UK-POLOS.NET - THE VW Polo Forum

Who recalls the much-rumoured supercharged and turbocharged engine that may be coming to the new speedster?

Sounds like it's not just a rumour, and it's not just for the speedster:
http://www.autoweek.com/news.cms?newsId=103048

I worry about the complexity a bit. The turbo setup on the Golf GTi was pretty progressively anyway, so why the need to "eliminate lag"?

Deek.

Sounds pretty cool...

Turbo lag is quite cool in it's own little way though... It's fun pulling away with someone beating you then the Turbo kicking in and you smoke 'em

intersting read! will certainly make an interesting noise with the eaton charger cutting out mid revs just as the turbo is spinning up!

interesting read, good find!

Found this on vwvortex today, looks like you were right.

http://www.vwvortex.com/artman/publish/ ... 1496.shtml

Looks interesting and 170PS from a 1400cc

Who will be the first to put that engine into a Polo?

was just thinking that!

170Ps from a 1400 is very respectable, but i also worry about the increasing complexity - could lead to some mad prices for parts... like an electromagnetic clutch for swapping from the turbo to the charger!

This line in the autoweek article amused me:

"“In the U.S., displacement is still king,â€

I think I just found my next car ... especially if the rest of it can be (or stay) sorted, not just the engine and drivetrain

course i may have to wait a few years.

only prob is that it gets about 40mpg combined or something, would have expected more out of a super-tech 1400cc, even with that power output; as stated, it's not 20% lower consumption overall, merely 20% lower than that of a 2.3 litre engine.... so approx that of a regular, slightly off-tune 1800, then?

still its far better than what most americans would be used to, but still remaining fast as excrement leaving a garden implement.
(or, the TDi.... hmm)

i even made some little graphs out of a mixture of curiosity and boredom to illustrate the potential of these engines.... the two on the left are the best ones possible from the supplied information - those on the right are speculative interpolations showing the maximum power of the 1.4 (output specified, but peak rpm not defined) at different places. I think the one where it peaks in the mid 5000s is more likely - "looks better", and more closely fits the usual VW "thing" of having low peak rpms... even if the revlimiter is set at 7000!

click the picture for full size


as you can see .... it's pretty awesome. You've got to love that 1.4 torque curve (which was the diesel, again?), and the tdi one is hard to beat also (if not quite so great - but it is even more economical and possessed of stonkingly larger peak figures)

the bottom left numbers say it all really - comparing it to standard mk2/3/ some mk4 engine outputs, in terms of what rpm you'd have to pull to better one of those screaming away on peak revs, assuming a body of equal weight. those are some pretty darn low rpms. that's what a geared-supercharger produced 200Nm at 1250rpm will do for you. The astra (already grunty at the bottom) comes off of overrun cutoff at about those revs when decelerating to avoid declutch stalls, it's that low.

edit: going to whip up a quick one overlaying the diesel and petrol curves (simply, mind) on the same rpm horizontal scale, mostly just to see what happens. bear in mind that the dotted lines show total guesswork, i dont properly know how the curves should really fall off at each end for either a petrol or diesel

original straight comparison graphs, in case you wanted to tow something in low gear or run a power take-off or something
(or in the unusual instance of both units sharing the same gearbox ratios)

power on the left, torque on the right



similar, but with the rpms (and in the case of torque, curve height) adjusted to take account of different revlimiter and assumed higher gearing on diesel (curves almost identical in midrange). shows how higher gearing reduces TDi wheel torque near to that of twinturbo petrol, despite being far higher at crank.

as it stands, looks like the diesel is best for everyday brain-off bumbling around in the 2000-3500 rpm range with good economy and immediacy, but for real full-range, and wide power band fun for the highly involved (or plain lazy) driver, the petrol is a much better bet despite being an on-paper (slight) loser and a bit less economic.

both however will kick the shades out of you considering the displacement. put em on a go-kart...

in fact, this holds true even if they're on the exact same gearbox - the limiter cuts in earlier, forcing you to change up on the diesel before the petrol has even got all that close to peak power ... i.e. changing up a whole lot earlier and, once you're out of 1st, having a very similar effect to a gearbox that's higher geared anyway.