$350 Turbo made 253rwkw @ .9bar

[DRD-00F]

when i was a young lad i built one of these turbo's... you wouldnt want to build one now though.

Just for the record, someone wanna clarify why?

[laujik]

Hmm this is the best thread I have ever read haha.

I was just about to go into the garage and start taking apart my turbo's (i have both sitting around) and wondering if this is the still the sweet of all sweet haha.

If you dont mind me asking, could I get another run down on what you need to do and have to get this hybrid going. And any other new ideas? Cause I actually have 2 of each turbo's lying around and willing to test with diff wheel/combo. I want to make one of these for sure though.

I have this but a little confused.

Quote by BOOSTD

"OK here it is the final product/s

RB25 BB turbo

Vg30 exhuast housing

T04B vtrim Compressor

Standard ceramic turbine wheel

Turbine snout enlarged to 52.2mm

result 15psi by 4100rpm

spool starts @2000rpm goes nuts @ 3600(hello tyre fry)

Result 266rwkw @ 17psi

Or Less power Quicker response

Same specs as above with

groove in inlet (same as standard rb25 inlet)(reduces compressor efficiency)

Turbine Snout 51mm

15psi by 3800rpm

spool @ 1800rpm no sledge hammer effect like above just smooth till 3800rpm

result 245rwkw @ 10-15psi will not make more power with boost increase"

Cause the only machining needs to be done on the exhaust snout side correct? Nothing to make the other wheel fit correctly or better? (what size is a v trim?)

Also you just need an upgraded ecu correct? I have fmic/exhaust/bc/powerfc. I dont think id need injectors.

Edited February 29, 2008 by laujik

[turbomad]

Hey boostd, with the 2 options above you mentioned to keep the snout at 51mm you have to groove the inlet same as RB25, I thought this turbo already was using the RB25 comp housing so therefore the groove is already there? Or do you mean something else by inlet?

Also you mentioned something about a T04S wheel, does that comp wheel fit in the stock RB25 comp housing with no mods whereas the T04B wheel needs mods to the housing, is this correct?

[rev210]

had a VG30 comp housing. Sam size as the Rb25 one but no groove.

[BoostdR]

Sorry for the late reply, my profile is stuffed so had to make a new account...

The Compressor cover(inlet side) is std RB25. This does have to be modified to fit either the T04B Vtrim compressor or the TO4S.

The turbine housing is from a VG30 turbo which has a larger A/R ..ie bigger scroll but uses the same size turbine wheel. This bolts onto the Rb25 center.

So the compressor housing is modified to fit the new compressor wheel, This is done by enlarging the inlet...which also takes out the std RB25 anti-surge groove so another is machined in.

The VG30 turbine housing is enlarged so there is a quite noticable gap between the turbine wheel and the housing this is done to slow down spooling other wise way to much boost is made at a low rpm which the engine cannot digest and as a consequence cause surge.

Hope that makes things clearer

[turbomad]

Yep ok thanks BOOSTD that makes more sense now, a few more q's, regarding the comp cover it's only the inside of the entry that's enlarged then, (to what mm?) is there anything else internally that only a turbo shop would know how to do or is it easy enough for any engineer shop to handle?

Same thing with the VG30 exh housing if the snout needs to be 52mm (I assume the snout is the part where you can see the exh wheel through that opening) then the same engineering shop would be able to enlarge just that opening, nothing internally there needs to be modified either?

Is the T04B comp wheel a direct fit on the stock RB25 turbo's shaft or does that need to be modified?

Reason I ask if the engineer shop can do the machine work is I'd imagine a hi-perf turbo shop would want to talk me out of building this turbo as they'd make more money if they sold me a hi-flow unit they produced, so the only way around it would be to take the parts to a turbo shop that mainly does repair/rebuild work and get them to balance and assemble it, what do you think?

Boostd do you have a preference as to which option you liked best, the 51mm or 52.2mm exh housing?

[BoostdR]

The comp cover in enlarged to whatever the inducer/exducer size of the compressor wheel is. An engineer should be able to do it all except the final balancing.

