The Defender was one of our more complex vehicles we did the R2.8 conversion in. The issues we ran into:
- Steering box clearance to the R2.8 Oil cooler
- Suitable Transmissions
- Different Bulkheads and Trans Tunnels
- RHD and LHD configurations
Manual Transmissions
We decide to go the TR4050 route, as we saw that the R380 was not a suitable transmission for this platform for a few reasons.
- Power Limitations.
- The R380 is rated at 380 NM of torque, which comes out to 280 LB-FT. Out of the Box the Cummins R2.8 is rated at 330 LB-FT. Which means the R2.8 puts out 50 LB-FT or 18% more torque than the R380 was originally designed for.
- R2.8 Power Tunes
- The R2.8 is capable of making around 380 LB-FT, which then equates to 100ftlbs or 38% over the torque rating of the R380.
- Weight of the Vehicles
- The second consideration we took into account is the shear weight of these builds. A stock D110 starts at 4600 lbs, which most of these conversions are not stock. On average we have seen weights of 5500-6500 lbs with it all loaded down with overland gear and what have you.
The Tremec TR4050 was the best transmission for this application. It has a torque rating of 425 LB-FT @ 15,000 Lbs GCVW. Which meets our requirements of the R2.8 torque with any tune, and the weight of these builds, even with a small trailer.
The ratio of this trans are 6.16, 3.11, 1.71, 1.00, .76 Rev. 6.03, so a new T/C ratio is required when doing this conversion. Depending on the build we have seen that a 1 to 1 or a 1 to 1.1 high range gear set works the best.
Auto Transmissions
We choose the Eco Diesel 8HP70 for the Defender
Our R2.8 Defender Kits are based around the engine landing behind the stock power steering box. This allows the use of the stock front suspension geometry. No modifications are needed to the suspension.