Interchanceable Turbo Housings And The Results?

[CEF11E]

All these turbos have the same size exhaust wheel. exhaust housings differ in size Here is a list of smallest to biggest exhaust housing.

RB20det

VG20det

RB25det

VG30det

Compressor covers in order of smallest to largest:

RB20det

VG20det

VG30det

RB20det

The compressor wheels are all different sizes meaning we must keep a wheel with its original compressor cover..

What is the best combination?

I was thinking a complete RB25 turbo with a VG30 exhaust housing.

So it will in effect it will be a VG30 turbo with a RB25 compressor and compressor cover and therefore produce more airflow for the same shaftspeed... Is this correct?

The aim is to produce a turbo that will provide enough airflow for a 2litre engine to produce 170odd rwkw at 11psi.

And no a RB25 turb won't do it as have one on the car ATM and it makes 149rwkw with auto transmission. manual would make more.

Has anyone done a rb25 front with a VG30 rear? if so please post your results:)

[thommo]

hey mate, there was a fair bit of discussion as to using the vg30det rear recently. they are bloody hard to find though...

http://www.skylinesaustralia.com/forums/in...topic=78983&hl=

some decent results here

[Cubes]

Your best bet is the R34 GTT Turbo.

Its the largest of all turbo's.

The VG30DET turbo is a Rb20DET turbo with a larger RB25 sized comp cover and larger R34 sized turbine housing. Meaning if you bolt the larger comp and turbine housings on to a RB20DET turbo it will be EXACTLY the same as a VG30DET BB turbo.

The R33 runs the smaller rb20 style turbine housing, from what I've measured the rb20 series 2 and R33 rb25 turbine housings are the same size. Only difference being the compressor and cover is larger with the rb25 unit.

The R34 and VG30DET BB turbo's run the same turbine housing. 'OP6'

Edited November 4, 2005 by Cubes

[CEF11E]

Your best bet is the R34 GTT Turbo.

Its the largest of all turbo's.

The VG30DET turbo is a Rb20DET turbo with a larger RB25 sized comp cover and larger R34 sized turbine housing. Meaning if you bolt the larger comp and turbine housings on to a RB20DET turbo it will be EXACTLY the same as a VG30DET BB turbo.

The R33 runs the smaller rb20 style turbine housing, from what I've measured the rb20 series 2 and R33 rb25 turbine housings are the same size. Only difference being the compressor and cover is larger with the rb25 unit.

The R34 and VG30DET BB turbo's run the same turbine housing. 'OP6'

<{POST_SNAPBACK}>

Thanks for the heads up Cubes,

Ok I will start hunting for a VG30DET or R34 turbine housing with "op6" written on it.

Is the R33 and R34 compressor housings and wheel the same size? I know the R34 comp wheel is polypropelene and the R33 is an alloy but are they the same size?

[Cubes]

Only the Series 1 Rb25DET compressor wheel is metal. The series 2 is the same as the R34 being 'plastic' or polypropelene as you said. So becarefull with the identification, an R33 Series 2 turbo will look like the r34 turbo but has the smaller turbine housing.

I assume nissan went the larger turbine housing on the R34 due to its neo variable cam timing. Obviously improving low end torque and turbo spool, as a result a larger turbine can be used with no ill effects.

I was thinking the other day.. Say the bearings went, the compressor wheel smashed in to the housing, if it were the plastic wheel would the plastic shavings do less damage to the motor or possibly none?

The metal compressor wheel, your poor motor has no chance in hell, metal bits entering the motor is an instant bore score and compression loss.

That being said I think the best turbo for the rb20det will be the R33 series 1 with the smaller turbine housing to help the mid range. Maybe look at the series 2 with the plastic wheel to help spool on the 2ltr.

No matter what your going to need some decent boost in the rb20det to get it making decent power. Especially with the power sapping auto.

14psi with an rb25 turbo and tuned ecu should see 190rwkw with a manual.

Being an auto.. pull what? maybe 15rwkw off it?

Edited November 4, 2005 by Cubes

[CEF11E]

Only the Series 1 Rb25DET compressor wheel is metal. The series 2 is the same as the R34 being 'plastic' or polypropelene as you said. So becarefull with the identification, an R33 Series 2 turbo will look like the r34 turbo but has the smaller turbine housing.

I assume nissan went the larger turbine housing on the R34 due to its neo variable cam timing. Obviously improving low end torque and turbo spool, as a result a larger turbine can be used with no ill effects.

I was thinking the other day.. Say the bearings went, the compressor wheel smashed in to the housing, if it were the plastic wheel would the plastic shavings do less damage to the motor or possibly none?

The metal compressor wheel, your poor motor has no chance in hell, metal bits entering the motor is an instant bore score and compression loss.