The turbine housing side is pretty straight forward, you have the right idea there. I would probably go a tad smaller than 52mm..say 50mm then use a jaycar boost controller to adjust the ramp rate of the boost....which will keep it out of the surge zone. That way you are getting the best possible response. The T04S wheel will be ok with this smaller 50mm outlet as its surge zone is smaller. I would expect more power aswell.

I'm not sure if the T04B wheel directly fits the RB25 shaft as I used a VG30 center which had in this case a larger shaft.

Bill At ATS -Adelaide Turbo Services has made a few of these for off road buggies as price is a major factor. They make around 230rwkw at 10psi.

[W0rp3D]

I now own this turbo, i dont think it is running the same power as it did when new as am running it at .9 bar but using standard injectors, fuel pump, afm and ecu, had it 1 bar and it starts to break down a little which i think is more about spark plugs as it didnt ping.

need to get fuel pump and injectors then i can put the afm and pfc i have on as well and tune it properly.

still going strong though and pulls hard.

Edited April 24, 2008 by W0rp3D

[MacGillaZ]

The turbine housing side is pretty straight forward, you have the right idea there. I would probably go a tad smaller than 52mm..say 50mm then use a jaycar boost controller to adjust the ramp rate of the boost....which will keep it out of the surge zone. That way you are getting the best possible response. The T04S wheel will be ok with this smaller 50mm outlet as its surge zone is smaller. I would expect more power aswell.

I'm not sure if the T04B wheel directly fits the RB25 shaft as I used a VG30 center which had in this case a larger shaft.

Thread Revival

I bought a VG30 turbo to go onto my redtop RB20, but hit a snag when i found out both seals are shot, so I'm looking to rebuild it (if the core comes up okay).

You mentioned that you were building a version for a 20, what specs did/would you use for such an example?

[BoostdR]

I would be going a 47-48mm turbine outlet...with the T04B Compressor, however there may be a newer compressor wheel avail thats more surge resistant. Gill Bill at Adelaide Turbo Services a call. He helped me no end when I originally made this turbo.

[MacGillaZ]

I would be going a 47-48mm turbine outlet...with the T04B Compressor, however there may be a newer compressor wheel avail thats more surge resistant. Gill Bill at Adelaide Turbo Services a call. He helped me no end when I originally made this turbo.

Thanks Matt, will do once I hear back from AG about the condition of the Core/shaft/Ceramic wheel.

[BoostdR]

To confirm the T04B I'm referring to is the Vtrim

[MacGillaZ]

To confirm the T04B I'm referring to is the Vtrim

Well the place was quoting me $650 for the required machining just to fit new Oil seals, so I said go no further and I'll pick it up tomorrow!

Have got first option on a GT2871R atm, which should reallistically be a better investment in the long run, if a little less original.

Thanks again Matt for the spec updates.

Andrew

[W0rp3D]

which should reallistically be a better investment in the long run, if a little less original.

Andrew

From this thread it seems this turbo started to get a work out in about august 03, now in november 08 it still has not missed a beat and is running 14psi every day, pretty good for a bolt on turbo i think.

Dont forget to add on all the extra bits needed to fit your other turbo, if its not a straight bolt on you will also need a new dump pipe, new piping from the compressor housing to both the intercooler and afm plus you will need custom water and oil lines, and if it is not internally gated you will also need an external gate, all those extra's add up and after that the high flow option is not so expensive any more.

[BoostdR]

For anyone still reading this old thread I would advise to not use the T04B Vtrim compressor wheel....there are many better options these days.

[W0rp3D]

For anyone still reading this old thread I would advise to not use the T04B Vtrim compressor wheel....there are many better options these days.

To update, I thought I had blown this turbo but then discovered a couple of snapped exhaust studs so I think that's the problem, if that's the case this $350 turbo is still going strong after 7 years.

[BoostdR]

To update, I thought I had blown this turbo but then discovered a couple of snapped exhaust studs so I think that's the problem, if that's the case this $350 turbo is still going strong after 7 years.

Thats good to hear

[W0rp3D]

Thats good to hear

R.I.P $350 highflow, probably rebuildable but not worth it!

[zebra]

After So long

I hope you are putting it in the pool room

[W0rp3D]

Unless a pool room magically appears then no, lol