hey guys so im thinking of doing the whole makeover for my A15, dicktator wated sperk engine management with an opel corsa coilpack only one prob, i have no clue witch throttle bodies to use, some people sugested the toyota rsi throttles but others say they are too big and i tend to agree, any ideas?

silver top 4age quad throttle bodies. itb I think for reliability would be the way to go..

if quad 32mm itbs are good enough for a 1.6L turbo making 148hp atw then toyota ones are too big starting and they start from 42-44mm. I learnt a single 48mm (halve a weber 48 dcoe) is enough flow for 200hp so going bigger is not always better.

so i have to het 32mm throttles? what size is the silvertop's?

The best ones to use are the ones with a close enough bore spacing to the port spacing and with the throttle connection in a convenient place. You could use some of the bigger throttle bodies but this is entirely relevant to your engine specifications.

Other options are to machine some chokes up, or to purchase throttle bodies of the correct bore size.

If you can put up with the poor low rpm performance then some of the bigger bore stuff shouldn't be a hurdle.

just realised you have a 9000+ rpm motor, how big are your ports?
32mm is a bit small for your app maybe 36/38mm is better but can
get away with much bigger yet some good results are had with
itbs just a tad bigger and as close as possible to your inlets
ports with long v. stacks like Mark Lanyard signature ITBs.
These units below are very well received by L series racers
and have shown to outflow anything on the market atm.

D, I know the bores on Toyota quads can be a bit big, 44mm from mem..
Where would you get 36mm from?
Toyota quads are meant to be a more relatively easy install, fitting on to a webber manifold yes?

bike ITBs are dirt cheap

Heres just one of the many 36mm setups on 4cyl 1.6-2L motors
http://www.bimmerfest.com/forums/showthread.php?t=528121&page=2

http://www.d-series.org/forums/natura ... 0mm-itbs-good-size-2.html

This is the best guide Ive seen for reference of all thing bike itbs
http://www.msextra.com/forums/viewtopic.php?f=94&t=6602

I guess 32mm throttle would fit in it.

okay so my engine spec is: a15 with heavily ported head and aftermarket valves as well as a double valve spring kit, lightweight conrods with pocketed pistons and a lightweight a12 flywheel and lightweight pully set, 290' highlift cam(11.2mm lift) custom branch and exhaust system, and upgraded rings and bearings allround and compression ratio of 10.7-1 and engine is capable of 9700rpm