im just hoping someone will have the info i need. ive got a GX head thats had A15 valves put in and ported slightly (all done by jts) ive also got a A14 bored with A15 pistons and crank. using jetted GX su's and extractors will i get 100-110hp out of this sort of setup. i want a lil sorta hp out of my 1000 ute but i dont want to go through so much petrol

Not 100% certain, but one thing's for sure, the SU's will hold you back, especially if you want to run a lumpy cam.

The Su's should be fine. Remember they are a much freer flowing carby than a weber as there is nothing at all in the way once the throttle is fully open. So you dont need as big size. I remember seeing a flow chart that someone put up or something that said SU's were good for around 7400rpm and twin 40s for around 8000rpm.

bump

115hp yes but more you will need to extrude hone the twin su manifold and run 1.75inch ones, knife edge the shafts and butterfly and youll see better economy and as much oomph as webers. Response is not like a weber but all round drivability is much better. Also very easy to adjust.

I have about 135 hp
with a15 1200 gx head light fly wheel
but do run twin 40 ml webers
Cheers

Sounds crazy, but i get great fuel economy out of my twin 40 setup on an a15. Its not much worse than a standard 1200. Honestly! Its been on a dyno to set it up properly and it runs sweet. And what about the sound! Sounds similar to a big capacity road bike. Ive never run strombergs or su's on a datto, but i wouldn't even consider it. Not after running the webers. I reckon it would be a definate step backwards, especially when you already have the twin 40's.

does it really matter if you make 100bhp? just see if you are happy with how it goes. So often i've seen young guys who are happy with the way their car goes come away really dissapointed from the drags or a dyno, because they didn't get the figures they wanted/expected. Who really cares - it doesn't change the way the car goes. Just enjoy what you get. SU's are a nice carby for a strong street engine. I've seen EH's run into the 13's with triple SU's so they can't be all bad.

The best thing about an SU type of carby is that it has a variable venturi. So if you have the correct needle for your engine the carbys should supply the correct air/fuel ratio through the whole rev range.

Of course you will get 100hp+. How big is the turbo?