That being said I think the best turbo for the rb20det will be the R33 series 1 with the smaller turbine housing to help the mid range. Maybe look at the series 2 with the plastic wheel to help spool on the 2ltr.

No matter what your going to need some decent boost in the rb20det to get it making decent power. Especially with the power sapping auto.

14psi with an rb25 turbo and tuned ecu should see 190rwkw with a manual.

Being an auto.. pull what? maybe 15rwkw off it?

<{POST_SNAPBACK}>

Its actually going on a VG20det and replacing the standard VG20det turbo. and yes the auto sucks!

I have had a RB20det cefiro with the following turbos.

RB20turb - putting out 154rwkw

RB25series1turb - putting out 179rwkw

RB25 series 1 turbo with VG30 exhaust housing putting out 204rwkw

I will take some pics and measurements of the VG20det turbo when it comes off.

[paulr33]

You should speak to "Al" has a had a hiflow rb25 done with a vg30 rear housing and its back on the road, he could give some good info on the combo and how it goes

[Bass Junky]

And I've got mine going on this week along with lots of other bits, so by the end of this week, I'll be able to tell you too.

[Dale FZ1]

The R33 runs the smaller rb20 style turbine housing, from what I've measured the rb20 series 2 and R33 rb25 turbine housings are the same size. Only difference being the compressor and cover is larger with the rb25 unit.

The R34 and VG30DET BB turbo's run the same turbine housing. 'OP6'

<{POST_SNAPBACK}>

If the R32 s.2 and R33 s.1 are the same housings, do they share the same ID on the castings, and was this a side-by-side examination please?

cheers

[Cubes]

Measurements were the same... Casting marks were different.

[whiteknight]

Great work Bass Junky!!!! Please let us know how your set up goes. As you know im looking forward to doing the same thing.

[Master_d]

i have a s2 rb25 turbo with vg30 exhaust housing and i have 262.4 hp atw

this is on an rb20 manual

[Cubes]

Thats 195rwkw.. Not too bad.

What boost are you running?

Any chance of a dyno sheet, I'm keen to see the power delivery.

[Master_d]

that is on 14psi, i have a copy of a previous dyno run that is basically the same just at 258hp

Thats 195rwkw.. Not too bad.

What boost are you running?

Any chance of a dyno sheet, I'm keen to see the power delivery.

<{POST_SNAPBACK}>

[CEF11E]

Noice,

When does boost start and when do you get 14 psi by?

Looks like i am hunting for a damn VG30 rear housing too now

[traphead]

"i have a s2 rb25 turbo with vg30 exhaust housing and i have 262.4 hp atw

this is on an rb20 manual"

Thats interesting master_d. At what rpm does the boost come on? Would you say it is laggy at all on the RB20?

I'm trying to make a decision on a new turbo for the rb20 at the moment. I was looking at the highflow option, but Michael from GCG said that the RB20 highflow would run out at around 220-230rwkw. He also mentioned that an RB25 or VG30 would be quite laggy on the RB20 due to the flow restrictions of the engine.

I was then considering a RB25 highflow with a RB20 turbine housing (I havent talked with him about this yet) to reduce the lag. This doesn't seem worthwhile if the turbine housings are basically the same size as cubes has mentioned.

Any ideas what is the best highflow combination for the RB20det guys??

(All supporting mods present of course).

[paulr33]

its going to run out at 220-230rwkw due to the engine and its inlet/exhaust system not the turbocharger itself i believe.

[Bass Junky]

I think the standard turbo on the RB20DET, but High Flowed.

As they have said, the RB20DET can only swallow a certain amount of air, short of building the engine strong and pumping a truck load of boost into it.

So, get it highflowed, keep some sembalance of response and stick with 220 rwkw.

After all (no offence intended) it's only 2.0 ltrs and you can only get a certain amount out of 2.5 ltrs.

The 2.5 ltr is 25% bigger, there fore, can swallow 25% more air at similar boost and so on.

BASS OUT

[Cubes]

http://www.horsepowerinabox.com/HPIAB2/category12_1.htm

Why not look at a cheapish brand spanker.

The GT28RS should make 200-220rwkw with some decent boost.

[traphead]

I was going to go for the highflow to avoid installation costs, being able to keep the same lines and all.

GCG basically said that the turbo would be limiting the power output in the case of the highflowed RB20 turbo. Thats why i though a larger compressor housing with the same turbine housing would allow for larger power without bringing in tons of lag.

Michael said the best option for the rb20 is actually a GT3040, but with a .48 turbine housing. (They bore the housing out to fit the larger wheel). The small turbine housing causes quick spooling and the large wheels and compressor housing allow for large power.

I was going to go for this option at $2450 for the whole internally gated system (including lines and actuator), I was just concerned about installation costs. Would need a spacer plate, new elbow joint to intercooler, new joiner fron afm to compressor inlet and a new flange on the exhaust (which could be an issue since i have a split dump).