VVC upgrade options?

[Mike Kirby]

I have just bought a VVC with anti-cav tank, wide track suspension, uprated brakes and a 6 speed gearbox. Although I am very happy with it at the moment I was wondering what engine upgrade options are available to me in the future. Does anyone have any experience of the Minister 170bhp upgrade for instance?

[CHRIS CLARK]

Try Dave Andrews website ('K' series geru!!!)

 

Edited by - chris clark on 12 Nov 2001 20:31:53

[Roger King]

Mike,

 

The VVC is a good basis for serious tuning because it already has a big valve head. To some extent, I would advise you to either leave it alone, or go the whole hog with a nonVVC solid cam conversion, forged pistons, etc. Like this, you could get 200bhp+ quite easily.

 

Not familiar with the Minister upgrade, so I can't comment on this.

[Bob Corb]

The minister upgrade involves fitting a larger throttle body and cleaning up the ports. Its basically the same idea as the new MGF Trophy 160. They charge over £3000 for this conversion, plenty of people in the club do this sort of thing themselves. Rovers own large throttle body (part no MHB000131) is hard to get hold of as they are in big demand for the production of new cars at moment. The TB alone is worth ~3BHP. The minister upgrade uses a std ecu.

 

Bob

[Bob Corb]

Sorry that new throttle body is a MHB000261.

[kenny.]

I had a Rover 200 VI a year or so ago with standard VVC motor and specced at 143bhp. The new MG 200 stlyle car has same VVC engine but I have heard it's specced at 160 bhp.....how have they gone about this I wonder?, it looks exactly the same under the bonnet.

 

Kenny HPC

 

 

[PAUL MARRIOTT]

Bob, you have told me twice which car the larger TB was fitted on, but can you remind me again please.

 

See you on Tues?

 

Paul M.

K7 PDM

 

 

[Bob Corb]

The new 160PS/158BHP (in the MGF Trophy and MG ZR) engine has a slightly higher compression ratio (10.8:1). This was done on the early MGF Trophy by skimming the cylinder head. Normally the compression ratio for a VVC is 10.3 to 10.4:1. Nowadays they have a new taller piston so the heads are std.

 

A big factor in the power increase eqn is the exhaust. The old MGF/25 exhaust had quite high back pressure. This has been cut down by fitting a special exhaust with an actautor operated flap. You can see the flap behind the bumper on the 25. The actuator looks like a turbo wastgate actuator bolted to the side of the tailpipe. This keeps noise (and hence back pressure and power) down at low speeds by closing one of the tailpipes and re-routing the gas flow thru the silencer. At high speeds the valve opens up to achieve full power. The good news for us low flyers is that all our exhausts are low back pressure (hence caterham quote 150BHP instead of 143BHP).

 

The ecu has been fiddled with slightly to although this doesn't do much for power, more for driveability. The larger (51mm instead of 48mm) throttle body is responsible for a further 3ish BHP. This throttle body can be retrofitted to most K series in current production but the VVC needs it most. The throttle is std right from 1.1 8valve to 1.8VVC. In summary I think the std engine produces about 145BHP usually, the head skim may be worth 3BHP, the exhaust 7BHP and the throttle another 3BHP (145+3+7+3 = 158BHP).

 

If you do a nice porting job on a VVC and manage to frig the thing to run happiliy with a caterham competition exhaust you should be able to achieve 180BHP. Considering that VVC engines can be found for a grand (new) and the fettling can be done for next to nothing it seams like a bit of a bargain to me. Although I put my engine in std form a friend of mine (Al Wain, say hello Alan) got his skimmed and ported before he fitted it. He doesn't have the large TB yet but that will be the icing on the cake. I'd love to see what it make on a rolling road in comparison to mine. I'm tempted to do mine over the winter even though I've only got 1500miles on the clock.

 

Paul, I'll see you tuesday.

 

Bob