follow ft86club on our blog, twitter or facebook.
FT86CLUB
Ft86Club
Delicious Tuning
Register Garage Community Calendar Today's Posts Search

Go Back   Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community - FT86CLUB > Technical Topics > Suspension | Chassis | Brakes -- Sponsored by 949 Racing

Suspension | Chassis | Brakes -- Sponsored by 949 Racing Relating to suspension, chassis, and brakes. Sponsored by 949 Racing.


User Tag List

Reply
 
Thread Tools Search this Thread
Old 03-10-2023, 06:16 PM   #4299
Tatsu333
Senior Member
 
Join Date: Jan 2017
Drives: 2020 BRZ Sport Tech RS
Location: Canada
Posts: 355
Thanks: 408
Thanked 240 Times in 139 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
With the OEM crash bolts maxed and the SS1 camber plates in the center position, I was right at -2.2.

- Andrew
Results from my alignment today weren't awesome.

With the stock bolts installed (16mm upper and 14mm lower), slotted upper holes maxed out and camber plates maxed out, the most negative front camber the tech could achieve was -1.9. That in itself wasn't totally unexpected.

Since I didn't have the OEM "crash bolts" (I.E. the 14mm lower bolts to install in the upper holes), I instructed him to zero out the camber plates and re-use my SPC 14mm camber bolts in the 14mm lower holes they were designed for.

Instead, he put them in the slotted upper holes and took a LOT of messing around to get things locked down (as you'd expect with an undersized 14mm camber bolt in a 16mm hole, never mind the slotted hole on the struts). Meanwhile, I'm sitting in the waiting area wondering what the heck was taking so long.

He was, of course, able to get LOTS of negative camber (I think with both the bolts and plates maxed out, it was around -3.9), and had to dial things back at the camber plates, ending up at +0.5 degrees from 0 on the camber plates to hit my -2.2 degree target.

Nearly $400 later, he's "confident" the bolts won't slip in the slotted upper holes, but I don't trust them.

So, now I'm torn.

My gut tells me to pull those camber bolts out ASAP for safety reasons, so for right now I'm going to put the stock 16mm bolts back in and max out the slots and camber plates until I decide where to go with this.

I do have my own ideas on this, but I'm looking for other people's takes on which is better and why:
  • Option A - Stock 16mm round bolts in 16mm slotted upper holes + SPC 14mm camber bolts in 14mm lower holes, or...
  • Option B - OEM 14mm round "crash bolts" in 16mm slotted upper holes + stock 14mm bolts in lower holes

Either way, I'm going to have to get another alignment done to be confident that my front toe isn't f'd up, so there's more money I'm having to spend twice...
__________________
Tatsu333 is offline   Reply With Quote
The Following User Says Thank You to Tatsu333 For This Useful Post:
strat61caster (03-12-2023)
Old 03-10-2023, 08:32 PM   #4300
Ohio Enthusiast
Senior Member
 
Join Date: Apr 2020
Drives: 2018 BRZ
Location: Dayton, OH
Posts: 904
Thanks: 1,370
Thanked 768 Times in 435 Posts
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Tatsu333 View Post
Nearly $400 later, he's "confident" the bolts won't slip in the slotted upper holes, but I don't trust them.
I think most people use the bottom bolt in the top hole to save money. If you're already $400 in why not get both sets of camber bolts (16mm and 14mm)?
Ohio Enthusiast is offline   Reply With Quote
Old 03-10-2023, 08:48 PM   #4301
Tatsu333
Senior Member
 
Join Date: Jan 2017
Drives: 2020 BRZ Sport Tech RS
Location: Canada
Posts: 355
Thanks: 408
Thanked 240 Times in 139 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Ohio Enthusiast View Post
I think most people use the bottom bolt in the top hole to save money. If you're already $400 in why not get both sets of camber bolts (16mm and 14mm)?
For my use case, I wouldn't do that because I don't have a need for that much camber adjustment range.

