Installed Exact Motorsports front camber spacers, but got question now about height?
05-28-09, 01:03 PM
#16
nope, but the were the bolts provided by exact motorsports. i did not see what the grade was on them, BUT they look exactly like the ones on their site.
i torqued them down to 120lbs as per their instructions. after reading the thread about someone snapping their bolt. i basically loosened them back until i could hand tighten them again. then torqued to 75, then to 105. should be good, i greased the threads a bit before putting them in the first time.
The bolt grade is 12.9
This was the thread...
https://www.clublexus.com/forums/sus...t-failure.html
as far as ive researched, those bolts can handle a lot more than 120lbs. so im not worried (cross fingers)
i torqued them down to 120lbs as per their instructions. after reading the thread about someone snapping their bolt. i basically loosened them back until i could hand tighten them again. then torqued to 75, then to 105. should be good, i greased the threads a bit before putting them in the first time.
The bolt grade is 12.9
This was the thread...
https://www.clublexus.com/forums/sus...t-failure.html
as far as ive researched, those bolts can handle a lot more than 120lbs. so im not worried (cross fingers)
Last edited by SorrGwa; 05-28-09 at 01:14 PM.
05-28-09, 01:05 PM
#17
according to the mechanic, the toes are within spec. they were within spec before i installed the camber kit for the rear and the spacers for the front.
you want the rears to be a bit toe in, and the fronts a bit toe out for drivability.
you want the rears to be a bit toe in, and the fronts a bit toe out for drivability.
05-28-09, 02:39 PM
#19
Posted on other thread but you should not go over 100ft lbs with the bolt (lubricated) by taking it up to 120 ft lbs you are dangerously close to the bolt surpassing its yieled point and it wouldn't be a bad idea to replace them.
Last edited by macd7919; 05-28-09 at 03:40 PM.
05-28-09, 03:30 PM
#20
back from the alignment shop, here are the specs:
- tein ss coilovers
- daizen front rear sway bars
- rear spc camber kit
- front exactmotorsport camber block spacers
Lowered from ground to fender:
Fronts: 25 1/2"
Rears: 26"
Front
Left: -1.75 degree camber / +7.78 degree caster / 0.12" toe
Right: -1.78 degree camber / +7.71 degree caster / 0.09" toe
Rear
Left: -1.25 degree camber / -0.06" toe
Right: -1.21 degree camber / -0.09" toe
- tein ss coilovers
- daizen front rear sway bars
- rear spc camber kit
- front exactmotorsport camber block spacers
Lowered from ground to fender:
Fronts: 25 1/2"
Rears: 26"
Front
Left: -1.75 degree camber / +7.78 degree caster / 0.12" toe
Right: -1.78 degree camber / +7.71 degree caster / 0.09" toe
Rear
Left: -1.25 degree camber / -0.06" toe
Right: -1.21 degree camber / -0.09" toe
05-28-09, 03:58 PM
#22
GS300Tom: honestly, i did think of this when i was installing the bolts. i noticed that the head was much bigger on the stock bolts, and so the washers should help compensate that. i think ill do this tommorow. just gotta run to homedepot and find me some washers.
macd7919: yup, i retorqued them to 105 (ok technically 102) i think this should be fine.
dashocker: car seems to drive fine. doesnt really pull to either side. maybe its psychological, but it seems the steering is a bit lighter. as to why you have different camber from right to left, oem factory spec on the programmable alignment machines adjusts the numbers a little bit to correct for the crown of the road. what i did was ask the mechanic to make the right side equal as closely to the left side as possible, screw the crown of the road, ill correct that myself with the steering wheel. i actually wanted my front camber to sit closer to -1.5, but if this is as much as i can get without going to adjustable upper control arms, then ill take it. i had some bad experiences with adjustable upper control arms on my previous car so im trying to avoid it (bolt would always come lose and thus camber goes to crap)
some cars are completely out of alignment at dead stop. eg, old merc benz's have the toe's completely off at rest, but as the car moves, the toe self adjusts. this was told and shown to me by my previous alignment mechanic (whom now works on british cars at some other shop).
macd7919: yup, i retorqued them to 105 (ok technically 102) i think this should be fine.
dashocker: car seems to drive fine. doesnt really pull to either side. maybe its psychological, but it seems the steering is a bit lighter. as to why you have different camber from right to left, oem factory spec on the programmable alignment machines adjusts the numbers a little bit to correct for the crown of the road. what i did was ask the mechanic to make the right side equal as closely to the left side as possible, screw the crown of the road, ill correct that myself with the steering wheel. i actually wanted my front camber to sit closer to -1.5, but if this is as much as i can get without going to adjustable upper control arms, then ill take it. i had some bad experiences with adjustable upper control arms on my previous car so im trying to avoid it (bolt would always come lose and thus camber goes to crap)
some cars are completely out of alignment at dead stop. eg, old merc benz's have the toe's completely off at rest, but as the car moves, the toe self adjusts. this was told and shown to me by my previous alignment mechanic (whom now works on british cars at some other shop).
05-28-09, 04:18 PM
#23
dashocker: car seems to drive fine. doesnt really pull to either side. maybe its psychological, but it seems the steering is a bit lighter. as to why you have different camber from right to left, oem factory spec on the programmable alignment machines adjusts the numbers a little bit to correct for the crown of the road. what i did was ask the mechanic to make the right side equal as closely to the left side as possible, screw the crown of the road, ill correct that myself with the steering wheel. i actually wanted my front camber to sit closer to -1.5, but if this is as much as i can get without going to adjustable upper control arms, then ill take it. i had some bad experiences with adjustable upper control arms on my previous car so im trying to avoid it (bolt would always come lose and thus camber goes to crap)
some cars are completely out of alignment at dead stop. eg, old merc benz's have the toe's completely off at rest, but as the car moves, the toe self adjusts. this was told and shown to me by my previous alignment mechanic (whom now works on british cars at some other shop).
