The standard 1.8 box will handle 150 to 160 Ftlb of torque which is ok if you limit the turbo boost to around 10 psi.
So there's no way to use L series gearsets and bearings in a K series bolt parrent housing?
It is possible to use the L series gear set in theory. I've never tried as I've only ever run a 180 gear set. I'll look at the ratios when I get a few minutes. Don't forget if you gear it to high it could be worse on fuel instead of better![]()
It's all about matching available torque with the desired road speed. If your engine is out of it's torque range you will need to put your foot down more which will use more food.
Well, given that the remapped turbo K will have more toque than the L series, I'd imagine it would be ok? But I do see what you mean. The 220T uses the same gears I believe.
Will.
Well everywhere I've looked says the Di produces approx 155 FtLb's, the map I'm considering sees a max torque of 200 FtLb's at 3000 Rpm. Because I'm looking for a more refined ride rather than all out power, I think it's fair to say that it would be sensible to bring the gearing down a bit so that the engine is doing fewer revs at motorway speeds thus conserving a bit of fuel and reducing noise.
According to this chart the K series box it geared at 0.848:1 in 5th whereas the L series is geared at 0.648:1 in fifth. So instead of doing 3000RPM at 60 like mine currently does it would instead do roughly 2300RPM at 60 according to my calculations. That does seem to be quite a big difference.
Incidentally the 1st and 2nd gear rations are identical on both gearbox's, so off-road performance won't suffer.
Could it work???
It would prob be easier to ask around and get prices to get the 1.8 box rebuilt to cope with the extra grunt!![]()
The standard bearing sizes won't take that kind of torque!! Even the High Torque box was designed to take 180Ftlb.
Ahhhh wait now, I have read the chart wrong!
S4EM Freelander 1.8 3.25 1.894 1.222 0.848 0.648 4.2
S7EMU Freelander T/D 3.25 1.894 1.222 0.848 0.648 3.647
So the L series has a taller final drive but the actual gearing is the same. Or am I a blind muppet?
The ird final drive is the same across the board int it? Just reduces the gearbox output rpm by a fixed amount?
The IRD reduction is probably to help the engine overcome the Freelander's extra weight and tyre diameter! The torque the gearbox sees is reduced by reduction ratio of 1.4 odd. A gear ratio giving an engine speed of around 3,000 rpm at 70 mph would be ok. This is what my MG is geared to.
So the NASP spec box should be good for the IRD adjusted torque of 140 ish ftlbs? The NASP final drive is something like 3500 RPM at 70 curently, way too high for a turbo engine in my thinking. You're right about being off boost at cruise speeds though, that's a pretty important thing. But the off boost toque and power is upped by about 10% on the map anyway so that might help.
Following with interest!!
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