Jump to content
SAU Community

Recommended Posts

After installing my vg30 last weekend I might have to put the standard turbo back on due to the vg30 being a little noisy after some dyno time, I was just thinking that maybe i could high flow the standard turbo but would it be worth it? Or should i just take the vg30 of and high flow that?

I'm not after huge power either, around the 170-180 rwkw mark so i could prob get that from a standard rb25 turbo at around 12psi?

The vg30 only made 147.5 at 12psi so yea I think its a little tired.

yeah if you only want 180rwkw the rb25 in std form should be good for that on RB20

agreed, dont bother with the rb20 one, yuck... lol. took mine off to change the exhaust gasket and i dont understand how it can push 10psi throw it. lol.

As others have said if you're going to highflow, better off starting with something bigger (Neo has bigger exhaust housing than normal 25).

But if you only want ~180rwkw my RB20 made 183rwkw untuned through an RB25 turbo.

Your call but I think you'll find the VG30 turbos turbine housing a bit big for an RB20 , don't forget that a 3L is half as big again as a 2L and they make considerably more torque off boost as well .

I'm not sure if you are aware but the BB VG30 turbo actually uses a slightly smaller compressor wheel than the RB25 ones do - at least the R33 RB25 ones . If you try to fit the compressor housing off the VG turbo on an R33 RB25 turbo it won't go over the compressor wheel .

For a straight bolt on the R33 RB25 turbos are probably the go . They don't look it but the RB25's turbine housing passage is slightly larger than the RB20's one so I think a good try .

The OP6/VG30 turbine housing is a reasonable amount larger than the RB25's one , more than the difference between the 20 and 25 .

A .

I just installed a rb20 hi flow. so ill shed some light =)

First day i was very un impressed with power :whistling:

but after about a week i boosted it to 12psi and its pretty good.

Has no trouble frying 10" wheels on the back.

Response is amazing to!! By far the best thing about it :happy:

Iv driven rb25 turbo r32's. The hi-flow is defiantly better, But it cost 4x more so it would want to be better.

but at least you know its new and tuff. Not a 15 year old ceramic rape victim.

hyper gear (who rebuilt it, and is a legend by the way) have said it will make an easy 200kw.

Well its not the best turbo for the money. But its still going to be more fun than a vg30 hi flow.Yuck.

I recon choose between rb25 stocky. Or rb20 hi flow if you got the cash. F**k the vg30.

good luck =)

  • 3 weeks later...

dragging this up but anyway.

a race car i have worked on for the past few years started life with a r33 GCG hiflow. laggy as hell. made about 240rwkw on an rb20.

it failed and joined the list of failed ones i know of. GCG said it would cost just as much as it originaly did to get it rebuilt

in the mean time put a stock rb20 turbo back on and changed the car 100% the bloke was wrapped with having response again.

so we got a rb20 turbo hiflowed by precision turbos. it was also cheaper. put it on and its grate. highly recomended. spools fast and makes 220rwrw. comparison on dyno graph shows it drops off at the top but better every where elce.

also getting a turbo hiflowed by billet turbos in the next few weeks for another car. they wheel specks are the same as the HKS 2530 going in to a rb20 turbo.

as far as stock turbo bolt ons on my own car i have run a neo rb25 turbo and it was grate. they are noticable better than the r33 turbos. i run a r33 turbo on my street car and after doing a swap between a stock rb20 turbo and the r33 turbo i found it has a few hundread rpm more lag and far better top end.

I'm not after huge power either, around the 170-180 rwkw mark so i could prob get that from a standard rb25 turbo at around 12psi?

yes, easily. no need for high flowing it. high flowing will hurt low end response. i had an Rb25 turbo (the later one with nylon compressor wheel) on my RB20 and it still boosted up nice and low, and was good to drive. Not quite the same response as the smaller RB20 turbo but there was more headroom.

I have a gcg highflowed rb20 turbo, the specs are basically identical to their highflow rb25 turbo, just slightly smaller housing I think but they bore it out to around the same.

It is on an rb25 but it is on full boost by 3500rpm and has made about 6-7psi by the high 2000s.

Very responsive and makes over 200kw on just 10psi, expecting about 240 on 16+

On the rb20 I would do as the others have suggested and stick with a stock rb25 turbo, anything much bigger and you will be sacrificing response for top end, won't be much fun to drive.

  • 1 month later...

im a bit confused by power quoted here. I have a R32 Gts-t with a highflowed turbo and I only get 220kw at 19psi running 104 oct race fuel. on pump it only has 200kws

has 444 inj, 040 pump, jjr coilpacks, apexi ecu, z32 afm. I was thinking of getting a R25 turbo highflowed so i could have more power and maybe less boost.

