Jump to content
SAU Community

Stuffed (new) Front Bushes

djr81
 Share

Recommended Posts

Beer Baron Grand Master

Beer Baron

Posted
Posted

yeah you can cut a standard upper arm in half and shorten it. but you would need some good measuring skills, and some good cutting, and some good welding, otherwise it's prone to go bad. but i guess if you did the cut and shut job and used the offset bushes then you could dial out whatever error you had in manufacture.

djr81 Grand Master

djr81

Posted
  • Author
Posted
yeah you can cut a standard upper arm in half and shorten it. but you would need some good measuring skills, and some good cutting, and some good welding, otherwise it's prone to go bad. but i guess if you did the cut and shut job and used the offset bushes then you could dial out whatever error you had in manufacture.

First up - thanks to all for their input - this has turned out to be a rather illuminating thread - somewhat better than the usual "which BOV is the sickest sounding" :)

It is not just the length of the arm that the accuracy of manufacture is important for. You need the two bush housings to be parallel & also there is an offset built into the upper arm that makes the outside of the arm forward of the rear of the arm - so that needs to be accurate as well.

A few other things (Mostly my opinion about stuff):

1. The Whiteline caster kit gives you compliance but not adjustability. This is why I am running a rod. Maybe if I could weld a thread up to the fat arsed offset bush & link it to the turnbuckle on the caster rod...

2. Early R32 GT-R's run very little caster & the different models carry different amounts (more on the later ones). Also GTS-T's are different to GT-R's, so please be careful when talking caster as it is model specific. The whiteline track setting for caster on an R32 R is only about 2 degrees (from memory).

3. Bump compliance should be about maintaining tyre adhesion, rather than avoiding suspension geometry issues. Unfortunately, in this case the caster needs to be reduced to prevent the top bush from shitting itself. Probably less of an issue with Whiteline rods as they have more compliance. My ride height of 350mm front should be enough to not to have to worry about it.

4. For my ten cents worth using upper arms with a sliding, bolted interface is a recipe for pain & suffering. I would hate to think what would have happened in my case if I had have been using such things. :rofl:

5. The combination of a big yump (bump that goes down) in the right hand corner of one of the local tracks will pretty much always put the front suspension on the bump stop. Combined with a reasonable amount of lock & you have a heavily loaded suspension. So it would pay people to have a think about their local track & decide if their circumstance is similar. Less caster or a compliance bush instead of a rose joint may be needed...

Beer Baron Grand Master

Beer Baron

Posted
Posted

all i know is i love caster... haha

i may try one of the dog bone looking upper arms around. apparantly they can twist in the middle so that takes away a little of the load being applied buy the shorter caster rods.

djr81 Grand Master

djr81

Posted
  • Author
Posted
all i know is i love caster... haha

i may try one of the dog bone looking upper arms around. apparantly they can twist in the middle so that takes away a little of the load being applied buy the shorter caster rods.

The other thing to be a little careful is with too much caster the front of the tyre can (& will) rub on the guard liner. Not earth shattering, but just something to be aware of.

With more caster the inclination (kpi???) of the upright changes, ie the bottom moves forward. With more negative camber the top outer link effectively moves forward thereby partly cancelling each other out. So you get a longer wheelbase for your money. Mmmm, LWB GT-R, just like a Fairlane, really. :D

Beer Baron Grand Master

Beer Baron

Posted
Posted

yes, my front tyre is very close to guard liner now running 245/45/17 semis. actually it may be 245/40 cant remember. so cant really run much more caster.

yeah LWB GTR sounds like a go... haha.

whitesky Contributor

whitesky

Posted
Posted

Hey DJr81,

nasty job on those bushes. I've been reading a few posts tonight and came across you a few times, we all seem to be attempting to dial out the understeer on our 32 GTR's.

I'm running these midori style upper arms now on mine, but havent been able to get the full amount of neg i wanted ( only 3 deg neg full wound in). It all helps but i was hoping for more adjustability.

post-23000-1147871142.jpg

Saw you at Barbagellos at xmas sprint ( i was still running road tires as only just got the thing licensed week before) hence my 1.03 eek.

