putting rb25 turbo on rb20

[Cubes]

That depends what cams it is running.

Bigger cams allows higher static comp and higher boosts to be run.

Run a too high static comp and you will actually loose power due to the fuel being too volatile for the setup.

There is a graph laying around some where on the net that explains boost vs comp ratio vs octane..

[joh21m]

straight turbo swap, depending on the boost u run, i would recommend a fuel pump anyway, saves hassles. Walboro intank pumps are my choice for mild setups anyway, fitted one to a mates cefiro with rb25det in it. Had to chop the wires and use connectors but that was not big deal

yeh i was planning on doing the fuel pump anyways...all this talk about rb25 turbos makes me wanna go out and do it...wat would be the expected rwkw with a setup like this:

3" turbo back zorst

POD

14psi

Fuel Pump

FMIC

[USRB25S13]

I wasn't talking about safe on the GSR motor but for the turbo.

[Targa Tom]

Will be interesting to see if it really makes 200rwkws. Thats pretty good power

We Just - well midnight - jerked on of our little RB20's off the dyno...

PFC, 3", xtr(RB25) turbo, spitfire coils, 550's, X GT-r FMIC.

Tucked her into bed with 235rwkW.... 1.2bar boost. 79 runs in a space of 31/2 hrs and top temp was 93degC

Now rush out the shed and think, I got one of them...

TT

PS Oh yeah and good fuel.

[rsx84]

i've looked into both the rb25 and vg30 turbos as a cheap upgrade for my rb20det, what figures i seem to get as to rwkws is around the 180-190 for the rb25 (14psi) and 200-210 for the vg30 (14psi) these figures are with the following other mods, good fmic, full turbo back 3" exhaust, POD, remapped ECU or piggy back system (safc), maybe upgrade the fuel pump to...the good thing is these turbos on the rb20 can run 14psi of boost all the time, set 14psi as low boost and 16-(18psi on the vg30) for high boost and your laughing...pulls all the way to the red line too...anything above these power levels and your going to need to look for larger injectors but now i'm going too far...

[Cubes]

I would forget about the vg30 turbo as it has an exhaust a/r too large for the rb20t.

You loose heaps of mid range accelerating power.

The rb25 turbo is the better bet.. Has a more suitable exhaust a/r which gives you much more mid range power hence average power.

A Rb25 turbo making say 180rwkw and a vg30 turbo making 200rwkw..

I had a VG30 BB Ceramic turbo on my RB20DET running ~ 13psi. The RB20det stocker turbo felt much much quicker on 1bar. I ripped off the vg30 and put back on the rb20det.

The VG30 also has a smaller compressor wheel compared to the rb25 turbo.

[sweetr33]

yeh i was planning on doing the fuel pump anyways...all this talk about rb25 turbos makes me wanna go out and do it...wat would be the expected rwkw with a setup like this:

3" turbo back zorst

POD

14psi

Fuel Pump

FMIC

would imagin u should get 180rwkw easily. Do not know whether ur engine is healthy or not. Putting a high flow 33 turbo on would see higher results

[Ronin]

Vg30 on an rb20 = lag beast.

[Roy]

We Just - well midnight - jerked on of our little RB20's off the dyno...  

PFC, 3", xtr(RB25) turbo, spitfire coils, 550's, X GT-r FMIC.

Tucked her into bed with 235rwkW.... 1.2bar boost. 79 runs in a space of 31/2 hrs and top temp was 93degC

Now rush out the shed and think, I got one of them...

TT

PS Oh yeah and good fuel.

What is good fuel?

That looks to be the figure im settling for with my TD06-20G. The guy tuning it seems to think it will make that power easily at 15-16psi basd on the power it has been making on lower boost levels in the intial stages of the tune.

180 something rwkws at 8psi. But if you are making the same power out of a low mount hi-flow which i imagine is more responsive based on other ppls experiences with the XTR Turbos...well i may just change the setup:(

PS i like your avatar Joel, putting the new RB20 in i see:)

Anyone in melbourne with an RB20 with a RB25 turbo makign 200rwkws: or a 2530 or any aftermarket turbo for that matter. Im very intersted in sampling a few RB20s, i went for wat i thought would be the biggest turbo a std RB20 could handle/use, but if ppl are seriously making 200rwkws out of small turbos?!?!?!? :bananaman

[hako]

hako what banjos and oil/water lines did you use?

hey dude,

i have an r32 motor in mine but for some reason i believe it still had r31 water lines??

the oil lines were exactly the same, only the water lines needed changing, and i used r32 ones

[Targa Tom]

What is good fuel?  

elf LMS... but only running std ignition map at this stage.

TT

[R31 POWER]

Ok helped do this convo last night and with RB25 turbo on a R31 ECCS RB20det

- We found out that the R31 oil line is the same and fitted the RB25 turbo

- Used the R31 oil drain on the RB25 turbo

- YOU NEED EIETHER THE R32 OR R33 WATER LINES FOR THE RB25 TURBO

- Used the R31 dump on the RB25 turbo

[R31 POWER]

Update.

Just finished putting a Series 1 RB25 turbo on a Series 2 R32 RB20det.Put the RB20 acuator on RB25 turbo for higher boost(11-12psi)

Easy just unbolt Rb20 turbo and put the Rb25 in it's spot.If you don't have the elbow on the RB25 turbo we used the RB20 one and drilled out the holes.Very easy people and it goes so much harder on 11-12psi than the shitter RB20 one.

[Cubes]

When you say much harder.

I still think the rb20t turbo has more low/mid range power than the rb25t turbo.

It gives the feeling of a quicker car. I've been in a Rb20det with an rb25 turbo and to be honest it felt slower than the rb20t turbo up to around 5000rpm. Then the 25 turbo pulled harder especially from 6000-7000rpm.

Overall on the street I still think my ol rb20t would have given it a real good run for its money. BUT I was running an extra 2psi than the rb25 turbo was.

14psi rb25 turbo vs 16psi the rb20t turbo.

[Ed G]

i thought 16psi was not safe for an rb20 turbs?

[R31 POWER]

Jeol I was'nt driving and the tacho was'nt working so it's hard to say what rpm it was going hard at.

Of course down low it has suffered a little but it's not that bad.Up top(guessing by the speed)like you said between 5000rpm and 7000+rpm it just kept on pulling and stayed at 11psi-12psi,before the RB20det nearly sounded like n/a coz it had nothing after 6000rpm.

Ed G thats not safe but we all do it.Some go pop and some don't :wassup:

[R31 POWER]

And the RB20det turbo feeling faster bit is true.Mine felt slow compared to it and I have a HKS GT2535.But then agian I had a plenum bolt missing and once another bolt was put back in i got boost 500rpm quicker rofl

[Cubes]

Mine didn't go pop...

I was waiting but it didn't..

I ran it like that for 2years, just over.

The AFR's were quite rich (High 10's) so I put it down to no detonation and more fuel helped keep the EGT's cool.

[Ed G]

so what would be best for 200-220 rwkw? std turbs or rb25?

[Angry]

top info guys .. thanks heaps.. *goes in search for RB25 Turbo*

Matt