RB26 Conversion Help!

[vsv6perth]

Well just like to say hey, cause its my 1st post here, but i'll get straight to the point. In shortI own a Holden commodore V6, and i was originally going to rebuild the motor and have twin GT30s installed and float aorund the 400rwhp mark.

But i have been thinking quite seriously for a while about installing an RB series motor into the VS.

SO ok here wot I basical know so far. Yes it will fit. The VL K-frame bolts straight into a VS, 2ndly an rb25 and 26 will fit the VL Kframe, so i got that part sorted.

The stuff i want to know is.... wots better and why between the 25 and 26. I know the Rb26 is a far more better engine. but wot I want to know, is it worth the extra 3000 to 4000 for a GTR half cut when i will be wanting to up the power of either RB series motor.

All im wanting to do as far as modding the RB motors are manifolds if needed, turbo/s cams and fuel sytem, depending on price maybe do the whole head.

OK... so wot are your thoughts? and wot advise do you have.

P.S. dont waste ur time replying with any holden bashing coments, cause i dont care for them. :bs!:

thanks guys

[Sneaker]

P.S. dont waste ur time replying with any holden bashing coments, cause i dont care for them.   :bs!:  

thanks guys

Don't worry. I own a Commodore too. My opinion is go the RB26DETT straight away especially if you are looking at power upgrades as the internals are good for 450kW+. Your biggest problem will be the weight of the Commodore. What are they weighing in at now? Your turbo choice and camspecs will probably lean towards a wider torque curve rather than top end power.

What power are you aiming for?

BTW: I'm in Perth too! :headspin:

[KamikazeR33]

given the weight ud prob want to stick something like a rb30det in with a nice big turbo... big torque big power

then u should see ur boat make some knots finally instead of being at anchor permanently

[vsv6perth]

thanks for the replies, last time i checked a VS was around 1450kg stock. not uch weight has been added. But the Ecotech V6 is about 170kgs whicch is bloody heavy, so by pulling out the v6 and putting in the rb26 and gona get some weight back. But tell me if im wrong, but dont r33 float around the 1400kg mark?

Yeah, dont really want to go the RB30, they have been done to the death with commodores, great motor but i want something i little different thats where an rb26 comes in handy.

Power level, well i was going to be rebuilding the motor with a 4.2Lstroker, forgies... blah blah blah. was aiming for a very doable 450rwhp+ A guy over in queensland with a very close setup to wot i was going to get is pulling 560rwhp at 21psi and getting a 10.5 1/4. I was originally going for low 10s.

Now im looking at an RB26 im not so much eager for 10s, i'd be very happy with with close to 400kw, but im not sure wot u have to do to get to the 400kw mark... power not so important because i dont know wot power levels = a good 1/4, but if i was in the low 12s Id be very happy man. even more happier to shit on some V8s. even the odd skyline

[vsv6perth]

COME on ppl, need some help here, really want ur input here guys

[Sneaker]

I think you will find that the Ecotec is a lot lighter than the GTR engine especially when you take into account turbo's etc... You can get 400kW to 450kW easily out of the engine. You need to look at some bigger turbos and bigger injectors as well as all the rest of the normal exhaust mods. Cams may be needed to keep the torque curve fat but turbo choice will have a lot to do with that. And of course a retune or Power FC should do the trick.

After thinking about. Your Commodre weighs the same as a GTR so expect similar responsiveness. Unfortunately 12sec in a GTR does only require 300kW but that is 4WD. You will have to work on the suspension of your Commodore to go anywhere close to matching the GTR's responsiveness. An extra 50kW should cover it.

The big advantage of this engine choice as opposed to a V8 is that you won't have so much of a problem getting the power to the ground as the torque curve will be a little more spread out. Whilst the V8 boy's will be slipping you will be well on your way.

[vsv6perth]

Yeah I suppose your right, was'nt really think about have two turbos, but at the same Time i did expect the weight of the vs to increase alot if i was going to keep the v6 with twin turbo. Yeah u pretty much have the suspension figured out, King springs, koni, getting it done after the engine and body kit goes on so we can get the right ride height. plus slicks at the drags.

wot do u guys think it is worth buying off the self parts for turbos and manifolds to fuel system and the sort to get the rb26 up to 400kw?

[vsv6perth]

Yeah I suppose your right, was'nt really think about have two turbos, but at the same Time i did expect the weight of the vs to increase alot if i was going to keep the v6 with twin turbo. Yeah u pretty much have the suspension figured out, King springs, koni, getting it done after the engine and body kit goes on so we can get the right ride height. plus slicks at the drags.

wot do u guys think it is worth buying off the self parts for turbos and manifolds to fuel system and the sort to get the rb26 up to 400kw? And how much?

Most of the install work I will do myself while the engine is out, ie, fuel system and turbo work. I'll leave cams up to an expert.

[Sneaker]

Yeah I suppose your right, was'nt really think about have two turbos, but at the same Time i did expect the weight of the vs to increase alot if i was going to keep the v6 with twin turbo. Yeah u pretty much have the suspension figured out, King springs, koni, getting it done after the engine and body kit goes on so we can get the right ride height. plus slicks at the drags.

wot do u guys think it is worth buying off the self parts for turbos and manifolds to fuel system and the sort to get the rb26 up to 400kw? And how much?

