SPOILER-cooling or stability?
Discussion
Having partially ripped off my front spoiler again its time to ask the question; do i need it ?
If its there to aid cooling ill probably leave it off as i run my Chim with a stick on-bonnet mounted- front no. plate cooling is well taken care of.
If the spoiler was fitted to aid high speed stability then ill replace it forthwith.
Checking out previous threads does'nt seem to give a definative answer to the exact reason for fitment.
Looking under the front of other Chims doesnt help,some have them some dont.
Cerberas seem to have them pointing backwards ( / )
rather than forwards ( )
Anybody know ?
Ta
Darren
If its there to aid cooling ill probably leave it off as i run my Chim with a stick on-bonnet mounted- front no. plate cooling is well taken care of.
If the spoiler was fitted to aid high speed stability then ill replace it forthwith.
Checking out previous threads does'nt seem to give a definative answer to the exact reason for fitment.
Looking under the front of other Chims doesnt help,some have them some dont.
Cerberas seem to have them pointing backwards ( / )
rather than forwards ( )
Anybody know ?
Ta
Darren
Not being an owner I wouldn't know for sure, but using my (limited) experience with earofoils, and aircraft I could probably make a rough guess.
Without
smooth air enters beneath the car and bounces off the road and the car causing the high speed instablility.
With
The smooth air goes in and some goes up into the engine bay, aiding cooling, and also, reducing air pressure, which means that the air has more room to move about, so keeping the car stable at high speeds, also the low pressure weould have the effect of sucking the car to the road!
It's obviously there for a reason, and if it is the reason I have described you might want to put it back on!
Without
smooth air enters beneath the car and bounces off the road and the car causing the high speed instablility.
With
The smooth air goes in and some goes up into the engine bay, aiding cooling, and also, reducing air pressure, which means that the air has more room to move about, so keeping the car stable at high speeds, also the low pressure weould have the effect of sucking the car to the road!
It's obviously there for a reason, and if it is the reason I have described you might want to put it back on!
On a Griff i think it is more for cooling, but then again the rad is at 45degrees. I have lost mine so many times i left it off and never noticed any "stability" changes.But i do have a new improved lip spoiler to ram air in for cooling, this along with half speed fans at low speeds.
Darren,
I've got this predicament too. The crunch is that they only cost £15 or so anyway.
I don't find a huge cooling difference or stability difference. Although, I'm tempted to buy a new one before Duxford so that I can test the 'upper envelope', see if it makes a difference when I'm hooning down the runway at naughty speeds.
TMS seem to always have them in stock, perhaps I should set up a DD or something, replace every month / quarter!!
Cheers
Steve
I've got this predicament too. The crunch is that they only cost £15 or so anyway.
I don't find a huge cooling difference or stability difference. Although, I'm tempted to buy a new one before Duxford so that I can test the 'upper envelope', see if it makes a difference when I'm hooning down the runway at naughty speeds.
TMS seem to always have them in stock, perhaps I should set up a DD or something, replace every month / quarter!!
Cheers
Steve
one thing to bear in mind ... main cooling problems occur when the car is stationary or moving slowly, and at these speeds a splitter won't make any difference, because their is no airflow under the car to effect.
After mine had been ripped off for the second time (the first time was expensive as there was damage to the GRP) I had a chat with the blokes who were servicing the car (TVR main dealer) and they said the purpose of the splitter was to aid high speed stability, suggesting that the main impact was at over 120mph. They didn't think it was worth refitting, so I've left it off. I've got the splitter, self tappers and mastic under the bed, so if I take the car to a track, I'll probably reattach it, but in the mean time its helping my sub-bed airflow.
After mine had been ripped off for the second time (the first time was expensive as there was damage to the GRP) I had a chat with the blokes who were servicing the car (TVR main dealer) and they said the purpose of the splitter was to aid high speed stability, suggesting that the main impact was at over 120mph. They didn't think it was worth refitting, so I've left it off. I've got the splitter, self tappers and mastic under the bed, so if I take the car to a track, I'll probably reattach it, but in the mean time its helping my sub-bed airflow.
The splitter may or may not do somethjing possible to the high speed stability/cooling but then again it may simply be a revenue earner...
To be honest... any cooling will only work at high speed where air flow is not an issue. Any stability improvement is probably outweighed by other factors.
As they catch sleeping policement, mine is off.
steve
www.tvrbooks.co.uk
To be honest... any cooling will only work at high speed where air flow is not an issue. Any stability improvement is probably outweighed by other factors.
As they catch sleeping policement, mine is off.
steve
www.tvrbooks.co.uk
I think the stability benefits are only at quite high speeds, above 90mph for example. That would probably be on a smooth motorway type road too ... at 90+mph on a country road you're probably too busy fighting other forces to be worried about/notice a bit of lift anyway (potholes, camber, bends, numpties, rabbits etc.).
