Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Ian_D on 17 November 2009, 13:35:52

Title: 2.5 / 3.0 Plenum
Post by: Ian_D on 17 November 2009, 13:35:52
I know the Plenums are designed for the engines.

And the 3.0 V6's have a longer plenum than the 2.5's.

What would be the outcome if I fitted a 3.0 Plenum to the 2.5? I'm guessing that it would effect the torque curve? but in what way, I dont know. ::) ::)
Title: Re: 2.5 / 3.0 Plenum
Post by: Boracic on 17 November 2009, 13:47:21
My old 3.0 has the short type, I did wonder if replacing it would make any difference
Title: Re: 2.5 / 3.0 Plenum
Post by: tunnie on 17 November 2009, 13:49:46
3.0 Snooped plenum enabled better breathing for the 3.0, 2.6 had this due to the DBW gubbins it needed, otherwise it would have had the short.

2.5 actually works better with the shorter plenum if i remember correctly, not sure why, just remember DTM saying so
Title: Re: 2.5 / 3.0 Plenum
Post by: Andy H on 17 November 2009, 14:00:26
Generally speaking tuned inlet (or exhaust) systems are longer for lower resonant frequencies and shorter for higher frequencies (or rpm).

It seems plausible that the 2.5 might be able to or need to rev harder than the 3.0 (due to smaller pistons or shorter stroke, can't remember which on the Omega)
Title: Re: 2.5 / 3.0 Plenum
Post by: Marks DTM Calib on 17 November 2009, 14:13:35
Plenum size needs to be proportional to engine cc....hence smaller plenum.

piston and stroke size are smaller on the 2.5
Title: Re: 2.5 / 3.0 Plenum
Post by: Ian_D on 17 November 2009, 17:07:32
Would there be much of a negative impact on fitting a 3.0 plenum to a 2.5?

Reason been is more to do with under bonnet space / layout. However if performance will be effected in an obvious way then I will leave it as is. :-?
Title: Re: 2.5 / 3.0 Plenum
Post by: tigers_gonads on 17 November 2009, 20:28:24

slight hijack of the thred here
but
is they any differance between the 2.5 and the 3ltr (short) plenum ?