Cool that you are using mock ups VelociTT. Interesting.
undertray for our cars?
- Thread starter bubbrubb
- Start date
This is great having some flow models for comparison. I can't imagine that it would hurt performance in any way, it could only improve things, so to me it seems like a worthwhile venture. I'm certainly going to play around with some fab work over the winter on this project, since I have a ton of metal equipment, as well as a lift. Should be fun. I actually had designed belly pans for my FFR '65 Cobra, but ended up selling it before I ever finished the project. I did put a custom splitter on the nose, though, it it improved high speed stability in a HUGE way - especially since that car was so light (around 2,150 lbs.). Prior to lowering the ride height, and adding the splitter, it would get extremely light in the steering as soon as you entered the triple digits. I have done much high speed driving with the Term yet, but it feels very stable at the speeds I've driven so far.
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these cars get pretty light in the nose at speed
lowering em a little can go a long way, but at least even just a front undertray would help dramatically
lowering em a little can go a long way, but at least even just a front undertray would help dramatically
bubbrubb
New Member
black10thvert, that's awesome I'm excited to see what you come up with over the winter! If I'm going to do this I'm going to need to put the car on jackstands so I'll be doing it relatively soon before the weather turns on me... maybe.
Anybody have any good pictures of the underbody of the front of the car specifically?? Any type of pictures would work, I'm looking for terminator specific if at all possible.
Anybody have any good pictures of the underbody of the front of the car specifically?? Any type of pictures would work, I'm looking for terminator specific if at all possible.
bubbrubb
New Member
Looks like Ford did it themselves on the 2010 mustang.
the difficult part in doing this with our cars is the design of the underbody and location of exhaust. The vette is designed so that the exhaust is in the tunnel and right above it is a cover for the torq tube. so it allows the floor pans to be perfectly flat where the passengers sit. with the tranny in the rear on those cars, it allows the bell housing to be smaller and for the long tubes or exhaust to wrap around it and be maintained in the tunnel.
if this thread is still going over the next couple of weeks, I will get some pics of the vette. I am getting ready to do a clutch job on another and the whole IRS and rear needs to be dropped out for that.
if this thread is still going over the next couple of weeks, I will get some pics of the vette. I am getting ready to do a clutch job on another and the whole IRS and rear needs to be dropped out for that.
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bubbrubb
New Member
Yeah I know exactly what you're talking about, the z06 was one of the cars I was looking up when I was pondering about all of this. The jaguar XF is the same way, believe it or not. Took it to a friend's shop the other day and we put it up on a lift and we both said holy shit. Flat as can be under that car!
no, I haven't done anything, but I figured I'd post that up if anybody had searched for it in the future. Not a lot of good underbody shots of mustangs on lifts on the net that I ran across.
I'm still thinking about doing it, Ford said that it makes a notable enough difference that the average driver can tell the difference at highway speeds. I think they said that in MM&FF? Regardless, I think that if it has that pronounced of an effect at legal speeds, it would benefit us a lot for those times when we go ludicrous speeds :beer:
Anymore progress on this guys? Yes I know it's old, but i used the almighty search function.
no a properly designed undertray would create less drag, and actually help cooling by forcing the air through the radiator and whatever cooling ducts you had in the car. All high-end cars have ever seen have had an undertray. I have thought about this for awhile now. I would have thought somebody would have already designed one for these cars.
I completely forgot about this thread! It was an interesting discussion, and hopefully someone continued with the process. Personally, I haven't given it much thought as I have been busy with other stuff unfortunately.
A properly designed undertray? I would think you would need to design with an undertray as part of the aero package. An undertray does not help with cooling. A splitter and a vented hood helps with cooling.
If you had an undertray you would also need another way to keep the car cool. Our cars are designed for the air going thru the radiator to escape under the car. The vettes do not have an undertray, the vipers do but they also have huge hood vents. I have an undertray on my car which is also part of the splitter but i only use it for open track event.
If you install a undertray without a way for the air underhood to escape the car will run hotter. I tried as an experiment. Under tray is only a small part of the equation.
You could make it work by removing the small black lip under the bumper, remove the black air dam under the radiator, get a vented hood. Make some side pods to cover the area between the seats between the side skirts and the tranny. Fab up a rear diffusser but it can be no more them a 15* rise. You will need to lower the car so that the minimal amount of air goes under the car. Extend the side skirts down a little also. You will need to plan your route because anything that had a dip of a bump will scrap the bottom of your car. It's just not worth the cost/ hassle for so little gain.