The way it helps cooling is, once the car is moving a negative airflow area thingy is created and air is drawn out of the engine bay, thus sucking more through the radiator (or other orifices
). I have noticed with the splitter on the car cools down much more quickly as you drive off from a traffic jam/out of town.
As for high speeds - I think your high speed will actually be slower with a splitter fitted (think about it from an aerodynamic viewpoint). Only by a tiny amount though.
T/.
The way it helps cooling is, once the car is moving a negative airflow area thingy is created and air is drawn out of the engine bay, thus sucking more through the radiator (or other orifices
). I have noticed with the splitter on the car cools down much more quickly as you drive off from a traffic jam/out of town. As for high speeds - I think your high speed will actually be slower with a splitter fitted (think about it from an aerodynamic viewpoint). Only by a tiny amount though.
T/.
Assuming we're talking about the small strip spoiler under the car at the back edge of the air inlet, I had mine off a little while back changing the main beam bulbs, forgot,and went for a drive. At about 75-80 the front started to chatter, a bit like having an unbalanced wheel. Panicked, put the spoiler back on and all was fine again.
BTW, mine's a Griffith 4.3 and the "spoiler" is a bit of door seal (!) so all this may be irrelevant.
Was surprised that a one inch strip sticking into the airflow could make a noticable difference
BTW, mine's a Griffith 4.3 and the "spoiler" is a bit of door seal (!) so all this may be irrelevant.
Was surprised that a one inch strip sticking into the airflow could make a noticable difference
Hi Darren, during one Service when I had my Chimaera the dealer told me that the front lip spoiler was missing. I'd never noticed it come off and doubt it was even fitted when I bought the car?
So in 3 years of ownership I didn't have one and it didn't seem to make any difference.
Cheers..... Andrew
So in 3 years of ownership I didn't have one and it didn't seem to make any difference.
Cheers..... Andrew
I had a splitter, until yesterday 
At Castle Combe, some idiot decided to have the TVR's park in a mowed field full of ruts you'd lose your dog in...despite careful manoeuvering, there was an *almighty* crunching noise, and a lot of um, expletives
I parked Ruby, got out, someone walked up to me, delivering my splitter, saying "This must be yours" 
Seeing as my car has always had one, I will have it refitted promptly, however, didn't really notice any cooling/handling difference as I hooned it home down the M4 yesterday afternoon...all within the NSL, of course
At Castle Combe, some idiot decided to have the TVR's park in a mowed field full of ruts you'd lose your dog in...despite careful manoeuvering, there was an *almighty* crunching noise, and a lot of um, expletives
I parked Ruby, got out, someone walked up to me, delivering my splitter, saying "This must be yours" Seeing as my car has always had one, I will have it refitted promptly, however, didn't really notice any cooling/handling difference as I hooned it home down the M4 yesterday afternoon...all within the NSL, of course
It all depends on what is causing the problem guys. If the car is feeling funny that is probably due to geometry/suspension problems/limitations which are often aided and abetted by inappropriate driving input. In other words, often the nut behind the wheel has more to do with the feeling than you would think. According to the instructors who have been coaching me recently, I tend to input too much steering which slightly unbalances the car and causes the floating effect as the car tries its best to break the laws of physics.
A splitter like the one specified is unlikely to do much for you. According to my I-Spy Book of Car splitters it is not deep enough to prevent air from flowing under the car and the air it deflects through the rad actually can be building up air pressure under the bonnet and causing the car to go light. Tyre pressures are critical. Any slight wear in the bushes will contribute to that funny feeling as well. However they don't cost much so might be worth a try but I wouldn't have too high an expectation.
Had exactly the same problem on the 520 which was solved using a rubber air dam spoiler that brushes the ground with a 80mm wide splitter and a metre wide vent in the bonnet to allow the air to flow through the rad and over the top of the bonnet. A little extreme but what the hell.
Steve
www.tvrbooks.co.uk
A splitter like the one specified is unlikely to do much for you. According to my I-Spy Book of Car splitters it is not deep enough to prevent air from flowing under the car and the air it deflects through the rad actually can be building up air pressure under the bonnet and causing the car to go light. Tyre pressures are critical. Any slight wear in the bushes will contribute to that funny feeling as well. However they don't cost much so might be worth a try but I wouldn't have too high an expectation.
Had exactly the same problem on the 520 which was solved using a rubber air dam spoiler that brushes the ground with a 80mm wide splitter and a metre wide vent in the bonnet to allow the air to flow through the rad and over the top of the bonnet. A little extreme but what the hell.
Steve
www.tvrbooks.co.uk
Mine didn't have one and living in London, if it had, it wouldn't have lasted long...
In terms of cooling, as mentioned above, at high speeds cooling is not an issue.
