Rover 'twin plenum'... still viable or past sell-by date?

[900T-R]

As subject line says really... on a 'sorted' engine (in my case a 4.3), where does it sit in terms of performance benefits (esp top end) compared to 72 mm throttle plates in OE plenums, carbon twin and triple plenums (v.v. expensive), JE triples et al? Or are they strictly worth something because of their rarity and for folks who want to retain a standardish underbonnet look?
What about the throttle response... will it be jerky around town with a small throttle opening producing most of available power, or is that just on std engines for which 2 x 65 mm might be a tad too mujch given the airflow restrictions in the engine itself, or is it just ballcocks period?

Ta muchly for any insight...

[tubbystu]

Seemed to work quite well on my Sdi Vitesse twin plenum - I don't know the science but you presumably get more airflow delivered more evenly to a wider area within the plenum

[eliot]

funny how you see these things appearing on ebay from time to time isn't it!
I would love to know how many get fitted and stay there. I bet there is only one in existance which just gets 'bayed around the country every 6 months.

[tubbystu]

The Sdi Vitesse Twin Plenum was only a 500 homogulation production run (engine spares were either obviously easy or almost impossible to source) so unless it was fitted to other RV8 powered vehicles there cannot be too many floating about - you also of course need the cast splitter for the AFM.

[eliot]

tubbystu said:

The Sdi Vitesse Twin Plenum was only a 500 homogulation production run (engine spares were either obviously easy or almost impossible to source) so unless it was fitted to other RV8 powered vehicles there cannot be too many floating about - you also of course need the cast splitter for the AFM.

And that splitter reduced the inlet back to around 65mm! I can only assume that the throttle would be very on/off, and make it tricky to drive unless you put a cam on the throttle to make it more progressive.

[Duke Thrust]

You need twin AFM's to get the best from it.

I'm planning to do exactly that with my Vitesse.

[clive f]

or just get rid of the AFM altogether, then achieve the gains that a twin plenum will give you.

[Else]

eliot said:

tubbystu said:

The Sdi Vitesse Twin Plenum was only a 500 homogulation production run (engine spares were either obviously easy or almost impossible to source) so unless it was fitted to other RV8 powered vehicles there cannot be too many floating about - you also of course need the cast splitter for the AFM.

And that splitter reduced the inlet back to around 65mm! I can only assume that the throttle would be very on/off, and make it tricky to drive unless you put a cam on the throttle to make it more progressive.

The throttle mechanism has a 'cam' effect built in. I tried mine without it and it was very difficult to pull away smoothly. You either, nearly stalled or spun the tyres at every junction, not pleasant (unless you like lighting your tyres up that is).

Andy