Returning to C3 Aerodynamics
Thread Starter
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
Returning to C3 Aerodynamics
There was a thread a couple of years ago about C3 aerodynamics, a lot of which was about the front end lifting at high speed. A chance meeting with a couple of Jaguar development engineers last year resulted in me re-thinking what would be required. The upshot of what they were saying was that at 100mph plus, very small changes have a significant effect. We looked at the front end of the vette and they suggested that a small splitter could have a big effect.
This is the theory:
and this is the result, not painted yet but its made from 3mm aluminium and its pop rivetted and araldited to the spoiler.
The proof will be felt as soon as I can do some proper high speed runs and that requires a quiet speed camera and police free road, increasingly difficult to find here these days
This is the theory:
and this is the result, not painted yet but its made from 3mm aluminium and its pop rivetted and araldited to the spoiler.
The proof will be felt as soon as I can do some proper high speed runs and that requires a quiet speed camera and police free road, increasingly difficult to find here these days
Thread Starter
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
These Jaguar guys (they had a couple of the new XKR mules with them) were really interesting to talk to, they seemed to think that a huge amount of downforce wasnt necessary to get the feeling back into the steering again. A fun thing to try anyway since I have another stock spoiler in the garage.
G
Tech Contributor
Joined: Jun 2004
Posts: 20,910
Likes: 962
From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Post any results you get. It's always interesting (to me) to see the occasional bit of test/engineering performed on these relics. 
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Thread Starter
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
Dont forget that most road circuits, in those days, they didnt spend much time over 130mph It was more about handling and acceleration. Still is of course, but I can remember several Le Mans cars in the 70's having the steering go light on the Mulsanne Straight, its only when guys like Colin Chapman and Jim Hall got into aerodynamics around that time that we began to understand.
G
Last edited by Graemeinvette; Apr 30, 2009 at 03:27 PM.
Safety Car
Joined: Nov 2005
Posts: 3,961
Likes: 573
From: Lompoc, CA. Santa Barbara County
I want to attach an aluminum extension to my Pace Car spoiler. Mostly for protection of my newly painted spoiler, but it should lower the overall height about 1/2". I have to have this spoiler repainted about every five years or so. Anyone do this to the Pace Car spoiler? Glue, rivets, or screws. It's the original spoiler so it's flexible urathane.
Bee Jay
Bee Jay
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
fixed with lexan covers with a couple bumps...kinda stupid looking if you ask me...but then again the only option back when....
do something like my concept, and headlights/lift is no longer a issue....
and my hood has a downdraft if anything at 100 mph....
so if the hood downdrafts, just how/where does any lift come from???
Melting Slicks
Joined: Jul 2002
Posts: 3,000
Likes: 22
From: Boulder Creek California
How do you figure?
Edit: I don't suppose there's a CAD model of a C3 floating around? I'd be happy to CFD it if there is. (Gotta make use of these use-as-you-want university resources while I still can...) Unfortunately modeling the outside of the car without optical scanning isn't an easy proposition.
Edit: I don't suppose there's a CAD model of a C3 floating around? I'd be happy to CFD it if there is. (Gotta make use of these use-as-you-want university resources while I still can...) Unfortunately modeling the outside of the car without optical scanning isn't an easy proposition.
Last edited by LiveandLetDrive; Apr 30, 2009 at 06:08 PM.
Thread Starter
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
I think the fixed headlight idea was to eliminate the problems with the stock lights standing up in the wind as it were when they were racing in the dark, 12 hour races etc. The hood creates a high pressure area immediately infront of the windscreen but that is in the centre of the car. The problem is that the front end which causes the steering becomes 'light' over 120mph or so with increased problems in cornering and in the rain aquaplaning. I have already changed the angle of attack of the front end by lowering it about 1" which helps, if this splitter works I will then need to look at the back end of the car which is becoming increasingly light - for various reasons. I carry no spare wheel so if I get rid of the spare carrier I should add a diffuser, whichy will be an interesting exercise, but, I like my car to look stock! Aarg!
So difficult!
Graeme
So difficult!Graeme
Racer
Joined: Dec 2008
Posts: 300
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From: Toms River NJ
I think the splitter can definitely help, so long as it stays straight and doesnt bend. next thing to try might be to get the splitter as close to the ground as possible (within reason, 'cause its a street car) to limit the amount of air going under the car and to increase the high pressure area above it.
this is a great thread, I love this kind of stuff.
this is a great thread, I love this kind of stuff.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
How do you figure?
Edit: I don't suppose there's a CAD model of a C3 floating around? I'd be happy to CFD it if there is. (Gotta make use of these use-as-you-want university resources while I still can...) Unfortunately modeling the outside of the car without optical scanning isn't an easy proposition.
Edit: I don't suppose there's a CAD model of a C3 floating around? I'd be happy to CFD it if there is. (Gotta make use of these use-as-you-want university resources while I still can...) Unfortunately modeling the outside of the car without optical scanning isn't an easy proposition.
now if you look at my site, you see the car, it's not stock by any stretch...but othing radical either....just the headlights are not stock, so subtracting one HELL of a lot of drag/lift...
look at the race cars of the era...almost NO stock headlights....
Melting Slicks
Joined: Dec 2008
Posts: 2,070
Likes: 5
From: N.Richland Hills Texas
Years ago I had one of the store bought front spoilers added.. I had run to Austin TX for Corvette Day and felt the "lift" at 100... The spoiler went on the next week. I also wanted to fair in the fronts of the front tires... Several weeks ago during a spirited cruise I was over 100 for extended periods of time .. no lift... I have a ZZ383 and custom 700R4, no spare and no carrier.The new motor ect is about 300# lighter than stock...
Le Mans Master
Joined: Apr 2007
Posts: 7,353
Likes: 72
From: Graceland in a Not Correctly Restored Stingray
Maybe it's an optical illusion, but that doesn't appear quite normal to the road surface. Also, at "speed" you may find it requires additional bracing, which is a certainty with a Pace Car dam (
), and that's before the added pressure owing to any additional splitter.
TSW
), and that's before the added pressure owing to any additional splitter. TSW
Instructor
Joined: Jan 2007
Posts: 115
Likes: 0
From: Jasper Indiana
I'm sorry, but I tend to hit 110+ at least twice a week on my lunch breaks in my 79. I get bored with cruising through town. I have never felt any lift or any change in the steering. I even hit 110 in the pouring down rain. I have a stock car with no mods whatsoever. I am running no front spoiler. The car, in my opinion, handles better at faster speed. The only reason I slow down is when I hit a dip in the road, it freaks me out because the whole car drops at least a foot. Don't listen to me, but I think my car at least is wonderful at higher speeds.
Thank you
Doug
Thank you
Doug
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
I think the splitter can definitely help, so long as it stays straight and doesnt bend. next thing to try might be to get the splitter as close to the ground as possible (within reason, 'cause its a street car) to limit the amount of air going under the car and to increase the high pressure area above it.
this is a great thread, I love this kind of stuff.
this is a great thread, I love this kind of stuff.
Race Director
Joined: Jan 2007
Posts: 14,950
Likes: 3,351
From: NYC NY
I dug this up from another C3 Aero thread http://forums.corvetteforum.com/c3-t...ics-et-al.html Post #5 in particular. Very much along the lines of what you're suggesting.