Ok first off I know this topic has been brought up a lot, but no one ever really gives a certain answer. I have seen purpose built track cars with only diffusers, only wings, or both which is the most confusing part. Can anyone weigh in here their thoughts on which way to go (at least which one to buy first). I grasp the concepts of both the diffuser and wing, but I am unable to make a clear choice on my own. I guess in I am just looking for some guidance here. Thanks guys.
Sean

 

i'd say whatever you find prettier, whether you reduce upforce by X amount or increase downforce X amount to achieve the same end goal, heck do both and stay super planted...

 

That is probably the best advice I have received yet. I went ahead and sent the guys at Evasive Motorsports a message about it too so I will see what they have to say.

 

Well I'd have to ask, what are your plans with the car?

I track often and the wing is the best bang for the buck in improving lap times. I've seen a few diffusers and most are not practical for the street as well as functional. I guess it all depends on your end goal with the car.

 

I autocross, but plan on only using it as a stepping stone to road course racing. I know this will sound ridiculous, but If I got a wing I would want one about level with the roof line just for aesthetics. Are there any reasonably priced wings that do that? I'd only want it to be within about 6 inches of the roof line, not dead even.

 

What's reasonable, hahaha. Voltex is your best bet as they offer several wing styles and different stand heights to achieve your look. Plus they are developed for track use. But....they start at $1600+ and those big wings create downforce that needs to balanced with front aero. But they do make some smaller styles that look great and are just above the rear window. Evasive has a great website with pictures of them mounted on our cars.

I hope this helps.

 

I have a rear diffusor and I will be the first to say that it will not do NEARLY as much for the rear grip of the car as a wing. The effect of a diffusor is very subtle. I would say a slight improvement in stability at high speed, compared to knocking seconds off your lap time like a wing.

 

Remember though.. Even with a wing you still need to hold down the front. That's when canards and splitters come into play. Holding down the rear is good but not if you are going to allow the front to be pulled up because of it.

 

nobody says upforce lol, it's lift. anyways, diffusers are meant to reduce DRAG... most of the technologies are taken from airplanes. like how most planes have vortex generators, diffusers under the wings, and splitters/canards on the bulk head.

so yea, they function differently. a lot of people think they do the same purpose, but not really. a rear trunk spoiler/wing is designed to generate downforce. look up bernoulli's principle it might help you a lot with these things. the higher the velocity of air passing under a car, the lower the pressure underneath. on the other hand, the lower the velocity of air passing on top of the car, the higher the pressure. when the pressure is higher on the top than bottom, it generates downforce. that is why you see a lot of track s2k's with an aluminum under body plate that covers the whole underneath. so that it will allow air to pass through faster. an underbody diffuser just helps split the air and reduce drag. which is another force you don't want when tracking.

 

For the first aero piece would it be worth it to get a front splitter before I spent all the money messing with the rear of the car? What is the most logical thing to do first?