74 replies to this topic

[V For Vendetta]

........ These things are for looks and looks alone.

   

  Robins splitter WILL be having an effect on the aero of this car,.......

 

Read the rest, quote the rest.

[siztenboots]

where's the fun in that

[Ben_mk]

How is it fitted ? If it's not fixed on correct it could be sagging and scrapping the road at speed ? My splitter never scrapped the ground but it was pot riveted bolted on :-)

[jamiewillson]

 

 

What wind tunnel development did robin do with his diffuser? These things are for looks and looks alone.

 
In contrast where is YOUR evidence that it doesn't work? 
 
Given that Jamies exige has spent a lot of time at mira and has a splitter of vaguely similar style, although not exactly the same, the evidence suggests it will generate downforce.
 
Robin is a good guy and has done a sterling job of his splitter so don't go hurling abuse until you know better.  Perhaps you should post up some of your results for the splitters / wings etc that you have developed.

Ok, first thing, that in any form isn't hurling abuse. That is a question and a reasonable one at that considering this is an aero appendage we are talking about.

Just because a splitter on an Exige looks quite like the one in question is completely irrelevant on a car of an entirely different shape.

Robins splitter WILL be having an effect on the aero of this car, but unless is has been tested in a wind tunel nobody can tell what effect it is having.

An example of how subtle aero is, the original Audi TT killed several people after its launch before Audi had to recall and fit the small wing to help control it at speed.

Lotus spent many hours developing the design of the mkI Elise, when it was put in the wind tunnel much to the dismay of JT it was a very unstable shape and it had to undergo many tweeks to the design to get lift under control.

Just cos it looks nice means jack.

It is not up to you as to what questions I place on a public forum. If Robin has been offended by my question I am sure he is capable of speaking for himself.

 

 

No, it's not irrelevant I'm afraid. Basically any car which has a splitter of some description bolted to it, which also has some sort of air dam, is going to have increased negative lift. Whether it actually produces any front downforce is another question though............On a VX220 however, broadly speaking the layout is very similar to my car, so you can make certain assumptions.

 

On my car, which was tested in the wind tunnel last year, our car/splitter produced significant downforce. Since we were running the sister car Time Attack car to Mike's car, I did chat to Simon McBeath about his car too. I was told that we could apply anything learnt from our car, to Mike's VX. That is coming from a world renowned aerodynamicist, so take from that what you will.

 

Fact is, a splitter on a VX will produce negative lift and a few careful mods will most definitely see the car producing significant downforce in relation to it's total weight. All you have to consider is that that are so many other variables, so you'll never know how much negative lift any single item is producing, without spending hours and hours in a full scale wind tunnel.

 

 

 

 

[V For Vendetta]

  Fact is, a splitter on a VX will produce negative lift and a few careful mods will most definitely see the car producing significant downforce in relation to it's total weight. All you have to consider is that that are so many other variables, so you'll never know how much negative lift any single item is producing, without spending hours and hours in a full scale wind tunnel.    

I would completely agree, and that is at the crux of my point. Until it has had some sort of test to at least quantify what effect it is having it can't be part of a balanced package, you can't just go placing aero items on a car willy nilly lick your finger stick it in the air and think you are the master of wind (only I can clam that ;0) ). Measuring and balance, that's all I'm saying.

Edited by V For Vendetta, 20 March 2014 - 11:48 AM.

[jamiewillson]

 

  Fact is, a splitter on a VX will produce negative lift and a few careful mods will most definitely see the car producing significant downforce in relation to it's total weight. All you have to consider is that that are so many other variables, so you'll never know how much negative lift any single item is producing, without spending hours and hours in a full scale wind tunnel.    

I would completely agree, and that is at the crux of my point. Until it has had some sort of test to at least quantify what effect it is having it can't be part of a balanced package, you can't just go placing aero items on a car willy nilly lick your finger stick it in the air and think you are the master of wind (only I can clam that ;0) ). Measuring and balance, that's all I'm saying.

