcutomz for it to look right in a wrap around. Although you don't want it ti look like an "after thought", I think it will unless you match the color to the body. The spoiler will defintely stand out as the blue and the black come together IMO.

[Yelcamino]

I'm really tired of having the front feel like its barely on the ground at high speeds, I just need to make sure that if I make this, put all the time in I can stop some of the front end lift.

If you're having a "floating" feeling at high speed, in addition to the aero of your car, your suspension could also be contributing to the affect. Have you done anything in that area?




84386

No Disrespect to either of these cars, they are real badass, just not what I'm going for.


No problem. I know my front air dam isn't for everyone. Crude looking, yes, but it was effective enough to help me run 163.5 mph at the Maxton Mile. I've since changed the air dam to this...

https://static1.pt-content.com/images/noimg.gif (http://s263.photobucket.com/user/hlumpp/media/Chevelle/Powdercoatedspoiler-01.jpg.html)

Again, I'm sure it's not for everyone, but it works.



Any suggestions on some designs that aerodynamically work, and look good for this body style?

Have you checked out this thread on aero (https://www.pro-touring.com/threads/101460-Designing-Aerodynamics-for-Track-Performance)?

[jlcustomz]

Thanks,71beast. I gave that diamond plate spoiler to a friend that bought my old custom nose & tilt hood (now have 2010 Camaro nose). The diamond plate material was partly done based on a joke, but I never managed to hear the insults I expected on it. Sorry I don't have a pic of the smooth version I first made.

Anyways, both versions are made from .063 aluminum, completely handbent with a 3/4" flange along the bottom edges. to bend the cornors,I actually tapped a 3" stiff puttyknife with a hammer against the metal (strategically) with it laying on a few layers of carpet. Sort of a sandbag/ teardrop hammer type of effect. No fancy tools needed ,just a little skill. The part you see attached to a simple aluminum angle frame which attached to radiator core support the g-body has. The original smooth version had flat 3/8" lexan between the center & ends. Used closed cell foam tape to pad the fender from the aluminum. Pretty simple huh.
On shape, I think that a large flat air dam just moves the air around the car while an angled design works as a downforce wing.
Herb, no disrespect meant to the flat spoiler, they do the intended job.

[Yelcamino]

Herb, no disrespect meant to the flat spoiler, they do the intended job.

No worries, all's well! My main goal with the air dam was to keep as much air out from under the car as possible. As for looks, the square shape of the early Chevelle doesn't help when designing aero!

[Munssey]

If you're feeling in the mood to learn and accept a little time\ maybe a few attempts at it, I say give it a try! If space, tools and time are at a minimum then I think finding someone to do a one-off (or work with them to R&D something that could be reproduced in a small number) would be the way to go.

Takes some skill on body work but nothing that can't be learned.

Heres a quickie show and tell on how i did the very first spoiler a ways back (consider it inspiration)

https://static1.pt-content.com/images/pt/2013/11/FrontBumperSpoiler20121216002_zpsf6552c9-1.jpg (http://s845.photobucket.com/user/munssey/media/FrontBumperSpoiler-20121216002_zpsf6552c92.jpg.html)
https://static1.pt-content.com/images/pt/2013/11/FrontBumperSpoiler20121224009_zps0a169f1-1.jpg (http://s845.photobucket.com/user/munssey/media/FrontBumperSpoiler-20121224009_zps0a169f14.jpg.html)
https://static1.pt-content.com/images/pt/2013/11/FrontBumperSpoiler20121226011_zps06b3831-1.jpg (http://s845.photobucket.com/user/munssey/media/FrontBumperSpoiler-20121226011_zps06b3831a.jpg.html)
https://static1.pt-content.com/images/pt/2013/11/FrontBumperSpoiler20121226017_zps74c9072-1.jpg (http://s845.photobucket.com/user/munssey/media/FrontBumperSpoiler-20121226017_zps74c9072c.jpg.html)
https://static1.pt-content.com/images/pt/2013/11/FrontBumperSpoiler20121226023_zps6870ca5-1.jpg (http://s845.photobucket.com/user/munssey/media/FrontBumperSpoiler-20121226023_zps6870ca5b.jpg.html)
https://static1.pt-content.com/images/pt/2013/11/FalconFrontSpoiler201302100012_zps3dc23e-1.jpg (http://s845.photobucket.com/user/munssey/media/FalconFrontSpoiler-20130210001-2_zps3dc23e6f.jpg.html)

Hope that helps get your juices flowing! Have more questions, PM me and I'll be happy to answer them.

