whats the worst that could happen? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Prefabbed Turbo Kits A place to discuss prefabricated turbo kits on the market
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools
Old 03-01-2007, 12:49 AM   #1
Junior Member
Thread Starter
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 129
Total Cats: 0
Default whats the worst that could happen?

what is the worst that could happen if a turbo lets go? the reason i ask is that im planning on using a turbo out of a junk yard without rebuilding it. what should i look for in junk yard turbos? i know to wiggle the impeller up and down and back and forth (I assume play in the shart should be nill).

P.S. thanks to all you guys. i registered just the other day and you guys have helped alot.
zebro racing is offline   Reply With Quote
Old 03-01-2007, 12:57 AM   #2
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

On a journal bearing turbo, some shaft play is normal. I would look for Nissan turbo's primarily but i'm biased towards the standard garret flanges because of my HKS mani. DSM turbos are also available off eclipses and...
cjernigan is offline   Reply With Quote
Old 03-01-2007, 01:41 AM   #3
Senior Member
 
Join Date: Apr 2005
Location: NAS Oceana/VA
Posts: 759
Total Cats: 0
Default

I guess the worst that could happed is peices of you turbo get sucked into your motor and blowing it up.
getsidewaysd1 is offline   Reply With Quote
Old 03-01-2007, 01:54 AM   #4
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

The pieces would hopefully get stuck in the intercooler, the smaller pieces will go through the motor come out the valves and get recycled through the turbine housing thus destroying the rest of your turbo that might have survived.
cjernigan is offline   Reply With Quote
Old 03-01-2007, 02:51 AM   #5
Junior Member
 
Join Date: Feb 2007
Location: Winona, MN
Posts: 198
Total Cats: 0
Default

shaftplay would mostly be the in and out movement of the impeller which would mean its about to go...
LOOINEY is offline   Reply With Quote
Old 03-01-2007, 07:54 AM   #6
Newb
 
Join Date: Jun 2006
Location: Manchester, UK
Posts: 25
Total Cats: 0
Default

This is isn't likely to be a problem on a Miata but on a Turbo Diesel Citroen Xantia I used to own the oil seal in the turbo failed whilst I was driving... oil got sucked into the inlet and the engine started to run on oil alone.

I pulled the key out of the ignition but the engine continued to run and revved straight up to the redline...it sat there at the redline for about a minute in a cloud of smoke before it cut out.

I assumed the worst (new engine) but in actual fact I fitted a new turbo, some new glowplugs and a new cambelt (just for safety) and it was fine!

As I said, not likely to happen on a low compression petrol engine like the Miata but thought you'd want to hear about a turbo failure...
ds23pallas is offline   Reply With Quote
Old 03-01-2007, 12:16 PM   #7
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,926
Default

Quote:
Originally Posted by zebro racing View Post
what is the worst that could happen if a turbo lets go?
Well, the turbine casing explodes, shredding the brake and steering lines. You car crashes into another vehicle, killing the Director of the CIA and his family. Conspiracy theories and political infighting paralyze the agency, causing America’s already troubled intelligence capacity to grind to a halt.

Meanwhile, hard-line extremists rise to power within Russia and their charismatic ways reunite the old empire under the Soviet banner. Seeing America’s military paralyzed, Russia (with the support of the African and middle-eastern nations, who are tired of the US and its colonialist tendencies) launches an aggressive campaign to seize control of the West and ensure the future economic stability of their fledgling nation.

Defenseless, and with western Europe cautiously refusing to cast their lot in what could ultimately trigger a Third World War, the US turns to China for aid. In a desperate bid for survival we mortgage our future to the Chinese, who ultimately betray us to our aggressors in order to strengthen the heretofore secret negotiations in a new Sino-Soviet alliance. And within five years we’re all living under the iron thumb of Communism.

