aerodynamic drag and body style

[Dragsinger]

Stan,

somewhere I saw a chart about body styles and aero drag. [may have been your chart]
that chart showed the 3rd gen Camaro with a relatively low COD and the 3rd gen Firebird among the lowest.

I have even considered installing a 3rd gen Firebird ft fenders and facia on my Camaro. Would doing that be worth the effort plus finding a Firebird ft and painting it?

Is the frontal drag the most critical? With rear drag less of an issue?

[Stan Weiss]

Larry,
Frontal Area is the area that the car has when looked at from the front. You should be able to measure width and height and calculate your frontal area. Google calculate frontal area of a car What year is your car?


Stan

[ss3011]

The aero package on the 91-92 Pontiac Firebird was reportedly the lowest CD of any GM car . Pontiac was very proud of that fact , and that was in many magazine articles . The frontal area was similar to the Camaro , but the front shape was way different . Rear shape was similar to Camaro , but air was able to flow under the spoiler.

[gsa612]

I remember reading an article by Lingenfelter back in the early 70's.On his S/S 69 Camaro rag the car picked up a bit of MPH using only the front spoiler,and lost using the rear.The car would MPH around 115.In those days you would have to run both (as part of the SS package) or none at all.On my '71 it picks up about a 1/2 a MPH (more in a strong headwind) with the front spoiler...gsa612

[nickh]

Larry I ran a 82 z28 with the ground effects and I had a large rear deck wing, car was very stable at 185 mph in 1/4 mile..LOL

[Jackie McCracken]

On a 79 Malibu wagon the factory rear spoiler is worth almost 3mph on car that runs just at 100 without it in the quarter.. and the reason for it is that it pulls air from the roof and routes it down the back window (to keep it clean in civilian life) which fills in the vacuum hole behind the car. and if you're wondering how big and powerful that "vacuum hole" is, it is what the cars that make turns use to create their ground effects downforce in sufficient quantities to be able to drive one across the ceiling upside down. The "vacuum hole" is also the reason behind drafting in nascar, if you can get in close enough it will damn near pull you along... need proof of what good aero can do? How about 174 on a bicycle...peddling.


what you really want to do with the front of the car is to smooth the air and keep it out from under the car, along the sides and roof you need to keep it flowing smoothly, and a the back you need to eliminate the "vacuum hole"...


Jackie

[Charles Stewart]

You will find here 2 articles to add more details to this post.
https://www.scientificamerican.com/a...es-in-golf-ba/
https://www.grc.nasa.gov/WWW/K-12/ai.../boundlay.html
I also like the FED387 informations regarding the one hand out of a car test... (relate to the coefficient of aerodymanic when the front of the car is more up in the air)
Enjoy,
Charles Stewart

[Mike Rietow]

Originally Posted by Jackie McCracken

On a 79 Malibu wagon the factory rear spoiler is worth almost 3mph on car that runs just at 100 without it in the quarter.. and the reason for it is that it pulls air from the roof and routes it down the back window (to keep it clean in civilian life) which fills in the vacuum hole behind the car. and if you're wondering how big and powerful that "vacuum hole" is, it is what the cars that make turns use to create their ground effects downforce in sufficient quantities to be able to drive one across the ceiling upside down. The "vacuum hole" is also the reason behind drafting in nascar, if you can get in close enough it will damn near pull you along... need proof of what good aero can do? How about 174 on a bicycle...peddling.

what you really want to do with the front of the car is to smooth the air and keep it out from under the car, along the sides and roof you need to keep it flowing smoothly, and a the back you need to eliminate the "vacuum hole"...


Jackie

Wow, excellent post.

This Chevy II has a All Pro RR 427 sbc we're getting ready to race with a 300hp NOS cheater plate per the rules of DXP Street, the car will be around 140mph 1/8 mile. We have the bumpers off for chroming but we still gotta ad a splitter under the front bumper. I'm more curious about the wake behind the car. Do you know anyone who has added a rear deck spoiler? This is a leafspring 275 radial car with a set of shocks on the back with a two way adjuster on rebound the azz of the car is up at the stripe to keep the nose down, you may have seen this on radial tire cars, not real conventional for drag racing but the shocks help get the power in the car early no wheely bar allowed by rules.

I'm just fishing around for Ideas, I think we can keep the air from under the car fairly easily.with a chin spoiler under the front bumper.

Are these chevy II's known for wake issues? the rear deck is long relatively speaking. I was thinking rear deck spoiler, not sure, looking around for experience with these cars. Would rather no spoiler.

Thanks ahead of time

.

[GTX JOHN]

Originally Posted by Jackie McCracken

On a 79 Malibu wagon the factory rear spoiler is worth almost 3mph on car that runs just at 100 without it in the quarter.. and the reason for it is that it pulls air from the roof and routes it down the back window (to keep it clean in civilian life) which fills in the vacuum hole behind the car. and if you're wondering how big and powerful that "vacuum hole" is, it is what the cars that make turns use to create their ground effects downforce in sufficient quantities to be able to drive one across the ceiling upside down. The "vacuum hole" is also the reason behind drafting in nascar, if you can get in close enough it will damn near pull you along... need proof of what good aero can do? How about 174 on a bicycle...peddling.


what you really want to do with the front of the car is to smooth the air and keep it out from under the car, along the sides and roof you need to keep it flowing smoothly, and a the back you need to eliminate the "vacuum hole"...


Jackie

ON my Aspen Wagon = a similar class to the Malibu
Wagon.....It slow the car down a MPH with the rear
factory spoiler!

[Steve Polhill]

Originally Posted by Dragsinger

Stan,

somewhere I saw a chart about body styles and aero drag. [may have been your chart]
that chart showed the 3rd gen Camaro with a relatively low COD and the 3rd gen Firebird among the lowest.

I have even considered installing a 3rd gen Firebird ft fenders and facia on my Camaro. Would doing that be worth the effort plus finding a Firebird ft and painting it?

Is the frontal drag the most critical? With rear drag less of an issue?

Hey Larry watch this video. in this case the front end was a disaster for drag but the most gains were picked up with work done on the rear of the car.