Variable intake runners

[einarp]

Mark,
So you have convinced me. Not that I hadn't expected this.
But _how_ do I go about it the DIY way? Anybody done this?

Hey! Where can I buy 6 cheap used trombones for hacking?

Seriously, I imagine lots of problems keeping such a
device from sucking false air in through the runner splices.

What about using runners tuned for say 2000 RPM, to give me
some more shove before the turbos cut in at 2000-3000?
Using the web page that calculate runner lengths, I found
that they would need to be really long to do that. Would that
have any adverse effect at higher RPM?

I realise I should have read the SAE paper(s), but I don't
have them. (I'm a DIY'er you see. Not working in the automobile
field at all.) Could you give some concentrated wisdom here?

I will swap to an injected engine this spring, and next winter
I plan on converting the current engine to injection. This
will include making a new intake manifold to take the injectors,
so I might as well make them the "optimal" length.

I'm also "brainpicking" the Weber Marelli ignition and injection
computers to gain some insight, and find what tables I can play
with. Anyone here who know these units? Both the boxes have
unused analog inputs, so it would be possible to influence them
by hanging pots on these ports. (And modify the software to look
at them of course.)

>          What do you think Mazda used to win Le Mans (1993 I think). Their
>triple rotor engine had a servo system like you propose. They had a
>serperate map just for inlet position (length). There is an SAE paper on
>this I will see if I can find the number. F1 has used this for a while. I
>think you guy's have to read more it's all out there if you look.


--
einarp at ade.no  ( Maserati Biturbo Spyder )