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Rb30 Pre Build Advice

raZ1911

By raZ1911,
in Engines & Forced Induction

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raZ1911 Proficient

raZ1911

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Posted (edited)

Yeah i think i just have to live with the fact its not going to work lol.

Is there any stock turbo that wont be to bad for the RB30 till i get another one.

Like a VG30 one over the RB25 or some others?

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TiTAN Grand Master

TiTAN

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the problem with using an RB25 or a VG30 turbo is it will be on full boost ~2000rpm, ask CEF11E what his is like to drive with his high flow stock turbo also by the time you hit 5000-5500 the turbo is totally out of puff.

From memory he could put his foot down in 5th and it would just lose traction the boost hit that hard.

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R32Abuser Mentor

R32Abuser

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well im planning to run the motor in with the stock rb20 turbo! it could get messy me thinks! but after that im putting a GT30R (0.82 A/R) to give me some massive balls down low and still have some head room left up top...then mite do some cams down the track if money permits.

Your best and cheapest option to put on it till you get money/time is a R34 turbo-the biggest of the stock gtst/gtt range and still go for a fairly low price...until then-start saving!

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bubba Grand Master

bubba

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I'm running a stock 25s1 turbo for now.. 12psi by 2200rpm, 183rwkw@4650rpm, dies in the ass after 5800rpm. IMO a 20 turbo would be ridiculously small, a VG30 would be the best "stock" option to start with with a neo turbo following closely behind.

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webbey Apprentice

webbey

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hey guys just reading this thread and some people have mentioned you cant upgrade cams with VCT is this true? as im looking to buy a fully forged rb30 and can get an Rb25head with VCT or an RB26 Head to go with it aiming for 300 - 400 rwkw so will prolly need cams will be going for a garrett 35/40 or T04z

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webbey Apprentice

webbey

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There are plenty of cams that retain the VCT, and if you buy a forged rb30 bottom end and put a an rb25 head on it, the comp ratio will be too low

[/quotes]

Ah sorry wasnt very specific its got forged CP pistons to give a desired Comp Ratio of 8.3:1 with an RB25 head on it the bottom end was built to take an RB25

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raZ1911 Proficient

raZ1911

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No you can get cams that keep VCT. But not very big ones, so once you get to a certain power level VCT has to go. Im pretty sure any more than 400 HP then thats where VCT is about dead? I havnt heard of anybody keeping VCT at 400KW, thats a very big number.

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webbey Apprentice

webbey

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Hmm thanks for the reply oh well thats a bit of a spew i will just have to disable VCT or get an RB26 head for it instead can i stil retain the VCT loom or would i need to source a loom off a non vct head and once i have disabled vct can i just purchase valve springs and bigger cams to suit a non vct head?

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GTScotT Grand Master

GTScotT

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umm my motor isnt complete or anywhere near being finished at the moment, yet im using a rb25det vct head and planing on using rb20 cams to not use the vct, i modified the plug at the end of the oil galery in the head to feed oil right to the end of the galerey so it comes out the cam like its ment to then closed one of the end cam galerys/ holes and restricted the other so its the same size as the other then welded up the vct feed at the bottom of the head and will just use a vct soliniod with no wiring to finish it off.

however, the water jacket when the 30 block and 25 head meet had like half a mill or so, very very tiny before the side of the block so i welded and reshaped that to be more like the standard 30 one, i would of thought this was nessasary as its realy to close to the edge otherwise.

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