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

    • Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...