Sport styling vs. current GTR
Discussion
Are you referring to the pylon wing or the F40 wing? I own a Sport and am probably a little biased 
but I've always loved the rear styling of the Sport and Spyder. Everyone who sees it says, "Wow...look at the A$$ on that thing!" Not to mention the pylon wing looks killer sitting behind the car. I'm toying with the idea of painting the wing a matching silver with black lettering to sort of finish it off, but haven't decided on which look I like best.
These are just my biased opinions.
Cheers!
-Mack
but I've always loved the rear styling of the Sport and Spyder. Everyone who sees it says, "Wow...look at the A$$ on that thing!" Not to mention the pylon wing looks killer sitting behind the car. I'm toying with the idea of painting the wing a matching silver with black lettering to sort of finish it off, but haven't decided on which look I like best. These are just my biased opinions.
Cheers!
-Mack
bigmack said:
Are you referring to the pylon wing or the F40 wing? I own a Sport and am probably a little biased
These are just my biased opinions.
Cheers!
-Mack
Mack,
I was talking about the F40 style (as shown in the "For Sale" thread). The pylon mount is seriously cool, but is it still adaptable to the current frame?
Thanks,
Dave
Hi Dave,
On the sports, Ultima designed a little sub-frame structure that bolts to the chassis at the back. The pylons attach to this frame and the wing sits on top. I can't remember ever seeing a GTR or CanAm with anything similar. The rear bodywork extends much further on these newer cars and you would probably need some kind of "L" shaped pylon.
I always thought the F40 wing was a unique aesthetically pleasing feature. It would probably look pretty cool on the back of a GTR or CanAm with its more square shaped rear. Hmh...maybe you ought to pass that idea onto the factory
Cheers!
-Mack
On the sports, Ultima designed a little sub-frame structure that bolts to the chassis at the back. The pylons attach to this frame and the wing sits on top. I can't remember ever seeing a GTR or CanAm with anything similar. The rear bodywork extends much further on these newer cars and you would probably need some kind of "L" shaped pylon.
I always thought the F40 wing was a unique aesthetically pleasing feature. It would probably look pretty cool on the back of a GTR or CanAm with its more square shaped rear. Hmh...maybe you ought to pass that idea onto the factory
Cheers!
-Mack
My GTR has two pylons mounted 240mm apart and they come up through the rear bodywork, they attach to a frame just under the body work where it is all held in place with pip pins so it can be removed without any problems, so now the aero loads are going into the chassis and not the bodywork, also had a single element carbon fibre wing made which helps with the rear vision because its not so deep and it gives good downforce with little drag, moved wing up to the roof height.
I recall 3 wing types on the Sport, the F40, the pylon and the carbon wing above the gearbox as described by markyp. This was on the Mk4 Sport Overland Racing Ultima that was often seen at the factory some years back. I chose the F40 wing for practicallity. I could see myself taking the pylon off at a petrol station to open the engine cover then leaving the wing behind. I also like the style best. The GTR is better though as the cam tail prevents some lift and provides stability. I have heard stories of the Mk4 Sport without a wing being unstable above 80mph with the added problem of lift.
Shouldn't the wing exert downforce on the body rather than the chassis (as with the pylon) since the airflow exerts lift on the body, not the chassis?
Shouldn't the wing exert downforce on the body rather than the chassis (as with the pylon) since the airflow exerts lift on the body, not the chassis?
ultiman said:
I have heard stories of the Mk4 Sport without a wing being unstable above 80mph with the added problem of lift.
Shouldn't the wing exert downforce on the body rather than the chassis (as with the pylon) since the airflow exerts lift on the body, not the chassis?
Yep, I had heard this story to, but its not as bad as you say as I've had my sports to 100mph with the wing off and it was fine in a straight line. A friend of mine told me about him running his sport without the wing when he had just completed the build. He was taking a turn at about 80mph and noticed something slipping. He was afraid it was the clutch. He checked everything over, mounted the pylon wing, and went back and didn't notice the slipping. He was able to spin the tires at this speed without the wing in other words.
The idea on the pylon mounted wing, is that the further back (out of the plane of the car) you can locate the wing the more downforce it will create. I believe the pylon wing generates 1000lbs at 160mph. I have some notes Ted sent me several eons ago giving the downforce numbers for the F40 and small body lip that I will try to locate.
Cheers!
