I know exactly where you're coming from, I have a rb30 carby and don't won't the hassle of an efi conversion. And besides a carby setup tuned with rising rate reg would probably cost under 1k, tuneable efi computers start at 1k no tune, then you still need upgraded afm, injectors, fuel pump.
Hi Ash, thinking the same about my own not wanting to efi but turbo or supercharge with a blow through style,these are my thoughts:
Turbo,oil cooler,manifold,intercooler,piping,air intake and carby mods, not sure what needs doing to the carb but years ago webers were the go and 1 of a xf falcon would be a good carby,there is a post on the forums about using faclon carbs on petrol patrols. but im sure the standard carb would work.....As long as the boost is under 7psi things should be good even for a higher k/m engine reliablity wise...
I myself have like the supercharger idea for the lown down tourqe they give and i think if u get your hands dirty both ways can be done for a grand and under......
But me personally like carbys cos im old,what im used to and if something goes wrong out the bush.........the old K.I.S.S method.....keep it simple stupid..
My two bob.....:bananada::bananada::bananada:
Scoob... i go with the KISS principle too which is why i'll be going the EFI turbo method on my RB30, way too much **** to sort out going with a carby turbo setup. Much easier getting everything from a VL turbo and fitting it to yr patrol.
Whats involved in getting the mixer to pump in more gas? Have you somehow modded it to equalise the pressure on the diaphram when it's on boost? Coz the straight gas turbo is something i may end up doing.
another thought use a side mounted blower and have the carby befor the blower so it is still sucking and not under any harsh boost a little thoughtful plumbing will be needed tho ill look later for pictures of something with this set up would make an easy power gain with less hassels
here is two different styles of the carby before the blower
1 is a valley style blower bolted to the top of the manifold
2 is the side mounted blower with the carby craftily mounted above it (this option would be better)
personally i reckon fittin the efi and turbo set up would be alot cheaper and easier than trying to get a turbo/carby set up running right.
This is what i plan on doing to my RB30 GQ eventually can either try source all the parts individually or just by a VL wreck for a couple hundred $$.
Fitting the EFI along with the standard ECU isnt overly complicated being same motor everything is pretty much plug and play run 12v and an earth to your ECU and its done.
GQ's run a series 2 RB30 block i believe so oil and water lines are already tapped making adding a turbo even easier.
my ultimate combo would be a RB30 ser 2 block, RB25de head with a medium sized turbo strapped to the side.
RB30 torque, twin cam head revs and a turbo with minimum lag
EFI is the way to go, ive been back yard playing around with carby turbo sixes (old holden engines) for over 15yrs, best thing i did was going EFI turbo (rb30et)
If you want a carby engine to run nice and not blow up ,be prepared to stuff around for a long time ,all up I think EFI will work out cheaper by the time you factor all that in.
If you think EFI will be a heap more expensive, keep in mind ,I sold a "complete" A8 engine (genuine vl turbo) only done 140Ks, including turbo ECU,wire loom, starter, aftermarket intercooler and surge tank all for $1000.
I have done two blow through carby setups now. I can only suggest going efi. Even an older aftermarket computer would be so so much better that a carby. Not to mention the frustration of getting a carb to give acceptable results. Must of the efi hardware you could probably get for free, and do your research and find a good value secondhand computer that will do what you want it to (maybe $500). I think the inlet manifold off a vl accepts the most common 14mm injectors so lots of choices there to scavenge bigger ones. Don't bother with a fancy fuel reg, a stock na vl one will work. If you really enjoy challenges id say give a blow through setup a go, by I can't see it being cheaper than efi. Sorry about the long post.
I'm in the process of fitting up my turbo to my rb30 as we speak, i went the efi mnths ago because of issues with the carby on hill climbs(nearly got me killed) i would think that a carby set up with turbo would still have float issues if you go off road and i couldnt imagine it would be very economical. The member to speak to about this is Brunsy he has been playing with this stuff since they were released, you can run all standard ecu, pump, injectors, etc and all on 7psi even on an old engine provided you dont kick the crap out of it day in day out. The exhaust place that i use to supply all my bits for my dump pipe said he has done this to plenty of patrols, r31's, vl's and said on average he gets around 170kw at the wheels which is pretty good and it has been said you should have more power than you will need for off road and everyday driving and towing.