2-N-D-pink

iTrader: (27)

I want to rebuild this turbo. I got it in pretty bad conditions so i started to take it apart and see what was good and not good.

First I took off the turbine housing and compressor housing and then noticed the rear wheel is beat up. I think i can clip or trim the wheel and be ok but im not 100% on that. After I took off the compressor housing the back plate was showing the same white stuff that was on the wheel so I undid the compressor wheel and found rock particles behind the compressor wheel. Looks really rough and I have pictures to show.

Since its getting rebuild i dont care about which parts I need to replace but im confused at what Im looking at and where I can get replacement parts. The only thing that looks like the FC hitachi turbo is the turbine housing and coolant/oil lines. THATS IT! Everything else: turbine wheel, compressor wheel (obviously because its a hybrid) compressor housing, wg actuator, even the center CHRA looks totally different and what made that clear to me was the dynamic seal and thurst bearing.

Here are some pics of both my stock turbo and the unknown turbo.



Stock turbo back plate




Mystery turbo back plate






Stock turbo thrust bearing



Mystery turbo



Oil drain (stock turbo on the left) also notice the center CHRA



Oil feed (stock one is one the left) mystery turbo is threaded on the feed??




Turbine wheel (stock one is on top)



Stock turbine wheel



Mystery turbo turbine wheel



Stock wheel is on the bottom

2-N-D-pink

iTrader: (27)

Center CHRA



Has any one seen this before? I tried to find the mystery turbo back plate using google and cant come up with anything. I also looked in garretts parts catalog and its not there.

2-N-D-pink

iTrader: (27)

^stock on is on the left

barkz

iTrader: (1)

dat ebay though... kidding, but it might be. either way that thing looks trashed

RXSpeed16

iTrader: (41)

Check what the compressor housing is: Should be a T04 something.
Use calipers to measure the exducer and inducer of the compressor and turbine.
Check them against the charts here: FC3S Pro v2.0: Turbo Tech

Whatever the turbine was, it's in bad shape.

Backing plate is a generic t04 backing plate with 360 thrust bearing. It bolts right to the stock CHRA. A T4 rebuild kit should have the parts you need.

I have one of those chra's from a core. Don't know where it came from, but it's interchangeable.

gxl90rx7

iTrader: (1)

G-Pop Shop :: quick links Rebuild Kits :: Garrett T3, T4, T3/T4 Rebuild Kits

you want kit #3

the turbine wheel may be a T3 stage II.. just measure the inducer & exducer and see if it matches up with one of these with standard shaft:
T3/T4 Turbine Wheels

2-N-D-pink

iTrader: (27)

Searching around on t04b's, I said something like that thing 7 years ago on this thread haha


The I've checked the size of the compressor wheel a while ago when I got the turbo and this one is a "V" trim compressor wheel. I planned on replacing the back plate, soda blast the compressor wheel and use my stock turbine wheel with a rebuild kit. But not until recently when I started to take both turbos apart did I noticed the two CHRA differences. Made me wonder who is using this center CHRA and not the stock S5.

Whatever this center CHRA is, its kinda like the stock one but the thrust bearing isnt interchangeable. It doesnt fit the stock CHRA and it has 3 torx bolts that hold the bearing on the center CHRA.

I couldnt find any info on part number 409322-12 which is whats on the back plate of the turbo. But looking in RotaryRocket88 turbo rebuild thread, I saw the same number on his back plate. I wonder if its possible for this center CHRA to also be a T04b25 like his. Except on this one..instead of taking the compressor wheel/backplate/comp. housing, they kept the whole turbo and switched out turbine housings.

2-N-D-pink

iTrader: (27)

I think you got it. Im also thinking T3 stage II now. The turbine wheel is pretty rough and it measures 64mm but since theres missing pieces im gonna pretend is 65mm inducer. I also noticed this turbine wheel is has a longer shaft and the wheel part is shorter than the stock one.

