Visit The Dirt Forum for More Information

Author Topic:   aero questions
rogracer2
Dirt Maniac

Total posts: 124
posted November 21, 2005 08:26 PM  
Whats everyones opinions on squaring off the front of a 77 Monte Carlo with a nose piece vs. cutting off the front sheetmetal and allowing air into the engine compartment through the fender and headlight holes?

What about running a 6 inch spoiler on the back? Will it help or hurt on 1/4 and 3/8 mi tracks?

The Flash32
Dirt Maniac

Total posts: 128
posted November 21, 2005 08:37 PM  
Been there, done that. The nosepiece will allow the motor to run cooler, keeps mud out of radiator. The spoiler will only be for looks mainly. Those short of tracks, aero doesn't really come into play. JMO

racer17j
Dirt Forum Champ
Total posts: 5429
posted November 21, 2005 08:55 PM  
A nose will keep you cooler if its set up right. On top of that, it will definetaly keep mud off the radiator. Personally, I really like the way that the nose keeps the fenders and hood from flappin in the breeze. That nose may not help you aero-wise, but it sure doesn't hurt. An ARCA crew cheif (I admit it was for a small team, but still) told me once that any race car from a street stock on a 1/4 mile to a Nextel cup car at Talladega is pushing air and anything you can do to manage that airflow will help you.

As for the spoiler, we debate this one every winter. Buckle up, boys - here we go again...........

dirtyboy58
Dirt Full Roller

Total posts: 44
posted November 22, 2005 03:18 PM  
on short dirt tracks aero dosent matter much a little maybe? nose good idea keeps frot together rad clean and looks better to me i keep my car lookin good as possible

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 22, 2005 04:00 PM  
On a 1/8th mile go kart track the top wing on a cart was good for about 1.5 seconds. There is NO WAY the carts were slower than your car on a 1/4 mile track. A 6 inch by 72 inch spoiler is 432sq inches of space to catch and direct air. The wing on the carts were 24 X 16 or 384sq inches. As for the rear deck lid slope it will pull air down to the spoiler as the air flow will follow the deck metal right to the spoiler, that is why there are rules against this in NASCAR. It keeps the spoiler out of direct airflow (=lower drag) but adds down force.

Steve Dupree
Dirt Freak

Total posts: 336
posted November 22, 2005 04:49 PM  
I just have to post to this!!!!!!!! Stick your hand out the window at 75 mph and then you tell me how the air flows. As far as spoiler very little and as far as front not much but every little bit helps and it does matter. make it flow dont make it straight up and also seel it it does help cooling

oceanridge motorsports
Dirt Full Roller

Total posts: 34
posted November 23, 2005 08:49 PM  
On a Six inch spoiler , a Gurney device ,(the part across the top of the spoiler that looks like a inverted c channel)and 12 inch tapered side supports will almost DOUBLE the down force .Your tech man might make you toss the sides but unless he is really slick he won't have any idea what the gurney device does , it looks counter productive , but it's not !

redneck racing
Dirt Forum Champ
Total posts: 867
posted November 23, 2005 09:08 PM  
I run a spoiler on my car, rules state 5in, doesnt do any good unless the rear window is enclosed. Eddie

J3
Dirt Maniac

Total posts: 195
posted November 24, 2005 07:08 PM  
[QUOTE]Originally posted by oceanridge , a Gurney device ,(the part across the top of the spoiler that looks like a inverted c channel)QUOTE]

Do you have a pic?


J3
Dirt Maniac

Total posts: 195
posted November 24, 2005 07:09 PM  
quote:
Originally posted by redneck racing:
I run a spoiler on my car, rules state 5in, doesnt do any good unless the rear window is enclosed. Eddie

Why do you say it does no good unless the rear window is enclosed?

redneck racing
Dirt Forum Champ
Total posts: 867
posted November 24, 2005 07:19 PM  
Because the air will follow the contour of the car down the rear windsheild to the spoiler providing down force, no rear windsheild the air no down force. Eddie

racer17j
Dirt Forum Champ
Total posts: 5429
posted November 24, 2005 08:56 PM  
here is a picture and some reading on the "gurney" http://www.allamericanracers.com/gurney_flap.html , as for the rear window enclosed , I agree with that some what , unless your car is decked in like a latemodel .I think most guys don't stand there spoilers up enough . Almost straight up is were I like it , your car also has to be just about on the money set-up wise to feel the full effects of it , sticking a six inch spoiler on a bad loose metric car on street rubber is not going to do a darn thing, stick a six inch spoiler on a good handling hooked up car and it will work . but the best part is it is free ! If it did not work they would not mandate size specs . I look at it like shock tech ,it works , but it is for fine tuning , not huge cures .

[This message has been edited by oceanridge motorsports (edited November 24, 2005).]

