Little Red Devil

[team_v]

Sounds really deep and throaty, can't wait to hear it at Happy Laps

[Lito]

Sounds tough as bro!

[h100vw]

Too quiet?

Gavin

[gavs]

hey mate, the effect of adding downforce is to add directed (useful) drag/resistence. Given the "black art" of downforce, lots of time and money goes into it with variable results, or at least hard to quantify. Could an alternative approach be to focus on minimising drag and therefore focus on say the polo bluemotion which has a very low drag coefficient. Low drag = high speed.

My train of thought is that lakeside has one high speed corner, the dog leg. QR has two, turns one and two, so downforce during cornering on these 2 local circuits isn't a critical component of putting together a good lap. All other corners on these 2 circuits are sub 100km/h or thereabouts.

Irrespective of if Anth goes with a diffuser at some point, the point I was making previously was that at the expense of less drag, the addition of high velocity, positive pressure into the negative pressure wake of the car would more than likely make the rear of the car unstable and render the wing useless. What I was suggesting was that he explore the addition of a flat floor on the car, with or without a basic diffuser to eliminate the drag issues cause by the rear bumper. I've seen many a Soarer or supra lose their expensive, votex rear bumpers on drag strips due to the drag from the bumper and I've also seen how just covering that area in can solve the issue cheaply, effectively an without the cutting of holes.

Undercar aero tuning does not increase drag and is why so many exotics now no longer sport the garish wings present during the 90's. you can have highly efficient negative lift without the traditional sacrifice of drag caused by wings and spoilers.

Anth I'll try to draw my thoughts up at some stage for you.

[VWindahouse]

Sounds really deep and throaty, can't wait to hear it at Happy Laps

Sounds tough as bro!

Too quiet?

Gavin

Haha I blame my prehistoric recording gear. It's a tad bit louder than the clip

Irrespective of if Anth goes with a diffuser at some point, the point I was making previously was that at the expense of less drag, the addition of high velocity, positive pressure into the negative pressure wake of the car would more than likely make the rear of the car unstable and render the wing useless. What I was suggesting was that he explore the addition of a flat floor on the car, with or without a basic diffuser to eliminate the drag issues cause by the rear bumper. I've seen many a Soarer or supra lose their expensive, votex rear bumpers on drag strips due to the drag from the bumper and I've also seen how just covering that area in can solve the issue cheaply, effectively an without the cutting of holes.

Undercar aero tuning does not increase drag and is why so many exotics now no longer sport the garish wings present during the 90's. you can have highly efficient negative lift without the traditional sacrifice of drag caused by wings and spoilers.

Anth I'll try to draw my thoughts up at some stage for you.

Thanks mate, that would be great! Found a thread that goes over under panels for the Golf. It's a bit long and most of it rubbish but I think it's what you may be suggesting

aerodynamics - better feel, increased efficiency - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com

[kaanage]

Irrespective of if Anth goes with a diffuser at some point, the point I was making previously was that at the expense of less drag, the addition of high velocity, positive pressure into the negative pressure wake of the car would more than likely make the rear of the car unstable and render the wing useless. What I was suggesting was that he explore the addition of a flat floor on the car, with or without a basic diffuser to eliminate the drag issues cause by the rear bumper. I've seen many a Soarer or supra lose their expensive, votex rear bumpers on drag strips due to the drag from the bumper and I've also seen how just covering that area in can solve the issue cheaply, effectively an without the cutting of holes.

I still find this highly improbable (although everyone seems to have ignored my posts) due to the large separation between the wing and the bumper on the Polo. Look at the picture of the Civic with the massive diffuser and rear wing again - if a hatchback was liable to loose rear wing effectiveness due to repressurising of the wake, as you assert, then that car would show the effects. Anthony's car would be even less prone to be affected since his wing is mounted higher and more forward than the one on the Civic.

Soarers and Supras are completely different since the low angle of the rear window means that airflow can stay largely attached down to the boot lid which is not far above the bumper.

Horses for courses.

[MountainBikeMike]

Irrespective of if Anth goes with a diffuser at some point, the point I was making previously was that at the expense of less drag, the addition of high velocity, positive pressure into the negative pressure wake of the car would more than likely make the rear of the car unstable and render the wing useless. What I was suggesting was that he explore the addition of a flat floor on the car, with or without a basic diffuser to eliminate the drag issues cause by the rear bumper. I've seen many a Soarer or supra lose their expensive, votex rear bumpers on drag strips due to the drag from the bumper and I've also seen how just covering that area in can solve the issue cheaply, effectively an without the cutting of holes.

Undercar aero tuning does not increase drag and is why so many exotics now no longer sport the garish wings present during the 90's. you can have highly efficient negative lift without the traditional sacrifice of drag caused by wings and spoilers.

Anth I'll try to draw my thoughts up at some stage for you.

+1. Been having a good read of this thread. Interesting stuff!

[VWindahouse]

Not ignoring you mate, and I agree with your comments regarding the wing completely.

[VWindahouse]

Ok so had a quick look under the car and there are two main area's of concern.

There is a large gap between the plastic panel that runs under the entire mid section of the car on left hand side and the torsion beam. This is where the exhaust snakes around and then over the bar then to the muffler. I guess VW were worried about the heat of the exhaust and left it uncovered.

Then the even bigger and higher cap between the bar and the wheel well. Everywhere else is pretty flat or a flatish transition like from the right hand side plastic underbody section to the fuel tank to the torsion beam so the air can't penetrate along the entire section.

Man I wish I had a hoist.

[gavs]

I still find this highly improbable (although everyone seems to have ignored my posts) due to the large separation between the wing and the bumper on the Polo. Look at the picture of the Civic with the massive diffuser and rear wing again - if a hatchback was liable to loose rear wing effectiveness due to repressurising of the wake, as you assert, then that car would show the effects. Anthony's car would be even less prone to be affected since his wing is mounted higher and more forward than the one on the Civic.

Soarers and Supras are completely different since the low angle of the rear window means that airflow can stay largely attached down to the boot lid which is not far above the bumper.

Horses for courses.

Sorry, I really need to learn how to be more clear in what I'm trying to say!

RE the Soarer comment, I was meaning that like Anthony mentioned earlier, the drag reduction he has performed is something that should have been done on these (much) higher powered drag cars because the air under the car was blowing out or even ripping off the rear bumpers until some bright spark thought to cover the area in with a flat piece of plastic, which is stopping the air getting behind the bumper in the first place.

I appreciate you opinion a lot mate as you know but to my mind, if these guys were seriously wanting the best package possible in a time attack car, they wouldn't have bought a civic to begin with because without undercar aero like this: then there is no hope of being able to compete with the evo's etc on an aerodynamic front. There could also be radiators etc behind there as well but to make that design better, I would have just hacked out the entire rear bumper, gone with a flat undercarriage and fitter the biggest damn diffuser I could get in there, then extended it out and lifted the lower edge of the bumper up.

I'm no aerodynamicist, far from it but what I have read countless times is in regard to the aerodynamic in-efficiencies in bluff ended vehicles every other month with what I do for a living, and how to resolve/optimize these flaws...