Rear aero mods?

Post by **Donald** » Tue Jun 26, 2012 6:39 pm

Ah yes, Bernoulli's principle

Post by **RattyMcClelland** » Tue Jun 26, 2012 6:51 pm

Over 56mpg any aero differences can be felt. 2 cars that are the same but one with a drag coefficient of 25 and one with 30 0-100 can be 5-8 seconds quicker.

Dino · Post by **Dino** » Tue Jun 26, 2012 10:03 pm

Merlin,

If you increase drag on the rear of the car, you will in turn reduce the speed of the car on the straight.

Secondly the extra drag you create at the rear will cause the front to lift, in turn increasing the amount of understeer you have through higher speed corners (less traction)

To compensate this, you will need to have some form of front aerodynamic aids to compensate for the lift. so you will need to look at this as a whole aerodynamic package.

If you reduce drag on the rear, you will make the rear of the car very light.... again, think carfeully what you do with the car as you dont want to spoil a well balanced package as it is.

Post by **Merlin** » Wed Jun 27, 2012 9:13 am

My idea was to reduce the drag of the car by blocking off the rear cavity. Agreed I dont want to do anything drastic as my car handles like a dream

Post by **Merlin** » Thu Jul 12, 2012 1:20 pm

Im starting to think the way forward is something like this:

Post by **NafemanNathan** » Thu Jul 12, 2012 1:29 pm

An Evo?

Post by **Merlin** » Thu Jul 12, 2012 1:48 pm

No, im not made of money. The large cut out of the rear bumper. I have seen a lot of car with this.

Dino · Post by **Dino** » Thu Jul 12, 2012 1:49 pm

Similar to what i have planned Al....

Post by **NafemanNathan** » Thu Jul 12, 2012 1:53 pm

This one...

... Is what I kind of have planned for mine. I had a bit of a play with a knackered bumper when I first parked the project up. It ended up looking like this...

But it looked a bit jobby from behind and there was still a good amount of pocket there. Although it was almost level with the underside of the chassis, so wouldn't take much to seal the pocket off, but as it didn't look great I planned on leaving the sides in place on the next attempt and also using a universal rear diffuser.

Not sure on how much work would be needed to clear everything beneath the boot floor yet though.

I had chopped up what I removed and made some rear spats and it looked much better (ignore the middle black bit)...

Post by **NafemanNathan** » Thu Jul 12, 2012 1:54 pm

If you go much higher than I went, then you will start bearing the uglies...

EDIT:

Just realised what I said!