I have a question that is nagging at me: Wouldn't putting a tray under the front end of the car create more instability in the front end, because of the compression of air under the car producing lift on the underside of the front end? Hence the reason to put a front splitter as low as possible at the front of the car, to keep air from entering under the car in the first place, limiting this condition. Just a question.
GoatSlayer
Banned
Haha, things are going to get hot pretty quick!
I have always wanted to make a flat undertray on the Mustang, would help gas mileage and top end speed where a vette or other sports cars have the advantage.
The newer mustangs do have an undertray.
Here is a 2012 Boss.
More:
A look at the underside of the 2012 Mustang Boss 302 | Mustangs Daily
Here is a SALEEN unit, and below that, a 05-09 OEM unit. Perhaps someone can buy one and mod it to work on his SN95
SALEEN Heritage Mustang Radiator Cooling Bottom Tray GT | eBay
OEM 05-09 Ford Mustang Lower Front Air Deflector Guard | eBay
As you can see from the Boss one, there appears to be some venting fins that might actually extract heat in a vacuum style method due to the rushing air from underneath. I have not seen evidence of added vents in the front to redistribute air movement.
Good Luck! :rockon:
Ken
Here is a 2012 Boss.
More:
A look at the underside of the 2012 Mustang Boss 302 | Mustangs Daily
Here is a SALEEN unit, and below that, a 05-09 OEM unit. Perhaps someone can buy one and mod it to work on his SN95
SALEEN Heritage Mustang Radiator Cooling Bottom Tray GT | eBay
OEM 05-09 Ford Mustang Lower Front Air Deflector Guard | eBay
As you can see from the Boss one, there appears to be some venting fins that might actually extract heat in a vacuum style method due to the rushing air from underneath. I have not seen evidence of added vents in the front to redistribute air movement.
Good Luck! :rockon:
Ken
The hood vent on our cobra's are designed to be in a low pressure area of the hood. And since we would effectively be increasing the pressure in the engine bay, with Racebronco's theory, we would be causing a greater amount of air to flow out of the vents, which would also promote cooling by decreasing the pressure behind the radiator thereby increasing flow.
Also as Racebronco said from my extensive research i have found that a 12 degree rate of rise is ideal for a diffuser.
1. You are correct.
2. Yes and no, the reason to put a splitter as low as possibly is to get more air on the splitter for increased downforce, secondary is to limit the amount of air going under the car.
Most of the vette's acceleration advantage is lower weight and weight bias. Top speed is the aero they have with such a small frontal area. Using a hood like mine actaully lowers our cd's. What else could explain my 3700lb 520rwhp out mph'd almost all the c6zo6's vettes and i was only 6mph slower then a modded zr1 in the mile.
Just because they have a undertray doesn't mean it will work as well as you think. Take our cars, did anyone know that the excessive heat kills our engines? Did anyone know they go into limp mode? A friend was part of the testing in arizona but i guess it wasn't in the heat of summer.
You are partially correct, the pressure would be increased but the size of our vents are not capable of flowing enough air going thru radiator. Our cars would be running warmer. Two vents or 2" x 8" does not flow the same as a 22" x 18" radiator. I am guessing on the sizes but you should get the my point.
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Undertray for our cars will do nothing for cooling and even with vents there is not enough airflow. To install an undetray you will need to remove the bumper lip and also remove the air dam under the radiator support, right there you just removed two items that promote air flow under the car and one that promotes cooling.
Cooling mods vs aero mods
1.Boxing in the radiator better for cooling but not any good for high speed runs.
2.Undertray with or without vents will be slower for high speed runs and cooling will be compromised, too much air trapped under the hood.
3. Splitter will increase downforce, helps cooling by directing more air into the bumper openings but slows high speed runs because of increased drag.
4. My hood, reduces the drag which in turn increases the top end, added cooling and increased downforce.
For speed runs i only have 3 sides of my radiator boxed in and a mach 1 front lip.
For open track i have 4 sides of the radiator boxed in and a splitter with an underetray only going back to the radiator support.
Cooling mods vs aero mods
1.Boxing in the radiator better for cooling but not any good for high speed runs.
2.Undertray with or without vents will be slower for high speed runs and cooling will be compromised, too much air trapped under the hood.
3. Splitter will increase downforce, helps cooling by directing more air into the bumper openings but slows high speed runs because of increased drag.
4. My hood, reduces the drag which in turn increases the top end, added cooling and increased downforce.
For speed runs i only have 3 sides of my radiator boxed in and a mach 1 front lip.
For open track i have 4 sides of the radiator boxed in and a splitter with an underetray only going back to the radiator support.
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