Doomsday diesel is about a month away from releasing his TDI to land rover r380 or zf slush box adapters.


The BHW motors I run are 2.0l and make 175hp and 300ft lbs of torque @2000 rpms. This is with a simple ECU reprogramming, stock they are about 135hp and 240ft lbs of torque, similar to a TD5 or 300tdi.

Since the stock programming makes the engine rev hang between gears I'm thinking it best to program this as a manual transmission so rpm drops as soon as you let off the throttle, like our throttle cable driven v8s do.

I'm going to use a local tuner to help me dial in the shift points on this via an HGM compushift. Since internet reports show a few people have brunt up different model transmissions attempting to diy tune I'm going to seek professional guidance. He does a lot of LS swap work so slush box tunes are in his ballpark.


The first thing he asked me was does this vehicle run any torque management. If this question doesn't make sense to you, well, he has to explain it to me as well. All my previous diesel conversions use a 4 or 5 speed transmission but the little lady won't have a manual shifter.

The torque management drops the engine power for a 10th or so of a second between shifts, putting less stress on the transmission. The 6l80 is probably the most common transmission that this is seen on from an aftermarket tuning standpoint.

The disco is the significant others rig, her daily driver. She lays the pedal down and goes. She doesn't care what the breaks or wears out, that's what she keeps me around for. So I wanted to ask the experts this as she's going to have 300 ft lbs of torque at her disposal at all times. When she hits the freeway I don't doubt she'll use every MM of pedal throw she has at her disposal. I might have to nerf this a bit.

In the little amount I've driven the rig I have noticed no drop off in power, feel or hear, as the zf is changing gears.

Are you guys aware of the ECU pulls timing or fuel curves as the transmission shifts, it would be momentary so maybe too quick for me to notice???


Thanks ahead of time gus

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Don't have access to a tune tool for disco to look at it but the 24 is known to handle that level of torque and maybe a little more. The biggest engine it was ever behind was a 5.0 BMW V13making 332 ft-lbs. The petrol 4.6 makes 300 ft-lbs and I do not notice any tm between shifts. I know they did not use any significant TM in the early 00's M class ZF's (my buddy was the powertrain tuning engineer and I got to ride in some of the development rigs). Wouldn't hurt to put a little bit of TM on it to protect it.

 

Thank you. I'm dealing with about 3 different companies on how to make this work and waiting on Ashcroft to chime in.

​​​​​​This isn't an easy project to game plan, but it's easier than convincing here to drive a stick.

 

I wouldn't worry about it. The 4.6 makes 300 lb-ft and they aren't known to have issues as a result. People that LS swap these things using the ACE kit utilize the stock transmission with no torque management with over 400 lb-ft. You should be fine - I wouldn't bother with it.

 

Yes. All ZF trans that I know of have max torque tables. The best thing you can do is to raise line pressure. The next best thing is to shorten shift times to minimize clutch slip. Lockup the torque converter early and keep it locked while shifting. The VW engine probably has half the rotating mass that a 4.6 with a big heavy flywheel has. The trans will be able to pull the rpm of the motor down easily. The ZF ECU sends a signal to retard the timing on the 4.6 between shifts to pull some of the power out to make it shift more comfortably. You don't have to do any mitigation between shifts for the sake of not breaking the trans. You could shift it full throttle at 300ft lbs. Your motor is also making way less torque at 4000 RPM than max. So if she was to floor it and it shifted at 4000 RPM, you would be putting significantly less torque into the input shaft than if you forced it to shift at 2500 and full throttle. Torque kills transmissions, not horsepower. Tuned BHW at 4000 RPM only makes 220 Ft/lbs.

 

Why a PD motor? Why not an ALH manual pump with a disco 1 4hp22? The simplicity is what I would want. You would have 1 wire for the fuel solenoid in the pump. You could make the same power and the trans is bulletproof and has 0 electronics.

 

Unless it's a racing set up there's no reason to ever rev that high on a stick 4 cyl tdi. I've been daily driving these BHW motors since 2018 and can probably count on one hand how many times ive shifted past 3000 rpms. About the only time I hit 3000 rpms is in 5th gear passing someone at 80-90 mph on the freeway.

But hank you for the info. I've spoken with doomsday, compushift and Ashcroft, they've alll said I won't have issues without the power disruption between shifts.

The compushift does allow for line pressure adjustment. My 24 hp has about 80,000 miles on it before the po dropped a valve due to carbon build up. I'm assuming it's in good shape. I've considered having a shift kit installed if one is available to help firm up the shifts as well.

 

The best part of the TDI motors is how smooth and reliable they are running on factory electronics. Anyone who has turned an ALH into and M-tdi has had to deal with quirky behavior and or less than ideal running characteristics at certain rpm or load ranges.

Then there's toque and power. The BHW is a 2.0 that needs a simple tune to make 175 hp and 300 ft lbs of torque. Do you have any idea what it would cost to mod the injection pump, upgrade the turbo/injectors and tune to make an ALH run at that level? And since the BHW has much beefier internals it will run at that level reliability... but the ALH..... probably want to use BHW rods in it.

Then there's the issue with mounting them in a 4x4 rig. The BHW came in the 04-05 Passat. The ALH came in the beetle and Jetta. Every popped the hoods? The BHW is mounted like a rwd vehicle while the ALH is mounted like a fwd.

The ALH turbo interferes with most rwd passenger side mount starters on Toyota/Ford transmissions from the ranger to 4Runner.

The BHW turbo sits higher.

Since the BHW is mounted like a rwd set up you have a mount bracket on each side of the block. Not on a ALH. On an ALH you have a bracket across the front that may not like you front differential or steering arms.

Good news is that many items from the ALH and BHW are interchangeable, you can put an ALH head on a BHW block... with lots of modification.

As for the wiring, it's simple. The wiring schematic are posted all over the tdi forums. Or pay 1k for a custom harness delivered to your door with an install instruction sheet. Stick with the electronics, it's a better running motor. Trust me, it's more simple to keep the electronics, it's also more reliable and will run better. 10x better. Telling someone to ditch the electronics on the TDI is like telling someone with a 6.0 LS to ditch fuel injection....they are reliable and proven systems.

Since you're swapping the engine you'll already have all the immobilizer stuff deleted. You'll be able to keep your cruise control with the TDI ECU, you'll also be able to run the tach with the TDI ECU. The support for the TDI conversion market is pretty good, although you'll need to get most of your gear from Canada because the EPA is a buzz kill.


On my 87 4 runner, the factory Passat gauge cluster is grafted into my dash. My speedometer is adjustable to I was able to dial it in within about 2mph at 70mph.

Again, trust me, keep the electronics. If you want non electronic use an om602/603/617 or a 606 with a 603 injection pump.

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