-Mack
>> Edited by bigmack on Wednesday 7th April 21:43
I believe the pylon wing generates 1000lbs at 160mph. I have some notes Ted sent me several eons ago giving the downforce numbers for the F40 and small body lip that I will try to locate.
[/quote]
Hi Mack
I heard the same about the pylon. I assume the leverage is greater and the air less disturbed further back too. I recall a figure of about 500lbs for the F40 wing. I did not take off at 160 mph, in fact the car remained very stable so I guess 500 lbs is sufficient for "normal" use.
I didn't know there were any Sports in the USA. How many are you aware of?
Nick
[/quote]
Hi Mack
I heard the same about the pylon. I assume the leverage is greater and the air less disturbed further back too. I recall a figure of about 500lbs for the F40 wing. I did not take off at 160 mph, in fact the car remained very stable so I guess 500 lbs is sufficient for "normal" use.
I didn't know there were any Sports in the USA. How many are you aware of?
Nick
Ugh...glad to hear you didn't take off at 160mph!
I was going to guess 500lbs for the F40 wing and 150 or so for the little rear lip spoiler they used to supply.
Well Nick, until recently, I had the only sports here in the US and another guy has a spyder who is up in Seatle. He bought his spyder before me(before 1998), and before him, a guy in California owned a red Sports but it was trashed in a hill climb competition.
Recently though a nice guy named John Wurth purchased a yellow Sports that had been tracked in the UK.
So 2 sports and 1 spyder.
Cheers!
-Mack
p.s.How long have you had the Sports?
I was going to guess 500lbs for the F40 wing and 150 or so for the little rear lip spoiler they used to supply.
Well Nick, until recently, I had the only sports here in the US and another guy has a spyder who is up in Seatle. He bought his spyder before me(before 1998), and before him, a guy in California owned a red Sports but it was trashed in a hill climb competition.
Recently though a nice guy named John Wurth purchased a yellow Sports that had been tracked in the UK.
So 2 sports and 1 spyder.
Cheers!
-Mack
p.s.How long have you had the Sports?
bigmack said:
Recently though a nice guy named John Wurth purchased a yellow Sports that had been tracked in the UK.
So 2 sports and 1 spyder.
Cheers!
-Mack
That would be me
I take delivery of the last crate full of parts next week, and I should be able to get the car together soon afterwards, God willing BM: Can you post or email me a pic or two of the pylon-mounting subframe? I'm trying to decide how to mount mine and any help would be appreciated.
Also, I know there was a blue ford-powered sports in IL a year or so ago, as I was considering buying it. They wanted $65k as I recall
So perhaps there are 3 Sports in the US now?
Hey John,
I'll get you the needed info on the pylon subframe this weekend. I need to replace a throttle cable and do a few minor things on the car anyway. Sorry for the late response, but I've been busy with a new business.
Just for the record, I was asked to edit my response to a previous post in this thread by the factory. It appears they have never supplied any customer with a fully paneled engine bay and they do not recommend it. Sort of a short to the point email without any explanation. The odd thing is that I have photos of Collin Blower's GTR, a few Prosport race cars, and a photo of a high speed, U.S., GTR customer's car and they all clearly had the engine bay paneled on the bottom. Stealth B6 went one step further and developed a carbon fiber rear tunnel and diffuser. I've not received a response from the factory, and was wondering if anyone here could enlighten me on this? If this is an issue of safety, then I would like to know. I would be more worried about air getting under the front of the car than the rear. Thanks!
Cheers!
-Mack
I'll get you the needed info on the pylon subframe this weekend. I need to replace a throttle cable and do a few minor things on the car anyway. Sorry for the late response, but I've been busy with a new business.
Just for the record, I was asked to edit my response to a previous post in this thread by the factory. It appears they have never supplied any customer with a fully paneled engine bay and they do not recommend it. Sort of a short to the point email without any explanation. The odd thing is that I have photos of Collin Blower's GTR, a few Prosport race cars, and a photo of a high speed, U.S., GTR customer's car and they all clearly had the engine bay paneled on the bottom. Stealth B6 went one step further and developed a carbon fiber rear tunnel and diffuser. I've not received a response from the factory, and was wondering if anyone here could enlighten me on this? If this is an issue of safety, then I would like to know. I would be more worried about air getting under the front of the car than the rear. Thanks!
Cheers!
