downdraft fuel injection

[unclemark123]

i recently posted questions about mappable ignition/fuel.
well i think if im going to do it i want to fit some sexy downdraft throttle bodies :-)

if anybody has done this can you help!

im good at the fabrication side of things, but not so good at the technical side.i will hopefully make a mock up on an old rv8,then have the ecu fitted and mapped in conjunction with fitting the efi.

for starters i was thinking bike throttle bodies, but any reccomendations? and how do you size the injectors/throttle bodies/bores?
and secondly does anybody make a suitable pair of inlet manifolds?
is there any advantage/disadvantage to having a really short inlet after the tb? so the bodies are close to the head?
pictures would also be most welcome
Mark :-)

[eliot]

do a search over at www.v-8.org.uk/forum/

couple of people have done it (and intrestingly, removed them)

Some photo's can be found on my rover manifold archive too:
www.mez.co.uk/ms12.html

Eliot.

[bluebottle]

Been thinking about the same for some time now, take a look at these two threads;

[url]www.pistonheads.com/gassing/topic.asp?h=0&f=&t=336807[/url]

[url]www.pistonheads.com/gassing/topic.asp?h=0&f=&t=257279[/url]

[shpub]

Been there etc. Bike throttles are simply not big enough if you want real power IMHO. Yes special inlet manifolds are needed and are key to getting the installation correct. It is an expensive route but the benefits are worth it as it does allow you to tame aggressive wild cams for daily routine use.

The question is why do you want to do the mods? If you want power and more power then it is the way to go but unless you know what you are doing then I would recommend going to someone like John Eales who can advise on all the details and set it up for you. John can get 360-375 bhp with this type of setup and without compromising reliability.

To be honest if you are thinking of this route along with an aftermarket ECU then it is worth considering selling your original engine, adding to the funds and then get a brand new engine to drop in. This is exactly what I did with the 520SE. That way you start with a strong fresh engine as a good platform for any other mods and not worrying about will this take it and so on.

If you want some more piccies try www.shpub.co.uk/tvrservices/index.htm

Edited by shpub on Thursday 3rd May 07:59