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So, I had this stupid idea seeing as how I scored two 350 holleys for nothing, that i could get an RB30 that costs about as much as last nights dinner at the pub, an RB25DE head which can be sourced somewhere, put them all together, and make an RB30DS.

First of all - I don't care if it's a good idea or not.

Second of all - how f**king awesome would it be? would it rev harder than an injected RB30DE?

would it run alright pending tuning or would it simply keel over and die?

My plan would be to set up an RB30 in a car, but rip off the top half of the manifold and all things to do with injectors, then fit the two carbys, utilizing the throttle cable or, just having one made up, then having a linkage between the two carbys.

what exactly would i supposedly need to rip off for it to run? could i rip out ALL of the computer and wiring harness? or would that f**k with sensors and such?

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what has the world come to...

lol might be a pretty ok idea for a f**k around.

but what about ignition control?

dunno how the stock computer would react to just ripping out the injector harness...

my guess is that you would lose power compared to the DE version for various reasons.

first of all, carby's don't give the same sort of fuel input as injectors. they don't vapourise it as well is about the best way i can describe it at the moment (brain isn't working today). i know that on the EA falcon they did 2 versions of the 3.9L engine. 1 was a single injection (basically a carby) and the other was multi-point injection (6 injectors). there was a 17kw difference in power.

secondly, you would need to do a lot of work to get the intake manifold right to suit the flow of the carbies. you can't just simply bolt on a carby and have it work.

thirdly, i think twin 350's would probably be way too big for a 3L engine.

and i highly doubt it would rev harder.

i don't think it would be a good idea. and the way it sounds like you plan on going about doing it sounds like it isn't going to end well. sounds like it will end with a poorly performing engine

yeah my GQ RB30S dosen't rev harder, it revs LESS than a RB30E, but I am speculating that it's the jetting on the carby that might be the culprit there. Good engine, but heavy on fuel (15L/100).

Dunno how you'd go trying to adapt a twin cam head without a custom manifold lol.

Marc I think you are saying about carbies being less efficient at atomising the fuel?

Pretty sure the R31House RB30S is a triple (Hitachi?) carburettor. There's a video on youtube of it, ironically the test driver reckons that while it is a 'man's car, it had a flat spot in higher RPM and was difficult to tune.

Injection will always be superior to a carburettor, it wouldn't rev anywhere near as hard as a RB30DE as it has inferior fuel and air delivery. In fact I would imagine a plain RB30E would be superior.

If you want something mean and cheap get a stock rb30e and put the biggest wildest cam you can in there and just bump the fuel pressure up. It will guzzle fuel and probably be an absolute dog to drive unless you are revving it, but at least it will sound mean and rev.

Wouldn’t put dirty holleys on it... SU's would be a bit of fun though, once you figure out how, they aren’t very difficult to tune, possibly the easy way to almost have ITB type induction. You could remove all the fuel setup and just run with the stock ignition maps OR remove everything and just run an aftermarket ignition controller.

I've done this at home, but for turbo application, there is nothing stopping you from getting an RB30e bottom end and sticking an R32 RB25DE on top of it. It cost me under $1k to do it, found a ported and polished reco rb25de head (without cams) for $500, bought GTR cams and valve springs for $100, and the rest to belts, and gaskets.

For N/A, shave 60 thou off the head, add adj cam gears, and you have a winner that will run on 91ron :P.

Or if you want it for a laugh, fit RB25DE pistons, deck the block 40thou, still shave the head, and run it on methanol. om nom nom (its cheaper than pump fuel anyways :D).

While i am just joking, you can happily do that, you don’t have to spend big bickies to make a car go spastic hard, you just have to be a mad man (and happy to sacrifice street drivability)... You only have to spend big money, if you still want to be able to drive mum to the shops, comfortably and legally... :down:

See dude, flamed...told you it was a silly idea only a country egg head like yourself would think of :P

If you want different + power, build an engine similar to the RB24S that we were talking about :D

20 Bottom end w/ slightly bigger pistons

25 Block

30 Heads

RB24S revs pretty hard, a built DE would belt it even harder.

theres a reason everyone builds the same motors, that's because from trial and error they have been found to be the best. If you want to be different just tell everyone its an rb24 or something lol, hardly anyone will be able to tell the difference.

Hahahaha, for those who are flaming. GTFO. Input not required.

For those saying it's not a good idea - its still an idea.

I get myself through work every day by thinking about shit like this, and, fundamentally, its flawed. by rights though, the RB24S DID rev harder than an RB20. thats kinda where it came from. and i thought that given how good the L28 sounds with triple SU's, i could replicate that with an RB.

Now i'm just thinking i ITB an RB30DE and fang the f*ck out of it while I build the RB25det. cheaper. easier. probs more fun and more reliable.

NA Drift is uncommon to say the least. unfortunate really.

For those saying it's not a good idea - its still an idea.

A red 202 is also an idea, personally I would give it the same merits as building an rb30d, its got .3 of a litre more capacity than the RB30 and it is pushrod so it will have that f**king mean sound to it as well.

That's fair. 202 would probably get the same power output as one anyway. I've seen some bloody quick 202s before.

Not the point however.

RB30DE with custom (bunky) ITBs will be on the cards in a few months time.

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