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ELBJ vs Offset Lower Bushings

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Old 02-11-2018 | 06:19 PM
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Default ELBJ vs Offset Lower Bushings

ELBJ vs Offset Lower Bushings


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Old 02-11-2018 | 06:37 PM
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Don't do both. I bought a semi-track prepared MS last spring and, unbeknownst to me, it already had offset bushings for more negative camber. I added ELBJs and then sent it off for corner-weighting and track alignment. The least camber I could get was -4 degrees, which is great for track but not so good for the street. On my trip to MRLS, I pretty much corded a set of RA-1s.

Also, the offset bushings started clunking in the fall. At first I thought it was (another) front wheel bearing but it's the bushings. Bottom line: While I'm told there are some geometry benefits to offset bushings, I believe the ELBJ option is the better and more reliable way to go.
Old 02-11-2018 | 06:42 PM
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ya I wouldn't do both. Thanks for your input. I think it is important to note that most offset bushings out there are for the upper control arms. I heard bad things about them so im only looking at the lower bushings.
Old 02-11-2018 | 07:27 PM
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I did both on accident. Way to much camber. I got rid if the ebj, mostly because they were easier to pull.
Old 02-11-2018 | 07:54 PM
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what is your alignment Lars?
Old 02-11-2018 | 08:01 PM
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Bushings are usually more friendly for staying compliant with certain rule sets at the track. Also if ELBJ fails or wears out, you now need a specialized part to replace it with instead of being able to grab a normal one from any parts store or online retailer like rock auto.
Old 02-11-2018 | 08:14 PM
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Originally Posted by MiataMan00
what is your alignment Lars?
It was one of the SuperMiata ones. I actually did not get the before and after print out.
Old 02-11-2018 | 08:22 PM
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One other thing to keep in mind: on any Miata (stock or otherwise), there is a tradeoff between camber and available caster range. For the same camber target and ride height, ELBJs and front bore offset FUCA bushings affect the available caster range in different ways:
  • ELBJs will have a higher minimum caster, and a higher maximum caster than offset bushings
  • Front bore (SADFab style) offset bushings will have a lower minimum caster, and a lower maximum caster than ELBJs
For many setups, the desired caster may fall within the achievable range for both setups. However, it would definite be a good idea to know what camber, caster, and ride height numbers you want a prior.
Old 02-11-2018 | 10:06 PM
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Theres a desired caster setting that isnt ALLOFIT?
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Old 02-11-2018 | 11:20 PM
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yea. in short, and from my understanding at least. the lower the caster the better turn in and lower steering effort you get. The higher the caster the more stable the car is at speed, but turn in suffers, and the heavier the steering is. so you wanna find a balance

Last edited by icantlearn; 02-19-2018 at 09:20 PM.
Old 02-12-2018 | 01:06 PM
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Caster is a hard concept, I find it best describe it has primarily a function of steering feel. The more caster the more the steering wheel will self center which does add to stability and it also increases steering effort.

Physically it adds camber to the outside wheel and decreases it to the inside wheel as you turn. On the surface this sounds great but in doing so it negatively affects the corner weights and this is referred fo as jacking. How much jacking is bad and at what point does it out weight the camber benefits.........well it all just depends. For the average HPDE guy it's best to adjust it based on the level of steering effort you want and focus on static camber to get the tire wear even. This of course is all just my opinion, ymmv.
Old 02-15-2018 | 04:04 AM
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Interesting, Given our car is very stable at speed.....

So to further improve turn in I can trade caster until I start losing straight line stability (or stability to a level i'm uncomfortable with...)?

Nothing is ever that simple so I presume its more complicated than that?
Old 02-15-2018 | 04:21 AM
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there is also camber behavior that goes along with caster. its called jacking.

edit: I just noticed Bronson posted about jacking 2 posts up. Lol.

Last edited by icantlearn; 02-15-2018 at 01:44 PM.
Old 02-15-2018 | 07:32 AM
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I don't know that I ever noticed turn in behavior being affected by caster, toe certainly affects it moreso.
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