Looking for infos on rear spoiler design

[denpo]

After seeing pics of Robert's "77Custom" car the idea of making a rear spoiler grew on me.


So I'm looking a good references on rear spoiler design/aerodynamic.

I got some remains from my college fluid dynamic courses and I had to deal with it all along my game programmer career (realtime Navier-Stokes solver), so I'm not afraid a paper with equation.

I just want to go further than the "planes' wing upside down" concept.

 

[mrvette]

Pardon my old ass, but about 99% of the 'spoilers' do just that, spoil the looks of the car,

whatever it takes to make a race car WIN is fine....

but there are simply NO designs going to out dooooo the Plymouth Super Bird, bar NONE....

and so, I like the early shark designs the best on that score....

and this has been my opinion for some decades now....

:hi::clap::flash:

 

[MYBAD79]

I don't believe there's a noticeable difference under 100mp/h that justifies putting money and time into a rear spoiler design.... now above 100mp/h it's going to be VERY significant but where are you going to go that fast ???

For looks: yes, spoilers can be pretty cool looking .... whatever you like.... I prefer the integrated look of this 80's style bumper/spoiler over the "add ons" but to me it comes all down to personal preference....

 

[denpo]

.... I prefer the integrated look of this 80's style bumper/spoiler over the "add ons" but to me it comes all down to personal preference....

I used to think just as you Karsten, but now I'm tired of the '80 bumper style, the tail is not blending right with the rest of the rear body lines IMHO.
I agree Gene, the shape of the back of the chrome bumpers is just perfect and it's my plan A, smoothing down a '80 bumper to make it looks like so.
I don't like the original 'sloppy' shape of my '76's back, but the spoiler pictured above breaks it and gives a more balanced look. Hence a plan B.
And while I'm thinking about making a spoiler/wing, better think it right.

 

[MYBAD79]

I agree, on a pre 78 model the later style bumper with the fin doesn't blend in as well as it does on a bubble window Vette....

I don't like the stock bumper all that much either, if it was me I'd probably graft the older style chrome bumper back on there, minus the chrome like this one....

 

[Kid Vette]

I agree, on a pre 78 model the later style bumper with the fin doesn't blend in as well as it does on a bubble window Vette....

I don't like the stock bumper all that much either, if it was me I'd probably graft the older style chrome bumper back on there, minus the chrome like this one....

That's my favorite Vette. :1st::wink:

 

[gkz]

I agree, on a pre 78 model the later style bumper with the fin doesn't blend in as well as it does on a bubble window Vette....

I don't like the stock bumper all that much either, if it was me I'd probably graft the older style chrome bumper back on there, minus the chrome like this one....

That's my favorite Vette. :1st::wink:

Mine too

 

[1Michel]

I agree, on a pre 78 model the later style bumper with the fin doesn't blend in as well as it does on a bubble window Vette....

I don't like the stock bumper all that much either, if it was me I'd probably graft the older style chrome bumper back on there, minus the chrome like this one....

That's my favorite Vette. :1st::wink:

Humm, I remember seeing that Vette, I dont know...
Beautifull but ...in my opinion, something's missing.

 

[JPhil]

Purely aerodynamically speaking with my limited knowledge, it seems to me that to get the true performance of something like that, you need to smooth the airflow over the rear deck first, like the Baldwin Motion cars with the rear window following the lines of the rear 'buttresses' did. That sexy vertical rear window creates a vortex over the rear deck which will not be effectively dealt with by a spoiler of that (or any) type. The rear camback design is a pretty good aerodynamic design for it though --especially when cleaned up by removal of the chrome bumpers like Kidvette's car.
But unless you have the front aerodynamics cleaned up first by lowering, engine compartment venting, airdam and the like (not to mention suspension), you'll find yourself in trouble at 'streetable' higher speeds (shall we say, up to double the posted speed limit) if the rear is planted but you're getting too much air under the front end.
Oh yeah, it does look good, but if performance is what you want, there are other more subtle areas to concentrate on first.

(Perhaps Phantomjock could help--he has a brand new book with all kinds of info about this type of thing!)

John

 

[Kid Vette]

I agree, the rear of the '74 to '79 need something back there. I would go old school.

 

[denpo]

...But unless you have the front aerodynamics cleaned up first by lowering, engine compartment venting, airdam and the like (not to mention suspension), you'll find yourself in trouble at 'streetable' higher speeds (shall we say, up to double the posted speed limit) if the rear is planted but you're getting too much air under the front end....

I have a '78 front spoiler, harder front suspension and I will probably lower it a tad once I get it back on the road and everything's seated.

I agree, the rear of the '74 to '79 need something back there. I would go old school.

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.

However, if the red beauty pictured above is yours as said, well, congrats, it's a freaking nice ass.
I think I'm gonna take a mold of Michel's '72 rear bumper for my plan A.

 

[big2bird]

KidVette, are those rear spoilers period-correct?

Yep. No rice there. Pure period muscle car, but mainly for looks.

