cooling spoiler / splitter?
Discussion
I've recently (yesterday!) become the proud owner of a Chimaera (having owned a Griffith for 9 years). The new car has an aluminium splitter under the front end that looks like it has grounded out on quite a few speed humps etc in the past. Seems like a bit of a liability to me and could do a fair bit of front end damage if it ever got caught and torn off on something. Does anyone have any opinions on whether these are really necessary in terms of day to day driving? If I took it off, would it be to the detriment of something?
Thanks
Rob
Thanks
Rob
Definitely beneficial as creates an area of reduced air speed / pressure helping to pull or suck the front end down, resulting in better front end grip, steadies the bonnet and draws air from the engine bay at speed. I've tried mine with & without and would never consider removing it, I may infact increase it's protrusion (as others have done) to increase it's effect!
On the Griff, air enters the engine compartment, and then thru the splitter' low pressure area, air goes thru the rad and out of the engine-bay under the car plus thru the shape of the bonnet, over it.
On the Chim, air enters at the front and leaves thru the bonnet vents...
Tho I am not an aerodynamisist, wouldn't combining these two 'systems' have a negating effect ?
On the Chim, air enters at the front and leaves thru the bonnet vents...
Tho I am not an aerodynamisist, wouldn't combining these two 'systems' have a negating effect ?
Edited by bluezeeland on Sunday 18th October 19:47
I had the aluminium one on my Chim when I got it. It fell of on a dual carriage way (nearly took a motor bike out in the process..opps). Anyway without it I noticed an increase in engine temp when cruising and the bonnet flapped about more.
Made a Polycarbonate one up and all good. The PC also bends when it hits speed bumps etc. Engine temp dropped and bonnet stopped flapping.
Made a Polycarbonate one up and all good. The PC also bends when it hits speed bumps etc. Engine temp dropped and bonnet stopped flapping.
My experience of the invaluable splitter (with photos & write-up)....
Click Here
Admittedly it's a pre-cat Griffith with a tiny letter-box grille, but principle the same.
Click Here
Admittedly it's a pre-cat Griffith with a tiny letter-box grille, but principle the same.
Edited by jay-kay-em on Monday 19th October 19:50
jay-kay-em said:
My experience of the invaluable splitter (with photos & write-up)....
Click Here
Admittedly it's a pre-cat Griffith with a tiny letter-box grille, but principle the same.
I don't understand the inner one, it's on backwards, so it's not a splitterClick Here
Admittedly it's a pre-cat Griffith with a tiny letter-box grille, but principle the same.
Edited by jay-kay-em on Monday 19th October 19:50
bobfather said:
I don't understand the inner one, it's on backwards, so it's not a splitter
My fault, splitter is misleading. Splitter/spoiler/gurney flap/bit of guttering(!); doesn't matter what you call it. The rearmost one that you question is to create a depression in the engine bay, thus drawing more air through the rad.Edited by jay-kay-em on Monday 19th October 20:35
jay-kay-em said:
My fault, splitter is misleading. Splitter/spoiler/gurney flap/bit of guttering(!); doesn't matter what you call it. The rearmost one that you question is to create a depression in the engine bay, thus drawing more air through the rad.
Okay, I hope you won't be offended but you're obviously not an aerodynamicist. Your second length of guttering will produce lift and at speed will lighten your steering. The negative pressure you are looking for is precisely what a splitter does. When driven at speed the splitter turns the airflow back on itself forming a higher pressure zone in front of the car. The high pressure air washes out of the sides and carries oncoming air with it. That way some of the air that would otherwise go under the car is washed to the sides creating a lower pressure zone under the car. As these cars don't have side skirts I suspect that air pressure will rebalance further along the car but that's not too bad, we only need the front wheels to stay down at speed. Edited by jay-kay-em on Monday 19th October 20:35
Google how a splitter works, this was my first hit and says exactly what I've said above
https://www.youtube.com/watch?v=MAESI47KV6E
bobfather said:
turns the airflow back on itself forming a higher pressure zone in front of the car...