[This message has been edited by oceanridge motorsports (edited November 24, 2005).]

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 25, 2005 01:06 PM  
quote:
Originally posted by racer17j:
it's not realy fare to compare a sprint car type wing on a 375# champ kart with 13 hp to a spoiler on a 3500# 350hp stocker. the top wing directs air on the side spoiler does not.thats where you gain your speed with it just like winged sprints compared to non . that and 2 hp on a kart is going to make that much difference also but 2 hp in a stock car you aren't going to notice. compare apples to apples not apples to water melons

[This message has been edited by racer17j (edited November 24, 2005).]



It was a comparison of the sq inches of spoiler to speed comparison. No matter what it is on it would be the same comparison. If it can benefit a cart at 20 + mph it will benefit a stockcar at 50+ mph.
The cart was not a champ cart, it was an open rule cart race, the only thing was you got the motor when you arrived. (it was for charity) It was a STOCK 5 hp briggs, The guy had NO sides on the wing, He ran lap times close to his modified 5 hp motor he runs weekly.
Spoiler to speed compared to Spoiler size at speed is apples to apples.


J3
Dirt Maniac

Total posts: 195
posted November 25, 2005 03:29 PM  
Thanks for the info.

Steve Dupree
Dirt Freak

Total posts: 336
posted November 26, 2005 07:14 AM  
As far as this areo delema or how ever you spell that. I think every little bit helps and its just hard to believe it wouldnt. When you are going down the highway and the wind is blowing in your face it slows you down compared to if it was at your back. So every little thing you can do to make it cut through the air or atmosphere will improve speed and down force.

We had a three day race at the end of the year and we have always run a pretty flat nose and i have ask this ? about areo before and was told it didnt matter that much. Well i relize the track changes every nite but the first two nites we ran a flat nose as usual and did ok but was not the fastest car on the track so the lastnite we put a little nose on the car and it was the fastest car on the track especially the last 4 laps. The only problem was we didnt have enough holes in it and we got a little hot and then a lap car got in our way and we chose low and another car chose high and he got bye us. We just kept pace because we were running 250 and almost pulled off but we stayed and caution came out and we were able to cool car off a little and gave it all the last 4 laps and on a dryslick it turned the best i have ever seen it and was really hooked up but couldnt get back around the leader so we took second but left 3rd,4th and 5th way behind turning a 18.40 when they were turning 19.00 or there about. So yes i think areo matters lol!!!!!!!!! Well that was long enough lol take care guys got to go build my rear bumper today i made a new one maybe i will just drive this car backwards next year lol

rogracer2
Dirt Maniac

Total posts: 124
posted November 26, 2005 09:14 AM  
My debate in my head is this: if I add a spoiler, it should help the car in the turns and coming off the corners, but it's also going to slow me down on the straights. So what is better - helping the car in the turns or on the straight?

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 26, 2005 12:34 PM  
quote:
Originally posted by rogracer2:
My debate in my head is this: if I add a spoiler, it should help the car in the turns and coming off the corners, but it's also going to slow me down on the straights. So what is better - helping the car in the turns or on the straight?

If it was that bad on the straights why would NASCAR and ALL of the top classes use them? Where do you pass people going into the corner, comming out of the corner, in the center of the corner or in the straight? The spoiler would help from start to finish going through the corner, now you just carried more speed through the corner and onto the straight so you will usually have a higher top speed.
Corner speed = more straight speed.

racer17j
Dirt Forum Champ
Total posts: 5429
posted November 26, 2005 07:10 PM  
17j---- I once saw a (then) Winston Cup team bring a car in under green to repair a spoiler at Bristol. Once in a while they have a "Run What You Brung" race here at Volunteer Speedway. The Super Lates add large Lexan sideboards and flatfoot the turns! It's wicked fast! 4/10ths in under 12 secs
Now with and average speed (per qualifying sheets) of 84-85 mph I can see how adding a deck and a 10"x60" spoiler with the side wings would make a measureable difference, I seriously doubt the affect of a 4" spoiler