05-28-09, 04:46 PM
#24
GS300Tom: honestly, i did think of this when i was installing the bolts. i noticed that the head was much bigger on the stock bolts, and so the washers should help compensate that. i think ill do this tommorow. just gotta run to homedepot and find me some washers.
macd7919: yup, i retorqued them to 105 (ok technically 102) i think this should be fine.
macd7919: yup, i retorqued them to 105 (ok technically 102) i think this should be fine.
The issue with re-torquing them after they have been over torqued is that the bolt has been stretched past yield. Once it's stretched past yield it will no longer provide a pre-load and is prone to loosening which can cause the bolt to fail under shear stress. The proper pre-load for a M12 12.9 bolt is about 100.5 lbs assuming it was lubricated, 120lbs is 20% greater torque than it required which is a significant amount, hence the reason I suggested replacing them with new ones.
Did Exact specify that you lube them when you put them in? I'm assuming so from their suggested value of 120 as un-lubricated is much higher of a torque for pre-loading. I would be interested to find how they came up with the number of 120 ft lbs. By the use of 12.9 bolts (which is considerable overkill for the application) I'm thinking that when the RCA's were designed they weren't analyzed by using any engineering methods and simple sourced the strongest bolt available. The reason I would come to this conclusion as that the grade of the bolt can be more or less determined from the stock torque spec of 83 ft lbs. This torque spec is what is needed to provide proper pre-load for the oem bolt.
By reverse engineering the calculations indicate that the factory bolt is a grade 8.8 bolt.
Last edited by macd7919; 05-28-09 at 05:06 PM.
, keep it in the LEXUS spec imo 
05-28-09, 06:56 PM
#27
exact did not specify to lube up the bolts, its just something ive always done.
the instructions were to torque both to 75ft lbs, then to torque them again to 120.
i lubed both bolts up before installing them. the 2nd time around, i loosened both, then took 1 out to examine, seemed fine to me, so i reinstalled them, torqing to 75 first, then to 102ish. im sure the bolts will be fine, ill just look for some regular washers tommorow.
the instructions were to torque both to 75ft lbs, then to torque them again to 120.
i lubed both bolts up before installing them. the 2nd time around, i loosened both, then took 1 out to examine, seemed fine to me, so i reinstalled them, torqing to 75 first, then to 102ish. im sure the bolts will be fine, ill just look for some regular washers tommorow.
05-28-09, 09:40 PM
#28
exact did not specify to lube up the bolts, its just something ive always done.
the instructions were to torque both to 75ft lbs, then to torque them again to 120.
i lubed both bolts up before installing them. the 2nd time around, i loosened both, then took 1 out to examine, seemed fine to me, so i reinstalled them, torqing to 75 first, then to 102ish. im sure the bolts will be fine, ill just look for some regular washers tommorow.
the instructions were to torque both to 75ft lbs, then to torque them again to 120.
i lubed both bolts up before installing them. the 2nd time around, i loosened both, then took 1 out to examine, seemed fine to me, so i reinstalled them, torqing to 75 first, then to 102ish. im sure the bolts will be fine, ill just look for some regular washers tommorow.
The reason it's important to get the correct pre-load is because bolts stretch when tightened, that's what keeps the bolt tight and is referred to as pre-load, you want the bolt to stretch to the point where it is still providing resistance from loosening. If the bolt is over torqued then it is brought past its yield point (the yield point is the spot where the bolt will not return to it's original length), once this point is passed the bolt is permanently stretched and will not provide any resistance to loosening which can cause failure due to shear. The same thing happens with an under torqued bolt, it's loose so it fails due to shear in many cases.
05-29-09, 04:47 AM
#30
nope, but the were the bolts provided by exact motorsports. i did not see what the grade was on them, BUT they look exactly like the ones on their site.
i torqued them down to 120lbs as per their instructions. after reading the thread about someone snapping their bolt. i basically loosened them back until i could hand tighten them again. then torqued to 75, then to 105. should be good, i greased the threads a bit before putting them in the first time.
The bolt grade is 12.9
This was the thread...
https://www.clublexus.com/forums/sus...t-failure.html
as far as ive researched, those bolts can handle a lot more than 120lbs. so im not worried (cross fingers)
i torqued them down to 120lbs as per their instructions. after reading the thread about someone snapping their bolt. i basically loosened them back until i could hand tighten them again. then torqued to 75, then to 105. should be good, i greased the threads a bit before putting them in the first time.
The bolt grade is 12.9
This was the thread...
https://www.clublexus.com/forums/sus...t-failure.html
as far as ive researched, those bolts can handle a lot more than 120lbs. so im not worried (cross fingers)
I did a quick search and found this torque spec. online. Obviously it would be better to find the "Actual" manufacturers spec. from Exact's bolt supplier, but nevertheless, this chart does show that 120ft.lbs "can" be within the spec of this bolt.
As for the one person who reported the broken bolt, without an actual failure analysis being performed on that failed bolt, there is no way we can do any more then speculate what the root cause could be. (over torque, torque wrench out of calibration, cross threaded, bolt manufacturer defect, lubricated thread, etc.)
If someone wants to ***-U-ME the root cause of the bolt failure, well you know what they say.
Note: I converted kg.m to ft.lb.
Last comment: I'm not implying that the torque specified is appropriate for the intended application, I'm merely stating that this torque spec shows it is not beyond the limits of the tensile strength for a bolt of this size.
Last edited by RMMGS4; 05-29-09 at 04:59 AM.