Downforce 12" spoiler vs. 8" spoiler

[PushinTheLimit]

Has anyone done a comparison of the downforce on these cars with a 12" spoiler and 8" spoiler? Just looking at some rules between two difference series and one allows 12" while the other is 8" only (along with many other area tracks too). Just curious how much angle it would take for an 8" to come close to equal of a 12"... and if 12" is too much downforce. I'd prefer to stick with the 8" as I've set my car up for that and maybe just adjust the spoiler angle pending the track we run at.

[billetbirdcage]

I doubt anyone will actually give you any actual numbers, but there is no argument on what is better the 8" or 12". Now there may be times where because the car isn't balanced with all the added rear down-force that a 8" might be faster but a correctly adjusted car will win almost every time.

There are exceptions to that rule but pretty rare.

[fastford]

saw RJ win a race in a spec powered late model with 45% rear and the then allowed 12 inch spoiler .....

[billetbirdcage]

your PM box was full so I couldn't reply



Sorry wrong person^^^

[Renegade Cust Susp]

your PM box was full so I couldn't reply

Heard a convo at PRI that a certain mfg had done wind tunnel testing and found that 90–70* there was enough downforce to be used as a tuning tool, from 70* to 0 there was little to no usable downforce.

Not sure what they consider “enough” just the convo I overheard

[Matt49]

I'm a firm believer that the spoiler acts much more like a Gurney flap than what would be considered a spoiler. Hence why 90 degrees actually works.

[Punisher88]

Is 90 degrees considered relating to the ground or rear decking?

[crownman25]

I was told by a very very well known chassis builder that did a test in the wind tunnel between the 8" and 12" and the 12" had 350 more pounds of downforce...

[MasterSbilt_Racer]

I was told by a very very well known chassis builder that did a test in the wind tunnel between the 8" and 12" and the 12" had 350 more pounds of downforce...

At the correct yaw, or straight ahead? I'd say that number is pretty believable, regardless.

[RW57]

I saw him win more than one Fast Ford with a 525 the big money big motor teams quickly whined till they took his advantage away. I saw him outrun Davenport at East Alabama with that combo.

[Krooser]

I saw a video where Bernheisel sez wind tunnel testing should the optimum spoiler angle is 85 degrees iirc. I'll check those numbers.