The least expensive option at this point is just to re-use my 14mm camber bolts in the bottom and return to the stock 16mm bolts in the top, but the 14mm OEM (round) bolts to use in the slotted top holes are only $16 CAD (for both), should get the camber I need (based on Andrew's feedback a few posts above) while still allowing lots of scope for more with the camber plates, and would be less problematic to set up than having adjustment at both knuckle holes (upper with the slotted tabs on the coilovers and bottom with camber bolts).
__________________
Tatsu333 is offline   Reply With Quote
Old 03-11-2023, 08:04 AM   #4302
Ohio Enthusiast
Senior Member
 
Join Date: Apr 2020
Drives: 2018 BRZ
Location: Dayton, OH
Posts: 904
Thanks: 1,370
Thanked 768 Times in 435 Posts
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Tatsu333 View Post
For my use case, I wouldn't do that because I don't have a need for that much camber adjustment range.
In that case I'd put camber bolts on the top hole. Camber bolts for the bottom hole are undersized while for the top hole they are not (the OEM top bolt has a 16mm shoulder but the threaded portion is the same as the camber bolt).
There was some discussion about that in a few threads here, people being concerned with slippage or breakage with a bottom camber bolt. Not sure if that is a real concern, though - I'm using top and bottom camber bolts (SPC 81280 and 81260) and they are fine on the street and on the track (had a mild off-track with them and hit some nasty curbs without issues). Other people use them as well (typically putting the OEM bottom bolt in the top hole).
Ohio Enthusiast is offline   Reply With Quote
Old 03-11-2023, 12:33 PM   #4303
Tatsu333
Senior Member
 
Join Date: Jan 2017
Drives: 2020 BRZ Sport Tech RS
Location: Canada
Posts: 355
Thanks: 408
Thanked 240 Times in 139 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Ohio Enthusiast View Post
In that case I'd put camber bolts on the top hole. Camber bolts for the bottom hole are undersized while for the top hole they are not (the OEM top bolt has a 16mm shoulder but the threaded portion is the same as the camber bolt).
There was some discussion about that in a few threads here, people being concerned with slippage or breakage with a bottom camber bolt. Not sure if that is a real concern, though - I'm using top and bottom camber bolts (SPC 81280 and 81260) and they are fine on the street and on the track (had a mild off-track with them and hit some nasty curbs without issues). Other people use them as well (typically putting the OEM bottom bolt in the top hole).
The 81260's are what I have - the 14mm camber bolts for the bottom holes. I ran those for about a year on the street with no issues.

IGNORE: So are you saying that the 81280 and 81260 are basically identical as far as the shaft is concerned, and the 81280 just has a larger head, or...?

EDIT: I do recall when I swapped the coilovers in that the upper bolt was the same shaft diameter and thread as the lower one, just with the larger shoulder - I.E. the nuts were interchangeable. But that means that the top hole in the knuckle was 16mm diameter because the whole "shoulder" section is what is in there. They also only fit into the coilovers one way because of that - I.E. on the driver's side, they have to go front to back, and on the passenger's side, the opposite because only one side is made large enough diameter to accommodate the larger shoulder.

So, the 81280's should be a larger shaft diameter, likely close to a 14mm round bolt, whereas the 81260's shaft diameter is likely something like 12mm - that's what I think you're saying here. Got it.

This further reinforces my feeling that I need to get the 81260's out of the upper holes ASAP, because they are too small for the hole in the knuckle.

It does, however, suggest that the 81280 in the upper hole might be a superior solution to the OEM crash bolt because the cam shape would more completely fill the hole in the knuckle while still offering a similar amount of camber adjustment. Hmm...
__________________

Last edited by Tatsu333; 03-11-2023 at 02:23 PM. Reason: Updated stock bolt info
Tatsu333 is offline   Reply With Quote
Old 03-11-2023, 01:15 PM   #4304
Ohio Enthusiast
Senior Member
 
Join Date: Apr 2020
Drives: 2018 BRZ
Location: Dayton, OH
Posts: 904
Thanks: 1,370
Thanked 768 Times in 435 Posts
Mentioned: 12 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Tatsu333 View Post
So are you saying that the 81280 and 81260 are basically identical as far as the shaft is concerned, and the 81280 just has a larger head, or...?
No, I meant that the OEM top bolt has the same thread as 81280. The difference is that the OEM top bolt has a full round shoulder while 81280 has an oval shoulder.
OEM bottom bolt is a regular bolt without a shoulder. 81260 has smaller threaded diameter than the OEM bottom bolt and an oval shoulder (otherwise it wouldn't provide adjustment).