 

No, you can't easily measure how much df each single part of the aero package is creating, but you don't need to either. Any good, experienced driver will be able to tell you what the balance of the car is like and you can tailor it to suit from there.

 

Anyone adding a splitter etc will know that they have to then use another device or a different setup to balance out the rear and get the correct front-to-rear bias. And with a splitter such as the one mentioned above, that shouldn't be too difficult. So basically, you can just bolt stuff on but in order to get the most out of it, you've got to be prepared to make some changes to the car through experience gained on track, or road..........

 

[V For Vendetta]

 [/quote]  Anyone adding a splitter etc will know that they have to then use another device or a different setup to balance out the rear and get the correct front-to-rear bias. And with a splitter such as the one mentioned above, that shouldn't be too difficult. So basically, you can just bolt stuff on but in order to get the most out of it, you've got to be prepared to make some changes to the car through experience gained on track, or road..........  [/quote] You would hope so, have a look at the OP's picy. That will be a no then?

Edited by V For Vendetta, 20 March 2014 - 01:57 PM.

[FLD]

Ha ha ha, i did think that my wing would possibly even it out.  Could anyone with a Robin splitter fitted measure the distance between the splitter front and the fixing please?  If i could upload the image of the splitter in its current state there would be no doubt that it is dragging along the road.  I have seen that some people use  toe joints but surely that is not necessary?

OP plans on fitting an MMG wing for just that.  Its on page 1.

[V For Vendetta]

Ha ha ha, i did think that my wing would possibly even it out.  Could anyone with a Robin splitter fitted measure the distance between the splitter front and the fixing please?  If i could upload the image of the splitter in its current state there would be no doubt that it is dragging along the road.  I have seen that some people use  toe joints but surely that is not necessary?

OP plans on fitting an MMG wing for just that.  Its on page 1.

But hasn't yet. As I was saying measurement and balance.

[FLD]

I must've miss-interpreted these posts then.

 

What wind tunnel development did robin do with his diffuser? These things are for looks and looks alone.

 

 

yeah i spent £1.2 million on wind tunnel testing and had Mclaren help me work out what was best to make a cup of coffee

with milk first then water or water first then milk. 

 

bit like asking what development testing vauxhall made on the the little turbo splitters....

 

 

 

QED

 

[Zoobeef]

Well my finger in the air method tells me I probably need a bigger and higher rest wing to balance out this monstrosity


My arse method tells me I'm not going fast enough to make the rear go light.

[V For Vendetta]

I must've miss-interpreted these posts then.

 

What wind tunnel development did robin do with his diffuser? These things are for looks and looks alone.

    yeah i spent £1.2 million on wind tunnel testing and had Mclaren help me work out what was best to make a cup of coffee with milk first then water or water first then milk.    bit like asking what development testing vauxhall made on the the little turbo splitters....  

   

QED

 

Yes you must, it's not the first time nor will it be the last, I'm sure of that.

[Nev]

Front splitter is far more important than a rear wing IMO.

[robin]

simple solution you stump up the cash and lets go wind tunnel testing!

 

Im no F1 superstar but without a splitter the front of the car above 110mph becomes light as this is from what has been said on previous

posts is down to the design of the vx.

Add turbo deflector thing and this will ever so slightly stabilise the front and i mean a tiny bit (i have tested these at various speed 110-125 mph)

add my own splitter and the car front is defiantly pulled down stabilising the front and make it feel a lot more positive even to the point where

i was doing 120 and thought i was doing 80 as the car felt a lot smoother.

 

roll onto my test ground the Isle of Man mountain road and a three piece bend called the veranda (where Conner Cummings crashed look up on youtube)this is a good 110mph bend and more if conditions are right and warm.

without splitters on the car the front is moving around and not feeling positive in any manner.

add a splitter and you have a whole more positive feel where you feel confident to push more into the bends with a 115-120mph possible without feeling like the 

car is going to let go.

 

Ok not wind tunnel tested with smokey streams to watch and work out what does and dosnt work but with my method I'm more than happy to leave the 

splitter on the car and that isn't for looks as it works and does what i want the car to do.