In terms of aerodynamics, a splitter of that size positioned where it was would make hardly any difference to a car like a TVR at anything below lift off speed! During my Aero Eng. degree I did lots of playing with cars in wind tunnels and below 150mph small things like that do not a lot to be honest. The splitter would have to be much wider and much deeper to significantly effect the airflow on a car like this as the underbody is hardly smooth.... Perhaps on a 360 spyder where the underbody flow is very laminar a splitter like this could make a difference....
In terms of cooling, as mentioned above, at high speeds cooling is not an issue.
In terms of aerodynamics, a splitter of that size positioned where it was would make hardly any difference to a car like a TVR at anything below lift off speed! During my Aero Eng. degree I did lots of playing with cars in wind tunnels and below 150mph small things like that do not a lot to be honest. The splitter would have to be much wider and much deeper to significantly effect the airflow on a car like this as the underbody is hardly smooth.... Perhaps on a 360 spyder where the underbody flow is very laminar a splitter like this could make a difference....
quote:If you did aero engineering degree then you may be aware of what the gliding community call tubulator-tape? This stuff is like masking tape in a zig-zag V shape pattern which is stuck along the trailing edge of the elevator and aleorons to imporve air flow. (I'm sure you don't want me to go into boring details here
In terms of aerodynamics, a splitter of that size positioned where it was would make hardly any difference ... at anything below lift off speed! During my Aero Eng. degree I did lots of playing with cars in wind tunnels and below 150mph small things like that do not a lot to be honest.
) It is only the thickness of say a sticky-plaster but has a significant effect on air flow, and as gliders do not fly at 150 mph (more like betwen 50 and 90) my point is that small differences can have an effect on aerodynaics. Rich...Yes, but gliders are extremely aerodynamic to start with ... and TVRs ... well, lets be honest...
IIRC that tape you refer to works a bit like the divots in a golf ball, as they create a little turbulence near the surface that helps position and control the "main" turbulence. I was wondering if something similar might be used to reduce the amount of whistle I get at the top of the windscreen?
IIRC that tape you refer to works a bit like the divots in a golf ball, as they create a little turbulence near the surface that helps position and control the "main" turbulence. I was wondering if something similar might be used to reduce the amount of whistle I get at the top of the windscreen?
It's all a question of where and what you are trying to do. Gurney flaps are another good example where turbulence is deliberately created by sticking an obstacle in the air flow and the turbulent air reduces lift and gives you downforce effectively. Trouble is it needs to be done at the back of the car on the top and not underneath it at the front.
The correct statement should be that small change sin the right place can make a big difference. The problem is finding them and understanding if they solve a problem or make it worse. Keep thinking about taking the 520 to Mira and having go in the wind tunnel... one day maybe.
Steve
The correct statement should be that small change sin the right place can make a big difference. The problem is finding them and understanding if they solve a problem or make it worse. Keep thinking about taking the 520 to Mira and having go in the wind tunnel... one day maybe.
Steve
quote:Oh ok then that's true (i hoped you wouldn't spot that!) As you say the "turbulator tape" actually works by causing the laminar flow of air over the wing to break away. For some reason this abrupt break away will be further to the rear of the wing surface than if the air flow is left to it's own devices, in which case you get a more progressive break away but starting further forwards on the wing.
Yes, but gliders are extremely aerodynamic to start with ... and TVRs ... well, lets be honest...
IIRC that tape you refer to works a bit like the divots in a golf ball, as they create a little turbulence near the surface
quote:
It all depends on what is causing the problem guys. If the car is feeling funny that is probably due to geometry/suspension problems/limitations which are often aided and abetted by inappropriate driving input. In other words, often the nut behind the wheel has more to do with the feeling than you would think. According to the instructors who have been coaching me recently, I tend to input too much steering which slightly unbalances the car and causes the floating effect as the car tries its best to break the laws of physics.
Steve
www.tvrbooks.co.uk
That's probably more like it in my case Steve!
quote:
quote:Oh ok then that's true (i hoped you wouldn't spot that!) As you say the "turbulator tape" actually works by causing the laminar flow of air over the wing to break away. For some reason this abrupt break away will be further to the rear of the wing surface than if the air flow is left to it's own devices, in which case you get a more progressive break away but starting further forwards on the wing.
Yes, but gliders are extremely aerodynamic to start with ... and TVRs ... well, lets be honest...
IIRC that tape you refer to works a bit like the divots in a golf ball, as they create a little turbulence near the surface
The pointg I was trying to make (obviously not very well) is that a TVR is unlikely to have a great deal if laminar flow - This delamination of the flow causes the wing to stall if it is too agressive hence the use on gliders, as you are generally fecked if you stall...
Gassing Station | Chimaera | Top of Page | What's New | My Stuff