Jump to content
SAU Community

Recommended Posts

Hey all, I just took the 'stock' (or at least I think it is) turbo off my rb20... and when I compared it to the turbo that I have been told is from a Rb25, I noticed something strange.

The compressor wheel on the Rb25 turbo is bigger as expected... however, when I look at the exhaust wheels, the rb20 turbo appears to have a larger exhaust wheel... why would this be?

I would have expected the rb25 would have been bigger at the exhaust wheel as well due to having more gasses passing thru it due to being bolted onto a bigger engine.

I've included pics, can anyone shed some light on this?

Also, when I took the rb20 turbo off, some coolant came out of the dump pipe... again, should this be a concern?

Thanks in advance

RB20 turbo on RHS in this pic:

DSC00248.jpg

RB20 turbo on LHS in this pic:

DSC00247.jpg

Edited by retox
Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/
Share on other sites

That's weird.

I noticed that the compressor blades are completely different too. I thought they would just be bigger on the RB25's.

Perhaps the turbo on your RB20 has had a rebuild and the exhaust side of the turbo housing has been replaced?

I'm not turbo pro but it is the only thing that seems logical about it.

Have you been able to get your hands on another turbo from a RB20.

Keep us posted

Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3169771
Share on other sites

Was given this reply on another forum:

look att he angle if the fins on the rear turbine side of the turbo's.... the RB20 one has pretty big gaps allowing the exhaust gas to spin the blades easier being on a smaller motor... The RB25 has them closer together to restrict it a bit so it doesnt spool up early. From the pics tho the Rb20 exhaust wheel does appear bigger... Only one way to find out and measure them. Also the Rb20 rear looks newish and the 25 oldish if that makes sense could possibly have been a hi flow... U never know with a second hand turbo unless u measure it all up and know exactly what ur looking for lol.

Liam

does this sound right?... seriosuly lost now as to which would be better on the motor!!!

Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3170073
Share on other sites

If it has been hi-flowed, wouldnt the compressor wheel be increased in size as well?... not sure.. still new to this turbo business :)

Either ways, hi-flow rb20 item vs stock rb25 item... which would be the better go-er on the RB20?

Also, as mentioned, I'm pretty sure some coolant came out past the exhaust wheel on the rb20 turbo when I was taking it off the motor... should I be concerned about that?

appreciate your input guys :P

Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3170118
Share on other sites

Turn the turbos round sideways and compare the iron bearing housings , the later R32 RB20 turbos should be ball bearing and the middle is larger in diametre or fatter if you like . If your RB20 one is skinnier and its exhaust housing bolts are on a smaller pitch circle diametre then its probably an early R31 RB20 bush bearing turbo . These used much smaller compressors in an attempt to spool them early . From memory the exhaust housing A/R was very small and they're not much good for anything .

The Hitachi BB ceramic turbos have a small bolt head in the side of the bearing housing , general consensus is that its some sort of bearing pre load device but anyway only the BB Hitachi's had them - from what I've seen anyway .

Cheers A .

Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3170234
Share on other sites

I can't beleive no one's said it yet, but from the top pic, theyr'e both rb20 turbos. nissan motor 16v.

One of them may be the earlier bastardised vg30 with the nissan 16v comp cover, and non op6 rear housing. We'd need more pics of the back housing numbers, and the wheel up closer.

edit: oops, you guys beat me to it. haha

Edited by MANWHORE
Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3170338
Share on other sites

ok, got some better pics.

New Turbo (larger compressor wheel):

Markings on exhaust housing: 5173 near flange, 04U, 8. <--- on front (compressor side) of housing. Nothing on back

new2.jpg

new.jpg

new3.jpg

Old Turbo (Smaller compressor wheel):

Markings on exhaust housing: looks like 0074 (or A) near flange, 2, 8. <--- on front (compressor side) of housing. On rear (exhaust side of housing): B, 59S

old.jpg

old1.jpg

old2.jpg

Sorry about quality of pics - camera phone

Edited by retox
Link to comment
https://www.sau.com.au/forums/topic/172063-turbo-help/#findComment-3170356
Share on other sites

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

    • Pressure when IDLING, is meant to be 51PSi... So that amperage value needs to go up a fair chunk... I'd personally be factoring for more like 12amp at least on those runs, and at that point you need to hope the already there wiring doesn't drop you a volt or two, as that's a lot of fuel pressure flow drop off from 13.5 to 12V! Taking idle pressure of 51psi, means the pump will be drawing a MINIMUM of 9amps all the time based on your reading of the graph (3bar base, then allowing an extra 0.5bar for boost = roughly 51psi)
    • Hi all,  I am in the market for an R200 longnose diff out of a Z31 300ZX, or S12 RSX, DR30 skyline, or similar, in a 3.9 ratio.  Preferably a late model one with the M12 crownwheel bolts.  The only easy to find advert for one of these was my ad back in 2007 when I sold it on this forum.  I sold the diff as I had sold the car it goes to, but as it turns out, after 18 years I got the car back late last year, so now I'm looking for the diff !  If anyone knows where to find a longnose R200 LSD with the M12 crownwheel bolts, drop me a line at [email protected] - Bonus paid if soomeone comes up with the original diff (stranger things have happened !).  Cheers   Ben D    
    • Hi everyone, I used to post here a bit from 2004-2013, when I owned various Nissans, in particular my S12 RSX gazelle, which was sold in 2007.  As luck would have it, after an 18 year hiatus, the car found its way back to me last year, and over the past 11 months I have had the pleasure of restoring it with my kids.  One thing that I am after in particular is a 3.9 ratio R200 LSD for it.  I actually sold the one out of the car here back in 2007 , and it would be incredible if I could track down who I sold it to, so I can see how they have progressed over the years (and to be honest, to see whether I can get the diff back !).  Anyways, hi all and let me know "where are the R200 Longnose diffs all at these days ?  Cheers Ben D  
    • Arms will be the same as the G35 or 350Z, but as above, there was a change in the lower control arm where it connects to the ball joint.  That said, you can remove the ball joint cone from your old ball joints and fit them to the new ball joints.  To be honest, I didn't think the ball joints themselves were different. The main ball joint is a bit awkward to replace, you really need to remove the steering knuckle to press out the old one.  Some people have used tools to remove it in place, but it just seemed too hard to get to. If you are going to press out/in that ball joint, then you may as well just replace the bushings in the LCA and the compression rod.  You can buy the compression rod bushing from Nissan, but the LCA bushes, you will need to go aftermarket. Much cheaper than buying the whole arm.
    • Ha, well, it's been.... a bit of a journey. Things have taken much longer than I'd hoped. I'll probably put up a thread at some stage. Hopefully soon. The car's not done any kms since my update in June though, put it that way.
×
×
  • Create New...