The Force Is With You

[highflyer]

The force is with you, but how much ? keep getting asked why the ironing board on the back of the Ultima, my reply is that it exerts so much down force at 70 mph and above, that it a definate requirement, but can anybody actually tell me, how much, please

[GTWayne]

^ I think it is safe to say that it is more than two washing machines full of smalls

[andygtt]

you don't need it..... I've done over 180mph with and without it.

Its actually a noble wing on your car, so maybe there is some info from their site?

[GTWayne]

In a straight line it won't make an awfull lot of difference, high speed corners, now that is a different kettle of sardines.

[steve_d]

I was told the restyle to the GTR created the small lip on the tail and the wing was not needed unless you wished to play above 180mph.

Steve

[bluesatin]

Makes a big difference when braking from 180mph as does front splitter

[andygtt]

when I say 'dont need it', I mean unlike the old Ultima models the car is not unstable without it..... I very much doubt any reasonable driver would ever actually need the rear spoiler on the road.

I agree with Guy on the braking at speed... due to the front splitter flying off, I did back to back sessions with and without the front splitter at brunters and the car was scarry under very high speed braking without the splitter.

[carmad426]

On the ultima site they have the downforce for the sports and spyder model.

The rear wing is more than cosmetic generating 1000 lbs of downforce at 160 mph. Lesser unit on the Spyder generates 400 lbs at the same speed

www.ultimasports.co.uk/sports/features2.html

So i would assume that the GTR's wing was somewhere close, i think i read somewhere that it made 800lbs downforce at 160mph but im not sure if thats correct.

[highflyer]

Yo carmad, totally spot on with 800lbs at 160mph that is what Mr Marlow quoted me, but he didn't have the specs for the lower ( legal ) speeds ie 70 mph

[kingb]

to be honest even if it doesnt need it for downforce it needs it for the styling

when ever i see one with out i just think it looks in complete!!
not that i want to insult anyone whos car hasnt got one because full repect to any ultima

[GTRMikie]

highflyer said:

Yo carmad, totally spot on with 800lbs at 160mph that is what Mr Marlow quoted me, but he didn't have the specs for the lower ( legal ) speeds ie 70 mph

I'm a little concerned about that amount of force being transmitted to the ground through the two rear clip mounting brackets. I recently had to reinforce the fibreglass around the "captive nuts" in my rear clip because they were loose - and I don't have a wing!
(Purely for cosmetic reasons. I prefer the look without and can spot the boys in blue behind me from a long way off!)

[splatspeed]

andygtt said:

when I say 'dont need it', I mean unlike the old Ultima models the car is not unstable without it..... I very much doubt any reasonable driver would ever actually need the rear spoiler on the road.

I agree with Guy on the braking at speed... due to the front splitter flying off, I did back to back sessions with and without the front splitter at brunters and the car was scarry under very high speed braking without the splitter.

have you meet wayne??

[andygtt]

Who's Wayne?

[Silent1]

highflyer said:

Yo carmad, totally spot on with 800lbs at 160mph that is what Mr Marlow quoted me, but he didn't have the specs for the lower ( legal ) speeds ie 70 mph

Or in proper language 362kg

[highflyer]

Hey you are all very good at quirky comments but nobody has come up with the answer yet, so what's the downforce in LBS on the rear spoiler @ 70 MPH ? I was under the impression we had a lot of testical engineers on this site

[splatspeed]

highflyer said:

Hey you are all very good at quirky comments but nobody has come up with the answer yet, so what's the downforce in LBS on the rear spoiler @ 70 MPH ? I was under the impression we had a lot of testical engineers on this site

drag increase with the square of speed

so i would guess

that it is the same for down force

there for it will be a 1/4 of what it is at 160 for 80 leptons

[RussF]

Assuming all other factors remain constant (wingspan,height,angle of attack,aerodynamic coefficient and air density) then

d=c*v^2

where d=downforce in newtons and v=velocity in m/s

in this case c=0.695 (calculated from 800lbs@160mph)

thus @ 70mph d=680Newtons=153lbs

[steve_d]

153.
Is that how much the wing weighs....

Steve

[andygtt]

It's not an Ultima wing, so even if they do have measurements for their its not relevant to your canam.

[highflyer]

Only wanted a gustimate