Corner balance: Preload versus shock height adjustment
#12
OK, thanks for the input guys. That confirms my thoughts. The context of my question was in regards to the well-documented Ohlins DFV rear and their need for additional preload. I had previously run the necessary preload to center the piston travel at static ride height, which of course is a lot of preload, but I had sufficient shock length adjustment to compensate and ahieve desired ride height. I had a corner balance guy freak out at all the preload and insist it would ruin the corner balance, even though he had headroom on the shock length to adjust corner balance that way and the preload was matched across the axle. He ended up setting it back to "stock" preload and then corner balancing with the shock adjusters from there. I don't have scales of my own to "prove" that the preload wasn't going to screw anything up. This was in the times before SakeBomb came along and added some professional backup to my previously unpopular assertion that the Ohlins rear need a lot of preload unless you get shortened bodies (like SakeBomb now sells).
I'm going to take my existing corner balanced settings and add back my threads of preload and remove equal threads of shock length with the assumption that static corner balance will be unchanged and I'll get back to the correct preload for these Ohlins rears. My corner balance feels great on smooth pavement but big bumps get into the bump stops all the time on the Ohlins at "stock" preload and that can do some unpleasant stuff if you hit them mid-corner.
I'm going to take my existing corner balanced settings and add back my threads of preload and remove equal threads of shock length with the assumption that static corner balance will be unchanged and I'll get back to the correct preload for these Ohlins rears. My corner balance feels great on smooth pavement but big bumps get into the bump stops all the time on the Ohlins at "stock" preload and that can do some unpleasant stuff if you hit them mid-corner.
__________________
SAKEBOMB GARAGE > Click here to contact Us
Check some of our most popular products for the S2000:
- Ohlins DFV Billet Lower Mount
- Rear BBK RX-8 Caliper Conversion
- Front BBK AP Competition
- Setrab Oil Cooler Kit
SAKEBOMB GARAGE > Click here to contact Us
Check some of our most popular products for the S2000:
- Ohlins DFV Billet Lower Mount
- Rear BBK RX-8 Caliper Conversion
- Front BBK AP Competition
- Setrab Oil Cooler Kit
#13
OK, thanks for the input guys. That confirms my thoughts. The context of my question was in regards to the well-documented Ohlins DFV rear and their need for additional preload. I had previously run the necessary preload to center the piston travel at static ride height, which of course is a lot of preload, but I had sufficient shock length adjustment to compensate and ahieve desired ride height. I had a corner balance guy freak out at all the preload and insist it would ruin the corner balance, even though he had headroom on the shock length to adjust corner balance that way and the preload was matched across the axle. He ended up setting it back to "stock" preload and then corner balancing with the shock adjusters from there. I don't have scales of my own to "prove" that the preload wasn't going to screw anything up. This was in the times before SakeBomb came along and added some professional backup to my previously unpopular assertion that the Ohlins rear need a lot of preload unless you get shortened bodies (like SakeBomb now sells).
I'm going to take my existing corner balanced settings and add back my threads of preload and remove equal threads of shock length with the assumption that static corner balance will be unchanged and I'll get back to the correct preload for these Ohlins rears. My corner balance feels great on smooth pavement but big bumps get into the bump stops all the time on the Ohlins at "stock" preload and that can do some unpleasant stuff if you hit them mid-corner.
I'm going to take my existing corner balanced settings and add back my threads of preload and remove equal threads of shock length with the assumption that static corner balance will be unchanged and I'll get back to the correct preload for these Ohlins rears. My corner balance feels great on smooth pavement but big bumps get into the bump stops all the time on the Ohlins at "stock" preload and that can do some unpleasant stuff if you hit them mid-corner.
Knowing what I do about the limitations of the Ohlins, it's all about compromise. To me The limited bump travel trumps using only preload to get the perfect corner balance. Your corner balance guy should understand you were running more preload for static bump travel. Depending on the weights he could have changed preload to the front, or use the length adjusters as needed. However you have a very good reason to run extra preload because of the short shock travel. I would have started the process by giving him some boundaries on rear preload. Say 8-12mm is the ok range. Once outside that, find another way to balance the car.
#14
Thread Starter
The point of the SakeBomb lower cups is to either allow you to run preload while still lowering the car, or to run very high spring rates and still lower the car. The shortened bodies simply allow you to lower the car with pre-load, not a substitute for pre-load. Just wanted to be clear.
#15
I've been meaning to take the time to jump in here but I'm just getting to it now. I'll share my overall process when it comes to setting up a car (once I know what spring rates etc)
First you set your static bump-stop clearance to ensure no fender contact is possible using pre-load or helper springs depending on total available stroke and spring rate. Essentially you are determining the available compression & rebound stroke. Then you set your ride you set the ride height using the lower mount adjustment.
The pre-load is used to set the bump-stop clearance and should not be adjusted during a corner balance. The point of a corner balance essentially is to adjust for the tolerances of the chassis and suspension. Unless you find your wheel weights are significantly different than expected you shouldn't adjust the pre-load.
For anyone who is interested we offer custom race alignment and corner balance services services out of our Santa Clara, CA facility.
-Greg @ SBG
First you set your static bump-stop clearance to ensure no fender contact is possible using pre-load or helper springs depending on total available stroke and spring rate. Essentially you are determining the available compression & rebound stroke. Then you set your ride you set the ride height using the lower mount adjustment.
The pre-load is used to set the bump-stop clearance and should not be adjusted during a corner balance. The point of a corner balance essentially is to adjust for the tolerances of the chassis and suspension. Unless you find your wheel weights are significantly different than expected you shouldn't adjust the pre-load.
For anyone who is interested we offer custom race alignment and corner balance services services out of our Santa Clara, CA facility.
-Greg @ SBG
__________________
SAKEBOMB GARAGE > Click here to contact Us
Check some of our most popular products for the S2000:
- Ohlins DFV Billet Lower Mount
- Rear BBK RX-8 Caliper Conversion
- Front BBK AP Competition
- Setrab Oil Cooler Kit
SAKEBOMB GARAGE > Click here to contact Us
Check some of our most popular products for the S2000:
- Ohlins DFV Billet Lower Mount
- Rear BBK RX-8 Caliper Conversion
- Front BBK AP Competition
- Setrab Oil Cooler Kit
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