[71beast]

If you're having a "floating" feeling at high speed, in addition to the aero of your car, your suspension could also be contributing to the affect. Have you done anything in that area?

Yea, my whole suspension was done last year, with the help of Mark from SC&C. I have SPC Uppers and Lowers, tall howe balljoints, SPC springs, single adjustable Varishocks, Hellwig protouring antiswaybars (rear is adjustable), outback I have UMI double adjustable uppers and tubular lowers with roto-joints. I also had rebuilt the front end using PST parts, and did the jeep cherokee steering box conversion.

I guess its hard to explain whats happening, but at normal low speeds the steering is nice and heavy, but once I get up to around 55+ it feels light, which is why I'm thinking its an aero issue. The floaty aspect is more like with the quick ratio box when I try to stay straight and do a small correction its more major, if that makes sense. I think it's also because its tight, rather then all loosey goosey like the original. With the original steering box it would still feel light at high speeds, but at low speeds it felt light too, and it was super sloppy.

Btw, I've loved your Chevelle for awhile, its one bad mother...... I actually think it fits the early Chevelle, and would totally do the same if mine was an early body style, my comment was more about if I put that on mine it would look just slapped on, ya know? This is why I'm having such a huge problem trying to figure out how to make mine fit my body, almost factory looking.

I found that post like two days ago, and had been reading it. Reading has me has me worried about making the aero worse.

BTW, hopefully I'll be able to catch you at 164mph when I'm done. :)

[71beast]

Thanks,71beast. I gave that diamond plate spoiler to a friend that bought my old custom nose & tilt hood (now have 2010 Camaro nose). The diamond plate material was partly done based on a joke, but I never managed to hear the insults I expected on it. Sorry I don't have a pic of the smooth version I first made.

Anyways, both versions are made from .063 aluminum, completely handbent with a 3/4" flange along the bottom edges. to bend the cornors,I actually tapped a 3" stiff puttyknife with a hammer against the metal (strategically) with it laying on a few layers of carpet. Sort of a sandbag/ teardrop hammer type of effect. No fancy tools needed ,just a little skill. The part you see attached to a simple aluminum angle frame which attached to radiator core support the g-body has. The original smooth version had flat 3/8" lexan between the center & ends. Used closed cell foam tape to pad the fender from the aluminum. Pretty simple huh.
On shape, I think that a large flat air dam just moves the air around the car while an angled design works as a downforce wing.
Herb, no disrespect meant to the flat spoiler, they do the intended job.

Nice, thanks for the idea of how i can go about. I saw your friends el camino with camaro front end. That's pretty crazy how you did that. Can you tell me the angle you used on your airdam, btw?

[71beast]

Wow, nice job man. Thanks for showing me how you did it. I've taken a few classes on body work, and I'm not half bad at it. I have plenty of time to get this done, I have till the spring to get this ironed out, so I can take as long as I need. :) Btw, I will definitely message you if I have any questions.

[jlcustomz]

I,d say the angle of my old spoiler was pretty near 45 degrees. You could just clamp a small scrap of metal a few inches wide to easily bend & determine the depth & angle you like.

The 2010 Camaro nose is mine currently, till I come up with the next creation, if there is another.

[71beast]

I,d say the angle of my old spoiler was pretty near 45 degrees. You could just clamp a small scrap of metal a few inches wide to easily bend & determine the depth & angle you like.

The 2010 Camaro nose is mine currently, till I come up with the next creation, if there is another.

Oh, I miss read your message. Amazing work, it looks like it was made for it.

[Yelcamino]

Yea, my whole suspension was done last year, with the help of Mark from SC&C. I have SPC Uppers and Lowers, tall howe balljoints, SPC springs, single adjustable Varishocks, Hellwig protouring antiswaybars (rear is adjustable), outback I have UMI double adjustable uppers and tubular lowers with roto-joints. I also had rebuilt the front end using PST parts, and did the jeep cherokee steering box conversion.

I guess its hard to explain whats happening, but at normal low speeds the steering is nice and heavy, but once I get up to around 55+ it feels light, which is why I'm thinking its an aero issue. The floaty aspect is more like with the quick ratio box when I try to stay straight and do a small correction its more major, if that makes sense. I think it's also because its tight, rather then all loosey goosey like the original. With the original steering box it would still feel light at high speeds, but at low speeds it felt light too, and it was super sloppy.

Btw, I've loved your Chevelle for awhile, its one bad mother...... I actually think it fits the early Chevelle, and would totally do the same if mine was an early body style, my comment was more about if I put that on mine it would look just slapped on, ya know? This is why I'm having such a huge problem trying to figure out how to make mine fit my body, almost factory looking.

I found that post like two days ago, and had been reading it. Reading has me has me worried about making the aero worse.

BTW, hopefully I'll be able to catch you at 164mph when I'm done. :)

Thanks for the compliments. :)
It sounds like you have your suspension in order, but at 55+ mph you should still have a tight, sporty feel to the car considering the parts you installed. Did you replace the center link? On my El Camino I thought my steering box was worn out and I replaced it only to find there was no improvement. While doing some other under car work, my wife moved the steering wheel for me and I noticed the pitman arm moved a tad before anything else moved. Upon closer inspection, the stud on the center link was loose causing the rest of the linkage to lag behind the pitman arm, which gave the car a floaty feel.

[71beast]

Yea, when I did the suspension and steering box upgrade I changed all the steering components using PST steering linkage kit. So the center link, tie rods, idler arm, and tie rod sleeves. Could there be a problem with my steering box or the power steering pump? Or I was just thinking could it be that the alignment is off. I had to put spacers for the springs in, but don't remember if I got it realigned to Marks specs. The car still feels sporty at high speeds, the steering feels light. Like I said its kinda hard to explain.

Plus I took some new measurements, from the ground to the bottom of the bumper is 12", but front the ground to the bottom of the chassis is 7.5". If I were to make an air dam how much lower then the chassis do I want to go, or should I just even out the chassis and front bumper?

[1965gp]

Just a suggestion but if you are looking for something to kind of mold as you go to figure out what you want- maybe start with a 70-72 GTO Judge front spoiler. Looks like it would bolt up relatively easy and would be the proper size. Then you can add or remove material as you go to see what you like. I would think you could mold plastic or sheet metal to the style you want and then just attach it to the GTO spoiler. Then paint it all black of course.

[djfxall]

I dont know how good you are with photo shop or with art but me owning the same year chevelle also having the same idea in my head has pondered your same question over and over again. You take pictures and print them out then draw right on the print outs. I have designed graphic paint jobs this way. Paper is always a good spot to start. Look at some older chevelle stock cars they will be more period specific for aero ideas. I have not taken the time to design one or make one yet not at that part of my build.

[Sean Cooke]

You can try the 69 Camaro splitter - that's what I'm running - some people like it, some people don't .... I think the front of your car is gonna lift until you stiffen up your suspension though

[71beast]

Thanks for the ideas gto and dj. Been working in it for awhile. Kinda getting where I want it, but have to make sure it's what I want before putting the work into molding it and spending all the cash for supplies.

Sam, trust me it's not my suspension at all. If you read closer to the beginning of the thread I mention everything in my suspension. In fact it was completed with the help of Mark of SC&C. The front end lift happening is due to air pushing the front of the car up, due to having about 12" of clearance from the ground to the bottom of the front bumper.