Find a new tuner imo

if its an rb20 turbo with a sleeve bearing then its possible it just has steel wheels and is barely bored out. I've got a highflowed rb20 turbo on a 25 making only 240kw on 18psi, depends on the housing, the bearings and the trim wheel used.

not to mention how much dynos can vary.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • LS is a good motor, but it hurts my soul when I see it in a RB. Guess it fixes the oiling issues lol.
    • I'm confused. Does this qualify as "Gregging" or are you somehow avoiding the Gregging?
    • More assembly going on, with all sorts of "bolt right on bro" scenarios going on here. Smartly, PTV clearance was checked. And I say smartly because it turns out that the intake was 0.009" from piston meeting valve. This is 0.23mm. This is very not okay. A fast meeting was facilitated between engine builder in Australia and engine builder in the USA which was actually incredibly helpful and constructive actually, various ideas thrown around to get around this issue including: 1) Retard the cam timing which would have brought the exhaust valve closer to meeting piston (it was 0.065") which was uncomfortably close to begin with, and change the cam profile making it 'laggier' 2) Much larger head gaskets which would reduce compression, but half the point of this was to increase compression. 3) New set of pistons ($$$$$$$$$$$$$$$$$) 4) All of the above 5) Get ghetto The concept is you get sticky sandpaper and stick it back to a valve, slightly larger than the valve you/I'm using, like say from a LS3/rectangle port head. You now have a very super advanced flycutting tool to modify your pistons in your block. Then you install it in your head, and attach the other end of the head to a drill. Then you just replicate your valve smashing into a piston with your spinning drill.   This is the result. Repeat many times. It is strongly recommended you have some kind of fixed stop when doing this for extremely obvious reasons because if you press too hard then you're well into apocalyptic repercussion land. The minimum clearance on the intake valve is now 0.075" this is still in the "Too close to be really comfortable" and into "It should be fine" land. Supposedly in the real world the clearances will be slightly bigger. Guess this is what happens when people push envelopes for N/A engines instead of adding boost! Time to move onto the new, upgraded, higher ratio roller rockers from Yellaterra, all tapped and threaded with a stronger bolt for better stability. Very nice. Lets see how they fit. For f**ks sake. Time to bring the grinder out for these aftermarket, machined and CNC'd heads. Looks like the new, beefier rocker from YellaTerra has gone from Bolt on part to "Bolt on part". Well, lets see how this bolt on crank scraper and windage tray goes then, shall we? There actually is more clearance than they specify for this thing, but seeing it all move as you check it is terrifying when you see it all so very very very very nearly hit things. But after all, this is what the item is designed to do after all and actually did bolt on perfectly and have enough clearance to everything and some very clear and direct instructions. So +1 to Improved Racing I suppose. As above with the windage tray on. Photo of breaker bar wonkiness for added lols. Next up: Oil pump/front cover/water pump/sump and then it's time to actually install the heads, pushrods, head bolts, valve cover gaskets and such is all there and ready to go. (except the oil pump bolts which were previously longer for more clearance with the previously perfectly installed double row timing chain). There's definitely a sense that someone other than us has been here before and done everything perfectly, or at least considered it and came up with working solutions. Perhaps the previous cam was 6deg advanced to avoid PTV issues with the milled stock heads? In any case when I attempt to sell this stuff the buyers are going to be very directly informed.
    • my catch can is pretty easy to empty but it overflows due to the blowby/crank case pressure etc. max I have drained is ~600ml even with a ~2.3L capacity. So it is not just about having to drain it out its the mess it makes down the firewall and under the car and rear passenger tyre from the overflow oil being blasted by screamer + air in general. Ending up on the ground cleaning the oil up and having oil on your arms when everyone else can chill and watch the other sessions gets old fast
    • Yeah - the secret learned a long time ago is that the RB likes to belch oil out the covers, and/or starve the pump because it drowns the head in oil, because the upflow of crankcase gases from piston blowby comes up through the oil drain holes in the block and prevents the oil from flowing back down. The external vents from sump are about creating an alternative path/much more XS area for gas flow to decrease the gas velocity up through the oil drains and allow the oil to get back down. So, it's not about pressure at all. It is about flows - gas up and oil down - or when it's not working, gas up and oil not going where it is supposed to after it arrives at the top, except out through the cam cover vents. And regardless of whether the catch can is vented to air or vented to the turbo inlet, it must still be vented because a sealed system would blow out the crank seals, or something equally bad.
×
×
  • Create New...