Who will be the first?

DzlToy

Explorer
Beginning in March 2018, the new FTR will be produced with Isuzu's 4HK1-TC (5.2L), which is mated to an Allison 2550 RDS transmission. Instead of the NPR's rating of 215 HP and 452 foot pounds of torque, the FTR has 215 HP and 520 foot pounds of torque. So, this engine CAN be tuned, albeit by the OEM only, most likely. The 4HK1 has an SAE 2 bellhousing, which allows it to mate to the Allison 2000 series. Based on displacement and current diesel tuning technology, something in the neighbourhood of 400 HP and 800 foot pounds of torque should easily be achievable. The current model Duramax, also built by Isuzu in a JV with GM, puts out at least 450 HP and more than 950 foot pounds of torque from a 6.6 liter V8. Why so much power, you ask? Safety. While it should not be built for speed, 215 BHP in a 26,000 truck simply is not enough power to merge, pull mountain passes and travel at 65-75 MPH on the freeway to get to your favourite surf spot.

The 4HK's B10 life is 375,000 miles, so the motor is quite robust and obviously detuned for longevity. Using the Allison opens many doors for tuning and four wheel drive conversions for larger trucks. Atlas and TWF both make beefy transfer cases that will bolt to the Allison. The 4HK1-TC engine is quite heavy at over 1200 pounds dressed, about the same weight as the venerable Cummins ISB 5.9/6.7, which carries a bit more displacement, but is also an inline configuration.

Anyone up for building a MoTec, Zeus or EFI Live controlled 4HK engine? Emissions delete would be quite easy for those who wish to travel outside of the US and the factory restrictive programming would go the way of the Mastodon. Allison transmissions have a robust aftermarket, including stand alone controllers, start in 2nd (snow), manual torque converter lockup in all six gear, choice of T/C ratios, 300M bits, readily available 4WD tailshafts and even a driver controlled touch pad, to eliminate that annoying center console shifter.

The rear axle is Eaton's 19060 and a driver actuated locker, is available, if not from Isuzu, then from the OEM. It is rated at 19,000 pounds and has a ring gear the size of a medium pizza, not friendly for off roading. Using a 4.88 gear set, a 2.05 torque converter and a 5.44 HERO case, the truck has a crawl ratio of 191:1. Locking the converter makes it 93:1, which is good for a large truck. Using a 10.54 Atlas, the ratios change to 370:1 and 180:1, which is much better. Why so low for a crawl ratio, you ask? Go drive a truck with 100:1 crawl ratio and you will be sold. The control and manoeuverability when off roading, backing a trailer or getting into a tight parking spot, will astound you. Isuzu's NPS sold in the ROTW has about 50:1, while the USDM Fuso FG has a pathetic 26:1, first gear high range in many pickups. Oh, wait, there is no low range in an FG.... absurd. A Torq 14 bolt or even a Dana 80 would handle the weight on the rear of the FTR with a lightweight composite camper box. Both axles are rated at 11,500 pounds and have a choice of ratios, lockers, hubs, etc.

If a light weight composite camper were installed, these 1 ton axles or maybe an F106 or D110, would be more than enough to handle the 3-4k pounds added to the rear of the truck. The front axle will need to carry at least 8,000 pounds and probably 9 or 10,000 to be safe. You are getting into Rockwell, Eaton and Marmon Herrington territory there. These axles are huge, heavy and do not lend themselves well to serious off road work due to mass, low ground clearance, high cost and lack of options, when compared to something like a Dana 80 or a steering 14 bolt. OEM curb weight for the 152" wheelbase model, the shortest available, places 6527 pounds on the front and 3722 pounds on the rear. Adding 3300 pounds to the rear, nets you about 14,500 pounds without people or personal gear.

At the end of the day, you have a huge truck with a 13-14 foot box on it. This is quite common on the Bimobile, Unicat and similar builder's versions of "larger" cabover trucks. Sure, they will make a 20 or 25 foot long box, but those are not common. Is it, therefore, beneficial in some way to have a 13 foot box on an FTR, versus having a 12-13 foot box on an NPR, or pickup/van chassis cab with lighter duty running gear, cheaper parts and years of trucks from which to choose for your perfect 4WD conversion?

One thing is for sure, the conversion to 4WD just got a hell of a lot easier thanks to the Allison 2550. A 250 HP PTO comes standard on this robust, commercial duty transmission, perfect for connecting your 40,000 pound winch to, so that you can haul your 26,000 pound behemoth off the sand dune on which you are perched. Stock ride height places the top of the cab 112" from the ground and the width is 94 inches. This is not a truck for narrow dirt roads in the hollers.

Who will be the first to build a four wheel drive 2018+ Isuzu FTR camper?
 
Last edited:
Top