Jump to content
SAU Community

Recommended Posts

Hi guys sorry if this is a stupid question..... iv search and cant find anything on this topic.

Just wondering whats actually involved in high flowing a turbo? and if you can buy the parts to high flow a rb25 s1 turbo????

im a boiler maker and pretty handy with tools and machining, just wondering if i can do this myself???

any info would be greatly appreciate.

cheers kel. :)

Link to comment
https://www.sau.com.au/forums/topic/322554-diy-high-flowed-turbo/
Share on other sites

new compressor wheel

new exhaust wheel

bore out the exhaust housing snot

near bearing chra kit

balance and clean

it spins at 100,000+ rpm so i dont think its something you can do at home

balancing is crucial

back in the old days, I purchased a T4 front wheel and housing off a mate and stuck it onto my standard FJ20 turbo without balancing or anything and it worked good... very good..

Sold the car and 4 years later the turbocharger was still boosting and making power!

Awesome! thanks guys great help, iv got lathe, mills etc all that kinda gear at my workshop so it wouldn't be a backyard job.

i also make blower impellars for work that spool up to about 8000rpm so hav kinda done abit of work with balancing etc just on alot BIGGER scale!

Will def right up a DIY thread if i attempt to high flow my rb25 turbo.

cheers kel.

Def take it somewhere to get it balanced..... Ive done turbos as part of my apprenticeship last week and its suprising how nice and smooth it looks rotating then the balancing machine says its a fair bit out.

as said they do spin very very fast so need to be pretty perfect

I put a n1 kit through my own gtr turbo's, haven't had any issues at all. The shaft's come pre-balanced.

Different to hi-flowing obviously, which you need different equipment for. Currently rebuilding a mates td0416h turbo of his volvo 850R using a genuine mitsi kit.

I put a n1 kit through my own gtr turbo's, haven't had any issues at all. The shaft's come pre-balanced.

Perhaps Stao could confirm:

According to the e-bay ad, the wheel comes pre-balanced.

But then you're coupling that to your old compressor wheel and that whole assembly was originally balanced as a unit with the old ceramic turbine.

$300 is a good deal for all those bits, but surely it still needs the new turbine/shaft assembly balanced with your old compressor wheel.

rebuilding and high flowing are waaaaaaay different . anyone with half a brain can rebuild a plain bearing turbo . i rebuilt a gtir turbo with a 360 thrust bearing and it went mint for ages at well above stock boost . the kaymak kits off ebay are pretty good

oh well this is just from my experience the last week rebuilding turbos, Mind you they are larger turbos for diesel engines but anyway

shaft/rotor (exhaust wheel + shaft) assembly is cleaned then thrust washers and compressor wheel are installed to the shaft and nut torqued. Shaft is then checked for run-out and the wheel, washers and nut can be rotated/changed whatever to get the minimum run out (the aim for these turbos was 0.02" max), after that the assembly is balanced taking weight off where required (balancing machine is needed for this, very handy) then all compnents marked in there position and removed, cleaned and assembled in the turbo facing the way they were assembled to get the good test results

Basically ensures everything is as straight and balanced as possible

Im sure you could get away with throwing it all back together however, but thats how we did it to get it to near new/new condition. So maybe you get lucky and it works, or maybe it doesnt.... its really one of those your own risk things if u want to do it without the right gear

As i said but this was for a different application to skyline etc so it may be completely different to the procedures used for garett, nissan etc

  • 2 weeks later...

