I wanted to discuss the way in which the multipla delivers it's power. For a start I usually drive a Fabia vRS and it is very different.

The Multipla isn't too bad off the line, but with a/c I have stalled it setting off no end of times which is very annoying. But the turbo kicks in at around 1500-2000 rpm you can hear the whistle and it smoothly pulls to 3000 revs where I usually change gear or indeed earlier depending on the circumstance; however once in a while I will 'pin it down' which is revving it to just before the governor enabling the car to stay in that 3000rpm+ margin, which I feel is a bit of a power band. It seems to rush round the rev range beyond 3k. It doesn't often sound too happy about it though, and thus it only gets used for overtaking or the odd slip road sprint.

Can anyone explain technically what is happening, or indeed if someone has a power graph I would like to see that.

Andy

What you are experiencing is the turbo lag. There is simply not enough pressure in the exhaust at low-revs to turn the turbo impellor, which in-turn is connected to a propellor that sucks air in to the engine.

The JTD is a gruff beast and indeed does sound a bit chunky when revved, but diesels don't like to be revved; they like to 'pull' at lower revs. I would have thought so long as you change-up in order to be above 2000rpm when in the higher gear you will get plenty of go without any lag.

The Punto JTD I had would pull like a train from 900rpm because it had a low-pressure turbo (i.e. very little exhaust pressure is required to spin the turbo), but because it is a small turbo it doesn't spin lots so it's not super-powerful.

So in conclusion:

Big turbo (like the Multipla JTD) need lots of revs before it goes BANG, but BANG it does go.

Little turbo (like the Punto JTD) needs hardly any revs to pull, but won't give the sort of pull that will move the earth.

Your Fabia is very light for the 130bhp PD engine so you won't notice the lag, but try the same motor in an Audi A6 Avant and it will feel 'laggy'.

This can be overcome with twin-turbo's (like the BMW 535d) which has one small turbo for instant go and one big turbo for high-rev power. So far the 535d is the only twin-turbo with different sized turbo's although Vauxhall have worked on the 1.9CDTi 16v (a Fiat Multijet engine) to give it twin-turbos to produce 212bhp, but this is not yet in production

Thanks for that reply - i didn't realise that was lag - not something i am used to lol.

I notice you have an A2 ? How are you finding the engine in that ?

It is a different beast to the 1.9JTD, that's for sure.

It has 'lag' below 1800rpm, so I need to keep it above that point, but I like the 3-pot thrum that it makes so revving it is quite fun; it has a lighter flywheel so gains and looses revs much easier which makes it more pleasent to drive. The engine is not as quiet at speed as the JTD (it pulls 2500rpm @ 70 in top where as the Punto was pulling 2100rpm) but the noise is nice; I now have 2 3-pot motors!

Still, I won't grumble at 60mpg (and it isn't properly run-in yet). Don't know if you were aware, but the 3 cylinder motor is the same basic engine as your 1.9PDI in the Fabia vRS, but with a cylinder 'lopped' off. It's 1422cc is 3/4 of the 1896cc in your car.

It's not fast, but that doesn't bother me; it is a beautiful drive! If I had gone for something quicker, I would end-up loosing my license

Multipla turbo lag is fine. Try driving a Vectra TD (I have had drive 2 recently). What a rubbish car. So much lag, you could insulate your loft with it.

I fancied a Lupo TDI once before - I bought a Saxo VTR instead as at that point the Lupo's were still very expensive. A good friend worked for a local VW place and often used 3 pot polo's and lupo's [courtesy cars] and I was really impressed and not a deal slower than my Saxo. So I know what you mean with the 3 pots being frugal.

But the Skoda I am happy with - it has been lightly tweaked and is now running something like what I am used to, but the fuel consumption isn't nearly as good as the 3 pot. I usually get 35 mpg average with a mix of town driving and country runs but no motorway, I also seldom 'potter'. So not actually that bad, and of course effortless to drive.

The Multipla is more of a plodder, but it is no slouch. Our 1500 mile round trip to France was a perfect test, and it passed with flying colours - comfortable, fast and not tiring at all.

My wife used to have a Volvo T5 Auto with just over 300hp, and i used to have a BMW E30 M3, so it has been quite a change for both of us - but we feel better in the pocket

Andy

disgusted said:

Try driving a Vectra TD. What a rubbish car. So much lag, you could insulate your loft with it.

Click to expand...

ROFL