MG ZT 160 KV6 Upgrade to 177

[BigRuss]

Originally Posted by SD1too

Here are MG Rover’s performance figures (from brochures) for the ZT 160 V6 and the Rover 177 engines in a manual saloon:

0 - 60 mph: ZT = 8.8 seconds; Rover = 8.2 seconds; difference = 0.6 s.

30 - 50 mph in 4th: ZT = 7.5 s; Rover = 7.0 s; difference = 0.5 s

50 - 70 mph in 4th: ZT = 7.6 s; Rover = 7.0 s; difference = 0.6 s

Top speed: ZT = 131 mph; Rover = 137 mph; difference = 6 mph.

Maximum torque: ZT = 230 Nm; Rover = 240 Nm; difference = 10 Nm.

Simon

And how Simon do you get faster acceleration on a 160 V6 with less power and the same gearbox ratios and final drive ratio as the 177?

The answer is you don't!!! It's impossible

Those figures quoted were possibly massaged to promote sales, after all who's going to go for a sporting MG model that's slower than it's Rover counterpart

I've done quite a few of these as have other T4 operators who offer the same upgrade, and every single owner has reported a huge difference in power and the way it's delivered.

I was the first to do it, it was on Canonites car if you'd like to look through his posts about it and the group dyno session against other cars including ZT 190s his came out on top of them all, the cone filter and stainless exhaust helped a bit. But it wouldn't have been anywhere without the upgrade

Here's the figures from the rolling road day:
https://www.the75andztclub.co.uk/for...72&postcount=1

Russ

[SD1too]

Originally Posted by BigRuss

And how Simon do you get faster acceleration on a 160 V6 with less power and the same gearbox ratios and final drive ratio as the 177?

Hello Russ,

If we are to believe MG Rover’s figures you clearly don’t get faster acceleration with the ZT. However, I would say that with a manual gearbox performance depends to a large degree on the skill of the driver so the small theoretical handicap could easily be reversed. Plus the exhaust tone and harder suspension all contribute to the impression of speed with sports cars.

You also ask why anyone would choose a “sporting” MG over the Rover. Therein lies the answer: image (and there’s nothing wrong with that).

By the way, according to MG Rover the final drive ratio isn’t the same:

Final drive ratio: ZT = 3.947:1; Rover = 3.944:1

Simon

[BigRuss]

The very slight difference in the final drive ratios quoted are just a result of the tyre size differences.

The gearbox itself is identical between the two cars. MG Rover didn't have the finances or resources for them to be different. New models were developed on a budget and the ZT160 V6 was a good example.
For the 190 the final drive they used the one from the 1.8 NASP. That's what helps give it the acceleration and why it revs a lot higher compared with the other 2.5s for a given road speed

Russ

[CivilSteve]

"Rover variant is 150, the MG is 160"
Or it can be 200

I'm still looking over the KV6 mapping , personal stuff is taking up alot of my free time and I'm now assisting with the pre-MEMS3 development. But if the stock files I have are correct (ECUs sold as Rover 75 180 & ZT 160) then there'll be a slight improvement in the drivability, especially in the mid/cruising range.
The ZT160 ignition table appears very rough with harsh peaks and dips with the 177 version being more smoothed out and having a little extra at the very top end. If I get time this weekend I'll try and post up a comparison of the two.

The ZT160 also as my understanding goes had the majority of it's power reduced through VIS motor control. Ie the top end choked off. Which would make quite the difference in the higher rev range

[Teflon]

Originally Posted by SD1too

Here are MG Rover’s performance figures (from brochures) for the ZT 160 V6 and the Rover 177 engines in a manual saloon:

0 - 60 mph: ZT = 8.8 seconds; Rover = 8.2 seconds; difference = 0.6 s.

30 - 50 mph in 4th: ZT = 7.5 s; Rover = 7.0 s; difference = 0.5 s

50 - 70 mph in 4th: ZT = 7.6 s; Rover = 7.0 s; difference = 0.6 s

Top speed: ZT = 131 mph; Rover = 137 mph; difference = 6 mph.

Maximum torque: ZT = 230 Nm; Rover = 240 Nm; difference = 10 Nm.

Simon

Genuinely puzzled here. Surely Simons post is supporting what the traders are saying regarding the 177 upgrade - i.e. the Rover in 177 guise has increased torque, higher top speed, and faster acceleration. Why the downer, or am I mis-reading (wouldn't be the first time )?

Cliff

[marinabrian]

Originally Posted by CivilSteve

"Rover variant is 150, the MG is 160"
Or it can be 200

Best of luck achieving that without substantial mechanical modification

[SD1too]

Originally Posted by BigRuss

The very slight difference in the final drive ratios quoted are just a result of the tyre size differences.

Russ; the final drive ratio describes the gearing only. It will not change whatever tyres are fitted. The "road speed per 1,000 rpm" will however.

The gearbox itself is identical between the two cars. MG Rover didn't have the finances or resources for them to be different.

The 3.947:1 ratio final drive quoted by MGR for the ZT160 was already in use in the Rover 75 1.8T.
There were eight different final drive ratios in total across MG & Rover models.

All data from MG Rover publications so please don't attack the messenger!

Simon

[trikey]

Interesting post, strangely enough the fastest ZT I have ever driven was a bog standard 160, the top end was amazing, the speedo was on 140 and the engine was still pulling when I ran out of road.

[BigRuss]

Originally Posted by SD1too

The 3.947:1 ratio final drive quoted by MGR for the ZT160 was already in use in the Rover 75 1.8T.
There were eight different final drive ratios in total across MG & Rover models.

All data from MG Rover publications so please don't attack the messenger!

Simon

The MGZT 160 V6 was launched in Jan 2001, both the Rover and MG 1.8 T models weren't launched until 2003.

The problem with quoting data from Rave and other MGR publications is that it often can be incorrect, some data is outdated, some is updated, but then leaves out the correct data for the earlier cars

Russ

[CivilSteve]

Originally Posted by marinabrian

Best of luck achieving that without substantial mechanical modification

On a 1.8T the stock hardware is good for ~200 give or take.





For fun, a comparison of the two base ignition tables. KV6 177(left) v 160(right)
The keener eye'd of you will notice the 177 appears more smoothed out with less dips, particularly in the midrange/light throttle zones