In the past month, I've managed to have a quick blezz in a 14 St Tropez and a TZD. Here's my findings.
Firstly, the 14 is a superb engine for the BX. Punchy thanks to the light weight and surprisingly rorty. It seriously put me in mind of the 16v albeit without the crazy hooligan 4000rpm effect. Perhaps it compares better with the 2CV. Keep the revs up and you can surprise a lot of people.
The TZD I found a bit of a disappointment. The 14 delivers instant power - it's actually a bit tricky to drive at first if you've just leapt out of a diesel. It's like a frisky mare. The lightest touch with your foot and she's off!
The TZD displays the characteristics that in the end made me fall out of love with my Peugeot 306 DTurbo (albeit after 40,000 miles!). Turbo lag and a narrow power band. It didn't help that today's drive started on a steep hill, and I changed from second to early so by the time I hit third, the boost was gone. That's the problem though - to keep a TD going quickly, you need to keep the revs up like with a 14. Problem is, by 4000rpm, the party's over, so you have to keep swapping gears to chase the power.
It's not the fairest test, as I've obviously done a lot more miles behind the 1.9 NA diesel, but with that, there's a good spread of torque (as well as what power there is) across the rev range. Sticking between 1500rpm and 3000rpm is easy (fifth most of the time, occasionally dropping to fourth for tighter bends) and so much more relaxing. Yes, there are times (usually uphill!) where more power would be nice, but if there was a turbo, you'd probably find yourself having to drop a cog anyway to find the power. Unless you've got a 1.9 TD Xantia engine installed perhaps...
Aside from power, jumping from Mk1 to Mk2 is quite interesting too. The Mk1 easily has the quirk factor, the Mk2 feels more cohesive. The biggest differences though (and I'm not sure that Mk1/2 is the switch-over) is that the brakes in the Mk1 are super sharp. All BXs stop well, but it's not until you jump from Mk1 to Mk2 that you discover just how much harder you need to press the pedal in a later car! I found this with both the 14 (which was bedding in new pads to be fair) and the TZD. To be honest, the Mk1 brakes are probably a bit fierce, but the first stop in a Mk2 is a rather scary experience!
