Why would this be a downsized SDI engine?
It's a downsized PD100 engine.
SDI is a VP engine and has different pistons and rods.
Reliability will be same as PD100 with 100 hp/L.
Runs quite nice in a small car.
I think I have read somewhere that the block on the 3-syl TDI's are not of the same metal and strength as the 4-syl TDI's? And therefore much weaker, and not suitable for serious tuning. Am I completely wrong?
I hope so, because personally I would love a 1,4 TDI with a 1749VB and ARL-injectors!!
K.I.T.T. on here has the 1.4 3 cylinder tdi and has it about 100bhp with just a remap as it's about 75bhp as standard. He has been looking at loads of info too and reckons it can go quite a bit further.
Page 4, post #49 onwards is where it really "starts". The engine is pretty robust, the first issue you have to address is the gearbox. Note the dyno print out above. I believe the torque peaks at 3000rpm as it has been restricted at lower RPMs to save the clutch.
The stock gearbox and clutch combo is only good for 250NM, which can be broken with a strong remap. I suspect the car above is running he Sachs organic clutch (the only oher readily available aftermarket clutch for this gearbox), which is rated for 15% more torque (~287.5NM). Note the peak torque is near identical to this figure. I suspect if the torque hadn't been limited, it would have peaked at about 320 - 340NM at 2500RPM and destroyed the clutch...
The engine itself is fine at around 340NM once the gearbox problem is addressed (ie swapped to a 1.9 TDI setup and use a strong enough clutch). Do the math and figure out how much HP that equates to