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Turbo repair or replacement to make stock power?

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Old 10-27-17, 11:10 PM
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Turbo repair or replacement to make stock power?

So my s5 turbocharger has chipped fins and isnt usable. ive searched and searched for some time now for an answer on what to do to get my stock turbo repaired with no avail. Bnr wont repair it to stock specs and i cant find a replacement turbine. If anyones had any luck please help.

i dont wish to mod the car past 250hp right now as its all stock and just had an engine rebuild. Anyone have any luck with an aftermarket turbo running close to stock power numbers? If so what turbo are you running?
i just wanna turn the key and hear it run again 🙃 lets get another rx7 back on the road
Old 10-28-17, 01:53 PM
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I'm amazed that BNR doesn't have a replacement.
Old 10-28-17, 03:13 PM
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I think you can find a compressor wheel for like a 100 bucks US.
Old 10-29-17, 12:18 AM
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There is absolutely NO point in going aftermarket turbo if you're chasing stock power goals. Aftermarket turbo will require a manifold, turbo (obviously), custom oil feed and return lines, custom intercooler piping, wastegate (unless internally gated) and a downpipe to be mated to your current exhaust. It's a lot of $ to spend for numbers that the stock turbo will do all day long.

Instead of being crazy, try to source another stock turbo. Make sure you stick to the same series that came out of the car because the hotside/manifold for s4 and s5 are different. I have a spare turbine and compressor wheel hiding in the garage somewhere if you want to go that route.
Old 10-29-17, 01:37 PM
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I know its unreasonable to upgrade, im just trying to find my best option. Somebody pm'd me saying they can rebuild it for me. Without naming names is there a way i can find out if i can trust this person? I would be so happy if i could get this thing running in stock condition so i can start modding it progressively and properly.
Old 10-30-17, 09:10 AM
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I know you said you didn't want to upgrade, but you might take a look at the BNR stage 1. It is the most similar, and you probably won't notice much difference if you keep the same wastegate actuator. It would be worth having him upgrade the bearings and such for reliability. BNR is a pretty reputable shop, so I'd still say that's your best bet.
Old 10-30-17, 10:41 AM
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If you get it repaired it will cost you about as much as a used S5 Turbo.
Why not put up an Ad and see if there are any available?
Old 10-30-17, 11:45 AM
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Originally Posted by professionalpyroman
I know you said you didn't want to upgrade, but you might take a look at the BNR stage 1. It is the most similar, and you probably won't notice much difference if you keep the same wastegate actuator. It would be worth having him upgrade the bearings and such for reliability. BNR is a pretty reputable shop, so I'd still say that's your best bet.
FWIW, I agree with going the BNR stage 1 route. That's basically what I did when my stock turbo started smoking a few years ago. Back then the BNR stage 1 was mechanically a "drop in" replacement for the stock turbo, in that all the plumbing connections can go back as-is (i.e., can use stock inlet duct, coolant & oil fittings). With that setup, and still retaining my cat & air pump for emissions inspections (MD), but adding 720cc Bosch FIs in all 4 holes, and an RTek 2.x ECU mod to control it all, I dyno'ed at 205 RWHP. I only did the fuel & RTek mods to have a safe & bullet proof baseline for future upgrades. Once I was able to get historic plates on my FC a year or so later, the cat & emissions gear was chucked (swapped in a RB downpipe & pre-silencer to replace the cat & DP), I got back on the dyno, re-tuned the RTek and the same setup was good for 296~303 RWHP.

I just checked the BNR website, and it appears he now includes a new TO4B compressor housing instead of machining the stock compressor housing to fit the bigger wheel on the Stage 1's, which means you'll need to fabricate a new turbo inlet duct to work with your AFM, as the stock part will no longer fit, but everything else is drop in. Not too hard to do, but it is extra work.
Old 10-30-17, 02:53 PM
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I have a S4 "supercore" (whole turbo except for the exhaust housing) which will bolt into the S5 exhaust housing and then you would have to add the metal tubes for the S5 boost controller onto the S4 turbo (which was just a hose straight to wastegate).

Thing is its out of my 140,000 mile '87 TII and while it worked fine and did not smoke when pulled 15 years ago it does have quite a bit of side to side shaft play. The compressor wheel does not touch the compressor housing when pushed all the way to one side and rotated so it is still serviceable according to Mazda spec- but I certainly wouldn't expect another 140,000 miles out of it.

Also should be a rebuildable core if the shaft where the oil seals ride aren't worn out (a common problem on FD turbos- don't know if its the same issue with FC turbos - ask BNR).

Let me know if you are interested in it for cheap. Its just a garage decoration for me.
Old 10-30-17, 08:15 PM
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CHRA issues with the HT18s usually lie in the land for the turbine carbon seal, not so much with the bearing bores. well that and expansion/contraction fissures in the castings, but those generally are cosmetic unless really bad.
Old 10-31-17, 03:35 PM
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Ill throw a wanted ad out there and see whats around me, but chances are it will cost similar to that of a rebuild plus turbine and a new rebuild will be more reliable. Id like to one day slap on a decent sized ball bearing turbo, but thats not gonna be for a long while
Old 11-01-17, 08:25 AM
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bite the bullet and pay for a rebuild




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