Adjustable Suspension/Alignment FAQ

[ansibe]

Originally Posted by KL

... Front gains negative camber under compression to a point and then begins gaining positive camber.

Really? I didn't know that. Do you know what point the neg camber increases? Are we into bump stops at that point?

[KL]

Originally Posted by ansibe

Really? I didn't know that. Do you know what point the neg camber increases? Are we into bump stops at that point?

Wish I could tell you where that transition point is though it only seems to matter when you start talking about changing geometry by lowering. That said, once you hit the bump stops, you're effectively not compressing the suspension anymore.

[Ashikabi]

Originally Posted by KL

Wish I could tell you where that transition point is though it only seems to matter when you start talking about changing geometry by lowering. That said, once you hit the bump stops, you're effectively not compressing the suspension anymore.

I'd be willing to bet that it's stupid low and not something anyone should be worrying about

[Calum]

This was covered a while ago, I can't remember the thread at the moment, but the result was (paraphrasing here) the tire would have to be poking up out of the fender before you start gaining positive camber.

[RiskyTrousers]

Are those front LCAs stx legal? It looks like they use bushings instead of heim joints.

[finch1750]

Originally Posted by RiskyTrousers

Are those front LCAs stx legal? It looks like they use bushings instead of heim joints.

I don't know myself. I have not seen any stx build include front lca and I dont know enough about the front lcas to say. If you find out let me know and I can update the thread here if they are. Maybe ask in the STX sticky

[finch1750]

Bump this as there have been a few posts where this may have helped. Will also be updating with some caster adjustment stuff soon.


Any other updates/new parts I may have missed?

[IndyBRZed]

Thanks for this thread to steer me in the right direction

[finch1750]

Updated with H&R rear camber bolts and Powerflex RUCA adjustable bushings

[radon55]

Originally Posted by finch1750

Front camber:


Camber bolts: Camber bolts are a cheap, easy way to gain adjustable camber in the front of the car. They do not have the range of camber plates but are enough for many (up to +/-2.5 degrees possibly). There are a few options for camber bolts.

OEM aka crash bolts (Toyota SU003-02818; Subaru 901000394): This is a 14mm bolt that replaces the 16mm bolt in the upper hole on your strut. It is able to take the torque needed to tighten with enough force to not slip since it is smaller than the hole it is inserted in. Adjustment is done by moving the strut in or out changing the camber and then tightening. While I can’t find specific numbers this bolt tends to add approximately between +/- .5 to 1 degree camber. This bolt is the same as the factory bolt in the lower hole on your stock struts. CS legal camber adjustment

SPC 81280 or Whiteline KCA416 : It is a 16mm eccentric bolt installed in the upper strut hole. This bolt has a lobe that adjusts the strut angle by rotating the bolt when installed. Adds approximately +/- 1.5 degree camber. Whiteline bolt is a repackaged SPC bolt listed first.

SPC 81305 or 81260: This is a 14mm eccentric camber bolt that is installed in the lower hole. This bolt has a lobe that adjusts the strut angle by rotating the bolt when installed. Adds approximately +/- 1.75 degrees camber.



Pro-tip: If you install 14mm eccentric bolts in the lower strut hole, you now have a "spare" OEM crash bolt. Swap the OEM bottom bolt into the top strut hole for greater adjustability. This is how to achieve upwards of -2.5 on stock struts with just camber bolts.

It seems after some research that there is a mix of people using the SPC 81305 in the bottom vs. the top. After asking FT86speedfactory, they recommend using it in the top, but the SPC website seems to say use in the bottom.

Is there really just no consensus on if the 81305 goes in top or bottom?

[churchx]

81305 is designed for use in lower, 14mm hole. Some may use it in upper, 16mm hole, but imho it may compromise a bit reliability of mount, as to not slip it probably will need to be tightened past reasonable torque value (as even with lobe it will still be smaller then upper hole diameter, and you can with same success use any regular 12mm bolt there with same "more" adjustment and with same reduced mount strength).

Use 81305 in lower hole, and KCA416 (81280) in upper, as it's meant to be. Yes, 81305 may net slightly more range in upper hole, but if you need even more camber then what two sets of proper sized camberbolts used in holes they were designed to can net, you'd be better off netting extra additional camber using other means, eg. lca offset bushing or offset topmount or camberplate, to accompany camberbolts.

[radon55]

Originally Posted by churchx

81305 is designed for use in lower, 14mm hole. Some may use it in upper, 16mm hole, but imho it may compromise a bit reliability of mount, as to not slip it probably will need to be tightened past reasonable torque value (as even with lobe it will still be smaller then upper hole diameter, and you can with same success use any regular 12mm bolt there with same "more" adjustment and with same reduced mount strength).

Use 81305 in lower hole, and KCA416 (81280) in upper, as it's meant to be. Yes, 81305 may net slightly more range in upper hole, but if you need even more camber then what two sets of proper sized camberbolts used in holes they were designed to can net, you'd be better off netting extra additional camber using other means, eg. lca offset bushing or offset topmount or camberplate, to accompany camberbolts.

Thank you for the quick response.
Personally, I am hesitant to use both the 83105 and the KCA416 (81280) due to slippage/reliability concerns from using two eccentric bolts at the same time. I have the a similar reliability concern with using the OEM bottom bolt in the top. Maybe unfounded but it still makes me uneasy.

[churchx]

83105 is even thinner/weaker then oem crashbolt. Probably comparable to KCA416.

After all, oem crashbolt is normal 14mm bolt, while 83105 needs to be even thinner then it to provide slack/adjustment range when used in same 14mm hole. While i'm ok with using 83105+KCA416 (actually am using for 3 years already) and probably would be ok with 83105+OE crashbolt on top (but as first combo nets slightly more camber, went with that), using 83105 at top sounds too much for piece of my heart, thus i voiced my opinion on it, that imho one shouldn't.

[finch1750]

Originally Posted by radon55

Thank you for the quick response.
Personally, I am hesitant to use both the 83105 and the KCA416 (81280) due to slippage/reliability concerns from using two eccentric bolts at the same time. I have the a similar reliability concern with using the OEM bottom bolt in the top. Maybe unfounded but it still makes me uneasy.

The bottom bolt is the OEM crash bolt, meant to help get cars back in spec that don't normally have adjustment or need a bit more. It is perfectly fine in the top.

I have ran 81305 in the bottom hole for over 130k miles. I have ran the bottom bolt/crash bolt in the upper hole the same amount of time. Half of that time was on OEM struts and the other half was coilovers with slotted upper holes. Never had any slippage with countless mountain runs, daily driving on horrible roads, and about 8 track days.

Like church I don't like the idea of extra wiggle room with an eccentric bolt. I never tried it though so can't give first hand knowledge.