Vvc
 

Following the discussion in http://www.themgzs.co.uk/vb/showthread.php?t=30464 I thought we could discus the merits or otherwise of the K4 VVC in the ZS.

We have a ZR160 VVC and a MGF mk1 VVC so the earlier 143bhp version.

I like both, the ZR is obviously more powerful than the MGF, even with the 52mm TB and a K&N Apollo but personally I prefer the extra torque of the KV6 (but then I even prefer it over the T16 turbo in my Maestro).

Imo I think its a waste of time, having had ZR120's and my ZS120, then my ZR160 track car for the little performance gain I dont see the point. The 160 is only any faster at really high revs. Though the mid range id say the 160 has a slower throttle response than the 120 anyway. Add in the time and cost of doing the conversation, the possibility of VVC faults a lot of those engines are having now cant see why and tbh I've never seen a stock VVC engine make 160PS anyway. I would go down 2 routes if you want more power but don't want to pay out big bucks for a piper cam kit, throttle bodies and so on.....

1. VVC exhaust system (4-2-1 and one catalyst), MGF 135 cams, 52mm throttle body and a remap.

Think my VVC TF 160 is a great little car.

My Derv with a few tweaks is as fast and so much better drive on a long journey.

the vvc in a zs needs the g box and the conversion doing in a way that does not sacrifice the gains of the vvc - amazing how many just bolt up a 120 exhaust to the 160 motor.

Whilst the vvc even with the 170 map offers no gain below 4 or 5k, it at least gives you the power/revs if you need it, either for a safe overtaking manoeuvre or a day at the track.

It is no v6 and never will be, but the k4 offers great economy and a lighter front end, the v6 has torque but needs a 4.2 final to bring it to life.

Horses for courses.

The vvc cost more to produce than the v6, hence rover building the k4turbo, which is a great engine for the road.

To add to that, the vvc in a zs is not much slower than a v6 at the circuit on raceday, the v6 is faster, but not by miles.

Of the 3 relevant cars we have the ZR160 is quickest off the line but the MGF143 is very close and soon quicker but by the time you get to 50mph the ZS180 is quickest and continues to be so to the (speed?) limit.

Where the KV6 really scores for me is when traveling at 30ish plus and you drop a gear and floor it.

I would love to up date my MGF with a MEMS 3 ECU so I can get it remapped and it'd be close to the later 160.

Think you would be surprised by a map, before my VVC hub failed at Bedford autodrome there was a MK1 ZS180 and he couldn't catch me on the back straight im sure I was almost at 130mph before braking. The guy actually came over and asked what mods had been done

I doubt the ZR will get mapped, it's my wifes car and she is happy with performance with no more than a loud exhaust.

I meant if you gad the 143 updated and mapped cant imagine be any real different between that and a 160