Quote:
Originally Posted by enigma
The 2004 & 2005 national champion SM BMW. Notice the flat surface and steady state turn. The slight lift is very much by design.
http://www.siastuning.com/Vic3.jpg
My m3 at laguna seca back in 2004. It looks like T9 from the pic but its hard to tell. Notice the slight lift of the inside front.
http://www.alternaterealities.info/v...s/IMG_6207.JPG
Elise at T15 thunderhill last month.
http://www.alternaterealities.info/v...s/HT4U6796.JPG
The cars with less than the normal BMW 50/50 weight split are more prone to lifting wheels. This is why you see pcars and the lotus more prone to lifting the front wheels. With less weight on the front and still the same need to keep the rear flat they tend to run out of weight to transfer much faster.
Getting a well setup BMW to lift the front wheel takes a ton of grip. Notice the distortion in the tires in the 2nd pic.
I didn't have any pics of pcars lifting but I have seen it plenty of times at the track. The GT3 is espically prone.
Note: I am not advocating that a BMW should have the same drastic lift you often see in RWD/AWD cars. However a slight lift where the tire is just barely off the ground isn't uncommon or even bad.
ps: Thanks to gotbluemilk for the pictures of my car.
[edit] The M3 was running a ground control suspension with 525/600 springs and very large GC race rate sway bars. The Elise is running a nitron race suspension. 425/600 (a lot for 1900lbs) I never asked vic what he was running in the yellow car. |
1. first pic is autox....whole different setup in autox than highspeed ...and you're right, at 35 whopping mph, you need to be able to do that...autox setup is completely different and doesn't apply to the ring
2. 425/600 spring setup is Soft. effectively that is 300 at the wheel in back, trying to control a 3500lb with driver in car, that is a street spring...due to the spring being at the midpoint...I've got the GC bars, GC hecka up front, which wasn't available in 04, and 1.125 .1875 wall in back 1100lb up front, 1200in back on motons....chances are you didnt' have those bars, although you may be able to still get them, maybe. the ptg cars you see in the photos i posted are running solid (not hollow) front and rear bars with blade adjustment in the rear......the spring rate they are on with a true coilover in back is about 700. and being that it is a true coilover, it works out to about 700 at the wheel......on a 2400llb car....this would be like you putting a 1400 on the back of yours. up front they are in the 900-1200 range....it just depends on the bumpiness of the circuit.
so yes, its lifting because the setup is soft.
elise is showing me the same thing....sways aren't able to control the roll at that point, leading to the lifting of the inside....granted, that may be the sacrifice for a given car at a given circuit....you can't set the car up for every turn...
if its coming from the bmw factory, the suspension compared to other bmw's may be sportier, but its not stiff..
you will often see the lifting of inside wheel usually at the slowest part of the track, often a carousel, where car is loaded completely to one side....however, you won't usually see it on pure race cars.....street cars like the gt3, with stock suspension, is soft, lotus with stock suspeny is soft...can guarantee the last pic'd car doesn't lift....nor do any of the alms/lemans/etcetc porsches'.....
front sway.
rear sway
hehe, 1200lb, my car.
Enigma, its no use...i've got springenvy, i am seeking help. thought you'd get a kick out of that.