-Mack
Mack
Re: the full engine bay lower panels, way back in time when Ted and I were talking more, I had asked if anyone had ever partially closed in the lower panels on either side of the engine. His answer was "no", as far as he knew. At that time, my reasons for perhaps doing it was to keep the engine a little cleaner from road dirt. His concern was cooling for the gearbox.
Once I'm through with this "new garage thing", I plan to fill in the 2 triangles on either side of the engine with removable panels. This will still allow air to flow over the gearbox, although I have a gearbox cooling system and temp. monitor if I need it.
What I am hoping might happen, is to reduce engine compartment pressure, thereby getting more air intake through what is supposed to be the engine air intake. Might even try louvers in the panels to try and suck out some air. Still trying to avoid the side intake setup.
Jack
Re: the full engine bay lower panels, way back in time when Ted and I were talking more, I had asked if anyone had ever partially closed in the lower panels on either side of the engine. His answer was "no", as far as he knew. At that time, my reasons for perhaps doing it was to keep the engine a little cleaner from road dirt. His concern was cooling for the gearbox.
Once I'm through with this "new garage thing", I plan to fill in the 2 triangles on either side of the engine with removable panels. This will still allow air to flow over the gearbox, although I have a gearbox cooling system and temp. monitor if I need it.
What I am hoping might happen, is to reduce engine compartment pressure, thereby getting more air intake through what is supposed to be the engine air intake. Might even try louvers in the panels to try and suck out some air. Still trying to avoid the side intake setup.
Jack
bigmack, can you explain how does a diffuser work on a car? Does it work the same as a front splitter? The deeper the diffuser from the rear bottom to the middle bottom of the car, the more downforce it generates. Is that how it works? Additionally what generates downforce with a diffuser? Is it the slots that generates the downforce or the gap between the lip of the rear and the top of diffuser? If the diffuser are deep below the car, that means it covers the engine bay too right?
Ex. slots
_______________
| | | | | <-
Ex. Top part of the diffuser
_____________ <- car rear lip
_____________ <-
| | | | |
I'm not sure if I can give you a real good explanation, but I will try my best based on the books I've read regarding aerodynamics and race cars. Real quickly, though, a terrific book to add to your library is "Race Car Aerodynamcis, Designing for Speed" written by Joseph Katz ISBN #0-8376-0142-8. My explanation is taken from this book on page 203-204 mixed with some of my own words . The underbody rear diffuser, also called venturi, is a set of two tunnels that are angled upwards towards the back of the car. There are a couple of things happening here. First, with a flat surface car, the lower you can lower the ride height, the more downforce will be generated (almost a suction effect). With a flat bottom car, this effect is maximized (as compared to a production car). A diffuser at the back of a car, will generate a low pressure area that sucks air in from the sides of the car (inbetween the front and rear wheels). As airflow is sucked into these tunnels, it creates vortices that keep the airlfow attached inside the tunnels and stabilize the underbody flow. Second, the diffuser generates downforce. So it stabilizes the airflow under the car and increases down force. A rear wing, closely mounted behind the car, will help pump the flow under the car and amplify this effect further. Now imagine looking at the side of a car in "side view" and draw a line from left to right starting at the vehicle centerline down low where the flat bottom is and draw it up and at an angle to the back of the car. The greater this angle, the more downforce that will be generated from the diffuser. Of course the down force would also increase, to a point, the further we can start this angle at the center of the car. A friend of mine, and I, were actually going to create a mini-diffuser for our cars with a paneled in engine bay. Never got around to it, but it sounds like some issues would need to be sorted with cooling the gearbox. Gearbox lubrication and cooler sounds like a must have item. Also, I think the airflow entering into the side pod vents would need to maximized, and I've seen photos recently of an excellent redesign of the GTR side pods that accomplishes this. On the photos I've seen of the racing Stealth B6, the diffuser is so deep(such a great angle), that the driveshafts run right through them with slots that they've cut out! Does this help D3vine? Not a real good explanation I know, but hopefully it helps a little.
Cheers!
