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MG ZR ZS ZT Technical - The ZR Turbo, should it be 160 or 200 BHP?

HI Gang
Just read an posting off another BB, it seems that MGR are thinking of a ZR Turbo with 160 ish BHP. WE all wanted to see the 200 BHP version, but just think.

The VVC can't produce much in the way of Torque, both Ford and Vauxhall are going to have 150 bhp Ish babys about. Lest we forget a good 160 BHP ZR could put the Cooper-S in its place (Other than the dealership on a recall that is)

What do you think?
Mike
Mike MEGA

There's already a 160bhp ZR without turbo.

Martin
martin woods

MG has added a turbo-diesel engine option to its Rover 45-based MG ZS sports saloon range.

MG now offers diesel engines across its full saloon range – from the ZR to the ZT, a move seen as crucial for success in European markets where diesel penetration is rising rapidly (the diesel accounts for 70% of UK Mercedes S-class sales, for example).

The 101Ps ZS turbo-diesel provides high levels of torque – 240Nm@2000rpm – and 0-60mph acceleration in 10.3secs on the way to a 116mph top speed.

Economy is also good – 52.7mpg on the official EC combined cycle.

The turbo-diesel is available in both the 5-door hatchback and 4-door saloon with two trim specifications – ZS and ZS+, the latter with air conditioning, electric front windows and special badges. UK prices start at £13,195 for the hatchback.

joe

Test - please ignore - sorry.
Russell Morgan

>>MG now offers diesel engines across its full saloon range – from the ZR to the ZT, a move seen as crucial for success in European markets where diesel penetration is rising rapidly <<

Yes, but the Rover engine is now a bit "dated"...
Figures of 130 bhp / 300 Nm are now the average for a 1.9 / 2.0 l
Not to mention technique : 16 valves, common rail, anti-pollution, etc.
Fabrice

MG Rover has now brought the L-Series diesel back in-house from Land Rover, and so can develop to suit its own requirements, also perhaps benefitting from any developments to Land Rover's Td5 five-cylinder offshoot of the same basic engine.
David Knowles

I always thought that Rover diesels were reworked Peugeot units?
marcus

Some were, Marcus, but not the 'L-Series', which had its roots in the 'O-Series' via the PRIMA diesel.
David Knowles

PRIMA diesel

wasn't that manufactured by Perkins for Rover?

Mike
ProMGR

It was. At their Peterborough plant IIRC.
Dave

Rover do have a 1.8 Turbocharged petrol engine as a replacement for the bigger engines in the 75 to make them more attractive to fleet buyers because of the lower emissions.
mcdude

Screwing more power and torque out of the new 1.8T or the L series is quite easy and 125 bhp versions of the L series makes for an interesting performance package. Two problems exist though

1, is in the economy/emissions area as more power means more fuel, means more exhaust. Now that the L engine has moved to Powertrain there is the internal flexibility of engine development. Witness Powertrain developments since May 2001 when it came back under the MG Rover umbrella to show how this freedom to develop cost effectively works.

2, is the gearbox and specifically it's torque rating as the PG1 comes in 215 and 240Nm capacities. L series and 180 spec V6 engines both peak with 240Nm and have the higher spec gearboxes. (the 190Ps V6 gives 245Nm) The 1.8T realises a peak of 'only' 215Nm in the current spec so there is some leeway to see increased power and torque. The old T16 2 litre turbo engine gave 200Ps with the 240Nm spec gearbox and that was fitted into the heavy 800 and slightly lighter 600 chassis's.

Clearly it would be quite feasible to raise the stakes of the 1.8T engine to circa 200Ps which would also give about 240Nm, but beyond this presents a potential reliability and warranty issue. Ten years ago the T16 turbo was restricted to 180Ps/216Nm in just the Rover 820 Vitesse, but in 1993 this engine was seen in 200Ps/237Nm form in the 200/400 body. The 200Ps engine spec was not fitted to the 800 because of gearbox worries and only when the uprated 240Nm spec gearbox arrived in 1995 was it then fitted.

The 200Nm spec engine was giving 237Nm of torque so during the first couple of years the 200/400 gearbox was being 'overstressed' by up to 10%. The reasons given why the 200/400 could live with this higher engine spec was from it's lighter weight ranging from 205 to 240kgs - kerbside - creating less stress on the transmission.

It is clear that a 1.8T could easily mimic the outputs of a 2.0 T16 turbo and live within the current limits of the higher spec PG1. 200Ps/240Nm in the ZR would be a very significant improvement on what is currently available. Traction control through the ABS and engine management would also be far more effective than the Torsen diffs used on the 1990's Rovers.

The same configuration could be applied to the ZS as well, but here you gain little in terms of torque, just a degree of flattening out of the torque curve and no peak gain. This makes a far weaker case for this addition as the biggest change would be in the paper figures, not in the performance, and then there is the loss of the V6 sound!

Translating paper gains into road performance is probably of more significance. Here top speeds are easy to calculate. A ZR 200 would be usefully quicker by 10mph and should crack 141mph, from 131mph. The ZS 200 should show smaller gains with top speed rising from 139mph to 145mph.

Acceleration is far more difficult to calculate as there are so many variables, however using simple techniques it would be reasonable to say that the ZR 200 would mimic the acceleration of the old 200 Turbo Coupe, giving 0 to 60 in around 6.2 seconds, but with it's slight weight advantage I would expect the 30 to 50 and 50 to 70 times in 4th gear to be sharper and record approx 6.1 secs for the 30 to 50 and around 5.5 secs for the 50 to 70 times. The ZS 200 would be about a tenth of a second ahead of the current V6 180 model, which posts 6 seconds for both segments.

I can see no fuel economy CO2 emission advantage for the ZR, but a quite reasonable advantage for the ZS with a 200 spec engine. This is perhaps the one argument that carries most weight at the moment.

If the same 10% torque to gearbox leeway as seen in Rover 200/400 Turbo were to be applied to ZR and ZS, which would appear to be in the same weight band as 200/400 Turbo, then things could really start to get interesting!!

I have some insight ahead of most outside MG Rover as to what is coming, but in this instance I am adding two and two together and getting these answers from simply looking in a little more detail to what is in the public domain. I know that these same issues and many more have and are being examined at Longbridge and that there are a few interesting announcements around the corner. Quite whether we shall see results to support what this thread is discussing I don't know. However I do know of some interesting things in the pipeline!

Rog
Roger Parker

Don't mean to nit pick but the Vitesse Sport definalty came out in 1994, and i've got a friend who has a Sport registered in 1993. So your saying that any car built before 1995 with the 200PS engine did not have the ToRSen box?

Gareth
Gareth Kidman

Yes your correct and from documentation they were available from at least July 1994.

The Torsen was a standard fit on all 200PS equipped cars, but the point I make is that for a period from intro of the 200/400 Turbo range to the arrival of the 240Nm uprated gearbox a calculated gamble was made with the potential of higher warranty returns on the gearbox.

This 'calculated risk' will be seen to have more relevance in due course.

Rog
Roger Parker

This thread was discussed between 05/08/2002 and 22/08/2002

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