 

[clutchdust]

I've always liked the first spoiler pictured, but make no mistake that it is purely aesthetics.
If we're truly worried about downforce though, I think our cars are better served with a rear diffuser. But all that depends on cleaning up the aero on the front and underside of the car. The problem is the c3 design, as cool as it looks, is inherently pretty ****** from an aero perspective. Far too busy trying to throw and push air all over the place instead of working with it. But what did Bill know or care about aero back in the 60's anyway?

 

[Kid Vette]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.

However, if the red beauty pictured above is yours as said, well, congrats, it's a freaking nice ass.

No sarcasm. Those spoilers are all bone stock from the factory. People kinda forget how wild things were back in the 60's

And thanks for the kind words on my booty. :blush:

 

[denpo]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.

However, if the red beauty pictured above is yours as said, well, congrats, it's a freaking nice ass.

No sarcasm. Those spoilers are all bone stock from the factory. People kinda forget how wild things were back in the 60's

So today's classic are yesterday's "ricer".

Surely my idea a rear spoiler is motivated by aesthetic, I was just trying combine form and function.
Thanks for all the inputs.

 

[mrvette]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.

However, if the red beauty pictured above is yours as said, well, congrats, it's a freaking nice ass.

No sarcasm. Those spoilers are all bone stock from the factory. People kinda forget how wild things were back in the 60's

And thanks for the kind words on my booty. :blush:

Tell you what's crazy, when I was painting my '72 a few years ago, I considered removing the chrome bumpers and redoing the body like you got there, and honestly was too chicken **** to try it...well, lazy too...but I like what you did there,....:bump::goodevil:

 

[Kid Vette]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.So today's classic are yesterday's "ricer".

Gotta remember this is period correct as well. :twitch:

 

[69427]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.So today's classic are yesterday's "ricer".

Gotta remember this is period correct as well. :twitch:

Yes, but also remember that this, and the Charger Daytona spoiler, were actually functional, not just decorative.

 

[JPhil]

Yes, the reason for it being so high was to get into the smooth airflow above the roof where it could be effective, instead of down in the rear deck turbulence.

 

[Kid Vette]

:shocking:

 

[69427]

Yes, the reason for it being so high was to get into the smooth airflow above the roof where it could be effective, instead of down in the rear deck turbulence.

I agree that having it that high improves the wing's efficiency, but I've also heard that it needed to be that high to allow the trunk lid to fully open. A nice side effect/benefit is that the substantial vertical area on each side support moves the center of aerodynamic pressure to behind the c/g, making those cars a lot more stable at speed than their contemporary competitors.

 

[Twin_Turbo]

Yes, the daytona and superbirds spoilers were so high to keep the trunk functional, nothing more nothing less

 

[mrvette]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.So today's classic are yesterday's "ricer".

Gotta remember this is period correct as well. :twitch:

One of my oldest buddies was literally crying in his soda pop over not having one of them.....serious alligator tears....

:friends::crap:

 

[JPhil]

I agree that having it that high improves the wing's efficiency, but I've also heard that it needed to be that high to allow the trunk lid to fully open.

Ah ****! I have no doubt whatsoever that that is a true reason! After all in those days, NASCAR actually meant National Association of STOCK Car Automobile Racing...I read the propaganda in Hot Rod Magazine or Car Craft or some such way back when and--and--I believed them.....

[EDIT] No, no, I retract the above.

They were over-the-top even then, & released to the public only in a very limited number only to be able to give them 'stock' car status so they could race in NASCAR. After all, those others allowed the trunk to open too. "Win on Sunday, Sell on Monday". The advantage they had was real (with that nose they had an equal part of it too) (& that nose was ugly even then, no matter how much we could excuse it for 'aerodynamics') and caused great protest from other makes & brought about rule changes. Those cars kicked ass for a year or two until rule changes directed specifically against them forced them off the race circuit. And I do remember that the rule changes were very much about the extremely limited number of those cars released to the public and so whether they could truly be considered 'stock'. I do remember that.

 

[big2bird]

:shocking:

You know what? Back in the day, I might have liked that.:suspicious:

 

[MYBAD79]

:shocking:

You know what? Back in the day, I might have liked that.:suspicious:

Any more pics of that car ?? Side view ???

 

[GT6Steve]

KidVette, are those rear spoilers period-correct?
Because some looks quite ricer to me, I not sure you're being sarcastic.
No offense.So today's classic are yesterday's "ricer".

Gotta remember this is period correct as well. :twitch:

Yes, but also remember that this, and the Charger Daytona spoiler, were actually functional, not just decorative.

Hmmm, I've read that the entire effort with the high spoiler was nothing but a decoy to lure the Tech guys away from some subtle rear deck mods. The actual spoiler contributed nothing but eye candy while the rear deck lid was doing the work.

I don't know but I like the story....

 

[Kid Vette]

:shocking:

You know what? Back in the day, I might have liked that.:suspicious:

Any more pics of that car ?? Side view ???

Sorry no.

Here's a pic of what I think is a pretty nice setup.

 

[denpo]

Here's a pic of what I think is a pretty nice setup.

Pretty nice indeed. What kind of rear mirror is it??

 

[phantomjock]

That's mine -- before I started to tear it apart. Can't see the front "Pace Car" chinguard.
Cheers - Jim