BP-51 Setup
Posted: Mon, 04 Dec 2023 8:13 +0000
Hey,
I have tried to search but I might be using wrong terminology to retrieve information...
I have fitted BP-51 kit to my 2022 hilux, originally they supplied me the incorrect rear leaf springs and swapped them to the EL105R which is the lowest spring rate they offer.
I've not driven the car yet, so it's just been moved around my yard and back onto the ramp, I've made sure to bounce the back and make sue the leaf springs are moving correctly. So it's defo settled as much as it's going to go. (I put some weight in the back also with the forklift to really compress it).
As I don't have any accessories on the front, I followed the instructions and used the +10mm preload setting on the front, I feel the front is still way too low. (or rear way too high)
Here is a picture of front to rear. (click on it to open it as front is cut off in my view).
Now I can add the +20mm preload to the front to lift it (So 10mm more then its currently), but measuring the stroke of the shock, its moving 15 mm down its stroke when the vehicle goes from full lifted to the weight fully on it, now this seems to me like that is already too close to topping out, and if I raise the preload by +10 from where it is now, its going to be 5mm down the shock travel (which is 100mm total). This seems like a really bad idea.
Not sure of the motion ratio on the front, but guessing it's about 0.5x, so 15mm at the shock is about 30mm at the wheel. (measured it to be closer to 27mm at a quick test).
I don't want the suspension to be constantly topping out as this will cause a horrible ride. (bearing in mind if your cornering at the vehicle is leaning a bit, you're going to be super close to topping out).
So the question is, if I trade say 10-20mm of preload for a spacer would this cause an issue for the CV's ? I.e I'm changing the droop of the suspension and the limiting factor.
Normally I want at least 1/3 to 2/3 of compression static on a shock, I appreciate that we are raising the truck so some compromise needs to be made, so if aiming for 1/3 of available travel, that would be around 33mm of travel, so in an ideal world, I would actually lower the preload around 18mm (giving 15mm I currently have plus 18mm gives me 33m of shock travel static), and add a 18mm spacer to get me back to where I currently am, then to give it some lift say add another 10mm, so 28mm spacer.
Now as its not possible to remove 18mm of proload as I only have 10mm added, If I set that back to the 0 position, this would give me travel of 15mm + 10mm extra, so would be 25mm of static compression. so to get back to the same height I would need to add a 10mm spacer minimum to top of the shock, again if I then what to raise it I would then need to add to that 10mm spacer. so again 25-30mm spacer.. but now at that height I'm no where near topping out... but cv's might suffer.
Hope that make sense, I know that will defo work, but your allowing a 30mm extended drop on the shock length.
had anyone run shock spacers with the BP-51's.
If not I will have to get some other leaf springs for the rear as it would be easier to just drop the back, for the lightest rear spring that ARB sell, and I have a large 33 Tyre (40Kg?) and rear summit bar, so another 50kg, so just about 90kg static on the rear.
Not that I think it will make any difference but I have ome uca.
If spacers are a no-go on the front, then rear leaf is going to have to be changed imho.
EDIT: To just clarify, I get full articulation on the front (well all the way to the bump stop anyways), I have modified the front to allow the wheel not to catch on anything so I don't need to raise the car to stop any rubbing, this is just to get the most out of the shocks and get a nice tune.
I have tried to search but I might be using wrong terminology to retrieve information...
I have fitted BP-51 kit to my 2022 hilux, originally they supplied me the incorrect rear leaf springs and swapped them to the EL105R which is the lowest spring rate they offer.
I've not driven the car yet, so it's just been moved around my yard and back onto the ramp, I've made sure to bounce the back and make sue the leaf springs are moving correctly. So it's defo settled as much as it's going to go. (I put some weight in the back also with the forklift to really compress it).
As I don't have any accessories on the front, I followed the instructions and used the +10mm preload setting on the front, I feel the front is still way too low. (or rear way too high)
Here is a picture of front to rear. (click on it to open it as front is cut off in my view).
Now I can add the +20mm preload to the front to lift it (So 10mm more then its currently), but measuring the stroke of the shock, its moving 15 mm down its stroke when the vehicle goes from full lifted to the weight fully on it, now this seems to me like that is already too close to topping out, and if I raise the preload by +10 from where it is now, its going to be 5mm down the shock travel (which is 100mm total). This seems like a really bad idea.
Not sure of the motion ratio on the front, but guessing it's about 0.5x, so 15mm at the shock is about 30mm at the wheel. (measured it to be closer to 27mm at a quick test).
I don't want the suspension to be constantly topping out as this will cause a horrible ride. (bearing in mind if your cornering at the vehicle is leaning a bit, you're going to be super close to topping out).
So the question is, if I trade say 10-20mm of preload for a spacer would this cause an issue for the CV's ? I.e I'm changing the droop of the suspension and the limiting factor.
Normally I want at least 1/3 to 2/3 of compression static on a shock, I appreciate that we are raising the truck so some compromise needs to be made, so if aiming for 1/3 of available travel, that would be around 33mm of travel, so in an ideal world, I would actually lower the preload around 18mm (giving 15mm I currently have plus 18mm gives me 33m of shock travel static), and add a 18mm spacer to get me back to where I currently am, then to give it some lift say add another 10mm, so 28mm spacer.
Now as its not possible to remove 18mm of proload as I only have 10mm added, If I set that back to the 0 position, this would give me travel of 15mm + 10mm extra, so would be 25mm of static compression. so to get back to the same height I would need to add a 10mm spacer minimum to top of the shock, again if I then what to raise it I would then need to add to that 10mm spacer. so again 25-30mm spacer.. but now at that height I'm no where near topping out... but cv's might suffer.
Hope that make sense, I know that will defo work, but your allowing a 30mm extended drop on the shock length.
had anyone run shock spacers with the BP-51's.
If not I will have to get some other leaf springs for the rear as it would be easier to just drop the back, for the lightest rear spring that ARB sell, and I have a large 33 Tyre (40Kg?) and rear summit bar, so another 50kg, so just about 90kg static on the rear.
Not that I think it will make any difference but I have ome uca.
If spacers are a no-go on the front, then rear leaf is going to have to be changed imho.
EDIT: To just clarify, I get full articulation on the front (well all the way to the bump stop anyways), I have modified the front to allow the wheel not to catch on anything so I don't need to raise the car to stop any rubbing, this is just to get the most out of the shocks and get a nice tune.