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

the main difference between the 145 and the 160 is the cylinder head and valves a remap won't simply bridge the gap.

Also remapping a NASP stock engine is fairly pointless anyway as there will be fairly small gains. Would be better off with fresh fluids and a filter change.

with the VVC engines you can "Lock" the exhaust cam to a specific profile and there is some info out there on this.

How is it possible to lock the exhaust cam when the VVC is on the intake cam?

:mbounce:Indeed this is a very good question...


I meant inlet :mbounce:


for info

http://forums.mg-rover.org/mg-r-modi...t-cams-499106/

Seen as we are on the subject of variable valves engine conversions... Have always been curious why no one ever had a go at dropping a Honda k20 into a ZS? Older civics (same chassis as ZS) get k20 conversions fairly regularly, so must be off the shelf engine mounts etc. Could go even harder and drop a K24 in there! Supercharged k20 is well over 300bhp...
Only reason i saw NOT to do it was purely cost!

Think you answered your own question there pal .... ;)

:joker:


George did a vvc ZS, it was ok, flew around track to be fair.

The biggest thing was how light the front end was compared to a 180.. It really had a nice precise turn in, which says as lot as i dont think the 180 is bad.

What good would that sort of power be in a ZS tho you wouldn't be able to use it all be lost though wheel spinning :hooray:

My MGF is a mk1 so runs MEMS 2.0 which isn't remappable. One would have to convert to MEMS 3 which isn't that difficult but does require some effort.

As above, there are some mechanical changes but there is also an updated management system.

As with any mapping, it isn't just about the headline maximum BHP, there is more drivability and the map can be written to suit any alterations within the mechanical package.

Dropping a Honda engine into a ZS is more than mating the engine to the gearbox, the engines are on the wrong side for a start.

k24's no harder than a k20, k24 285bhp nasp!

not if the jobs done properly, granted most diy/pseudo professional attempts built with a box of 'off the shelf' shiny bits are rarely much cop, but a well designed conversion will be both tractable and drivable

If your clever with your right foot any power level is manageable, with 322bhp on tap i can't remember the last time i had an uncontrollable wheel spin? And thats driving hard.

Granted, but most parts are available easily from old Hondas? Drive shaft would be tricky but I would imagine something is available. Not as easy as a T16, VVC or turbo K but.... Do able

there is honda civic I know of with 560bhp (low boost, higher boost is over 800bhp) and its as drivable as any other car regardless of the right foot, the power delivery from the engine and its mapping make it easy to drive and even with such fast acceleration the chassis design prevented it from lighting up its wheels and steering itself to the nearest ditch.
That was was a complete car design tho, rather than just chucking in a bigbhp motor into an otherwise unmodified car.


The k conversions would be hard work with lots of custom parts.

The b16 motor such as used on the mb civic should be easy enough? The b18 is essentially the same thing as found in the teg (which is similar also).
The b18 nasp will tune to 285bhp (I know of one out there and its fast)

Problem with a fancy honda motor in the zs is it will always be a 4/5 door zs and carry the weight, the honda eg/ek/dc2 came as 3 doors and were lighter, the eg weighing in at sub 900kg.

Zs doors don't weigh a lot when stripped though I've not weighed my zs yet but am aiming at 950kgs ish, not a massive amount off?

Doors come in at around 29kg with glass, winder motor, locks etc.

990 with cage is about the lowest zs weight I've heard of.

Weighed mine at 11kgs as they're stripped out with Perspex instead of glass

Dry? Can't see how a dc2 can be 100kgs lighter than a zs

wet, some fuel no driver.


the eg is the light one, the ek is still lighter than the zs as is the dc2, the jdm dc2 of certain years used a thinner steel which saved 40kg in itself.

so you'd be better off with a mk2 with it's thinner steel and thinner paint.

lol.

did the mk2 really have thinner steel? the front wings certainly 'seemed' thinner, but what about elsewhere?

They suffer more with rust but that may be down to quality of the steel and paint.

I don't think the metal itself was thinner, more the quality and coating which caused the apparent corrosion issues.

I remember my old workshop Manger brought a MK1 ZS180 new then when the MK2 came out he traded the MK1 in and got a new MK2 180. I'll always remember when he packed it up and brought it into work next day you could see the base coat though the paint. Not sure of the paint code (but was the black which has the green base coat) and it had to go back in to have a complete respray believe it or not. It also had a full set of door handles before was a year old he wasn't happy as he never had any problems with the MK1

Pearl Black - PBT

Oh if anyone wants a VVC engine I have one in my garage :)

I might be interested in a spare maybe what you asking

143 or 160?

145

Can get full info if people are interested

Might as well buy my 1.4 lump and swap the top end over if it's going in a zed.