Most of the install work I will do myself while the engine is out, ie, fuel system and turbo work. I'll leave cams up to an expert.

Yes buy off the shelf, or look around the second-handers for decent turbos. Do your homework on the turbos though. You can pick your cams out as well, just look for relevant articles on cam specs, even brochures. Cam gears you can probably fit yourself if you know what you are doing. Don't worry about custom manifolds as the standards are fine if you are aiming at 400kW. The engine really is ready to be pushed already.

Should be an interesting project.

[Sneaker]

As far as turbos go you will need something like: GT2530's up to 2540's or equivilant. 2530's will probably be your best bet to make the torque curve fat. Upgrade to some 500+ injectors and that wil give you plenty of room for movement. Not sure, but I think a pump upgrade might be required as well. Tomei cams are good for torque but look around at HKS and Trust as well.

There are as much aftermarket choices with the Skylines as there is with your Commodore engine so just do the same and hunt around the shops and internet sites for what is out there and prices. The import videos are good as they show what people runat the drags and then show how the car performs on the strip.

Prices. Once you start replacing turbos the price jumps up. Think the same ballpark as putting a supercharger kit on a Commodore V8.

[vsv6perth]

fuel system will be after marker, due to the standard V6 being way out of ballpark, I will be looking at installing the turbos while its out the motor, once motor is installed its of to get a custom dump pipe and exhaust made up. What else would it cost for bigger turbos, apart from the turbos?

Next one is, wot sort of exhaust does a 400kw RB26 need?

[JH32]

dude there's a guy in the commodore car club with an RB25 in a vs ute ... that thing absolutely hammers !

i'd just go the 25 over the 26 ... the torque from the 26 with big turbos will make it rather 'interesting' to drive

[PHATR32]

defently go the 26, you cant go wrong there.

good luck with the wiring, ive so far spent roughly 20 hours merging rb26 loom with a rb25 loom, so the rb26 will run in a r34 gtt. and that cause they are simular!

i imagine the commodre wiring will be completly differant, so youll need to go with a aftermarket computer etc, unless you know someone who can do custom wiring.

unless the vl turbo wiring plugs into vs.

good luck!

steve

[vsv6perth]

as far as I know u can piggyback both ECUs, leave the VS on inplace to look after the odds and ends, and let the othe ecu look after the motor, yes i do know some, looking at around 400 bucks

i have left myself 24gs to do the v6 twin turbo, so that will go a long long way on a rb26 conversion for wot i want.

rb25; Touqe doesnt worry me, the more the better, HELL FUN.

i was going to get a mountain of tq anyway from the V6 so an upgrade rb26 will be pretty close to the same.

with the comment bad earlier with needing an extra 50kw to match a GTR on the 1/4 would i gain that extra 50kw atw by not having the AWD?

[Abo Bob]

More like 20.

[vsv6perth]

really, only 20, cool, not bad then. So does anyone here know any good companies in perth to buy stuff off?

[Sneaker]

with the comment bad earlier with needing an extra 50kw to match a GTR on the 1/4 would i gain that extra 50kw atw by not having the AWD?

It was more a comment about the superior handling the GTR will have over your car and that you would need an extra 50kW on your's to make up for that. Don't get excited about having extra kW because it is rear wheel only. The amount of loss through the front of a dirive-train on a GTR is minimal especially considering it is part time 4WD and only comes in to prevent loss of traction.

[gts4diehard]

hi, just to throw another option in the ring, a guy who i work with has a commodore ute, i think 98-98 model, has a na 3.0l supra bottom end (apparently quite cheap to get) with the 1jzte?(2.5 l turbo head I), one very large turbo and everything else done to suit, putting out 650 hp at rear wheels.

everything toughened up to suit, he's finding out the hard way, everythings breaking then being upgraded with tougher bits.

not to knock the good ol rb, but i think a 1jzte is about $1500, and a 3L na under a grand from memory.

Stephen

[vsv6perth]

Yeah I had a look at the supra motors, and if i were to use one i'd use the TT version, the problem is im looking at alot more custom work to fit the supra motor, but i have to look alot more into, The RB motor fit alot better due to the VL K-frame, plus i'd prefer the skyline motor.

[Sneaker]

hi, just to throw another option in the ring, a guy who i work with has a commodore ute, i think 98-98 model, has a na 3.0l supra bottom end (apparently quite cheap to get) with the 1jzte?(2.5 l turbo head I), one very large turbo and everything else done to suit, putting out 650 hp at rear wheels.

everything toughened up to suit, he's finding out the hard way, everythings breaking then being upgraded with tougher bits.

not to knock the good ol rb, but i think a 1jzte is about $1500, and a 3L na under a grand from memory.

Stephen

Would be a good choice too. Dare I say a better choice due to the larger capacity. Shame it isn't a simple drop in though. Could always use the RB30DE bottom end with GTR top.