The problem with the camaro spoiler on a car as big as the chevelle is that it's not going to stop air going under the car, it's short and narrow. In order to be functional it needs to be like herbs I'm trying to figure out how to make it so it will blend in more with the 71 chevelle body style. This is why I'm looking into making one that fits and will work correctly for my size car.

[71beast]

Been a long time since I posted any updates. Before the massive amounts of snow hit NJ I was messing around with some foam core trying to get some idea how it will look. Here you can get an idea how low its going to be, in fact this is only about 4" down, and I might make it 6" or so.

My general concept is going to be to create a shape similar to an upside down "Z", which will mount under the bumper to cover the opening, then about 3-4" backwards behind that the air dam will come straight down, and bend backwards to create a flat area which will have turnbuckles that will mount to the core support. The splitter itself will form a "V" shape to help direct air away from the car, and flat to stop the air from moving under the car. It will extend to the front of the fender, where the factory brace is located to help prevent the wheels from messing up the air flow.

I bought some 2" pink insulation foam that I'm going to carve to shape, then make it out of fiberglass or carbon fiber. The flat underside will allow me to add a splitter when racing, or extend lower to block more air.

What do you guys think? Oh, and keep in mind it's either going to be flat/semigloss black, or natural carbon fiber, so I think it should blend in/sorta disappear under the car.

Temp Form:
90581

Temp Form:
90581

Rough Sketch:
90582

I just need to figure out the turnbuckles. I'm not sure if I can get away with light duty aluminum ones from McMaster-Carr, or if I would need heavy duty stainless ones, or it it would be better to use heim joint rod ends instead to allow some movement/flex.

[chuckd71]

How did you come to the conclusion that it s air lifting your car up? It that were the case why does every other chevelle not have that problem? It seems unlikely that at 55 mph that is what is going on. Air simply flowing under the car isn't necessarily going to push it up anyway, if it did, wheelies would never get landed at the track and every car on the road would be flying into ditches.

[71beast]

How did you come to the conclusion that it s air lifting your car up? It that were the case why does every other chevelle not have that problem? It seems unlikely that at 55 mph that is what is going on. Air simply flowing under the car isn't necessarily going to push it up anyway, if it did, wheelies would never get landed at the track and every car on the road would be flying into ditches.

Chuck, its based on basic aerodynamics. The car generates both lift and downforce based on how the air flows above, around, and below the car. The faster you go the more air is going to go under the car generating lift. This is why when you look at modern performance cars, and race cars they are very low to the ground and have air dams to block air going under the car to stop the lift. There are also high and low pressure areas on the car, which are attempted to be controlled by vents, and ground effects as well.

Every muscle car, not just Chevelle has front end lift, its based on the design of our cars. Think about a box moving through the air. If you lower your car you create a lower center of gravity, and reduce the amount of air flowing under the car. An air dam is the next step to continue reducing/controlling this air flow.

To go even further you would want to have ducts, vents, a splitter, etc to increase the aerodynamics of the car.

You also have to remember that even though the air is a gas, as you drive through it it acts like a solid. The faster you move the denser it gets. I remember reading/learning in a physics class something like at 70mph its like trying to drive through fog, 120mph its like driving through whip cream, 170mph its like angel food cake, and 200mph+ like a Christmas fruitcake.

Yes, at lower speeds its not really that noticeable in normal driving situations, but what you will find is that the front end will feel light. What you mentioned about wheelies not getting landed isn't 100% true or false. Look at what happens to a lot of drag cars when they do not have wheelie bars. Or an even better example is the 1st & 2nd gen beetles which will flip over due to a high pressure buildup under the car at certain speeds.

If you read through the post, there was something else at off with the alignment that made the car twitchy besides the common lift. I intend on going further to reduce the lift, hence the air dam.

Ron Sutton started a thread on aerodynamics for muscle cars under the Advance Tech section that was a huge help in understanding how to increase aerodynamics of our cars for racing. In fact through my conversations with him, he helped in the design of my air dam, and its location in my car.

[71beast]

I hope my comment didn't come across as me being rude or a d**k. I was trying to be a honest and factual as I could about the cause of the list, and as much about the aerodynamics involved in for the given situation.