Fitting a splitter. What angle? How far should it protrude?
Discussion
I'm fitting a splitter to my Tuscan. Does anyone know technically how far it should protrude forwards and what the angle of attack should be. I've assumed it needs to protrude minimaly and the further forward it protrudes the more likely it'll get damaged by curbs and the forces acting on it. But I think it looks ace when you see more of it.
P.s. Has anyone else found 4 brass threads along the bottom edge of their tuscan? I'm assuming it's for the splitter and was fitted to non S models by default?
P.s. Has anyone else found 4 brass threads along the bottom edge of their tuscan? I'm assuming it's for the splitter and was fitted to non S models by default?
On race cars Splitters are usually set as low as regulations allow. On road cars things like speed humps govern how low you can go. 4" is about the limit, unless you want to run the risk .... Nowadays potholes must also be a consideration.
They are usually set level. Yes the splitter is mounted via 4 threaded inserts on my car, but it's a Mk2 with a split splitter (!). Ie a small splitter on each side. I seem to remember that on the Mk1S there was also a centre fixing to carry the full width splitter.
Splitters carry significant loads especially at speed so be wary of pushing it out too far. The further forward you set it then the load on fixings is increased. For that reason you should also beware of making it too light. I've seen a flimsy splitter flex to the point where it dragged the road. And it's surprising how young children see these things as steps that help them climb up the car. On a road car I wouldn't go further forward than the bonnet edge.
I'm sure someone can give you engineering answers to your questions, these are just my thoughts.
They are usually set level. Yes the splitter is mounted via 4 threaded inserts on my car, but it's a Mk2 with a split splitter (!). Ie a small splitter on each side. I seem to remember that on the Mk1S there was also a centre fixing to carry the full width splitter.
Splitters carry significant loads especially at speed so be wary of pushing it out too far. The further forward you set it then the load on fixings is increased. For that reason you should also beware of making it too light. I've seen a flimsy splitter flex to the point where it dragged the road. And it's surprising how young children see these things as steps that help them climb up the car. On a road car I wouldn't go further forward than the bonnet edge.
I'm sure someone can give you engineering answers to your questions, these are just my thoughts.
I've made a aluminium support that runs behind the lower lip of the "mouth" and that has 3 bolts going through it, through the fibreglass and into the splitter where I've used massive penny washers to spread the load. So I'll use this rear threaded mounts and hopefully it'll be secure enough, even in I use the position shown in the bottom picture.
I'm no expert on aero but I do have a good idea. A lot will depend on the under side surface area of the splitter producing down force. Where you have it in the second picture is about right I would have thought. For racing you are limited to protruding no more than 100mm from bonnet edge forwards. Air needs to accelerate under front of car to produce higher air speed, then expand into low pressure as air travels from the splitter under the car, as it expands it creates low pressure and down force. To aid that theory you want your front splitter angled down to wards the front edge ie lower at the leading edge than the rear edge. I would have thought for the road you could try say some think like 2o mm but with out seeing the area of the splitter from front to back that could be miles out and you will no dought have to play with angles until it feels good in high speed corners. If you are just fitting the splitter to look good and it does look pretty in your picture, I would mount it flat when nose of car is at speed when the front of the car is picked up to it's maximum angle.
First picture is me making my splitter and the second is it fitted to the car.......
First picture is me making my splitter and the second is it fitted to the car.......
Thanks for the advice. I'm not sure I have that much control to be able to mount it with a couple of mm of acuracy. Surly my fat arse getting into the car would upset that setting;). I'll go for a very slight downwards angle and see how that feels. Cheers, martin
That's a massive splitter you've made there! How much difference does that make? Do you race in the standard Tvr series or in a gt3 open category/class?
That's a massive splitter you've made there! How much difference does that make? Do you race in the standard Tvr series or in a gt3 open category/class?
m4tti said:
Hi Martin
Did you fit the splitter? How far forward did you decide on setting it?
I fitted it so that the Middle protruded about 3.5". My "mouth" section is custom so don't use it as a guide for a standard grill. I definitely feel a difference now. The rear feels a bit light, so may have to look at an "S" spoiler! Did you fit the splitter? How far forward did you decide on setting it?
Martin
phazed said:
77racing said:
Peter that's so far off the floor it is only going to be cosmetic i'm afraid ,still looks good none the less
Nothing wrong with cosmetics 
It can't go any lower for the road, it's marginal enough at 5"!
Theres a reason these bits are spec'd on pretty much every road car. They are normally almost vertical though - allows a deeper splitter for the same ride height (maintains the speed bump/drive max entry angle)
.MPETT said:
Mines close to 130mm from the road surface, so could be an issue with curb stones!
I have two splitters on my Mk 1 - when one gets damaged enough (and it will either on sleeping policemen or against curbs etc. regadless of how hard you try not to) I take it off and put the other one on, repairing the orignal ready for the next bout of damage. having said that, the further back it sits the less likely it is to get damaged.
MPETT said:
Mines close to 130mm from the road surface, so could be an issue with curb stones
I believe you chaps are talking about race car style splitters at the front of your cars but I just measured the splitter under the nose of my Griffith and it's 80mm (or 3.5") and I've only ever busted it off once in 15 years of ownership. But yes, it's low! 
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