Stock one on the left








On the T3 turbine wheel, from the closes spot of the center of the bottom of the wheel to the top, it measures 26mm +/- but at the from the bottom of the wheel to the edge of the top side, it measures 24mm while the stock one measures 26mm all across +/- since my tool doesnt measure in .00

Im really thinking about using the aftermarket CHRA and replacing the dynamic seal. I have a new backplate and this comp wheel I have fits perfect. Stock CHRA looks like it has a oil restrictor on it and the other one doesnt. Plus i kinda like the bolt on thrust bearing.


New back plate



Stock S5 turbo on the left with an oil restrictor or something behind the thrust bearing







These look good to me but the dynamic collar and piston ring on it dont.

bumpstart

ta34/ stage 2 t3 turbine wheel, V trim compressor, front dynamic ring conversion .. 360 degree thrust bearing conversion , generic t3/t04 b wet type CHRA


the combo is fairly common , doesnt really need the 360 bearing conversion till it goes to the H or 60-1 compressor

i have built a few very similar, though i err to a steel HD 270 thrust beaing
and keep the front carbon seal setup
and sometimes use the U trim front [ 1 smaller than V ] as it hifis into a stock cover easily

2-N-D-pink

iTrader: (27)

My junk is looking a little better after some bead blasting








I think what Im going to end up doing is using the stock FC turbine wheel but with this center CHRA.

GrossPolluter

iTrader: (1)

the damaged turbine wheel looks like it was clipped. I've ran my to4b hybrid with clipped and non clipped turbine wheel and I liked it flipped a little more. It has slightly better top end

2-N-D-pink

iTrader: (27)

What do you mean better top end?

Like actual numbers or a "feel" to it?

Also how much boost do you run and did that change after you clipped the wheel?

GrossPolluter

iTrader: (1)

Clipped turbines are put on a lathe and a little of the front is cut ata certain angle. It won't spill as fast but in high rpm the turbo spins a little better. These differences are pretty small. I felt the non clipped turbo hit peak torque and power slightly sooner but didn't have as much pull in the higher rpm, like about 5500, 6 +.

GrossPolluter

iTrader: (1)

I ran 12 to 14 psi on a street ported s4 13bt with s5 turbo with ported wastegate

2-N-D-pink

iTrader: (27)

That 6k rpm boost fail is the reason why I want a better compressor wheel. The stock turbo would hit 13 psi but after 6k rpms itll fall back down to 6-8 psi. I was thinking maybe the stock wheel is just too small and an upgrade would help. Its a bummer to hear that going hybrid wont help keep boost up in the higher rpms

2-N-D-pink

iTrader: (27)

Im at 13psi with the stock turbo on a tial. .9 bar spring and still wont keep the boost where I like it to be

GrossPolluter

iTrader: (1)

Where do you want your boost? Is it dropping off or going to high? Boost controller?
Most of us are on a budget or else we would have fd or something nicer, but I know a few people that we're just tired of playing around with these hybrid turbos built from 87-91. I ended up buying a new bnr which I only had to send him my exhaust housing. I'm still doing stuff to my cat and haven't ran it yet.

2-N-D-pink

iTrader: (27)

I just want boost to stay in place. Id like for it to stay at 13 psi with the hybrid set up until I can get something bigger all together.

no boost controller. Just an external wastegate with a .9 bar spring (Tial) Even with the .9 bar spring itll still fall on its face.

Itll go from 13 psi to 6-8 psi after 6k but that was the stock unit with the tial and not the hybrid. I figured changing the front wheel would help out but now it may not. All I can do right now is rebuild this turbo and hope itll hold boost and touch the 300hp range.

j9fd3s

iTrader: (3)

i looked at compressor maps a while ago, and noticed that the 3rd axis is turbo rpm. when you start plotting different boost and hp's with a stock (ish) compressor map, you soon see that boost drops off because the turbo cannot spin any faster.

to get more boost at a higher rpm, you need a compressor that moves more air at less shaft rpm, IE bigger.