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

    • well mate, while I hear your pain, turns out I don't feel it this time! Must have been a bastard of a job crammed into the boot The tank was very empty (probably pumped out, not dropped and drained because there were some fumes still) and in very good condition internally. I'm sure he never ran e85 in it I don't know what the hell Nissan's fuel tank engineers were thinking about their clipping system, this hanger was really hard to get moving but came out in the end All looks very good (as I'm starting to hopefully expect) and Matty was right it is an 023 (044) bosch which should be plenty for the injectors and turbo
    • Saturday 8th February 2025 8:30am Capped 26 entries Standard Entry Fee: $89 Members Entry Fee: $55 (SAU Victoria Only) Entries Close: Thursday 6th February 8pm. Supp Regs: TBC Disclaimer: Download  Please electronically sign and email to [email protected] or print and hand in and Driver Sign In. email [email protected] To compete in this event you will require A valid AASA General speed licence Or (Day license is $35.00 via the AASA Website) MA licenses no longer accepted A helmet, long sleeve clothing and it is reccomended a 1KG mounted fire extinguisher (But not Mandatory). Further details within Supp Regs Above. You can bring and have a passenger in the car but they need to comply to the same safety and clothing as driver. Entry Link >> https://www.sauvic.com.au/entry/deca/20250208 Entry List: 1. Martin Sullivan 2.  3.  4.  5.  6.  7.  8.  9. 10.  11. 12.   13. 14 15.  16.  17.  18.  19. 20.  21.  22.  23.  24.  25. 26.    Reserve list 1.  2.
    • I had absolutely no symptoms whatsoever that anything was wrong.... I'm very happy it was all spotto'd and re-bled and re-torqued and aligned though. Will be picking it up tomorrow and undoubtedly be like "Oh, that clunk is gone" "Oh, the car really wants to drive straight" "Oh, that pedal feels better" "Oh, it feels like I've gained 25hp" "Oh, the handbrake works now" It should have been a sign that the new Project Mu shoes had 3mm of pad depth on them out of the box, and the OEM ones from 25 years ago that we took out also had 3mm of pad depth, implying the issue was not, and never was the shoes, but we put that down to it not being adjusted correctly. It wasn't, but it wasn't even adjustable at all given one side was boned and the T Junction of the cables was on a 45 degree angle, the non-working side being the one on the massive angle. Obviously when I had adjusted it and reset it and re-tensioned it I had either got it stuck or something along those lines. Oh well. Live and learn and absolutely could have been catastrophically worse so I'm rationalizing it as a win, kinda. I also got the chance to measure the distance between rear rim and the suspension arm/shocks and found a 30mm rubber block only just doesn't fit there. Which is great to know before ordering wheels, when I assumed 30mm was easy. The man with the Porsche adapters has rims that use 23.9mm of that space, so it's safe to assume I have between 23.9 and 29.9mm of space there to play with on the inside. The wheels looked pretty stupidly pokey with the 20mm spacers on the rear, only for me to find that the studs come out another 12mm and the wheel doesn't actually sit flush with the hub because you're supposed to cut your original studs. The wheels do have cutouts that kinda accomodate it, but not fully. So my 20mm spacer was anywhere between 25mm and 35mm. ~25mm and send it will determine on where the wheels sit with the spacers on. When I put the pads in for the track day I will mess around with spacers (with wheels that do not clear studs properly when mounted to spacers) and do more math, for the last time, for the 7th time.
    • Lucky pick up Best to find these things before something horrible happened to the yoke flange thingies I would hate to think what would happen if it dropped the tailshaft  Hopefully the holes are not flogged out in the yokes and it was just the bolts that got munted  As for the hand brake.....ouch, look like the disc got rather hot, and I assume smokey, I recall when I had a front caliper seize on the Commodore, there was lots of smoke and the disc was glowing cherry red when I was able to eventually stop and have a look, and stopping a big heavy car, going down a big hill with some rather high RPM down shifts and some hand brake action is something that makes you think hard about life
    • One of the things that never seemed right was the handbrake. Put in some nice new Project Mu shoes. We figured the rears were out, so why not. We're right there. My handbrake never worked well anyway. Well, this is them, 15km later. 67fdcf94-9763-4522-97a4-8f04b2ad0826.mp4 Keen eyes would note the difference in this picture too:   And this picture: Also, this was my Tailshaft bolts: 4ad3c7dd-51d0-4577-8e72-ba8bc82f6e87.mp4 It turns out my suspicions that one side of the handbrake cable was stretched all along were pretty accurate, as was my intuition that I didn't want to drop the tailshaft to swap them on jack stands and wasn't entirely sure about bolt torque. I have since bought the handbrake cables which have gone in. I'm very glad that I went to my mechanic friend who owns an alignment machine to get an alignment before the track day, because his eyes spotted these various levels of "WHAT THE f**k IS GOING ON HERE?". Turns out the alignment wasn't that bad, considering we changed the adjustable castor arms out for un-adjustable castor arms, and messed with the heights. Car drove pretty good with one side of the handbrake stuck on, unbleedable rear brakes, alignment screwy, and the tailshaft about to go flying and generally being a death trap waiting to happen! (I did have covid) (I maintain I adjusted the handbrake correctly, but movement caused shennanigans and/or I dislodged the spring on the problem side somewhat, or god knows what). G R E G G E D
×
×
  • Create New...