spoiler,rear difuser,vortex gen

[scarei]

I well be ordering a rear gurney flap for my puma from hus tuning, but I would like to no performance while :thumbs: what spoilers are out there that actually produce rear down force.

And I am thinking of a rear difuser, huts there better than a spoiler and look quit good,well be getting a vortex gen (what evo's have and impreza's on the roof)as well if I get a spoiler to help with the air flow around the rear of the car for the spoiler.

Any forts?

 

[Flying Scotsman]

F2 Rear Wing produces real downforce, desogned for low speeds in the corners.

 

[Ginger Tom]

Rear diffusers are good, if built and fitted correctly but ideally require the rest of the floor see floor to be flattened off aswell. Where are you thinking of fitting the vg's?

 

[ScubaSteve]

have you actually done some research? aerodynamics is a massive massive subject and im having a big enough task just researching front splitter dynamics.

 

[Ginger Tom]

Me?

Yeh I've done and am still doing research into aerodynamics.

 

[ScubaSteve]

no the OP lol

 

[Ginger Tom]

Lol fair do's

 

[scarei]

Yh I no a little bit about airo ,did help built a car for my tutor at clollage,put on a spliter and a rear wing,and a diffuser,stuck to the track like bubble gum to the sole of ur trainer, Bascily I wanted to no when I fit my car with a rear gurny flap will the air flow over the top and bk reach the rear gurny flap,its more about the vortex gen's,because the scobbys have big rear wings and vg's,but well they work on air flow that low over the back of my car,and It would be ni on impossible I well be able to get it fast from the front to the rear axle,but then part that its ganna be hard to do.

 

[Ginger Tom]

For the vg's to work the way they do on the scoobies and evo's you'll need the sort of spoiler they use, as like you say the vg's will have trouble getting the air flow down low enough, also I would think, may be wrong here, the angle of the rear window on the puma is a lot less acute than it is on the affor mentioned cars, which causes the point at which the air flow comes off the boundary layer of the vehicle to be much lower down the rear widow, meaning if you were to fit the vg's they would probably need to be a third of the way down the rear window.

If you look at the TVR Segaris it has the same sort of roof line and rear window angle as the puma and that uses neither the vg's or the massive spoilers. The spoiler it does have is quite small tho fairly abrupt in it's form.

Obviously these are all my theory's and would need to be proven in a wind tunnel, but from what I've read on vg's they are the conclusions I've come up with.

 

[scarei]

Cheers ganna have a look at the tvr now,think I am being a bit of a whimp just cos lift of over steer is unpredictable, but it the rear of the car is planted u gain confident, any one on here made a front spliter,think I am just ganna get some perspex, seems to do the job

 

[scarei]

Just remberd I can get a eve style rear wing, I wonder If the vg's well work with that better and if I leave the gurney flap on the boot lid the air over the top and under the spoiler should create down force

 

[warrenpenalver]

we are talking about a normal puma arent we?

in which case unpredictable lift off oversteer is NOT a normal characteristic on the puma. Normally they are very predictable and very controllable when inducing lift off oversteer.

I would suggest either something is up with your suspension, probably rear beam bushes, or you are entering a corner waaaayyy too fast and lifting off waay too aggressively.

 

[scarei]

It is a normal puma but won't be buy next year well be at least 160 H :?: P, I ain't saying my car is unpredictable I am saying compared to rear wheel drive car lift of over steer is unpredictable, but the thread ain't about that its about rear down force want as much as possible same as the front,ganna get a spliter and candars, more mods better in my mind

 

[warrenpenalver]

unless youre going for an all out track monster with superlight shelll and decent power to boot, then you will get more grip by just fitting a set of R888's rather than going for loads of spoilers and a splitter.

You MUST balance any aerodynamic aids you fit, otherwise at speed you will make things worse.

 

[XIIVVX]

As has been noted above, the very last thing a Puma needs is to trade performance for downforce at the rear.

It understeers FFS! What would be the point of adding drag, degrading performance and economy in order to make it understeer more?

 

[scarei]

Yh they do understeer,but not if u get the grip with the downforce,that's y,and ur saying u don't need all that its a personal opinion at the end of the day,I mearly wanted to no what affect well vg's and a diffuser have on a puma thats it.

 

[XIIVVX]

Sorry, I was actually trying to be helpful.

If you want to reduce its tendency to understeering any downforce you add needs to be at the front, not the rear.

But then you will trade performance and economy for that improvement. Look at the Cd of an F1 car as an example.

That is not opinion, that is merely stating the obvious.

 

[scarei]

That that worried about understeer its easy contoled and can get rid of understeer with a LSD,bigger and slick tyres on tack and better road ones,I really aint worried about Economy.and what u said earlyer I don't want drag I want al little drag as possible bit much downforce that's posible, the reson I won't downforce at the rear of the car is cos of the lift of over steer, its unpredictable say compared to rear wheel drive oversteer, with lift of u ain't cos control of the weight trasfor, do If I give it down force and rear suspension hopefully it well be more manageable.

 

[ScubaSteve]

Sounds to me like you arent driving the car properly.

Rear spoilers and such will only affect downforce at speed, 60+, you shouldnt be lifting off at those speeds on any sort of gradient anyway, recipe for disaster

 

[scarei]

I am talking about the track not road,and down force don't just work a 60+ mph can eork lower