TSI or TDI

[VdubDownthePub]

Gt Tdi

I've had a GT TDI Manual for a month now and it's a bit of a love hate relationship...
I love the torque, it just pulls like a train (when you get it right!)
Someone on here described it as a ferral car, yeah that sums it up, to drive this car for optimum performance is going to take a lot of practice after years of mostly underpowered front wheel drive cars. The power band is narrow but extreme and also sometimes doesn't seem to happen for whatever reason, as if the turbo hasn't quite hooked up, I still have lots to learn.
My three biggest gripes:-
1. in traffic, let the revs fall below say 1200 then have to speed up quickly, no time to change down results in very slow pickup followed by ferral wheelspin..Maybe I need a DSG map implanted in my brain!
2. After the buzz of the kick from 1800rpm to say 2250 it seem to be gasping for breath as it revs out, I can surely see the attraction of the TSI's broader power band.
3. Wheelspin is excessive, I cannot flatten it in 1st and if there is any hint of turn in the steering it spins out in 2nd too, today in Perth in the wet I was spinning in 3rd too, In wonder what the GTI's are like? Roll on R20!

Having said all of that, I love the car, it's an almost unique combination of power and economy and perhaps points 1 to 3 are deficiencies in the driver rather than the car!!

Mark WA

[benno]

I've always thought an SC would suit the characteristics of a diesel better than a turbo.

Imagine having stonking great massive torque from 900rpm to 3000rpm

[Greg Roles]

The blower problem is more the fact that diesels flow SO much air, that you need quite a large unit to supply usable boost, yet it will rob a good 50hp plus down low just to turn. Then there's the added stress on the already loaded crank etc. Bottom line that made me change my TSI-TDI dream is that virtually none of the monster SUV diesels in the states run a blower, and they all aim for compound turbos. I was looking at a blower from the 2.4L Merc Kompressor series cars with a mag clutch, and although it would fill the turbo lag area nicely, there's no way it would supply the TDI with boost beyond 2500rpm in a solo application. With good gas flow even below 2000rpm compared to a gasser, it seems logical to use this to turn a small second turbo, as VW are rumoured to be doing, if it ever makes production.

I'm waiting to see what happens there!

I've had a GT TDI Manual for a month now and it's a bit of a love hate relationship...
Mark WA

A perfect summary Mark, in manual form it's very much a "drive" around the lag type car, a real on / off power delivery. Definately not everyone's cup of tea ( you'd spill it! ), but given my teens spent racing 125 MX bikes, and my first turbo car was a Starion, with heaps of lag, then a decent hit, I kinda get juiced by that sort of power delivery.

Still be nice to fill in the hole though.....just need more cash!

[Preen59]

Yeah its a very good point there, Greg. I'd still like to have a crack at it one day on a smaller early diesel though, possibly with a centrifugal puffer like Mazda did in the early 90's with their 626's etc.

I don't mind the snap power delivery. I'm used to it now. When i feel it coming on i simply halve my throttle input, then apply it progressively and it's smooth sailing. Generally, however.. I like to rev the engine a bit and keep it in the mid range (better oil pressure and ring seal) so i don't really have any trouble with it.

I really think that the people that complain about these sort of things are just bad drivers and are complaining because the car doesn't compensate for their lack of ability.

[Greg Roles]

...seems to be if you gear up a blower hard enough to supply low down, it's going to run out before max rpm, or if you run a big unit to cover this it's going to rob too much down low anyhow, and overstress the crank etc.

Centrifical would work, but I just don't see the advantage over a turbo, as both need to spool up to work, but perhaps if you could match one so that it's already about mid boost at idle, and has enough ceiling to cater for the max rpm flow of the engine....hmm, be fun to try!

If it was a good thing, surely the excessive yanks would be all over it.