-Mack
>> Edited by bigmack on Saturday 10th April 19:25
. The underbody rear diffuser, also called venturi, is a set of two tunnels that are angled upwards towards the back of the car. There are a couple of things happening here. First, with a flat surface car, the lower you can lower the ride height, the more downforce will be generated (almost a suction effect). With a flat bottom car, this effect is maximized (as compared to a production car). A diffuser at the back of a car, will generate a low pressure area that sucks air in from the sides of the car (inbetween the front and rear wheels). As airflow is sucked into these tunnels, it creates vortices that keep the airlfow attached inside the tunnels and stabilize the underbody flow. Second, the diffuser generates downforce. So it stabilizes the airflow under the car and increases down force. A rear wing, closely mounted behind the car, will help pump the flow under the car and amplify this effect further. Now imagine looking at the side of a car in "side view" and draw a line from left to right starting at the vehicle centerline down low where the flat bottom is and draw it up and at an angle to the back of the car. The greater this angle, the more downforce that will be generated from the diffuser. Of course the down force would also increase, to a point, the further we can start this angle at the center of the car. A friend of mine, and I, were actually going to create a mini-diffuser for our cars with a paneled in engine bay. Never got around to it, but it sounds like some issues would need to be sorted with cooling the gearbox. Gearbox lubrication and cooler sounds like a must have item. Also, I think the airflow entering into the side pod vents would need to maximized, and I've seen photos recently of an excellent redesign of the GTR side pods that accomplishes this. On the photos I've seen of the racing Stealth B6, the diffuser is so deep(such a great angle), that the driveshafts run right through them with slots that they've cut out! Does this help D3vine? Not a real good explanation I know, but hopefully it helps a little. Cheers!
-Mack
>> Edited by bigmack on Saturday 10th April 19:25
USCANAM said:
Re: the full engine bay lower panels, way back in time when Ted and I were talking more, I had asked if anyone had ever partially closed in the lower panels on either side of the engine. His answer was "no", as far as he knew. At that time, my reasons for perhaps doing it was to keep the engine a little cleaner from road dirt. His concern was cooling for the gearbox.
Once I'm through with this "new garage thing", I plan to fill in the 2 triangles on either side of the engine with removable panels. This will still allow air to flow over the gearbox, although I have a gearbox cooling system and temp. monitor if I need it.
What I am hoping might happen, is to reduce engine compartment pressure, thereby getting more air intake through what is supposed to be the engine air intake. Might even try louvers in the panels to try and suck out some air. Still trying to avoid the side intake setup.
Jack
Jack. I have panelled the underside of the engine bay on my Sports with removeable, louvred panels. These are held in place with M5 screws into rivnuts. I did it primarily to keep out the dirt. The car has been on the road now for 4 1/2 years without problems. I know of at least one other Sports with the same set-up. I am building a GTR at the moment and have panelled this in exactly the same way. I have some photographs which I would be happy to send you if you e-mail me through my profile. Alan.
Just a couple of comments as I just got done with my first trackday with James' former Sports.
I didn't have time to fit the wing, so I ran the car wingless at a low-speed track here in LA (Streets of Willow Springs). The highest speed was probably about 120mph, and the car was ok without the wing. I did, however, take the higher-speed corners a lot slower than I would have due to the lack of a wing. The car did want to rotate regardless, but the car is definitely driveable on the street without a wing.
Also, this car has a perfectly flat, unbroken bottom from the radiator to the rearmost frame member. It unquestionably raises engine compartment temps, and you'll want to do something about getting the heat out of there. In fact, we put a pyrometer on the engine cover after coming off track, and in the area over the exhaust the bodywork was 300F! It actually blistered the new paint a bit, unfortunately, so beware of that. The problem would easily be solved by a heatsheild over the exhaust cans and perhaps a small fan to keep the air moving over the exhaust, or so I theorize. I'll be trying that out in 2 weeks when we do the next track day, so I suppose I'll have more data to report soon.
I didn't have time to fit the wing, so I ran the car wingless at a low-speed track here in LA (Streets of Willow Springs). The highest speed was probably about 120mph, and the car was ok without the wing. I did, however, take the higher-speed corners a lot slower than I would have due to the lack of a wing. The car did want to rotate regardless, but the car is definitely driveable on the street without a wing.
Also, this car has a perfectly flat, unbroken bottom from the radiator to the rearmost frame member. It unquestionably raises engine compartment temps, and you'll want to do something about getting the heat out of there. In fact, we put a pyrometer on the engine cover after coming off track, and in the area over the exhaust the bodywork was 300F! It actually blistered the new paint a bit, unfortunately, so beware of that. The problem would easily be solved by a heatsheild over the exhaust cans and perhaps a small fan to keep the air moving over the exhaust, or so I theorize. I'll be trying that out in 2 weeks when we do the next track day, so I suppose I'll have more data to report soon.
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