What do you have your OME BP-51s set at?

I have a set of BP-51s on order and I am wanting to make sure I get my pre-load set right prior to install. I called ARB, and they said that out of the box they are set to 20 mm of pre-load (I am assuming that is exposed thread above adjuster ring). That setting is supposed to be for trucks with a steel bumper, winch and armor. ARB said that for stock trucks, they recommended 10mm of pre-load. For my truck, with an aluminum plate bumper and steel IFS skid, he would recommend between 10 and 12mm of preload.

I have seen a number of threads where guys have mentioned getting 3-4" of lift, and wanted to start a thread where people could report how their truck was outfitted (bumpers, winches, armor, etc) and what kind of lift they got with a specific pre-load setting.

Personally I want to use these as intended, for about 2-2.5" of lift. I am going to be using stock UCAs and don't want to have to mess with the clam shell bearing. I will report what I get once I have the shocks installed which will be about 10 days out.

 

@IronPeak4x4

 

I didn't change the preload before installation, with the Dakars in the rear I am at level/slight rake. I have no armor up front except for an aluminum ifs skid.

 

@Camel51 @Pyrite Mica

You guys mind telling us what sort of pre-load and set up you're running and how much lift it's netted you?

 

Factory setting for mine. I plan on adding a hidden winch mount, winch, and bed rack with some tools and a tent. So things may change

 

Thanks! That looks like a solid 3" or so over stock, but the tires could be throwing my eye off, and I am not sure I am well calibrated for what the 3rd gen looks like.

 

I've never taken any measurements but I saw a second gen tacoma today with the bp51 kit and same size tires as mine and I feel like mine is taller. I haven't even put 300 miles on it yet, so maybe it'll settle?? Who knows. But after I do a cmc I'm going to bump up to a 34" tire. Currently running 285 75 16s and I can fit a larger tire if I do some cutting

 

Dude, your truck looks so awesome.

 

Add a couple photos for ya

 

Nice, this winter has definitely served up plenty of snow for playing around in.

 

Truck looks huge.

 

Factory preset, which I understand is set up for the ARB bumper and winch.
Rear Springs are the Dakars that came with the set. OEM bumper upfront but dual Odyssey batteries, ARB twin compressor, and a couple extra pounds under the hood. Full aluminum skids (90lbs). Custom bed rack and swing out with spare tire and MFC (estimated at about 200lbs). I would say I had a full three inches over stock with maybe 1/4 inch settleling at most.

 

sub

 

So this is a little off topic, but one of the things you can think about when setting preload is what that "600 lb" spring really represents. What it means is that the spring will compress an inch for every 600 lbs of load it carries. So when you are thinking about adding (or subtracting) weight over that spring, the amount of pre-load you need to add or subtract can be pretty easily calculated.

In the case of the OME springs on the front coil overs, I was told by ARB that the springs are 600 lb per inch. So for example, if you have a stock truck and you want to add a 175lb plate bumper, a 50 lb winch, and 75 lbs of armor, you're adding a total of 300 lbs. Since the springs are 600 lb/in, you can calculate how much preload to add using this formula.

Preload Formula:

Preload (in inches) = (Weight Change (lbs) / Spring Rate (in lb per inch) )

Using our example from above:

Preload (in inches) = 300 lbs added / 600 lb per inch spring rate

= 0.5 inches of added preload to maintain ride height

In the case of our example, you would need to add a 1/2 inch or 12.7mm of preload to maintain your right height prior to adding the weight.

You also want to bear in mind that not all of the weight added to the front of the truck is supported strictly by the front end, some weight is distributed to the back. So it probably makes sense to hedge just a little on the amount of preload, but not much. You also want to think about the offset of the weight of any parts you are removing in the process or adding a new bumper, skids etc. Hopes this helps when anyone is getting ready to make changes.

 

Set at factory preload, turned compression down to 2nd bar. It was pretty stiff the first day. After comp adjust and settling it's a lot nicer. With initial install I was at 4" of lift in the front. It has settled to 3-1/4. Its a solid 3" in the rear with the Dakars. I will be welding on my sliders today, see what that does to the ride.

 

Finally got my BP-51s in. I took the fronts down to a local spring shop to have them adjust the preload to 12mm before I mounted them up. They ended up having a hell of a time getting the preload ring to turn, even with all of the spring pressure off it and the set screw removed. It ended up taking two guys holding the coilover and another guy on a modified ring turning tool to get the preload ring to turn. It did begin to get easier after we got 2-3 turns in, but it was still something I would not have wanted to deal with at home. In the end, I think that it was a combination of the rings having no lubrication when installed at the factory, the spring rubbing against the shock body because of the way it has been compressed that caused the difficulty.

If I could make a recommendation to ARB, I would tell them to lube that preload ring at the factory, and to beef up those threads so this adjustment can be done on the vehicle. I did call the ARB Tech Support line while we were having problems, and they did have one good suggestion, which was to make sure we were grasping the adjuster ring in such a way that we weren't pulling the gap in the ring closed (tightening the ring on the body). And they said if I couldn't get it sorted out, they would replace the coilovers, so it was a good customer service experience.

 

Now on to the mounting details. I found the rears were quite a bit stiffer than the stock shocks, and required a jack to compress the shock enough to get it into the lower mount in the rear. The front's were pretty easy in comparison to the rears (which is counter intuitive). The only issue in the front was a spinning ball joint on the tie rod end, but a little tension with a pry bar and I was able to get it tightened back up.

The Baja Bilstein 5160 next to the BP-51. The body of the BP-51 significantly larger.



The 9100s from the front the Baja are a little closer in size.


After getting the fronts installed, I had no problems getting the rubber flap back over the reservoir body. I don't know if this will cause any issues with engine heat, but I'll be keeping an eye on it.


So in the end with 12mm (1/2") of preload in the front, a 65 lb aluminum plate bumper and steel IFS skid (for a net about 80-100 additional pounds up front over stock), and the Wheelers 8 leaf progressive spring pack in the rear unloaded. I ended up with a hub to fender height of 24 3/8" all the way around. Based on the numbers for a stock Off-Road, this sounds like about 2" of lift. I am still playing with the compression and rebound settings.

Stock Baja front shocks and springs, Wheelers rear springs and stock Baja shocks:


OME BP-51 front and rear, 12mm of preload on front, Wheeler's 8 Leaf progress springs on rear:

 

Mine is configured this way too. I would be hard pressed to think this should cause any issue. Six months on mine now.

 

Truck looks fantastic.

 

Thanks, it'll look even better with the 285 Duratracs back on it in the spring.