My car has started to smoke a ton of blue smoke at idle. So I took the turbo off to see if its the turbo or internal. 3 hours later, a broken thumb and I finally got it off due to one stubborn bolt and taking it apart, its dry and clean. Now the issue is I had to start it up to move it up the driveway and it doesn't smoke when cold so if there was oil in the turbine housing it might have burned it off?

Anyway, does anyone know if a turbine housing without the CHRA exists to run it N/A as a test to see if its internal?

thewird

 

Yea just gotta block off te inlet where the chra went. There used to be a company that sold machined disc for this purpose.

 

Isn't your turbo brand new from Precision?

Anyways, just cut some thicker sheet metal into a round piece, drill 6 holes around it to match the housing, and use some Permatex copper silicone to seal it temporarily.

 

Yah the turbo is new and ball bearing but **** happens right. Haven't even ran the car this year yet, one problem after another. Finally got everything else sorted and then I start smoking out everyone when sitting in an intersection

Hmm, that's an interesting idea, guess I'll try to find a plate to cut up. Would be easier if I could just buy something.

thewird

 

If you don't want to do it yourself, just go to a local grinding shop with the turbine housing and tell them what you want. I doubt they'd charge you more than $20 for the piece?

 

Did you try an oil change before you pulled the car apart?

 

I actually had considered that as the oil is still from last year but I was kinda convinced it was the turbo so went ahead and took it off. Do you really think old fuel contaminated oil could cause a leak at the control rings and then seal up again once good oil is put in there? I was planning to change the oil once everything was fixed and track ready again.

Anyway, since the car is already apart, going to be trying the N/A turbine housing and if it still smokes will try to change the oil. Thanks.

thewird

 

Well its always best to rule out simple things first. And yes I have seen engines doing funny things before when they needed a charged battery, spark plugs, leads, oil or even just fresh new petrol.

 

I had a breather filter on a hose get pushed too far onto the hose at a race (probably fidgety tech fingers).

It left the hose end butted against the flat metal filter cap and pressurized the sump so the car started to smoke like crazy out the turbo rear seal till I pulled the filter back.

So, check your sump vent- taking off the turbo would stop the smoke in this case, but the turbo wouldn't be the problem.

As far as running without the turbo- I had a friend machine a metal disc to fit where the CHRA goes into the turbo housing for running NA and is held down by the same bolts/bridge washers as the CHRA would be. Then I made block off plates for oil/coolant feed/drain.

 

I have 3 separate breathers which are -8 to -10 in size so I doubt thats it . Thanks for suggestion though.

thewird

 

Got to watch out, from what I've seen, Precision ball bearing turbos are junk and have seen a few **** the bed within a couple thousands of miles

 

I ran a 6765 all last year with hard abuse at the track (road coarse) for about 20,000 km without issues. I bought a new one with the H cover to see the difference and it hasn't even seen 500 km's and zero track use. Could just be random failure but anyway, the turbine was clean so things are looking to internal.

thewird

 

So I went to a local machine shop I knew. Told him I just needed simple plate made of scrap. He gives me this lol... Nice piece...

Tomorrow or most likely weekend I'll go get a cap for the oil line and test it out.




thewird

 

we might have the same friend!

running NA-t is/was a really great way to tune the vacuum parts of the ecu map too.

MY friend took his turbo off, and found his 20B was pinging. its scary when a 3 rotor pings!

 

Well, good news, bad news. Finally got around to installing the blockoff and buying a cap for the oil feed. Took it for a 20 minute drive, got home and the exhaust was CLEAN, zero smoke at all. So its not the engine, thats the good news.

Bad news is the turbo is pretty much brand spanking new, maybe 1-2k on it at most, barely ran a month. Arg... what to do.... Here's a pic of the setup ^_^

Note: I did not change the oil or anything on the car so everything was the same as when it was smoking.

I wonder if a GT4094R would fit where the 6765 is....



thewird

 

Are you running a restrictor in the oil feed line or fitting? Is it all the same fittings and plumbing as your setup with lots of miles and no issues? I've heard of several failures from not restricting oil flow to a BB chra.

 

The Precision BB turbo's have a builtin restrictor so its not needed. This is the same identical setup I ran last season with zero issues except its a new turbo (same one).

thewird

 

GT40 won't fit, turbine housing is slightly bigger. That housing has got nice and hot

On a side note I built a block off plate like that for my Tial 42R housing.. I found I was way too rich in low vacuum past 6k rpms...

 

LOL, it saw maybe a 1-2 laps at mosport and wasn't even full bore cause car had crazy vibration due to loose pinion on the diff. I think thats thanks to your inconel heat shield :P

Tune seemed ok except when I gave it WOT it was a richer (high 11's) then I would tune an N/A at WOT but then again its not supposed to be running without a turbo hehe. I also didn't take it much over 4k, I was just testing the smoking, not power runs lol.

Hmm, no way to fit the 4094R in there?

thewird

 

I had a problem with my turbo smoking from excessive oil pressure at low rpm.

One way I fixed it was to put my sump under vacuum so the oil drained more easily from the turbo, but even with an oil air separator I could never keep from pulling oil into the intake manifold.

The final fix was when I put in race rotor oil jets in the eccentric shaft instead of the stock check valves that close at low rpm as it lowered the oil pressure at idle and low rpm.

Now I run a simple vented catch can and get an ounce or two of oil from vapors collected after several races.

 

That sounds like a hack, rather then a fix. I'm sending the turbo back to precision, its still under warranty.

thewird

 

I just read the entire thread, glad you figured out what was wrong. I'm surprised the turbo is leaking in such a short amount of time but then again in a way it's good that you caught it now rather than later.

 

That sounds like a hack, rather then a fix. I'm sending the turbo back to precision, its still under warranty.

The Mazda factory race parts are hacks indeed.

 

The race rotor jets were never intended to be street driven.

thewird

 

By the sounds of it you track your car quite often, so you'll have to pick the worse of evils, you are asking a lot of your car to perform equally well at both.

On that note, the jets lower oil pressure at idle in order to provide better rotor cooling at higher RPM, but how much oil pressure does a rotary really need at idle?