BD Diesel Performance’s Throttle Sensitivity Booster is a popular, easy to install, plug-and-play product. For folks that like to hot rod around, or do a little racing, it’s easy to understand why a Throttle Sensitivity Booster, or TSB, would be a popular item, but this product’s appeal dives deeper. Few complain about a lack of torque or power from modern turbo-diesels, although not all would judge them responsive.
Many late model Ram owners complain about accelerator pedal lag, a dead pedal. So it’s not surprising that increasing the fuel delivery for a given amount of pedal travel could eliminate a drivability complaint while simultaneously adding a perceived performance enhancement. With an automatic transmission’s fluid-coupling, there is less concern about shock-load, jumpiness, or other potentially negative drivability behaviors emanating from increasing the sensitivity. However, on manual transmission trucks, might boosting the accelerator impact driver finesse and vehicle sympathy?
Skeptic Turned Into A Fan?
Do I want a more sensitive accelerator? My answer had been no. As I have shared in past columns, my additional pedal return springs and take-up slack spacer do much to improve the feel, feedback, and drivability of my rigs. I am extremely satisfied with these home brew modifications. So what spurred me to try the second version of BD’s TSB?
Heavy return springs and spacer add greatly to overall control and feel.
An acquaintance with a 2014 crew cab 3500 with automatic transmission let me drive his Ram, to judge what the 3500 leaf springs feel like unloaded. (I don’t know what some are complaining about, must be car people, it wasn’t too stiff or firm with appropriate tire pressure.) His truck had been deleted before he purchased it used, sported a mild fueling tune, and a BD Throttle Sensitivity Booster. His rig really scooted with little pressure on the go-pedal.
Some of that energetic behavior was from the automatic transmission, which goes and never stops until you release the skinny pedal. There is no loss of momentum during upshifts like occur with a manual, combined with a higher-rated A/T engine and the performance tune. Though it was also clear that the 3500 was really moving with a small dip into the accelerator. This experience made me rethink trying a BD TSB on one of my outfits.
Slow To Start And Occasionally A Jerk
My Fourth Generation 2500 G56 Rams have been great, complaints have been few, but there has been a minor irritation: a light throttle surging or hesitation. This behavior is not uncommon on modern drive-by-wire vehicles (cars, trucks, and motorcycles), particularly if fuel metering is held at the exact spot between some, and none. However, the hesitation my 2500s exhibited didn’t occur only at that sour spot, rather a little deeper into the pedal. Fuel delivery would sometimes pulse with a steady but small accelerator application of approximately 10–20% of total travel. It was also slow to respond to input changes.
The choppiness could be reduced or eliminated with a deeper, more aggressive pedal application, but that is not always desirable or safe. More precise and consistent response from all inputs is better for optimal control, smoothness, and fuel economy.
After some online research I called BD to confirm what I’d read. The second version of the BD TSB has three different positions: stock, 50% increase, and 100% increase. The control module must be opened to select the different sensitivities, and the boxes are typically under or behind the dash.
If the optional button kit is ordered, you get three additional choices: a valet mode that reduces pedal sensitivity substantially, a 75% setting, and a “ludicrous” mode, all of which are easily selected with the press of a dash-mounted button. Ludicrous held no appeal, but I was interested in having the 75% setting, plus the easy ability to revert to stock for bumpy off-road situations. With the exception of the ludicrous position, the BD TSB remains in its current mode after an engine shut-down and restart.
Initial setup involves the using stock position, pressing the pedal learn button, then cycling the accelerator a few times.
The optional Button Kit includes a button, mounting plate, and mini harness that goes from the button to the main TSB harness.
Geno’s Garage sold the BD TSB Version 2 for $285, and the optional Push Button Kit was $65. The just introduced TS Booster V3 is even less; $265 at Geno’s for 2007–2020 Rams.
In 2019, BD received California Air Resources Board (CARB) Executive Order (EO) approval for their TSB for 2005–2018 heavy-duty Ford diesel applications, and was working on approval for the Dodge/Ram and GM products. That is a big deal!
Install Notes And Tips
According to BD Diesel, if one is going to run their TSB in conjunction with the BD High Idle Kit (which I have on my 2014 crew cab) one needs to put the Sensitivity Booster on the pedal side, and the High Idle on the truck side of the wiring chain. That’s because if the signal coming out of the High Idle Kit is sent through the TSB first, before going to the ECM, the High Idle module will have a harder time controlling the rpm (just like a person might with a more sensitive accelerator pedal). However, stacking them the other way around, letting the High Idle Kit communicate directly with the ECM, does not adversely affect operation of either accessory.
Initial test in my 2014, before mounting the module or button.
The installation is a very simple. If one chooses the optional Button Kit, it must be connected to the main TSB wiring harness. The short and adequate instructions tell how, and my closeup images show some details. After following a brief pedal-learning procedure, one simply needs to mount the control box and button where desired and continue motoring.
To add the Button Kit, first remove the blue plugs on the TSB main harness.
Instructions tell which color wire goes into each numbered port.
This orange plastic block is removed from the front of the main harness connector before inserting the Button Kit wires.
Each wire in the correct position, before fully inserted and clicked into place, and replacing the orange block.
Does the lowest, 50% sensitivity increase make the truck feel like it has more power? Absolutely! The perception is that the truck has a higher-power rating, like the maximum fuel delivery has been increased though it has not. Nothing mechanical has changed, the driver is simply getting more juice from the same squeeze. There’s no need to push the skinny pedal unnaturally deep to get moderate or brisk acceleration. If you want more than the 50% setting offers, the optional button puts 75% and 100% at your fingertips. The difference between each position is dramatic. To experience this, one can keep constant pressure on the pedal while toggling from stock up through the higher sensitivity levels; it will make the truck accelerate quicker.
