At the most recent meeting of the engine working group last Tuesday it emerged that constructors are looking for an engine formula that will provide simpler and lighter engines, following a considerable weight increase since the introduction of the Hybrid power units in 2014.
The current engines are V6 and 90-deg. So they do not have even firing intervals. If sound improvement is desired in 2021 then mandate even firing intervals. You can make it easier by allowing 60-deg V's instead of 90-deg, or you can keep the 90-deg requirement and the manufacturers will have to use cranks with offset journals like the old 90-deg GM V6.
The mandated 90-deg V-angles is what prevents current engines from having even firing intervals and therefore good sound. It's almost like the current rules were written by people with lots of racing experience and very little real-world (road car) experience!!!
this seems to be a good time to say (given that I have said otherwise about the Dino in the past) ......
60 deg V6 4 strokes 'of course' don't have even firing intervals unless they have 6 crankpins
ie all those F1 F2 and sportscar and production Ferrari Dino V6s (65 deg) had 6 crankpins (spaced 5 deg off) for even firing
though they presumably had road car use in mind from the start
but by 1961 the dominant (eg Phil Hill WDC) rear-engine car was 120 deg 3 pin so a lower smaller lighter higher-revving engine
no 60 deg 'real' ie 3 pin 4 stroke V6s seems to have ever existed
the balance and the crank design potential are quite poor
though Nye seems to say that TAG-Porsche initially offered to McLaren angles from 60 to 120 inclusive
how close to even do firing intervals need to be for a good sound ?
we might wangle the present engines to eg a 100 deg bank and 3 slightly split pins and firing intervals 110 - 130 - 110 - 130 etc
90-150 is my favorite for V6, nice and rumbly, I suspect at least one manufacturer is doing this, it can be done with the current V6 with the right firing order(there's at least 2 that will give this). The one I favor also works well to suppress 1st 3rd 6th and 9th order harmonics.
On an unrelated note, these engines I feel, do have road relevance, if for nothing else it shows how efficient high compression air diluted motors with forced induction and dual injection can be.
These regulations don't exist in road cars so with economies of scale some of the tech can be implemented into road cars, particularly since the trend is going to high compression forced induction. Using only a motor on the turbo would save massively on the control electronics. Transmission integrated MGU's are already well developed by most manufacturers so I could see an super lite version of this tech at least considered.
Last edited by godlameroso on 30 Dec 2017, 19:10, edited 1 time in total.
90-150 is my favorite for V6, nice and rumbly, I suspect at least one manufacturer is doing this, it can be done with the current V6 with the right firing order(there's at least 2 that will give this). The one I favor also works well to suppress 1st 3rd 6th and 9th order harmonics.
All of them are using it since its the only firing spacing for a 90 deg V6 )
I don't think that you can twin scroll a turbo from a 3 cyl bank alone, so the lag would be awful without MGUH. Better to keep a larger twin scroll single turbo. It's a common RB26 Nissan mod for track use.