That's exactly what my rear most bit of plastic does; creates a build-up of air in front of it. The downside of this is lift, I totally agree.... and I understand how that would be relevant for a LeMans racer down the Mulsanne Straight.bobfather said:
and at speed will lighten your steering
At what speed will I notice the lift from a 20mm piece of guttering from Build Center? At what speed will that be a safety concern? 100? 150? 180?This was a sketch of my thought process - a cross section of my nose cone. My two pieces of guttering are in red. The second bit of plastic is what I will now call an 'air dam' creating that pressure differential.
I angled the rearmost bit of plastic that way so it was more speed-bump friendly - i.e. it will be dragged over rather than rammed into a sleeping policeman. The rearward curve gives it that rearward flex rather than destroying my nosecone.
Sorry, i'm confused at what I have done wrong? Is it just the terminology 'splitter' I used wrong? Can I call it an 'air-dam' instead?
Basically, I cut up a bit of gutter, fitted it, and it totally sorted the cooling fans cutting in all the time. I don't need a PHD in air-o-dynamiks to drink to that. And besides, i'm only replacing what was OE fitment anyway give or take.
If you like it on backwards because it's better over speed bumps then all power to you. The forward facing splitter blocks the passage of air, if you mount it backwards it simply acts as a wing and lifts the car, yes there will be a rise in pressure but you are placing that high pressure air under the car rather than in front of the car.
I challenge you to show me one example of a front spoiler mounted that way round on a race car
I challenge you to show me one example of a front spoiler mounted that way round on a race car
Again, I am confused. Where have I said I am building a race car? Why must I compare my design with race cars? My car is not a race car. It's a fibreglass, poorly made classic car I burble to the pub in for Sunday lunch. And one I enjoy most greatly.
So just to clarify, you agree my design is more speed bump friendly and that it also creates the desired build up of forward pressure at the detriment of some created lift. I agree. Yet, you didn't answer my question. At what speed will I notice the lift from a 20mm bit of guttering from Bulld Centre? I suggest it's at speeds well beyond the capabilities of the vehicle. Due to such, the benefits it brings to radiator airflow and everyday usability (speed bumps) far outway the lift you talk about.
I'd go even further. For that bit of flexible plastic guttering to generate enough lift to raise a front axle weight of 500kg significantly, I would expect the guttering to bend back, deform, or perhaps even snap first.
Also, where does this lift act upon? There is very little front underside of the car because it's just a big gaping hole for the radiator. Any positive pressure just gets lost through the radiator, it would raise the car insignificantly. My diagram shows this. Obviously this doesn't apply to the Chim as that has an upright radiator (I think) and extended snout. If I have posted mis-information that doesn't apply to the Chim I apologise, it was merely my positive experience for a cooling spoiler with a pre-cat Griff.
So just to clarify, you agree my design is more speed bump friendly and that it also creates the desired build up of forward pressure at the detriment of some created lift. I agree. Yet, you didn't answer my question. At what speed will I notice the lift from a 20mm bit of guttering from Bulld Centre? I suggest it's at speeds well beyond the capabilities of the vehicle. Due to such, the benefits it brings to radiator airflow and everyday usability (speed bumps) far outway the lift you talk about.
I'd go even further. For that bit of flexible plastic guttering to generate enough lift to raise a front axle weight of 500kg significantly, I would expect the guttering to bend back, deform, or perhaps even snap first.
Also, where does this lift act upon? There is very little front underside of the car because it's just a big gaping hole for the radiator. Any positive pressure just gets lost through the radiator, it would raise the car insignificantly. My diagram shows this. Obviously this doesn't apply to the Chim as that has an upright radiator (I think) and extended snout. If I have posted mis-information that doesn't apply to the Chim I apologise, it was merely my positive experience for a cooling spoiler with a pre-cat Griff.
Edited by jay-kay-em on Monday 19th October 23:56
jay-kay-em said:
Yet, you didn't answer my question. At what speed will I notice the lift from a 20mm bit of guttering from Bulld Centre?
Not sure about that but in my experience (albeit in a humble Chimaera) I've experienced the benefit of a properly mounted, originally designed splitter (i.e with the front edge facing forward cutting into the airstream)at anything above about 85 mph. Those benefits being better front end grip, engine cooling etc. as previously mentioned.Hope this helps and for heaven's sake....chill out chaps!Edited by jay-kay-em on Monday 19th October 23:56
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