Advice needed, chinacharger vs sr20 Pics added 3/10
 

I don't post here very much because I am still reading and learning, but Ive come across a situation where I need some advice.

I bought some used turbo stuff- a FM cast iron manifold, FM cast upper and SS intermediate downpipe, and a Garret SR20 turbo. After cracking open the turbo to measure the bearing size, I believe I overpaid. The turbo itself was only $80, but from the beginning it was missing the external wastegate actuator. After taking it apart I found a damaged turbine impeller. It looks like it ground something at its outermost diameter. The housing is unaffected. From the assembled view (upper downpipe removed) the impeller looked fine, but it clearly is not usable.

So my problem is, after I buy a turbine impeller and shaft (~$100), a wastegate actuator (~$45) and a rebuild kit (~$40), I can buy a new chinacharger on EBay.

What would you do?

which chinacharger? there's like 300 different ones to choose from.

that's like saying should I buy a red car or a corvette?


pics of turbo now please.

Buy a chinacharger, when you replace the turbine I'm pretty sure you'd need to send it out to get rebalanced too

Any suggested chinacharger.... Similarly sized, so the t25 flange on my manifold will work. My goal is a fairly dependable and durable system, with a max HP of about 220 or so.
I guess my question was really is a Garret sr20 with this many issues going to be any better durability wise, vs price, than a new similar sized chinacharger?

[QUOTEBuy a chinacharger, when you replace the turbine I'm pretty sure you'd need to send it out to get rebalanced too][/QUOTE]

I think this too- except that I read when you buy a turbine wheel it comes balanced on a shaft, ready to install a compressor wheel/nut. I guess it doesn't *require* balancing. How much does balancing the assembly usually cost?

That's a great question for the Google search bar

the turbine wheel, shaft, compressor wheel, and nut all get balanced together. it usually costs 80-100. best place to do it is gpop shop.

you need to search moar

For a turbo that old, you'd want to balance it. Newer name brand turbos are all component balanced first, and the assembly is checked for balance and it rarely needs altered. I've messed around with changing wheels on some MGT series Honeywell turbos and never needed to rebalance.

Go find another good Sr20 t25 in the $100-200 range. None of the t25 china chargers are "great" on a miata. Don't waste time or energy rebuilding them. Just go pick up another cheap used one if it breaks.

I have yet to find a 100-150$ working t25 without a wierd flange, must be few and far between. What about the t25/28 turbo begi sells

it is an utter piece of junk

basically exactly same as ebay, but with a $400 markup :)

I have purchased 4 over the past 8 years. 3 of them are still out on cars being used. Get on searchtempest and 240 forums. It shouldn't take you longer then a month to find one.

The t25 Begi uses is garbage. Every t25 chinacharger I have seen dyno for have horrible spool and lackluster power. The t3 chinacharger that I used on my setups is about the best china charger you can get.

So for 400$ it's rip, but for 200$ it's OK?

I was zilvia.net and couldn't find one for the life of me, guess I know where to find one now

its actually 600 from begi iirc

junk either way, but I'm sure it's more "acceptable" when it's 3x cheaper


the key with finding stuff like this is patience. there isn't a steady supply. you gotta wait for it

I'm curious to see the damage as well...

Sorry I didn't even see the request above for pics. I'll try to get some tomorrow when I'm off work

Send my your sr20 turbo and I will rebuild it for you as I've done for many other members in the past. I have a pile of sr20 parts...I'm pretty sure I have a used turbine wheel/ shaft.

Sorry for the delay, here are some pics. Sorry again- they are big!
https://www.miataturbo.net/attachmen...ine=1457622805


https://www.miataturbo.net/attachmen...ine=1457622805


https://www.miataturbo.net/attachmen...ine=1457622805


https://www.miataturbo.net/attachmen...ine=1457622805


https://www.miataturbo.net/attachmen...ine=1457622805


This is not an exact measurement- the caliper couldn't accurately reach the back side-
https://www.miataturbo.net/attachmen...ine=1457622805


no visible damage to the housing
https://www.miataturbo.net/attachmen...ine=1457622805

Thirdgen- do you work at a turbo shop? Can you do balancing? I have no problem rebuilding the turbo myself aside from farming out the balancing job and sourcing a turbine. Ive already taken this one completely apart to measure the bearing sizes. Would you sell me a used turbine impeller? How much? Thanks

if a compressor wheel has been balanced, and a turbine wheel has been balanced, logic suggests it will still remain balanced when put together.

buy a new/used turbine. replace the bearings/piston rings. slap it on. enjoy blowing your motor with massive boost.

your logic sucks

they balance both together, hence why all competent shops will mark exactly where the comp wheel should end up relative to the shaft and relative to the nut

I highly recommend G-pop shop for your spare parts and balancing needs

Boost Lab is local and fantastic. They do tons of work.

my logic has never failed me.

I've probably cobbled together 5 Frankenstein turbos and never had an issue with them

the only turbo i ever has an issue with was the one I paid WAY too much money for, whose wheel hit the compressor housing cause the shop MJM Turbos has no fucking clue what they are doing. The owner of the place hung up on me multiple times.

they blamed me because I rotated the compressor housing.

I will quote here:



I ended up paying to have it "repaired" since they were holding it hostage. when I got it back, it hadn't been touched still did the same thing (AND TO TOP IT OFF--they roated the turbo back, so i still had to clock it again to fit my installation).

I ended up swapping out the compressor wheel and housing and ran that turbo for years. then i changed the wheel and compressor again, and ran for more. then i changed the chra. then the turbine wheel. and i think one other combination i cant remember. rebuilt it at least twice, changed out the thrust bearing as well. ask me how many times i got it balanced.

i was going to swap the chinacharger wheel and compressor housing on it but the chinacharger worked so well i saw no point to try.


If I was in this situation, knowing everything I know today, I'd still just buy a new turbine, rebuild the chra, and slap it all together and run it. I'd be more concerned with the tolerances of my bearings than any balancing. If I was talking about a turbo that cost more than an hours pay, i might respond differently.

No I don't work at a turbo shop...I'll have to check to see if I have an impeller.

I just got a text today from a guy with a "slapped together" vf39. It "worked for years" (no really, it worked for exactly 2 years) and now " sounds like a supercharger".
I can forward you the text :D
I mean, it's a $100 t25. Even with rebuild you're looking at $200. So I guess not a terrible loss if it does 'splode from being unbalanced

My experience:

1. Acquire $120 SR20 t25 in need of lovin
2. Poorly mark the position of the nut-compressor-shaft alignment
3. Disassemble and put in G-pop rebuild stuffs
4. Reassemble and realize I can hardly see the alignment marks I made
5. Guess... close enough.
6. Spend lots of time researching and worrying about the explodey possibility of a massive $200 loss
7. Drive daily for 3 years and 40k miles with zero issues
8. Post anecdotal evidence on forum that may or may not work for you

Wish they would just balance each component individually so this was never a concern.

:likecat:

You're likely right.
I'm likely overthinking things as usual.

...but when people text me that their turbo sounds like a supercharger, it makes me worry.

it's not fun:


especially when you just paid $600 the turbo, and it was you first drive...

I was expecting it to sound like this:






I couldn't find the George Michael one...

Thirdgen- Keep me posted

pretty sure i deleted that one.


The BEST one was actually Boyz II Men.