Lowered floor VS handling
Discussion
steve_d said:
Who says it limits downforce?
Steve
I do
A flat bottom is more effective in creating down force. The "boxes" will also force the air to leak out on the sides before the rear wheel instead of making low pressure and exit through the rear diffuser and the steep angle on the lowered floor will create a high pressure vortex that hurts the down force.
I would be very glad if I was proved wrong
chuntington101 said:
is there anything proventing you boxing the engine in????????
is there suficent ventilation to keep temps down???
Chris.
Chris, this is the underside of the engine bay on my GTR (not yet on the road) which is a repeat of what I did on my Sports. The area under the gearbox is also panelled and louvered but this isn't shown in the photograph. All of the engine bay and gearbox panels are fixed with M5 s/s screws into rivnuts so are easily removed for maintenance and access. I have been driving the Sports for more than 6 years now with no overheating problems at all. However, I did make some modifications to the cooling system. I'm not sure about the aerodynamic effect of having these louvered panels but it certainly keeps the engine bay lovely and clean.
You'll have to click on the x to see the pic. Why doesn't it appear directly like everybody else's?
>> Edited by Alan 2 on Tuesday 14th February 19:54
gtr-tt said:
However other parts may be more effected by lack of air flow and therefore be very hot.
It is probably the fuel pumps that would be most affected by high engine bay temperatures so I did this to keep them cool.
The other side looks like this.
Again, it's a repeat of what I've done before and it seems to work.
You'll have to click on the x's I'm afraid.
I don't want to think about what speed you would need to notice any difference. Get the ont that allows you to sit in the car with a helmet on.
It is a water cooled engine with a radiator in the front, likely next to zero BTUs lost directly from the engine when compared to the radiator and oil cooler. I can't remember anywhere in the build manual that specifically warns against this. If so let us know.
ken
It is a water cooled engine with a radiator in the front, likely next to zero BTUs lost directly from the engine when compared to the radiator and oil cooler. I can't remember anywhere in the build manual that specifically warns against this. If so let us know.
ken
I'm a total novice at all this. However, I've been reading up on the design of F1 cars and a part of the design is the underbody profile. Compared to the extremes that they have gone to in the past with ground effect aerodynamics (and what the F1 rules are put in place to limit), I can't believe that the lowered floor plan in the Ultima will make that much difference to handling.
It may even be that lowering the weight of the driver (about 9% of the car weight) by 1 inch makes more difference than a completely flat underside...
It may even be that lowering the weight of the driver (about 9% of the car weight) by 1 inch makes more difference than a completely flat underside...
I would think that you would gain more benefit to actually controlling the airflow under the car rather than actually insuring that you had a flat under body of the car.
If you do a research on the Honda NSX type R, the Japanese’s version, and review the underbody diffusers that they had at the front of the car you will notice that they included a few longitudinal fins or strips running lengthwise or north south across the width of the car. This was to stop air from escaping out the sides of the car once it had started under the car. I think this would result in an increase in the air velocity under the car if you are containing more of the air with a resulting lower pressure and higher down force.
If you do a research on the Honda NSX type R, the Japanese’s version, and review the underbody diffusers that they had at the front of the car you will notice that they included a few longitudinal fins or strips running lengthwise or north south across the width of the car. This was to stop air from escaping out the sides of the car once it had started under the car. I think this would result in an increase in the air velocity under the car if you are containing more of the air with a resulting lower pressure and higher down force.
ezakimak said:
I would think that you would gain more benefit to actually controlling the airflow under the car rather than actually insuring that you had a flat under body of the car.
If you do a research on the Honda NSX type R, the Japanese’s version, and review the underbody diffusers that they had at the front of the car you will notice that they included a few longitudinal fins or strips running lengthwise or north south across the width of the car. This was to stop air from escaping out the sides of the car once it had started under the car. I think this would result in an increase in the air velocity under the car if you are containing more of the air with a resulting lower pressure and higher down force.
the best example of this was on the 80's (i think) F1 cars and a Lotus 340R! they ran what where effectily daft excluders on that gapped these fins to the floor! effectly making a tunle for the air to go through! mabe the rear diffusers VERY efficent! in fact too effficent on the F1 cars so the FIA band them!
Chris.
Is that the ground effect era of f1 that you are talking about, is that’s the case then they were using strips of wood that effectively floated underneath the car and dragged along the road. Later the FIA mandated a minimum ground clearance, thereby destroying the effect of the tunnel and reducing the amount of down force. If I remember correctly this was done for safety reasons as the drivers were blacking out in the corners due to the excessive g-forces.
Anyway I would think that if you are going to add a under tray and rear diffuser to the car then you should look at the airflow under the whole of the car and control/duct it to were it is going to be more effective.
I was reading an article about the 9ff that beat the Mac F1s top speed the other day and it made a reference to them having to remove their boundary layer devices as they were getting too much down force on the front of the car at speed and were running out of front suspension travel. I haven’t seen any photos of what these so called “boundary layer devices” look like but assume that they would be similar to the Honda NSX’s devices.
i will have to have a look at the 340r again
ryan
Anyway I would think that if you are going to add a under tray and rear diffuser to the car then you should look at the airflow under the whole of the car and control/duct it to were it is going to be more effective.
I was reading an article about the 9ff that beat the Mac F1s top speed the other day and it made a reference to them having to remove their boundary layer devices as they were getting too much down force on the front of the car at speed and were running out of front suspension travel. I haven’t seen any photos of what these so called “boundary layer devices” look like but assume that they would be similar to the Honda NSX’s devices.
i will have to have a look at the 340r again
ryan
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