cletus Posted October 13, 2022 Share Posted October 13, 2022 Yeah that would be fine. 1 Quote Link to comment Share on other sites More sharing options...
Stu Posted October 13, 2022 Share Posted October 13, 2022 Thanks mate! Quote Link to comment Share on other sites More sharing options...
chasinthemirage Posted October 17, 2022 Share Posted October 17, 2022 Okay another suspension question for @cletus. Is there a minimum amount of arch required for a leaf spring? I've measured the Fairmont, if I lower it 40mm it'll even up the guard gap, leave the structure of the vehicle about 110mm from the ground and should give about 50mm between the unmodified bump stops and the diff. I'll get an extra over load leaf fitted but the springs will be fairly flat, I'm hoping fitting an extra leaf will mitigate this. Am I likely to run into any other issues? Couldn't see anything in the Virm. Quote Link to comment Share on other sites More sharing options...
RXFORD Posted October 17, 2022 Share Posted October 17, 2022 3 hours ago, chasinthemirage said: Okay another suspension question for @cletus. Is there a minimum amount of arch required for a leaf spring? I've measured the Fairmont, if I lower it 40mm it'll even up the guard gap, leave the structure of the vehicle about 110mm from the ground and should give about 50mm between the unmodified bump stops and the diff. I'll get an extra over load leaf fitted but the springs will be fairly flat, I'm hoping fitting an extra leaf will mitigate this. Am I likely to run into any other issues? Couldn't see anything in the Virm. Seems to depend on the cert mans opinion of how it rides. The packs on my B2000 are flat or maybe even slightly inverted at ride height but it rides ok. I have always worked to max allowable is flat at ride height without it being too bouncy, but if I can keep some arch it would be less likely to be denied/questioned by Lvvta. 1 Quote Link to comment Share on other sites More sharing options...
igor Posted October 17, 2022 Share Posted October 17, 2022 Front leaves on my old work Hilux were curved the wrong way but it always got wofs. Perhaps it shouldn't have? Quote Link to comment Share on other sites More sharing options...
cletus Posted October 17, 2022 Share Posted October 17, 2022 15 hours ago, chasinthemirage said: Okay another suspension question for @cletus. Is there a minimum amount of arch required for a leaf spring? I've measured the Fairmont, if I lower it 40mm it'll even up the guard gap, leave the structure of the vehicle about 110mm from the ground and should give about 50mm between the unmodified bump stops and the diff. I'll get an extra over load leaf fitted but the springs will be fairly flat, I'm hoping fitting an extra leaf will mitigate this. Am I likely to run into any other issues? Couldn't see anything in the Virm. There isn't a spec for how much arc a leaf spring has to have, it would be up to the certifier to assess it. I have certed a few that have been flat or slightly the wrong way. An old bloke who was clever with suspension once told me his theory that a reverse arch spring is not ideal because the spring and shackle start trying to do opposite things- ie a normal arch spring gets longer which pushes the shackle away and up A reverse arch spring gets shorter so pulls the shackle towards the spring and the shackle is then straightening up Some points = getting leafs reset, technically, requires certification. A complete aftermarket new leaf pack would not necessarily need cert. However its one of those things where if it wasn't too extreme you would likely get away with it Another thing that can help is getting the spring guy to reverse the spring eyes which keeps the leaf pack flatter while lowering the car As well as the bumpstops, check the pinion snubber clearance, there's usually less clearance there than the bump stops 1 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted October 17, 2022 Share Posted October 17, 2022 7 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted October 17, 2022 Share Posted October 17, 2022 Whether the reverse arch vs spring shackle thing actually makes a difference to how a vehicle handles, I don't really know , usually something with a big reverse arch drives like shit for other reasons haha 2 1 Quote Link to comment Share on other sites More sharing options...
tortron Posted October 17, 2022 Share Posted October 17, 2022 Was gona ask a question but I found the answer https://vehicleinspection.nzta.govt.nz/virms/entry-certification/reference-materials/eg-structural-damage-corrosion/under-body-damage-crushing-of-floor-pan-stiffening-members Wow, a little forklift damage doesn't seem so bad 3 1 Quote Link to comment Share on other sites More sharing options...
Nominal Posted October 17, 2022 Share Posted October 17, 2022 Watch out for this bit though Quote Link to comment Share on other sites More sharing options...
tortron Posted October 17, 2022 Share Posted October 17, 2022 So if it runs between/under the seat rails it's not energy absorbing? Like all of those show fuel lines, so must be front to back, The seat rails take up 95% of the width of the car, so it would have to be hard against the sill, or in the tunnel to be considered a rail Quote Link to comment Share on other sites More sharing options...
RXFORD Posted October 18, 2022 Share Posted October 18, 2022 4 hours ago, cletus said: Oh wow, you have used the whiteboard for drawing something other than dicks. 2 2 Quote Link to comment Share on other sites More sharing options...
GARDRB Posted October 18, 2022 Share Posted October 18, 2022 5 hours ago, cletus said: A possible drawback of that would be reversing the bumpsteer in the rear wouldn't it? So instead of the spring getting longer and moving the wheel back under compression the spring would get shorter and pull the wheel forward? I'm not sure how much toe this would introduce and the other side would obviously move with that wheel, and I'm probably overthinking it? 1 Quote Link to comment Share on other sites More sharing options...
tortron Posted October 18, 2022 Share Posted October 18, 2022 Horse and cart rear end probably wouldn't notice 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted October 18, 2022 Share Posted October 18, 2022 1 hour ago, GARDRB said: A possible drawback of that would be reversing the bumpsteer in the rear wouldn't it? So instead of the spring getting longer and moving the wheel back under compression the spring would get shorter and pull the wheel forward? I'm not sure how much toe this would introduce and the other side would obviously move with that wheel, and I'm probably overthinking it? You are right though. Lifted 4wds suffer from this when the arms get on crazy angles, same theory, they end up driving a bit like a backwards skateboard haha I think that's why there's a few videos around of lifted safaris and patrols lifting the left front tyre off the ground . It's not the unbridled horsepower of a TD42 doing that, it's body roll and shit geometry. it's good to think like that as you can consider the effects of doing things instead of just doing the things and wondering why you ended up in a ditch 4 Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted October 18, 2022 Share Posted October 18, 2022 Always get the eyes reversed. 1 Quote Link to comment Share on other sites More sharing options...
chasinthemirage Posted October 18, 2022 Share Posted October 18, 2022 Thanks @cletus! I do remember being told about the shackles once upon a time. I'll have a decent look at it and have a chat to the spring makers. Ideally I'd like to only do stuff that can be reversed, if I'm going to cert it then I'd be tempted to bag it but thats a whole other can of worms that I'm not clued up on. 1 Quote Link to comment Share on other sites More sharing options...
Bling Posted October 19, 2022 Share Posted October 19, 2022 Don't open that can of worms. Are you leaving the blocks in with this setup or removing them and having the pack made to suit? 1 Quote Link to comment Share on other sites More sharing options...
chasinthemirage Posted October 19, 2022 Share Posted October 19, 2022 13 hours ago, Bling said: Don't open that can of worms. Are you leaving the blocks in with this setup or removing them and having the pack made to suit? I'm going to leave the blocks in so that I can easily raise it again if I need to without having to do anything to the spring pack. That's the plan at this stage anyway. 1 Quote Link to comment Share on other sites More sharing options...
Mof Posted October 19, 2022 Share Posted October 19, 2022 @chasinthemirage get Bellamy and east to make up two main leafs with the same arch but the eyes the other way. Then swap that onto your spring pack. 2 Quote Link to comment Share on other sites More sharing options...
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