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 26, 2005 08:05 PM  
Rules in NASCR Dictate SIZE, PLACEMENT and ANGLE. The fastest close course record for NASCAR was the superbird with a spoiler 3 feet up in the air. There were NO rules then requiring them. MOST dirt Late Model rules allow an 8 inch to 12 inch. THERE IS NO RULE SAYING THEY HAVE TO RUN THEM! When allowed MOST run a larger spoiler. If they were not an advantage but a disadvantage why would rules state a maximum size and not a minimum! If they were no good they would allow you to run them as big as you wanted! The record for a 1/4 mile aspahult car was 164mph he had a 38 inch tall spoiler and 5 foot lexan side boards with a nose that sloped form the radaitor to the track! If spoilers slowed you down how did he get that fast with a spoiler over 3 feet tall?
OH and last time I checked there were no dirt street stocks running 200mph straight away speeds to worry about the top speed drag and not the benefit from the corner speed!
THE GUY ASKED ABOUT A STREET STOCK AND YES IT WILL BENIFIT FROM ONE! PERIOD!
Racer17j you are always trying to argue any information I offer anyone! I have been racing DRAG, Dirt and asphalt for over 19 years, I have been a winning crew chief on asphalt cars from Hooters cup, Open wheel modified and mini stocks, on dirt in open wheel modifieds, limited late model, super late models and now crate motor late models. I have driven and won in dirt and asphalt in Florida All Pro Late models, Open Wheels on dirt and asphalt and Street stocks on dirt and asphalt. I have won in cars that I built and cars we have purchased, I won in my first time out in a Late Model I designed and built.
So PLEASE if you have NO information pertaining to the posts and have NO knowledge in the subject do not waste my time or the time of the people who are looking to expand there knowledge and quit trying to mislead someone by claming knowledge you do not have!

[This message has been edited by Ego Racing (edited November 26, 2005).]

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 26, 2005 08:25 PM  

quote:
Originally posted by Eljojo:
17j---- I once saw a (then) Winston Cup team bring a car in under green to repair a spoiler at Bristol. Once in a while they have a "Run What You Brung" race here at Volunteer Speedway. The Super Lates add large Lexan sideboards and flatfoot the turns! It's wicked fast! 4/10ths in under 12 secs
Now with and average speed (per qualifying sheets) of 84-85 mph I can see how adding a deck and a 10"x60" spoiler with the side wings would make a measureable difference, I seriously doubt the affect of a 4" spoiler

FIRST: Volunteer Speedway is fast enough in a regular car!
SECOND think of it this way. If everyone was running an 8 inch spoiler at Bulls Gap would a 12 inch be faster?
That is adding 4 inches. Now if everyone was running without a spoiler and you were running a 4 inch it would be about the same advantage.

bobaluuu
Dirt Freak

Total posts: 482
posted November 26, 2005 08:26 PM  
You two guys need to take it to the ropes and not this forum

racer17j
Dirt Forum Champ
Total posts: 5429
posted November 26, 2005 10:54 PM  
Well i wonder why so many ?s went to the spoiler instead of what he ask about sqauring off the front. Also he mentioned a 1/4 and 3/8 mile track and something that stumps me is i am asuming this is a streetstock not just a hobby because of where the post is. So my ? is who does 50 to 60 miles an hour on a 3/8 miles track. If you do you are going to be laped every 2 laps lol.

On a 5/16 track we turn around 76mph and on a 3/8 we turn berween 84 and 87 mph and this is in a 360cu,2barrel,castiron intake and 9.5 compression.

So make the front as aero as possible and if allowed to run a spoiler put it on and get all you can get!!!!!!!!!

Ego Racing
Dirt Forum Champ
Total posts: 759
posted November 27, 2005 08:08 AM  
quote:
Originally posted by Steve Dupree:
Well i wonder why so many ?s went to the spoiler instead of what he ask about sqauring off the front. Also he mentioned a 1/4 and 3/8 mile track and something that stumps me is i am asuming this is a streetstock not just a hobby because of where the post is. So my ? is who does 50 to 60 miles an hour on a 3/8 miles track. If you do you are going to be laped every 2 laps lol.

On a 5/16 track we turn around 76mph and on a 3/8 we turn berween 84 and 87 mph and this is in a 360cu,2barrel,castiron intake and 9.5 compression.

So make the front as aero as possible and if allowed to run a spoiler put it on and get all you can get!!!!!!!!!


GREAT ANSWER!!! The big thing is areo is aero weither it is on a go kart or a rocket. I know at SCREVEN (1/4 MILE DIRT) we took the wicker bill off of the helmet because it was keeping the drivers head smashed down in the corners. Not the straight but even in the corners. At the end of the straight the 4cyl bombers were probably close to the speed we were at in the corner.

Steve Dupree
Dirt Freak

Total posts: 336
posted November 27, 2005 09:40 AM  
What did i miss spell that word it dont look right to me at the moment lol. We live in the southwest of New Mexico and boy today would be a great day to check that aero or however you speel that thing lol. Check your weather report for 88031 zip and see what we are in for today Hold on too your hats high 54 lol yea right 25 to 50 and gusting above 50 at times. I sure would like to race a flat forntend car today compared to a sleak smooth frontend Especially we we came off turn 4 heading right into it. Be good guys

PEwaste
Dirt Full Roller

Total posts: 39
posted November 27, 2005 10:57 AM  
Add a crate motor to all of this talk of spoilers and such and you can make a top 10 car run top 5 with a 604 400 HP crate against 700+ Hp Latemodels.

LOL

    

Back to the Archives