To me this means that 81260 (bottom camber bolt) is thinner than the OEM bottom bolt and potentially weaker. In practice it might not matter, but if I was in a position of only using one camber bolt I would prefer top.

Both bottom and top OEM bolts have the same thread and their nuts are interchangeable (top bolt is to the left, bottom bolt is to the right). The SPC camber bolts are on the car, so can't take a picture to compare them.
Attached Images
 
Ohio Enthusiast is offline   Reply With Quote
The Following User Says Thank You to Ohio Enthusiast For This Useful Post:
Tatsu333 (03-11-2023)
Old 03-11-2023, 01:34 PM   #4305
Tatsu333
Senior Member
 
Join Date: Jan 2017
Drives: 2020 BRZ Sport Tech RS
Location: Canada
Posts: 355
Thanks: 408
Thanked 240 Times in 139 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Ohio Enthusiast View Post
No, I meant that the OEM top bolt has the same thread as 81280. The difference is that the OEM top bolt has a full round shoulder while 81280 has an oval shoulder.
OEM bottom bolt is a regular bolt without a shoulder. 81260 has smaller threaded diameter than the OEM bottom bolt and an oval shoulder (otherwise it wouldn't provide adjustment).

To me this means that 81260 (bottom camber bolt) is thinner than the OEM bottom bolt and potentially weaker. In practice it might not matter, but if I was in a position of only using one camber bolt I would prefer top.

Both bottom and top OEM bolts have the same thread and their nuts are interchangeable (top bolt is to the left, bottom bolt is to the right). The SPC camber bolts are on the car, so can't take a picture to compare them.
Yup - just edited my response above as you were posting this.

EDIT: So for now I swapped back in the stock bolts (top and rear), maxed out the negative camber with the slotted holes on the coilovers at the knuckle and maxed out the camber plates.

Eyeballing it, it looks like there's more negative camber in front than in the rear (which would put it at something beyond -2.3 degrees), but if the shop was right, that's just wishful thinking - they said that combination was around -1.9 degrees. I don't think my eyeball has that fine a calibration...LOL.

I'll get the alignment checked again elsewhere, make sure the front toe is still zero (if not, have it adjusted so it is) and see if I still need more front negative camber.

If so, after thinking further on the feedback from Ohio Enthusiast above, I plan to go with the SPC 81280 or Mevotech MS50201 16mm camber bolts in the top holes to keep it to a single adjustment point at the knuckle and have the *slight* added security of the 16mm cam spanning the entire hole in the knuckle vs. the OEM 14mm round crash bolts which would just be free-floating.
__________________

Last edited by Tatsu333; 03-11-2023 at 06:28 PM. Reason: Added info on current / future direction
Tatsu333 is offline   Reply With Quote
Old 03-11-2023, 11:23 PM   #4306
Racecomp Engineering
 
Join Date: Nov 2011
Drives: 2016 BRZ, 2012 Paris Di2 & 2018 STI
Location: Severn, MD
Posts: 5,408
Thanks: 3,420
Thanked 7,242 Times in 2,963 Posts
Mentioned: 303 Post(s)
Tagged: 9 Thread(s)
Send a message via AIM to Racecomp Engineering
You should definitely be able to get more than -1.9 with OEM bolts and the camber plates. Shop or technician is doing something wrong, or measuring incorrectly.

- Andrew
Racecomp Engineering is offline   Reply With Quote
Old 03-11-2023, 11:52 PM   #4307
Tatsu333
Senior Member
 
Join Date: Jan 2017
Drives: 2020 BRZ Sport Tech RS
Location: Canada
Posts: 355
Thanks: 408
Thanked 240 Times in 139 Posts
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Racecomp Engineering View Post
You should definitely be able to get more than -1.9 with OEM bolts and the camber plates. Shop or technician is doing something wrong, or measuring incorrectly.

- Andrew
To be clear - STOCK bolts (16mm round on top, 14mm round on bottom), not OEM crash bolts. All the same, I was still quite surprised that was all they got with the camber plates and the slots maxed out.

I wasn't allowed to go into the shop area, so didn't see exactly how they had it set up at that point in the process and can't say for sure whether they actually had the camber plates all the way negative.

