Jump to content
SAU Community

Recommended Posts

Hey guys, ive got a question I couldn't specifically find the answer to.

Is toe affected when adjusting rear camber on an R33 GTST, using adjustable rear camber arms (upper arms), like these? >>

308-S14%20R33%20Rear%20Camber%20-%20Smalhardrace-rear-UCA-s14s15r33r34c34c35.-pi

If it is affected, how much would it change vs camber?

Does that makes sense?

ie. I adjusted the rear camber myself, adding about 1 degree positive. From my measurements & calculations, around -1.8 deg >> to -0.8 deg. (possibly off, but moved + towards zero some amount)

18 inch wheels, so lip to lip, rim height measures 495mm.

Cheers

Is toe affected when adjusting rear camber on an R33 GTST, using adjustable rear camber arms (upper arms), like these? >>

As far as I know, yes. Camber and toe are normally adjusted together when doing an alignment. I'd suggest dropping by at a wheel joint and getting them to measure it for you?

It will almost certainly affect toe, and using my logic: adding negative camber will increase toe-in, subtracting negative camber (as you've done) will increase toe-out.

Did you adjust both upper arms for camber?

The change in toe would be minimal but you'd want to verify it by taking it to a shop.

Edited by colourclassic

It will almost certainly affect toe, and using my logic: adding negative camber will increase toe-in, subtracting negative camber (as you've done) will increase toe-out.

Did you adjust both upper arms for camber?

The change in toe would be minimal but you'd want to verify it by taking it to a shop.

I would have said the exact opposite. Assumnig you do not change the lengths of the radius/traction arms, then shortening the upper arms (adding neg camber) will effectively push the front of the wheel outward. This is because the traction arm stops the front of the upright leaning inward with the rest of it as the neg camber is increased.

Logically, in order to increase neg camber without causing toe out, you would also need to have adjustable traction arms that you could shorten at the same time.

As to how much.....well, toe is measured in mm and camber in degrees, so it would be hard to come up with a relationship that made sense without going and measuring everything carefully. But I would estimate that because the traction arms are about 45° to the upper arm, then you'd get about 1/sqrt(2) change in toe angle with each change in camber angle. Or about 70% of the camber angle change might turn up as toe change. Might be a bit less, depends on how close to 45° that arm is, and also the influence of the tie rods/toe rods at the rear. What might actually happen is that the traction arm bushes end up soaking up a lot of the force and so you don't actually see so much angle change but you do increase the binding load in the traction arm bushes.

I would have said the exact opposite. Assumnig you do not change the lengths of the radius/traction arms, then shortening the upper arms (adding neg camber) will effectively push the front of the wheel outward. This is because the traction arm stops the front of the upright leaning inward with the rest of it as the neg camber is increased.

Logically, in order to increase neg camber without causing toe out, you would also need to have adjustable traction arms that you could shorten at the same time.

As to how much.....well, toe is measured in mm and camber in degrees, so it would be hard to come up with a relationship that made sense without going and measuring everything carefully. But I would estimate that because the traction arms are about 45° to the upper arm, then you'd get about 1/sqrt(2) change in toe angle with each change in camber angle. Or about 70% of the camber angle change might turn up as toe change. Might be a bit less, depends on how close to 45° that arm is, and also the influence of the tie rods/toe rods at the rear. What might actually happen is that the traction arm bushes end up soaking up a lot of the force and so you don't actually see so much angle change but you do increase the binding load in the traction arm bushes.

Good point, I was assuming you adjust the traction arm with the upper arm when adjusting camber to compensate for rake/caster changes? If that was the case then the HICAS linkages would dictate toe. If in fact you only adjust the upper arm, then your theory would be correct. Any suspension experts out there?

Edit: It looked like he does have adjustable traction arms, hence my logic stated above.

Edited by colourclassic

Yes, i thought as much re: toe being affected one way or the other..

Just wasnt sure.

It will almost certainly affect toe, and using my logic: adding negative camber will increase toe-in, subtracting negative camber (as you've done) will increase toe-out.

Did you adjust both upper arms for camber?

The change in toe would be minimal but you'd want to verify it by taking it to a shop.

Do you mean both sides (driver and passenger) equally? Yes.

I adjusted both sides to about 7-8mm below zero camber. (495mm / 8mm) x (INV)tan = 0.89 degrees.

Of course i did this at home, and didnt use precision measuring tools, but it looks good to me.

However, toe is much harder to measure and gestimate, so I should prob get this looked at anyway.

Do you mean both sides (driver and passenger) equally? Yes.

I adjusted both sides to about 7-8mm below zero camber. (495mm / 8mm) x (INV)tan = 0.89 degrees.

Of course i did this at home, and didnt use precision measuring tools, but it looks good to me.

However, toe is much harder to measure and gestimate, so I should prob get this looked at anyway.

No, I meant did you adjust both the 'camber' and radius/traction arms on both sides? It looks like both your upper arms are adjustable on each side. The Nissan multi-link is a pretty complex setup, and adjusting just one parameter changes the whole suspension dynamic; toe, caster, camber etc.

Edited by colourclassic

no thats not a photo of my car. Just showing which type of adjustable arms i was using.

i only have the one that bends around the coilover. as in the 2nd pic.

i dont think there is any adjustment in the other arm in stock form.

ive had my camber adjusted a while ago, and the guy had it spot on. but since then it's been lowered a little more and it was bugging me, hence the home adjustment.

no thats not a photo of my car. Just showing which type of adjustable arms i was using.

i only have the one that bends around the coilover. as in the 2nd pic.

i dont think there is any adjustment in the other arm in stock form.

ive had my camber adjusted a while ago, and the guy had it spot on. but since then it's been lowered a little more and it was bugging me, hence the home adjustment.

Ah! That explains it then. If you only have adjustable camber arms, and non adjustable traction arms, then GTSboy is right, your toe has increased inwards.

yeah but I'm pretty sure you can rectify that by adjusting the hicas (lock bar) rods.

also, i'm pretty sure i can feel more rolling resistance now. so thats what made me think maybe toe was not zero anymore.

  • 2 weeks later...

FYI for future searches.

I had the rear alignment done.

My calculations were a little out. I had -1 degree on the passenger side, -1.2 degree on the drivers side.

The toe had hardly been affected. Was sitting on zero. I suspect it was previously just under zero.

So i guess adding positive camber = increase in toe out??

Anyway, new rear alignment is -0.8 deg, 0 toe. I think that's reasonable for street driving.

Cheers for the help guys!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Look for broken wire or bad connector at the motor. Might not be it, but is worth starting there, as it is easy.
    • Hi everyone, I’m having an issue with my R32 GT-R. Sometimes, when the car goes over a bump or experiences some vibration, the 4WD warning light comes on the dashboard. When I check the code from the control unit in the trunk, it shows Code 19 – ETS Motor. However, everything seems to be working fine — if I turn off the engine and restart the car, the light goes away and everything functions normally. Has anyone experienced this before? Where should I start troubleshooting this issue? Thanks in advance!
    • I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
    • 310mm rotors will be avilable from Australia, Japan, and probably a few other places. Nothing for the front can be put on the back.
    • The filter only filters down to a specific size. Add to that, the filter is AFTER the pump. So it means everything starts breaking your pump even if its being filtered out.
×
×
  • Create New...