Re: May buy a 156 2.4 JTDm
As far as I know, the Q2 only fits the 2.4 with the 5 speed box, and the 1.9 needs a 6 speed box to take the Q2. The 2.4 6 speed is the Vauxhall F40 gearbox and therefore I'd not expect it to be compatible with the Q2. Unless it can be made to fit in a different way.. Ned knows his stuff, but its an easy mistake to make as to remembering which gearbox it'll fit. The 6-speed in the 156 1.9 is the same gearbox & bellhousing as the 5-speed in the 2.4 and 6-speed in the V6. Its the same box as the 1.9 box in the GT JTDm and GT V6, 147 JTDm and both 147 and 156 GTA's, only the ratio's are different. But it is NOT the same as the one in the 156 2.4 JTDm. But maybe there is also a way of getting the Q2 to fit that gearbox? Afterall, Jamie Porter reckons they can get the Q2 to fit the Brera/159/Spider (for a fair bit more cash) which no-one else says will fit..
However, now you've gotten onto the merits of 1.9 JTDm vs 2.4 JTDm, I would maybe be tempted to say go for the 1.9 if you are a guy who is happy to modify your cars. Q2 is straight forward direct fit, there's less weight over the front end, the car is cheaper to run and cheaper to buy, and its the same engine as the CDTi in modern Vauxhalls, so tuning mods are much easier to come by. In fact there's a fella on here with a 147 1.9 making 270bhp..
You just have to ask yourself if you want big power without much modding, besides the remap, and don't mind spending a few K more in the purchase price, in which case go for the 2.4.. But if you prefer big power and nimble handling, but a don't mind doing a fair bit more work and spending a bit more on the car after you buy it, then I'd go for the 1.9..