Sydneykid Grand Master

Sydneykid

Posted
Posted

Most of the “retail” camber kits are designed to REMOVE the negative camber that occurs when Skylines are lowered. This is because the “road car market” is far larger than the “race car market” and they are looking at excessive inside tyre wear as the major problem that they need to overcome by adjusting the camber.

Keeping that in mind, the standard R32 style upper control arm is around 190 mm long, centre of the outer bolt to the centre of the inner bolt. Using the off the shelf adjustable, offset, outer bush (Whiteline etc) reduces that to 184 mm. This gives around 2 to 2.5 degrees of negative camber on an R32 with a ride height around 355 mm centre of wheel to guard with around 6.5 degrees of caster on a 2wd and 4.5 degrees on a 4wd.

That is usually enough camber/caster, provided sufficient anti roll is used (larger stabiliser bars), for most circuits. High speed circuits with long sweeping radius curves (eg; Philip Island) need slightly more camber.

So we use the off the shelf adjustable, offset bush (Whiteline etc) in the inner of the upper control arm. That reduces the length to around 180 mm. This gives around 3.0 to 3.5 degrees of negative camber on an R32 with a ride height around 355 mm centre of wheel to guard with around 6.5 degrees of caster on a 2wd and 4.5 degrees on a 4wd.

This 180 mm length seems to have been the minimum that ALL of the R32 camber adjusters have been made to. All of the brands of upper control arms that I have measured (Midori, Noltec, Nismo, Ikeya etc) all stop at 180 mm or longer. So choosing one brand over another to get more negative camber is pretty much a waste of time.

Enough of the theory, let’s get onto the practical stuff……………….

I do a lot of suspension set up clinics and when I hear guys say that they need/run more than 3.5 degrees of negative camber and 6.5 degrees of caster, 99% of the time they have insufficient anti roll. If you don’t have a 30 mm adjustable, solid, front stabiliser bar for 2wd or a 24 mm adjustable, solid, front stabiliser bar for 4wd then the front anti roll is insufficient. If you don’t have a 24 mm adjustable, solid, rear stabiliser bar for both 2wd and 4wd then the rear anti roll is also insufficient.

That’s where I always start, rather than trying for more negative camber which is simply a band aid for the real problem of too much roll.

:thumbsup: cheers :)

djr81 Grand Master

djr81

Posted
  • Author
Posted
Beer Baron, i got mine from Ken at Hyperdrive here in WA. But you can also buy them from UAS.

They are on their website for $495 under product cat, GTR http://sard.com.au/

Hope this helps.

Hey Whitesky - I have a question about those upper arms. Do they allow the inner link to rotate about the lateral (ie left/right) axis? The reason I asked is that if they do they may go some way to reducing the load imposed on the back end of the upper, outer bush that occurs when you wind in caster. Will have to hurt my brain and figure out if that is actually possible...

Didn't see you at the twilight (January) SES round what happened?

By the way don't, under any circumstances listen to Ken's set up advice. I'd hate for you to suffer the burden of going faster than me. :thumbsup:

Beer Baron Grand Master

Beer Baron

Posted
Posted
Hey Whitesky - I have a question about those upper arms. Do they allow the inner link to rotate about the lateral (ie left/right) axis? The reason I asked is that if they do they may go some way to reducing the load imposed on the back end of the upper, outer bush that occurs when you wind in caster. Will have to hurt my brain and figure out if that is actually possible...

the ones i looked at do allow that. that's what i was talking about earlier in the thread. :unsure:

whitesky Contributor

whitesky

Posted
Posted

yes they do allow rotation, they are solid mounted with bearings in each end.

you can adjust them on the car, although thats a bit of a waste of time, as most peeps just max them out and leave them there.

Yes dude, they are on the car, also have bilsteins, Re55's now too. Bigger front bar next and i think its all starting to get there.

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • 04-LOOX
      R34 GTR Vspec Garage Sale - All must go!

      By 04-LOOX · Posted

      Hi, is the HKS  Tower Bar still available ? negotiable ? 🤔
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Duncan
      Duncan's V37.......race car?

      By Duncan · Posted

      Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
×
×
  • Create New...