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[Diamond Black Geezer]

So my hypothetical question today is... if I want to swap my short plenum for a long plenum - what do I need? From years of Omegas and OOFing, I think...

-The long Multiram plenum itself
-Top-mounted black breather 'panel' from throttle body to rear of Multiram
-The 2 x front thick black rubbery plastic hoses, part of the induction
-Longer throttle cable (and Cruise Cable?)

I think throttle body can be reused, and there aren't any other hoses etc I've forgotten... Would I need anything else?

Also (am I going too anal/pedantic?) it needs to be a model fitted with an EGR, so 2.6 / 3.2s are no good, correct?

Because I aim one day to fit G-Cams to my lovely, so too, the long plenum change was on the cards. Because the threads that join the EGR to Multiram are rather worn on my short plenum, it might be worth doing the changeover now-sh. (G Cams will have to wait unless someone wants to sell me some for £20! 

Cheers! 

[The Red Baron]

got most of the bits here in the shed. no g cams though. 

[Diamond Black Geezer]

No G Cams?? But I offered you £20 goddammit!!! 

Good stuff. It's another 'on the cards' thing, same as the shock absorbers, painting and poly-ing a set of wishbones etc... Seems a lot to change just to repair three worn threads, but as mentioned in the previous post, it's also helping power/smoothness of operation etc..

Stay in touch...may be interested 

[Marks DTM Calib]

The 2.6/3.2 plenum has the advantage of no EGR.....so it can be removed and the solenoid only left to fool the ECU....or you could be an EGR tricker circuit.

Throw in some 2.6/3.2 manifolds and it gets even easier.

[Diamond Black Geezer]

Ah so.. I thought when the EGR went, so too did the 'proper' throttle cable, replaced by the drive by wire type? Not an expert on the YxxXE engines.

Getting rid of the EGR completely suits me!

[Marks DTM Calib]

Oh good point, I had forgot about the need to secure a throttle cable to scrub that idea.

[Nick W]

The 2.6/3.2 plenum has the advantage of no EGR.....so it can be removed and the solenoid only left to fool the ECU....or you could be an EGR tricker circuit.

Throw in some 2.6/3.2 manifolds and it gets even easier.

As I have the later manifolds, I've blanked the EGR by cutting the connecting tube and turned a bung to fit with the nut. What is required for an EGR tricker circuit, as this would be a much neater solution.

[Marks DTM Calib]

Something like this:

https://z22se.co.uk/threads/fitting-the-egr-cheater.5891/page-6

[Diamond Black Geezer]

 

This is me recognising when something's above my head! Impressed with anyone that understands this electrickerey, and more than happy to pay for the time and skills of those people. Are there any OOFers willing to make a run of EGR cheaters? It's a very neat, subtle solution to a problem we all have. Just need a suitable small 'box' for it to sit in, keep the engine crud off it and you're there 

[minifreek]

The long nose conversion on the 2.5 is well worth the foort, I did it to mine...

I'll give you an example...

Spec of my engine...

X25XE 2.5 Ecotec engine
Long nose plenum conversion off a 3 litre MV6, using 2.5 throttle body, used same throttle and cruise cables, no need to extend them or replace them...
Vectra Challenge blueprinted race heads (not much difference or much gains to be had from these heads, they're built more for slight better flow than standard heads)
4 x G cams fitted
3 litre lower divider fitter (slightly better flow than the 2.5)
3 litre bottom pulley (quite a bit lighter than the 2.5 bottom pulley)
Long nose plastic intake pipes fitted
Vacuum actuators for the mutliram wired open (I know theres haters out there but meh....)
Standard exhaust headers, will be replaced with either 2.6 or 3.2 headers at a later date...
K&N airfilter with cold air intake

This spec made 190BHP on a rolling road Sunday 12th October, the operator said it would produce more but the gearbox kept changing down when he planted his foot whne trying to get a power run... he estimated it would be just over 200BHP at the flywheel...

All worth doing, but if you change the 4 cams for 4 G cams you WILL lose bottom end torque, but most of it will be replaced with the long nose plenums...

Good luck

[Broomies Mate]

This spec made 190BHP on a rolling road Sunday 12th October, the operator said it would produce more but the gearbox kept changing down when he planted his foot whne trying to get a power run... he estimated it would be just over 200BHP at the flywheel...

It's an Auto, those figures mean nothing.  RR cannot possibly give anything accurate due to the Torque Converter.

I've had RR results ranging from 170BHP to 220BHP from the same car on the same day.

[Diamond Black Geezer]

The long nose conversion on the 2.5 is well worth the foort, I did it to mine...

I'll give you an example...

Spec of my engine...

X25XE 2.5 Ecotec engine
Long nose plenum conversion off a 3 litre MV6, using 2.5 throttle body, used same throttle and cruise cables, no need to extend them or replace them...
Vectra Challenge blueprinted race heads (not much difference or much gains to be had from these heads, they're built more for slight better flow than standard heads)
4 x G cams fitted
3 litre lower divider fitter (slightly better flow than the 2.5)
3 litre bottom pulley (quite a bit lighter than the 2.5 bottom pulley)
Long nose plastic intake pipes fitted
Vacuum actuators for the mutliram wired open (I know theres haters out there but meh....)
Standard exhaust headers, will be replaced with either 2.6 or 3.2 headers at a later date...
K&N airfilter with cold air intake

This spec made 190BHP on a rolling road Sunday 12th October, the operator said it would produce more but the gearbox kept changing down when he planted his foot whne trying to get a power run... he estimated it would be just over 200BHP at the flywheel...

All worth doing, but if you change the 4 cams for 4 G cams you WILL lose bottom end torque, but most of it will be replaced with the long nose plenums...

Good luck

Cheers for the details. There's a couple of bits in there I never thought of, too. I don't know exactly what power I'll be pushing out, and I appreciate that Autoboxes do do strange things to power outputs etc.. I'm not actually too fussed about the figures, on a rolling road (might be fun to do it one day, though) However, safe to say its releasing some extra potential from the engine, which was 'stifled' in order to keep the power output different enough from the 3.0 / 3.2.

Really looking forward to doing this. One day!

[minifreek]

This spec made 190BHP on a rolling road Sunday 12th October, the operator said it would produce more but the gearbox kept changing down when he planted his foot whne trying to get a power run... he estimated it would be just over 200BHP at the flywheel...

It's an Auto, those figures mean nothing.  RR cannot possibly give anything accurate due to the Torque Converter.

I've had RR results ranging from 170BHP to 220BHP from the same car on the same day.

Im still happy with the results from basically 'off the shelf' components that are quite easy to get hold of

But I do understand what you mean