Diffusors

[Firebass]

i got this one http://yfrog.com/5mdsc00398sxj

[saxophonias]

i got this one http://yfrog.com/5mdsc00398sxj

this isn't a real diffusor right? Have you seen any difference?

[Firebass]

nop its just a rear bumper and it looks cool , they fron bumper is also very nice but the problem is that for greece its not worth i ll try to find a pic

[Firebass]

thats it http://www.youtube.com/watch?v=wmZ0xN8WVbg
i ve seen one ej9 black in patras , and lowered but i guess this guy would drive only in central streets and even though he will have probleps and a lot of scratches down there

[flimmer]

Is the result of af diffusor not more drag and more downforce?
I will agree, that an underbody will reduse drag, but not the diffusor?
Please explain.
Thanks

[mynameisowen]

A Diffuser normally fulfills the following roles:

*To guide fast-flowing underbody air into the negative pressure region behind the body thereby disturbing the large negative pressure there: reducing drag.

*To expand the fast flowing underbody air to more normal speeds by increasing flow cross-sectional area. This ensures that air flow exits the car in a controlled manner.

In answering your question, a diffuser alone will reduce downforce (since it increases pressure due to area expansion) but it has the effect of vastly reducing drag downstream (negative presure region behind the car). The important thing to realise is that in aerodynamics there is a large amount of interaction between different components and so for example a diffuser has to be tuned along with the rear wing for the desired effects.

On our cars the underbody is no where near an ideal shape and as the addition of the diffuser is mostly pointless in my opinion. Maybe the removal of the rear bumper cavity and addition of a diffuser-like shape would be a benefit but I don't think it would be very noticeable.

[BETEK]

Sergeant Japan rear diffusor



Seeker Japan Modified rear wing

[saxophonias]

ek9's diffuser seems very neat but it must way too expensive

[mynameisowen]

Looks beautiful! Shame about the big gap around exhaust though.

[archyman]

It looks ok, but i don't think its functional. They are using the lip to create the diffuser, but that way the angle is too small to let the air escape before the bumper. In addition, to be effective in guiding the air in a controlled manner the small vertical wings on the diffuser should be a lot bigger and formed earlier. In order to create downforce the air beneath the car have to travel and exit faster than the air above. They have actually created a semi flat bottom, which is better then stock but sitll not a diffuser...and if the price tag is what i think it is then