Hello, I'm trying to balance the scales. I can't deal with the rear axle. I always get a difference of about 40 kg. The measurement was made with the driver's load of 95 kg. Can I leave these settings?
last measurement
I have set up an SR3 two seater and it was impossible to get rear corners close to equal without sacrificing the front corner weights. I set the springs according to factory setup, and adjust the pushrods to corner balance. On cars older than the SR3 XX such as the RS and RSX, there are adjustable pushrods only on the front, so you must adjust the corner weights in the rear via the springs. Get it as close as you can without adding excessive preload in the rears, and try to keep the fronts within 5kg. If you have adjustable pushrods in the rear it is a little easier, but even with a center seat I am often 20kg off on the rear corners.
Hello, can anyone tell me if this suspension height setting is correct? Measured according to the instructions. Front height is 170 mm, rear height is 217 mm. Which according to the table gives 73 mm body height. The bodywork is level on each axleIs . This the correct setting ? Should the floor be perfectly level then?
You are in the correct ballpark for drop heights. In the SR3 RSX manual (Gen 3), there is a drop height table for Dunlop and one for Hankook -- I guess because they are slightly different diameter tires? Assuming you started with the correct preload in the front and back, target tire pressure, and you disconnected your Nick links (ARB), you are looking at the calculated rake as the significant number. To calculate, take the difference of the rear chassis height and the calculated lowest point on the front chassis height.
With your measurements 170mm/220mm front and rear, the tables show that your rake is 68mm - 50mm = 18mm for Hankooks, or 70mm - 53mm = 17mm for Donlops. Now reference the factory setup sheets for the tire you are using and the rake spec. For Hankook/Donlop the desired rake is 18mm/14mm.
For my XX with Hankooks, I think I am usually around 165mm in the front, and about 215mm in the back.
Edit:
I misread your rear ride height -- it is 217mm not 220mm. Your rake for Hankook/Dunlop is then 21mm/20mm. You should take some rake out by raising the front and lowering the rear if possible, however you might not be able to lower the rear ride height.
Notes:
- when you adjust the ride height, you should perform a complete setup again, and then check the ride height
- Camber affects ride height
- Used tires with pickup can skew the measurement
Where should I measure this 14mm difference? From the front splitter to the ground I have 40 mm. From the floor (measured in the middle of the car) to the ground I have about 60 mm. The car seems to be very low.
Where should I measure this 14mm difference?
You do not need to find the actual ride height because this is a computed value based on the drop height. The factory has done all of the careful chassis height calculation based on drop height measured with the 4 inch bar across the tires. The greater the drop height, the lower the ride height. So all you need to do is measure the drop height across your front and rear tires (as described in the RSX owners manual -- level with the top of the front tires and 4 inches above the rear tires), and then find the values in the table of the owner's manual.
The two values in the table are rear chassis height and the calculated chassis height under the lowest portion of the chassis in front. To answer your question, I think this would be the front of the chassis but not to include the front splitter. The splitter is lower because there is rake and it extends beyond the chassis. Actual ride height is difficult to measure because you need to to find a level and flat plane under the car as it sits with ballast on that plane. Then you would need to measure the height between that plane and the chassis. It is much simpler and sufficient to use the calculated values in the owner's manual table.
Yes, I think your car may be sitting low in front, but more concerning is the rake is too great. Low is good generally, but too much rake would cause high speed understeer.
And remember that as you change camber, this will affect ride height, so you may need to do a couple of iterations before it all comes together. I recommend starting with the factory setup spec because the car is very well balanced in high and low speed corners with this setup at most tracks. Once you nail the ride height and rake, the remainder of the setup is pretty easy.
I measured the height of the chassis. It looks like the front is higher than the back.
Which Generation of Radical SR3 do you have? I assumed that you have either gen 3 or 4 because you referenced the drop height table which is found in Gen 3 and Gen 4 owners manuals. I am unsure whether the drop height table is relevant for Gen 1&2.
The Gen 1 manual says this:
