Jump to content
SAU Community

Turbo Help!

retox

By retox,
in Engines & Forced Induction

 Share

Recommended Posts

retox Collaborator

retox

Posted
Posted (edited)

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
leb Community Regular

leb

Posted
Posted

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
retox Collaborator

retox

Posted
  • Author
Posted

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
retox Collaborator

retox

Posted
  • Author
Posted

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
discopotato03 Grand Master

discopotato03

Posted
Posted

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
MANWHORE Grand Master

MANWHORE

Posted
Posted (edited)

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
retox Collaborator

retox

Posted
  • Author
Posted (edited)

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • DatsunBanana
      Rear subframe stay bracket bolt removal issues

      By DatsunBanana · Posted

      Thanks both. All good advice. Reminds me of drilling through stone wall for drainage pipe 😬 I'll let you know how I get on if I still have use of my hands afterwards 😅
    • The Bogan
      NC MX5

      By The Bogan · Posted

      Finally got shipping number for the intake and throttle body, shipped by UPS, so "should" be in my hands sometime next week, fingers fracking crossed
    • GTSBoy
      [HOW-TO] Winter Steam-Clean & Odour Removal in 30 min

      By GTSBoy · Posted

      I'm so far behind in the jobs I have to do at both work and home (including car) that I have become immortal. There's simply no way that I can die now.
    • The Bogan
      [HOW-TO] Winter Steam-Clean & Odour Removal in 30 min

      By The Bogan · Posted

      Each to their own I guess  Me, I put just as much time into cleaning inside of the cars as I do on the outside As for getting wet, it is really no different than steam cleaning the carpets at home, apart from the cars carpet dries alot faster than the house, again, I only do it in the hotter months and leave the car opened up for a few hours As I only do it yearly, it is just before I do the diff and gearbox service, so I clean the carpets, then it's up on stands, wheels off, service, clean the undercarriage,  grease the bushings and do a nut and bolt check on everything  Disclaimer: I typically had all the time in the world to kill when I was working 🤣, so spending a full day or 2 cleaning, serving and "looking at stuff" was,  easily achievable, and a fun mental therapy day As for time to kill, I retired last Wednesday, so apart from my physical training, my days are filled with lots of random jobs around the house and garden...."Idle hands are the Devils something something" I am also buying a new house sooner rather than later, I'm actually looking at a potential property tomorrow, I'm looking forward to getting a car hoist as I'm starting to get to old to crawl around under a car, I can only imagine all the undercarriage cleaning and looking at stuff when that gets set up
    • GTSBoy
      [HOW-TO] Winter Steam-Clean & Odour Removal in 30 min

      By GTSBoy · Posted

      Yeah, I'm not interested in wetting the carpets, and I don't care about brown dirt/dust that lives deep in the pile or underneath. It's not like I crawl around on them in my birthday suit or eat dropped food off them (because there is never any open food in my car). The seats are alcantara (cheap Chinese imitation alcantara, to be sure!) with barely 1" of foam pad behind the surface. That's not getting wet either. Any car that I would be happy to get the interior wet, I would not care to put the effort into.
×
×
  • Create New...