Again, to my eye, it looks like the front is at least as negatively cambered as the rear, but I've learned before that my eyes can deceive me. I guess I'll find out when I get it measured again!
__________________
Tatsu333 is offline   Reply With Quote
Old 03-16-2023, 04:54 AM   #4308
bradsm87
Senior Member
 
Join Date: May 2016
Drives: It has 4 wheels
Location: Australia
Posts: 101
Thanks: 17
Thanked 32 Times in 23 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
I've always loosened and re-tightened ALL rubber bushes that get twisted after changing ride height any more than minor adjustments (eg when installing coilovers). I was surprised to see that most "coilover install guide" do not mention loosening and re-tightening rubber bushes in order for them to not be permanently slightly twisted at rest height.

Do you guys loosten and re-tighten all rubber bush mounting bolts after installing coilovers to reset them to their un-twisted state?

A side question:

How much rear camber can you change by loosening all the rear suspension bolts, having someone (or a jack) hold the camber hard one way and tightening the bolts? Mine has more camber one side than the other which is common but I'm thinking I might be able to even it up a bit by doing this.
bradsm87 is offline   Reply With Quote
Old 03-18-2023, 04:12 PM   #4309
strat61caster
-
 
strat61caster's Avatar
 
Join Date: Nov 2012
Drives: '13 FRS - STX
Location: SF Bay Area
Posts: 10,366
Thanks: 13,733
Thanked 9,479 Times in 4,998 Posts
Mentioned: 94 Post(s)
Tagged: 3 Thread(s)
I found zero difference in tightening under load, you might get a tenth of a degree with loosening and retightening.
__________________
Quote:
Originally Posted by Guff View Post
ineedyourdiddly
strat61caster is offline   Reply With Quote
Old 03-20-2023, 10:47 AM   #4310
Tokay444
Anti stance.
 
Tokay444's Avatar
 
Join Date: Feb 2016
Drives: 17 White 860. RCE Tarmac 2. RE-71RS
Location: Not Canada
Posts: 1,630
Thanks: 897
Thanked 958 Times in 547 Posts
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by strat61caster View Post
I found zero difference in tightening under load, you might get a tenth of a degree with loosening and retightening.
It's less about added range, and more about eliminating torsional stresses in the bushings at static ride height. Otherwise known as bind.

Last edited by Tokay444; 03-20-2023 at 11:35 AM.
Tokay444 is offline   Reply With Quote
Old 03-20-2023, 01:36 PM   #4311
bradsm87
Senior Member
 
Join Date: May 2016
Drives: It has 4 wheels
Location: Australia
Posts: 101
Thanks: 17
Thanked 32 Times in 23 Posts
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by Tokay444 View Post
It's less about added range, and more about eliminating torsional stresses in the bushings at static ride height. Otherwise known as bind.
It was in response to my second question 👍
bradsm87 is offline   Reply With Quote
Old 03-20-2023, 01:42 PM   #4312
Tokay444
Anti stance.
 
Tokay444's Avatar
 
Join Date: Feb 2016
Drives: 17 White 860. RCE Tarmac 2. RE-71RS
Location: Not Canada
Posts: 1,630
Thanks: 897
Thanked 958 Times in 547 Posts
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
AH.
Tokay444 is offline   Reply With Quote
 
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Air Suspension Discussion Thread - Let's Get Nerdy Andrew@ORT Suspension | Chassis | Brakes -- Sponsored by 949 Racing 174 02-13-2016 03:17 PM
RallySport Directs Everything Suspension thread!! RallySport Direct Brakes, Suspension, Chassis 21 07-02-2014 05:31 PM
The OFFICIAL Ohlins Coilover Suspension thread - High End Competition Suspension ModBargains.com Suspension | Chassis | Brakes -- Sponsored by 949 Racing 63 05-22-2013 08:15 AM
2012 Team USA vs the 1992 Dream Team ERZperformance Off-Topic Lounge [WARNING: NO POLITICS] 1 09-14-2012 06:19 PM
Team build thread; PROJECT.STH trueno86power Other Vehicles & General Automotive Discussions 0 03-02-2010 10:13 AM


All times are GMT -4. The time now is 12:48 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
User Alert System provided by Advanced User Tagging v3.3.0 (Lite) - vBulletin Mods & Addons Copyright © 2024 DragonByte Technologies Ltd.

Garage vBulletin Plugins by Drive Thru Online, Inc.