I bought a TDI!

[Piotrsko]

Zf makes a 5 speed? No low or no overdrive? Most everyone with a ZF6 ignores 1st.

It's also possible the cummins will exceed the input shaft torque limit of 600 lbft.

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Zf makes a 5 speed? No low or no overdrive?

IIRC it had an overdrive.

It's also possible the cummins will exceed the input shaft torque limit of 600 lbft.

It was rated around 413lb.ft. anyway.

[hayden55]

Originally Posted by Taylor95

They have both HEV and PHEV kits. I believe the 144% is for the HEV according to their website.

The PHEV kit sounds interesting but I did not get much info on that. It would have a range of 20-25 miles though.

TBH the main benefit for me from a hybrid was the amount of time you could have the engine off when coasting or at stop lights. Steady state cruising you will get the same mileage as a non hybrid. Since we are all psychos and EOC and shut our cars off at lights anyways there's not a huge difference. The benefit with the prius is it does it smoother and you don't have to bake at stop lights since you have electric AC that doesn't need the motor to kick on. But the more you lean into using the AC or EV mode when the engine is off the more awful your mileage.

[Isaac Zachary]

Originally Posted by Ecky

The major benefit of hybrids on the highway is that they tend to incorporate much taller gearing, and smaller engines, than would otherwise be acceptable to typical drivers.

Agreed!

On the highway a hybrid engine can be smaller and tuned for fuel mileage, which for a non-hybrid could make the car feel underpowered. But by adding a hybrid drive you can have that extra burst of power when you need/want it without having to resort to an engine built more for power than fuel mileage.

So, for an example, say you have the time and resources to convert your engine to something more efficient, say a Miller cycle or Atkinson cycle engine. Basically you'd need to increase the compression ratio and rework the cam profile so that your intake valves close much later. For the Miller cycle you may need a different turbo, or even change it for a supercharger since you'll be getting less exhaust pressure as the combustion stroke will now much longer than the compression stoke which will soak up more combustion gas pressure, leaving less for the turbo. All of this would result in a less powerful but hopefully more efficient engine. If by that point you can't stand the lack of power you can make up for it by adding a hybrid system.

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

For the Miller cycle you may need a different turbo, or even change it for a supercharger since you'll be getting less exhaust pressure as the combustion stroke will now much longer than the compression stoke which will soak up more combustion gas pressure, leaving less for the turbo.

Even though the original Miller cycle featured a supercharger, absent from the so-called Atkinson engines available nowadays which are not proper Atkinson engines (there are different linkages between the piston and crankshaft due to the Otto's patents which James Atkinson was attempting to circumvent), maybe resorting to something like Volvo's PowerPulse system featured to its latest twin-turbo Diesels could get the job done better. It does surprise me this very same approach wasn't applied to its T6 and T8 gassers instead of the twincharger featuring both a turbo and a blower.

[freebeard]

Originally Posted by Isaac Zachary

So, for an example, say you have the time and resources to convert your engine to something more efficient, say a Miller cycle or Atkinson cycle engine.

I kinda like the Brayton Cycle en.wikipedia.org/wiki/Scuderi_engine air hybrid system.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

I kinda like the Brayton Cycle en.wikipedia.org/wiki/Scuderi_engine air hybrid system.

Even though I doubt some Diesel engine could be adapted to operate with some split-cycle, sometimes it seems quite pointless the air taken out by the blow-off valve is simply discharged instead of providing some sort of motive power.

[Isaac Zachary]

Warning! Thread derailment!

I've actually been thinking a lot about a Brayton-like design.

1. It can have a smaller compressor piston than the combustion piston (an atkinson cycle)

2. If used with more than one compressor piston (starting large and getting smaller), or a turbo or supercharger, the charge can be intercooled up until the last compressor piston (miller cycle).

3. Between the compressor piston and combustion piston the charge could be fed through a heat exchanger that preheats and expands the charge before combustion (perhaps would work best on a diesel cycle or some other sort of stratisfied charge).

This would basically be similar to this type of turbine engine, but in piston form:

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

It can have a smaller compressor piston than the combustion piston (an atkinson cycle)

Piston-type air compressors are worth for either pneumatic accessory drive at a vehicle (such as air brakes fitted to heavy-duty commercial vehicles) or some random stationary appliances.

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

Piston-type air compressors are worth for either pneumatic accessory drive at a vehicle (such as air brakes fitted to heavy-duty commercial vehicles) or some random stationary appliances.

I was referring to a theoretical engine in which one cylinder does all the compression strokes and another does all the combustion strokes.