I best point out i don't run any rear wing and have a tat defuser (again probably does jack sh*t) and run stander exige shocks.

 

Im no expert but feel free to design a splitter spend the money to prove what it does and market it to the vx forum, a few thing you will find is

a) the splitter will cost a small fortune

you will sell hardly any

c) you only have one very small market being a vx fitment only

d) no doubt some armchair expert will crop his ugly head and tell you how he knows xyz and put people off purchasing your splitter

 

i work on a simple method if you don't think it works then go find another and if i didn't think it works i wouldn't sell them not that i sell many as its not everyone

cup of tea.

 

ps i hope you have a good crap before getting into your car as you wouldn't want uneven weight distrabution on the finely balanced car now.

 

[FLD]

 

I must've miss-interpreted these posts then.

 

What wind tunnel development did robin do with his diffuser? These things are for looks and looks alone.

    yeah i spent £1.2 million on wind tunnel testing and had Mclaren help me work out what was best to make a cup of coffee with milk first then water or water first then milk.    bit like asking what development testing vauxhall made on the the little turbo splitters....  

   

QED

Yes you must, it's not the first time nor will it be the last, I'm sure of that.

 

 

 

Its not the last time in this thread.  I read this one (below) as the OP doesn't understand he needs both to balance it

 

 

 [/quote]  Anyone adding a splitter etc will know that they have to then use another device or a different setup to balance out the rear and get the correct front-to-rear bias. And with a splitter such as the one mentioned above, that shouldn't be too difficult. So basically, you can just bolt stuff on but in order to get the most out of it, you've got to be prepared to make some changes to the car through experience gained on track, or road..........  [/quote] You would hope so, have a look at the OP's picy. That will be a no then?

 

Clearly this cant be the correct interpretation as he's states he has one to fit to balance the car and I have no doubt you'd have read the whole thread

Edited by FLD, 20 March 2014 - 08:51 PM.

[e7 jmc]

I lowered the number plate, that worked..........

[2-20]

Have a look at these articles,

 

http://www.reverie.l...est_Session.pdf

http://www.reverie.ltd.uk/techdata.php    see the 3 published articles about exige wind tunnel testing

 

Edited by 2-20, 28 March 2014 - 02:08 PM.

[jameso]

Front splitter is far more important than a rear wing IMO.

 

Interestingly I would say the exact opposite. At 100mph+ the void above the boot lid on the vx causes quite a bit of lift whilst the standard front causes a reasonable amount of downforce (from its natural shape) which I personally feel causes a little imbalance in stability at high speeds.

 

Anyway we are all arm-chair experts Winstar is our resident aero guru surely and will no doubt be along to clear it up!

[FLD]

 

Front splitter is far more important than a rear wing IMO.

 

Interestingly I would say the exact opposite. At 100mph+ the void above the boot lid on the vx causes quite a bit of lift whilst the standard front causes a reasonable amount of downforce (from its natural shape) which I personally feel causes a little imbalance in stability at high speeds.

 

Anyway we are all arm-chair experts Winstar is our resident aero guru surely and will no doubt be along to clear it up!

 

 

If you consider an aeroplane wing profile (curved on top) which generates lift and then consider the curved upper surface of the front over the wheels you might change your mind on the lift / downforce generated by the front of a VX.

[Nev]

The reason that I know that a (ultra low) large front splitter works is by actually installing one and experimenting with ride height from 12 cm to 8 cm). When at 7 cm running height off the tarmac (ie 8cm chassis ride height) and driving my car the down force was really really noticeable even from 75 leptons+. This was not marginally perceived, it was dramatic and astonishing, it made the car feel like it was way more planted and grippy. My postings are based on genuine testing/experience, rather than modelling theory or advanced armchair/keyboard theory. It's worth noting that raising the ride height even a bit from 8cm made the front splitter stop working very quickly, so height is very important for downforce (on the VX anyway).

Edited by Nev, 04 April 2014 - 02:47 PM.