BP-51

Old Man Emu BP-51 Coilover & Shocks Review - Toyota Tacoma

Posted by Sean Reyes on

Clear Winner

After debating between the Fox 2.5 DSC, King 2.5, Bilstein 6112, and BIlstein 8100, we settled on the Old Man Emu BP-51 Internal Bypass setup, featuring compression and rebound settings for the front and rear, mixed with their internal bypass technology. This is a ‘first’ in the light truck and Jeep market, no manufacturer has combined all these features into a single setup. Through the ingenuity at ARB and OME, they were able to provide a decent sized internal 51mm piston, internal bypass for optimal ride comfort in the easy stuff, while allowing fine tune adjustments to vehicle control through compression and rebound damping adjustment. Bilstein’s 8100 external bypass series are close to these features, and even excel at certain aspects, but they do not feature adjustability or bypass for the front coilover setups on the Toyotas.

BP-51 Internal Bypass - While most shock absorbers only generate damping based on fluid flowing through the piston, the BP-51 offers an alternative path from one chamber to the other, around the piston in the form of bypass passages. Some fluid flows through the piston and some fluid bypasses around the piston in the bypass passages. This results in an ability for the shock absorber to provide the best of both worlds, with a comfortable and compliant ride during normal driving and a more controlled ride over more challenging terrain.

While the feature list is mouthful, all those specs and options play a significant part in ride control dynamics and vehicle behavior, IF that’s something you’re after! Most of what we’re going to get into here is nit-picking and shock nerd-talk. But straight off the bat, these are some of the most comfortable shocks we’ve equipped on the Tacoma.

Highway Comfort & Control

A lot of our customers are looking for a smooth buttery ride, but often dont understand that there are tradeoffs there. The BP-51 shocks can be setup for that creamy soft feel on the highway, but that can also result in poor handling where the vehicle can easily be destabilized. There’s a fine balance you can achieve to mix the comfortable ride with good handling, our trucks with lots of gear, dont like too soft of a setup.

A poor combination of low compression and high rebound settings can result in dramatic changes in vehicle control if you don't know what to watch out for.

I attribute the soft and compliant road ride to the internal bypass feature, absorbing all the regular small abnormalities of the pavement without much feedback to the driver, while providing adequate handling through turns, driveways, and maneuvers. The changing of the compression settings will make noticeable differences to how the vehicle will handle, so its up to you the driver on what you want that to be.

Off-Road Performance

One of the baselines I was looking to achieve with the BP-51 shocks was how the ICON setup handled medium-high speed desert terrain, which could be categorized as non-aggressive, predictable, visible, and in the range of 30-50mph. It took setting the (front) compression levels in the medium-high (6-7) range, with the Rebound in the medium (5-6) range, in order to allow the front suspension to work well enough to take the unexpected big changes in terrain, while not being uncomfortable. The rear required near-maxxed out compression levels, with a medium-high rebound setting in order for the shocks not to top and bottom out on the same terrain.

Having to play with the settings in order to dial in this behavior, made me appreciate the ICON setup in high speed environments. The ICON with CDCV adjustment wasn’t able to go as soft as the BP-51 on the same vehicle, so there’s a big advantage there with Old Man Emu shock offering.

BP-51 Advantages

Where I think the BP-51 setup excels at is the slower trail terrain, where there are a lot of rocks, and varying obstacles, and speeds usually not exceeding 20-30mph - either due to unpredictable terrain and/or visibility. The most underappreciated feature is the internal bypass which arguably contributes the most to every day road comfort, since that piston is able to essentially float in the middle ride zones without harsh feedback.

Comfort definitely improved on the slower mountainous trails and terrain, and with the correct combination of compression/rebound settings you can get that ‘plush’ feeling on obstacles that usually only occurs accidentally. Adjustment settings will vary drastically between vehicles and loadouts, the settings for my Tacoma carrying aftermarket front and rear bumpers, camper shell, roofracks, rooftop tents, and 600lbs of gear require specific parameters if I’m being picky.

Washboard handling and comfort drastically improved, one of the worst behaviors of most vehicles tend to be the rear end sliding or swerving while turning in washboard terrain. WIth the wheels oscillating at such a rapid rate, its hard for normal dampers to maintain good contact, but proper rebound setting adjustments can really improve this behavior for your vehicle. The rebound adjustment makes a huge difference in washboard comfort.

Another big improvement is body roll on hard obstacles or big rocks. While most vehicles that equip these shocks wouldn’t be classified as rock crawlers, there’s almost certainly going to be times in your adventure where there is a rock garden that needs to be navigated. With a loaded vehicle increasing body roll dramatically, the suspension damping can be the difference between scrapes and crunches or escaping unscathed. The Icon setup was regularly pretty harsh in the slower stuff, while so far the BP-51 are much more forgiving without also resulting in too much body roll.

Once again, all of these adjustments really only matter if you’re a stickler for ride quality while off-road for days at a time, that’s where these shocks excel at. Are these the best shocks we’ve ever ran? I think so. Are they the best shocks for everyone? Certainly not - and we continue to express that not all drivers are alike nor are all ride control needs.

If you’re reading this and interested to hear more about how you can utilize the settings and features of the BP-51 shocks for your vehicle, we’d love to help and guide that decision.

Compression Damping Troubleshooting

Symptom Remedy
Bottoms out easily on large bumps Increase compression damping
Suspension feels harsh and does not soak up small bumps Decrease compression damping
Shock Absorber rarely bottoms out, even off big drop offs Decrease compression damping
Shock Absorber is not using all of its available travel Decrease compression damping

Rebound Damping Troubleshooting

Symptom Remedy
Vehicle bounces and carries on repeatedly after larger bumps Increase rebound damping
Suspension tops out too hard Increase rebound damping
Wheels lose traction on gravel corners with corrugated surfaces (washboard) Decrease rebound damping
Suspension feels harsh Decrease rebound damping
Packing in repetitive bumps Decrease rebound damping
Loss of traction when braking or accelerating on corrugations (washboard) Decrease rebound damping


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