Button was mounted on the bottom right of dash, using and existing screw. Easy to reach but also out of the way.
With the key on, BD becomes red. In this image the top center light is also on, indicating the 75% setting.
With the lively 50% boost, smooth and precise application of fuel is not difficult. Even the 75% position is fun and controllable with a manual transmission, though my extra return springs and much firmer pedal are surely helping. I’ve mostly preferred 50% when routinely rowing through the gears. The aforementioned light pedal stutter/hesitation is all but gone.
Initially I connected the BD TSB to Clessie the Carryall Crew Cab. After a few days of testing, I moved it to the Pack Mule regular cab camper outfit. I liked it on both, maybe a bit more in the ‘Mule because of the full-time GVWR load. It really helps the truck accelerate as if it has more toque and power. After the first weeklong road, hunting and camping trip to Eastern Nevada, I knew the BD Throttle Sensitivity Booster was a winner; I ordered a second for Clessie the Carryall. That was several months ago, and I’m still pleased with the modification on both Rams.
The custom auxiliary fuel tank project for our 2017 Ram/Cummins 2500 is underway! June 2019 I added two additional aluminum toolboxes aft-axle on my Hallmark Nevada Hillsboro flatbed camper outfit. My idea was to eventually remove one of the large, 30-inch-long front boxes and replace it with a fuel tank, preferably a commercially available aluminum saddle tank for a medium-duty truck.
The tank project was moved to the back burner and a year passed quickly. For a while I considered a much smaller 10 or 12-gallon tank, hoping to fit one under the chassis between the frame rails, and in front of the spare tire. Just 100 miles of additional range would be a game changer during long highway trips.
Evan a commercially available tank would have required custom mounts and modifications, and surely some compromises. After discussing the project with Chris at High Sierra Fabrication several weeks ago, we decided on a custom tank for my original under-bed location. The goal was to fabricate a tank that looks extremely similar to the toolbox that was removed, and the matching 30-inch box still on the passenger-side.
Custom costs more, takes time, and is never snag-free, but if you have the right business and people involved, the results can be fantastic.
A beautiful tank was constructed using 3/16-inch diamond plate aluminum. Then High Sierra Fabrication proceeded to drill and cut holes in the box, weld-in fittings, a sump, and clean-out port, etc. We are getting close, but still working on it.
After High Sierra Fabrication completes most of installation, I will still need to plumb and wire the external pump to transfer the auxiliary fuel into the 2017 Ram’s factory tank.
Cooper STT PRO 295/65R20 (35.4″), ready to winch under a 2017, fourth generation Ram/Cummins 2500.
Question: How much spare tire can you fit under your truck?
Answer: It depends.
This post is about squeezing a large (35.4-inches) tire into the stock location on a late-model, fourth-generation, Dodge Ram Cummins pickup.
Both my Ram 2500 trucks (2014 and 2017) have had the tailpipe heat shield removed to facilitate winching a much larger tire into the factory spot. Obviously a bigger tire sits closer to the tailpipe. Only you can decide if it’s too close for you and your application. This Cooper Tires STT PRO is only about one-inch from the tailpipe; close!
35.4″ Cooper STT PRO spare is close the factory tailpipe on this 2017 Ram/Cummins.
For several years I have carried oversized rubber in the factory location on my fourth-generation Ram/Cummins trucks, mostly tires that were 34.8-inches tall. The 295/65R20 Cooper Discoverer STT PRO is substantially taller.
This 2017 Ram has plenty of clearance for the rear-axle track bar.
My 2017 has less room overall than my 2014, as the factory trailer hitch receiver is still in place. (It was removed on the 2014.) There are also steel plates on the inside of the frame to mount the Hillsboro 2000-Series aluminum flatbed. The 3/8-inch plates, one on each side, consume 0.75-inches.
3/8-inch steel plates inside the frame are part of the flatbed mounting.
There are advantages to choosing 35-inch or smaller tires on late-model, heavy-duty trucks instead of the popular 37-inch versions, particularly if they will fit in the factory spare location. These include, but are not limited to, not needing an additional tire carrier or pushing a truck camper further aft to fit a spare in front of the camper (which increases rear-overhang, tail-swing, and impacts weight distribution). Unless your rig is geared low—and most new vehicles have tall gearing—the taller overall gearing that results from fitting larger diameter tires is often a negative, as it results in less torque at the wheels.
Many should ask themselves if they really need the extra clearance provided by 37-inch rubber, or are they just following the crowd, and potentially making unnecessary compromises. There are positives and negatives for nearly every modification and upgrade choice. Generally we need to give something to get something. Everyone should decide for themselves if the juice is worth the squeeze.
35.4″ Cooper STT PRO stuffed under a 2017 Ram/Cummins 2500.
Attempted to establish a baseline for fuel economy/mpg at 65 mph, with the 35.4″-tall, 295/65R20 Cooper STT PRO tires under a heavy Hallmark flatbed truck camper outfit. There was too much wind for this to be a true baseline, but efficiency was still good for this not-aerodynamic configuration; just under 13 mpg. I probably will revisit this in the future.
Recent photoshoot (June 2020) with Cooper Discoverer STT PRO, 35.4″-tall, 295/65R20 tires. My 2014 Ram crew cab with Cummins Diesel and stock-height suspension was the model. Pressures were 27 in front, 17 in the rear.
Disclaimer: As with all things, proceed at your own risk, only you can decide what is appropriate given your training, experience, knowledge, the conditions, etc.
Mount and balance, and first look at the 35.4-inch tall, LT295/65R20 Cooper Discoverer STT PRO tires I’m running on my diesel truck(s). There will be more in the weeks and months ahead, here, and also @RoadTraveler on Instagram (typically extra content in Instagram stories).