What are these?
- Thread starter TURBO2GO
- Start date
So it's just drilled into the body? I am assuming most of the ones I see are strict bling. Are they necessary if you do a large splitter like the one CL65captain made?
Depends on the material you use and the length overhanging. In my case no, as the aluminilte is very, very rigid and does not bend. I have seen track photos of my car on the track and at 130 mph it is not bowing. Some people such as that S2000 do it for bling.
- Joined
- 19 January 2011
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They rarely support weight, more typically they are used as a dampener too keep the edge of the splitter and bumper in frequency and stop it from oscillating and tearing itself away from the body. A splitter the size above does not really need them unless all the attachment points to chassis are at the very rear of the splitter.
My old splitter was much like cl65's and mounted to the battery tray and lower lip, which was connected to the bumper facade it was decent; and you do feel gains, I ran mine like that for a couple years. The trouble with mounting the splitter on the lip is all the downforce is being created on the surface of the front edge protrusion, since the stock NSX front bumper isn't mounting to anything substantial (literally 6 10mm bolts take it off) and the lip itself had even less attachment. all that down force is just pulling down flexing the plastic. The vast majority of the force is dissipated in flexing the bumper before making it into the frame where it needs to be. I've got some pictures of my car at Big Willow and can see its doing the job but flexing pretty substantially.
For my v2 splitter i created a fully frame mounted set up (the splitter can be fully installed without the front bumper on the car)
After settling on a size for the overhang of the splitter itself and running some tests I decided that I needed some strakes to keep the frequency between the bumper and the lip the same, a smaller protrusions likely wouldn't have needed it. They attach from the crux above the ac ducts supported by 4 inch 90* angled brackets and huge washers.
You can see its a similar story with the FXMD areo except they take off the entire bumper via quick disconnects
My old splitter was much like cl65's and mounted to the battery tray and lower lip, which was connected to the bumper facade it was decent; and you do feel gains, I ran mine like that for a couple years. The trouble with mounting the splitter on the lip is all the downforce is being created on the surface of the front edge protrusion, since the stock NSX front bumper isn't mounting to anything substantial (literally 6 10mm bolts take it off) and the lip itself had even less attachment. all that down force is just pulling down flexing the plastic. The vast majority of the force is dissipated in flexing the bumper before making it into the frame where it needs to be. I've got some pictures of my car at Big Willow and can see its doing the job but flexing pretty substantially.
For my v2 splitter i created a fully frame mounted set up (the splitter can be fully installed without the front bumper on the car)
After settling on a size for the overhang of the splitter itself and running some tests I decided that I needed some strakes to keep the frequency between the bumper and the lip the same, a smaller protrusions likely wouldn't have needed it. They attach from the crux above the ac ducts supported by 4 inch 90* angled brackets and huge washers.
You can see its a similar story with the FXMD areo except they take off the entire bumper via quick disconnects
- Joined
- 19 January 2011
- Messages
- 714
Well sort of, it depends on a great deal many other things as well and also ramps up depending on speed. Generally figuring out DF on a non-3d plane wing is relatively easy but gets much harder when taking into account radiused surfaces near differing pressure zones, i.e the front of your car.
I have a chart that my Dad created to help me try and balance things. Hes got a double Master in aeronautical engineering from MIT, He does mostly aerospace but has also done automotive design formulation as well. I learned really fast that unless you have the correct instrumentation and facilities to really truly come up with accurate mesurments a lot of this stuff is 'best guess' based on a few proven formulas.
I had him make me up an editable .xls but cant post the link here and have it show up correctly. I inputted the rough dimensions for my splitter and screen capped the output. You can see even with the huge dimensions of my splitter because its a non cambered airfoil it calculates DF is just about 52.5lbs @100 mph.
this is compared to my rear wing 262lbs @ 100mph
even with the less DF the splitter creates other function that will increase its ability to suck the car down. there are a few bugaboos that you just have to consider gimmes when calculating anything thats this close to the ground. Wheel speed, ambient air pressure, variation in track surface, attitude to ground etc have to all be basically nullified for such general calculations to make sence.
As far as your question- there is an inherent nonlinear increase in DF from 0 to super sonic speeds. The affect of actual pressure will depend on a cambered or non cambered surface and will also be affected by its proximity to stagnation or pockets of disturbed high/low pressures such as the flat surface of the splitter where it hits the bumper at 90*. So Yes, generally it is like 100lbs or more lbs pushing down. But there is alot more at work than just 'pushing down' It really irks me when people stand on splitters in one spot to 'test' them.
I have a chart that my Dad created to help me try and balance things. Hes got a double Master in aeronautical engineering from MIT, He does mostly aerospace but has also done automotive design formulation as well. I learned really fast that unless you have the correct instrumentation and facilities to really truly come up with accurate mesurments a lot of this stuff is 'best guess' based on a few proven formulas.
I had him make me up an editable .xls but cant post the link here and have it show up correctly. I inputted the rough dimensions for my splitter and screen capped the output. You can see even with the huge dimensions of my splitter because its a non cambered airfoil it calculates DF is just about 52.5lbs @100 mph.
this is compared to my rear wing 262lbs @ 100mph
even with the less DF the splitter creates other function that will increase its ability to suck the car down. there are a few bugaboos that you just have to consider gimmes when calculating anything thats this close to the ground. Wheel speed, ambient air pressure, variation in track surface, attitude to ground etc have to all be basically nullified for such general calculations to make sence.
As far as your question- there is an inherent nonlinear increase in DF from 0 to super sonic speeds. The affect of actual pressure will depend on a cambered or non cambered surface and will also be affected by its proximity to stagnation or pockets of disturbed high/low pressures such as the flat surface of the splitter where it hits the bumper at 90*. So Yes, generally it is like 100lbs or more lbs pushing down. But there is alot more at work than just 'pushing down' It really irks me when people stand on splitters in one spot to 'test' them.
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