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Author Topic:   To spoiler, or not to spoiler
Dirt Freak

Total posts: 376
posted February 07, 2005 07:40 PM  
In our limited mod class, we were told that this year we will be allowed to run a 6" spoiler,(no specified angle). There was alot of discussion as to whether or not it would make a difference in the handling. Just thought I would throw it out here to get some opinions.
We run 360cid max.,no compression limit,4412 Holley 500cfm unaltered carb, 27lb.(min) 10.25" stock clutch, stock 3 or 4 speed or automatic with working torque converter, 2 link or leaf spring rear suspension with any pullbar. Track is a semi banked 3/8 clay that usually turns dry by feature time. Whata ya think?

Dirt Full Roller

Total posts: 28
posted February 07, 2005 08:16 PM  
whats faster, a winged sprint or a non winged sprint. I know the size of the wing is the thing, but every little bit helps.

Dirt Forum Champ
Total posts: 753
posted February 07, 2005 08:23 PM  
I would definitely put a spoiler on it.

Dirt Freak

Total posts: 280
posted February 07, 2005 08:29 PM  
I think it would make a difference on your long straights. Probably tighten it up getting in the corner. Not sure how much it will drag down your two barrel motor though. A winged Sprint has the horses to cary it's big wing. A stop watch would be the best way to find out on playdays with and without the spoiler. Try to pay attention to where it helps you. If it helps where you pass cars then it's be worth it even with with a little lower lap times.


Good luck,

Dirt Forum Champ
Total posts: 874
posted February 07, 2005 08:43 PM  
We have found with a spoiler it helps tighten the car getting in like you said. We have heard that some guys claim you can gain about 2 percent of rear at 100 MPH, but your also not going 100 MPh thru the turns too.

Dirt Roller

Total posts: 25
posted February 07, 2005 09:18 PM  
I ran a spoiler when i frist started we could run 8" if i remb right. I took it off had to add in rear weight to keep from spinning the tires so i'd put it on the car !!

Dirt Forum Champ
Total posts: 2007
posted February 08, 2005 07:52 AM  
At our track 2 years ago they took away our spoilers and the track champion from the previous year said the only difference in his car was losing the spoiler. He went from winning 10 races one year to 0 the next year, same car, same motors, everything except spoiler. Took him the whole season to get everything sorted out and he definetly thinks the spoiler makes a difference.

Sure it may be worth 'x' amount of traction at 100mph but I would think you would gain something even at 70mph, just not as much.

FYI: long straight, tight corners, 1/2 mile track.

[This message has been edited by dirtbuster (edited February 08, 2005).]

Dirt Freak

Total posts: 376
posted February 08, 2005 07:59 PM  
I myself am kinda torn on this. I've never run one. We probably hit somewhere between 65-70mph,(just a guesstimation) at the end of the straights on this track. Last year at our fall special they allowed spoilers cause some of the out of town cars had them & they didn't want to turn them away. Several of the locals added them for the 2nd night. We did not, & still led 23 of the 25 laps in the A-feature. Unfortunately, it was the first 23 laps. LOL. The car that led the last 2 laps, was an out of towner... with a spoiler.

Dirt Maniac

Total posts: 195
posted February 08, 2005 10:26 PM  
The next your cruisin down the highway (I know it's cold out!) roll down the window and stick out 6"x12" piece of aluminum at the same angle as your spoiler. Try to hold it up! Other than looking awful goofy, you will be able to make your decision.
BTW-wear gloves, Im sure it's coooold up there!

unregistered Total posts: 195
posted February 09, 2005 08:57 AM           send a private message to madmodshoe   Edit/Delete Message   Reply w/QuoteBBBBBB
I was running a spoiler in '03 and fighting a tight car through the first half of the year. One night I kinda swung it wide going into 1 and riped the spoiler right off the car. I imeadeatly noticed a difference with the car being freed up through the turns. This was on a 1/3 high bank tacky and I ran without the spoiler for the rest of the season. I have since managed to free the car up and am back to running with a spoiler. Believe me, it makes a difference even at those speeds. If you want to find out just drive down the highway and stick a 5 foot long piece of lexan out the window and see just how much force there is on it! (don't actually do this , you get the picture.)

Dirt Freak

Total posts: 251
posted February 09, 2005 10:41 AM  
Hey guys, Input from a Northeast DIRT guy...(DON'T SHOOT)...I would say in an estimate you should see a 3-5 % increase in rear percentage (exagerates rear dynamics)...have been to some runwhatyabrung shows where these big rear sails and wings show up..they have trouble keeping the front tires on the ground to steer, but man can they get through and off the corner,,Put it on then take a little of your set up rear percentage away,,,will help the tightness you will feel getting in. It really does help put the power to the ground down the straights

Dirt Freak

Total posts: 376
posted February 09, 2005 04:37 PM  
Alrighty then, It seems that it is unanimous. I guess I'll be buying some lexan & building a spoiler. Would we need to take out LR bite, or total rear percent, or both. We were right at 60% rear last year, & about 60lbs. of LR bite.
madmodshoe, may I'll strap the kid in the back of the truck with that piece of 6"x12" aluminum, & head down the hiway so he can see for himself. LOL.

Dirt Forum Champ
Total posts: 2007
posted February 09, 2005 05:02 PM  
i woudl say you could start with taking our rear%. Then adjust from there. I wouldnt go much, maybe take 50# off the rear total, ea car may be different.

Also just from thinking about it I would think you might need more LR because the driver is going to be blocking airflow to the left side or at least creating turbulence in the airflow while the right side is pretty much a clear shot, possibly getting more downforce on the right side. Just a theory though.

Dirt Forum Champ
Total posts: 879
posted February 10, 2005 05:02 AM  
Speedway is sellin' an 8" lexan spoiler w/alum. supports that looks like a decent deal. Anybody run one of these?

Dirt Freak

Total posts: 376
posted February 10, 2005 04:53 PM  
Performance Bodies has about the same thing as Speedway Motors on their website for $55.00.

Desert Mod
Dirt Full Roller

Total posts: 60
posted February 11, 2005 07:46 AM  
The scanction I run under allows spoilers. The only big difference I've seen so far is when someone gets into a quarter panel real hard and bends the back decking, the spoiler usually takes a hit, too. I've been using an old lexan spoiler I had laying around and it's starting to look a little patched up.

Dirt Forum Champ
Total posts: 1875
posted February 11, 2005 07:53 AM  

check out my spoiler. it works great.
people are scared to pass when its flapping in the wind.

[This message has been edited by zeroracing (edited February 11, 2005).]

Dirt Full Roller

Total posts: 45
posted February 11, 2005 02:50 PM  
What angle are you guys running? They have a good article about a L/M in the wind tunnel in the latest Speedway Ill. They were running between 63 to 73 degrees. Does that sound about right?

Dirt Freak

Total posts: 251
posted February 11, 2005 06:08 PM  
Don't forget that they were running at 100mph of air...the slower the top speed, the higher the agle needed...I would shoot for the higher end of their curve.

Dirt Freak

Total posts: 269
posted February 14, 2005 12:49 PM  
Besides the angle (I would recommend 70 degress) you should also add a gurney lip (I think this is what it's called) to the top of your spoiler (rivet a 1/2" aluminum piece of angle). This will greatly improve your downforce and doesn't add to the drag. Anything over 70 degrees of spoiler angle won't do anything.

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