As an amateur aero dynamicist ( I ran an avaition basis involved in the design and operation of 'special operations' ) it didn't seem logical to have two airflows hitting each other as in the case of the stock airbox and its lid with lateral fins moulded into its top and the Mr.5 just entering the inner plenum chamber from the opposite direction.
I though blending the airflows was intutively better but as I discussed with both the fluid dynamacist and the dyno operator you never really no till either you dyno it and /or use something like Dragy on the road..but for me its scary enough trying to do 3 rd gear pulls on a public highway in rural Scotland where most roads are not flat and pretty bumpy.
I did mess around with 3 dimensions of tubing 30mm , 40mm and then 50mm..plus 5 different Pipercross foam filters, mostly smaller foam ones.
I wonder if the coen design of the Pipercross filter housing helps..alledgelly a copy of a Lotus design..
Only the final design was road tested and dyno tested.
For completeness I've pulled all the data logs I've done with these guys on both my N20 powered E89 and then the current N54 powered E89 for discussion and any observations.
For safety reasons (I didn't want bits getting sucked into the turbos) all my Mr.5 assembly immediately either side of the airbox hole I made are all glued together.
I would have liked in an ideal world to alter the angle / remove the right angle feed in the inner plenum chamber but time / cost and the sheer surprise that it worked (so well) meant we just quit while we were ahead.
As it debuted on V13 adn made such good numbers we then did re-flash V6 to confirm that the Mr.5 mod was the cause of the changes, as well as changing filters etc..the only thing we didn't do, apart from DCIs was try a V6 run with no airbox lid on at all..
However since I don't like the DCI sound (and have DVs rather than BOVs) neither a no lid and / or DCIS were considered useable for me..appreciate for science and the record that in an ideal world it should be tested.
At the moment no plans to go back to the dyno.
My tuner suggested on the basis of the numbers /Mr.5 that we could maybe reach 600 bhp with more boost but I've decided for street use / longevity I'll stick..he does plan to do a 'polish' to the V13+ which was a rough and ready last minute update.
We have had a boost leak that took me as a newbie much head scratching to solve ( although once as suggested I got a vacuum leak kit it was straight forward to find the hose that had been incorrectly fitted by the Indy who had fitted the turbos) plus a cyl 6 shutdown misfire which I understand my tuner after much datalogging has desensitized..I think..I do have a M2 DCT DMF to fit over the winter.
Maybe I'll get curious..again!
I'd like to thank my tuner Carabuser for all his help, patience and the 15 tunes he supplied plus much techncial discussion.
Also Dark Peake for discussions on the Mr.5 plus other E89 mods.
