(G) Twin turbo 1.9 JTD

Just wondered if anyone saw the road test in one of the major car mags this week of the latest Saab 9-3 diesel with a 177 bhp 1.9 Tid (JTD) twin turbo engine. Is this the first showing of this engine in any car or is there a FIAT group vehicle on the UK market somewhere that I haven't seen yet?

Saab is indeed the first to use this engine.
It's supposed to be used in Fiat cars also (incl. Alfas and Lancias) but I don't know when.

i don't understand how twin turbo is benefical on a 4 cylinder diesel. we have varible geometery turbos now, so having a small turbo for quick spool up and a larger one for high end power isn't needed anymore. one VGT will do. and it's not like there's two banks either

Maybe work might give me one for a company car when i reach 21

See this thread: http://www.fiatforum.com/lets-talk-f...engines-3.html. Good the other marques are testing out Fiat's development first in the lower bhp version Fiat have sold them. When Fiats get one, hopefully next year, it should be the more powerful version.

According to a copy of "Quattroroute" magazine I picked up while on holiday in Italy earlier in the year, the 180 bhp model will be available to other makers ie. Vauxhall/Opel, Saab and Cadillac as well as FIAT, the 190 bhp model will be reserved for the three main FIAT group brands. The same magazine described the engine as using the small turbo at lower revs for quick response and good low speed torque, while the larger one will be responsible for higher revs and higher power/torque. This is obviously more complicated (and more expensive?) than the variable geometry turbo but as the competitors produce more power the Italians must feel they have to respond.

A VGT is a compromise between having a small turbo for low revs and a big turbo for higher revs. Obviously the best scenario is 2 turbos.

on a perfomence engine, yeah twin turbo would be better - but this is a 1.9 diesel. i'm not knocking it, but surely you can see my point?

You still have to deal with the lag problem.

a VGT turbo on the 1.9 JTD in one version of the Stilo has lag until around 1600rpm and kind of dies at around 3500rpm? or somewhere round there.

My Stilo doesnt really stop acclerating until it gets to about 4200rpm just before the redline, but i dont like to push it that much so always upchange at around 3500rpm

unless im driving for economy and its 2200rpm lol

This discussion seems to be going nicely, but, how about this? Does a Bravo, Focus, Golf et al. really need a 180 or 190 bhp diesel engine? I can see the thinking behind this sort of power output for a 159 as it comes up against the 3-series, A4 and the like it'll need that sort of power and torque. There's always the possibility of an Abarth diesel Bravo of course, but would a car with this engine need traction control and other aids therfore pushing the price up until it starts to get a little too close to the 159 and its ilk?

You certaily have got a point here. But the ideas behind these high powered engines is that in some key markets the demand for powerful engines is there regardless of the size (within reason) of the car.

People want to have performance and comfort but also demand low fuel consumption. The smaller the engine, the less drag is pushing up fuel consumption. The more power can be extracted at low rpm the more mpg. Also smaller units mean less weight and the smaller dimensions mean engine compartments can be designed accordingly.

The new PSA (Peugeot/Citroen) CEO comes out of the aviation industries. His goal is to make cars rather smaller than bigger and reduce the weight considerably in order to maintain fuel consumption figures at low levels and have the little creature comforts demanded as well as performance.

Interesting you should mention weight. So long as you don't make it too light. If you remember, the early Citroen AX s had problems on the Motorways in cross winds because, according to certain journalists, they were too light. But, weight is an important consideration. If aerodynamics are extremely important to economy and performance at high speeds, then weight is the enemy of low speed acceleration and fuel consumption. On that basis I don't understand why more manufacturers don't follow the lead of Renault with the last Clio in using more and more plastic in body construction, the front wings of that car were, if you remember, made out of that material. So long as the basic structure is strong enough, then with the possible exception of the doors, the rest of the body could be made of material that does not rust and would be lighter than steel. It's possible they could be self coloured at the factory and if you wanted a replacement panel it could come ready "painted". Flexible panels would also be less liable to minor impact damage.

With the demand for remaps upto 200bhp.. I'd say the answer is yes