Not sure if this is new to you all, but it caught my eye since there is a lot of aero discussion going on.

Interesting how the major changes included less AoA on the rear wing / canards / some venting mods / and most importantly a rake change to positively affect balance.

Speed Academy / Sasha On Point Dyno wind tunnel testing:

Article:
http://speed.academy/wind-tunnel-tes...350z-uoit-ace/

 

I wish they did an analysis of drag. A lot of times the butt dyno can feel aero changes pretty well through a corner, but its hard to say what more wing or canards will do to your straight line speed. Thats always the toss up, more downforce = more drag.

Cool stuff though, it would be great to get a baseline of rake and have that for reference at the track what wing angle means what.

The other thing I would want to test is my flat bottom panels and diffuser. I think you would need a rolling floor tunnel to get good data there though.

 

Definitely it is always a tradeoff with the drag and will be track dependent. If you can achieve a better corner exit, the drag difference may be negligible depending on the length of the straight, especially with something small like canards. I too am curious re their drag/downforce ratio.

Underbody would be more difficult to test with a baseline (measured baselines are expensive for the lay person in this regard, as you would be paying $$ for them to wait to install the floor panels between test, lap times are probably a cheaper indicator of the practical benefit).

Racecar engineering computed a 6.5% net downforce increase from a smoothed floor vs rough on a Nascar model (less lift on the body, more downforce on the underside), and a mere 1% drag reduction, as a general reference point (Jan 2005). Of course this was using CFD not real life.

 

Is that 'boosted perfromance' sasha?

Great video btw..

 

Cool video.

 

Makes me really wonder about my aero and it seems that if you need a hair if front grip, just raise the rear ride height a couple MM.

 

Thanks for posting that.

 

I know, right...now everyone is gonna go 18" front 19" rear...

note to self, invest in wind tunnel in denver metro area..

 

Or just go adjustable coilovers. But on a serious note I thought that keeping a rake on our cars was common knowledge?

What angle do you think his splitter ended up at after raising the back. He was at .7 up at the start. Maybe he has been inadvertently creating a bit of lift in the front.

 

Sasha said early on that the cost of that time in the tunnel was only a bit more than a few sets of tires. If that is true, it is something I could entirely see myself doing in the next year or two. You really have to go into that time with a set plan and orchestrated routine.

 

Definitely agree, for the average racer its not something you do to test the viability of already-verified aerodynamic concepts. Unless you are made of money, one is well advised to bring their package at 100% (in theory based on rules) to improve on it from there.

Most recently in the 10/11 F1 seasons Red Bull incorporated additional vehicle rake into their blown diffuser design which made it vastly more effective. Other vehicles quickly followed suit and soon everyone was running more rake than before.

And it is a pretty tricky topic to get right, considering how many variables influence or are influenced by dymanic ride height (spring rate, static ride height, aero, suspension geometry, fuel level, etc). Since then blown diffusers have been banned, but you still see the rake angle on cars because they have compensated with airflow in other ways (ie. using directed air as the effective 'side skirt' to the extent they can).

Everyone is trying to get the front splitter kissing the tarmac, but side skirts need to be as low as possible as well.