That’s pretty much the worst that could happen.
Joe Perez is offline   Reply With Quote
Old 03-01-2007, 02:03 PM   #8
Junior Member
Thread Starter
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 129
Total Cats: 0
Default

jokes aside; could the turbo granade under the hood and realistically take something out? would it be a good idea to put a skatter sheild around the turbo just incase?


joe: if the sino-soviet alliance took over, do you think they would bring some lada or yugo turbos over here.
zebro racing is offline   Reply With Quote
Old 03-01-2007, 02:35 PM   #9
Elite Member
iTrader: (13)
 
cjernigan's Avatar
 
Join Date: Oct 2006
Location: Atlanta, GA
Posts: 8,147
Total Cats: 6
Default

I have never seen a scatter shield on a turbo, just heat shields. That goes for cars running 30 psi even. If you are running a turbo under conditions that you are afraid it might "grenade" then you need to change something because it's obviously not safe.
cjernigan is offline   Reply With Quote
Old 03-01-2007, 02:38 PM   #10
Junior Member
Thread Starter
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 129
Total Cats: 0
Default

so the worst that could happen is my $50 junk yard turbo goes up in smoke and I go get another, right?
zebro racing is offline   Reply With Quote
Old 03-01-2007, 02:49 PM   #11
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Delicious and Moist.
Posts: 26,326
Total Cats: 1,926
Default

I doubt seriously that an automobile turbocharger could ever grenade in the same way as an aircraft engine. The turbine wheel itself is fairly stout, and the pieces that might actually tend to break off would have very little mass (and thus very little inertia) relative to the strength of the housing. I've heard of engines ingesting hardware and people finding bits of the turbine blades stuck in the catalytic converter, but never an "explosive" failure of a turbocharger.

And I doubt seriously whether we would see any Ladas or Volgas here. If our benevolant overlords permitted us to own private vehicles, it'd more likely be Chery QQs or some other Chinese brand. Which already seems pretty likely to happen...
Joe Perez is offline   Reply With Quote
Old 03-01-2007, 02:57 PM   #12
Ben
Supporting Vendor
iTrader: (33)
 
Ben's Avatar
 
Join Date: Jul 2006
Location: atlanta-ish
Posts: 12,689
Total Cats: 99
Default

You don't need to worry about the turbo physically exploding, allowing shrapnel to scatter into the engine compartment. You may need to be concerned with the internal parts of the turbo fragmenting and following the intake charge into the motor. That could cause substantial damage to the motor.
Ben is offline   Reply With Quote
Old 03-01-2007, 04:07 PM   #13
Elite Member
iTrader: (2)
 
Join Date: Jun 2006
Location: ABQ, NM
Posts: 1,850
Total Cats: -8
Default

Though worrying about an oil line breaking and catching the vehicle on fire is valid.
BenR is offline   Reply With Quote
Old 03-01-2007, 04:09 PM   #14
Elite Member
iTrader: (14)
 
Join Date: Mar 2006
Location: Edmonton, AB
Posts: 4,921
Total Cats: 0
Default

If the car has an IC I doubt that the turbo coming apart would get to the engine, there just isn't a path for anything big through the IC is there?
jayc72 is offline   Reply With Quote
Old 03-01-2007, 04:30 PM   #15
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,367
Total Cats: 1,331
Default

Even if a piece of the turbo broke off, it would have to get down the tubing (not very difficult), through your intercooler (difficult), back UP into the intake manifold (very difficult), through the throttle body (WOT: not hard, no throttle: near-impossible), and then make it into the engine through the intake valves, and THEN it has to be a big enough piece to either wedge in a valve or dent a piston. If it's not, it goes right back out the exhaust valve and eats the rest of your turbo.

As long as you have less than 1mm of shaft play (some turbos come stock with up to .75mm of shaft play) you are good to go.
Savington is offline   Reply With Quote
Old 03-01-2007, 04:45 PM   #16
Junior Member
Thread Starter
 
Join Date: Feb 2007
Location: Tallahassee, FL
Posts: 129
Total Cats: 0
Default

how much wiggle is acceptable: in and out? up and down?
zebro racing is offline   Reply With Quote
Old 03-01-2007, 07:38 PM   #17
Senior Member
 
Join Date: Mar 2005
Posts: 531
Total Cats: 0
Default

savington mentioned 1mm of play, that sounds reasonable.
VRTSid is offline   Reply With Quote
Old 03-04-2007, 01:16 AM   #18
Elite Member
iTrader: (1)
 
Join Date: Jun 2005
Location: Charleston, SC
Posts: 2,980
Total Cats: 14
Default

Quote:
Originally Posted by Joe Perez View Post
Well, the turbine casing explodes, shredding the brake and steering lines. You car crashes into another vehicle, killing the Director of the CIA and his family. Conspiracy theories and political infighting paralyze the agency, causing America’s already troubled intelligence capacity to grind to a halt.
LOL - nice post!
rmcelwee is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
Are my coils failing? viriiguy General Miata Chat 5 09-28-2015 08:39 PM
Got bad Crank Angle Sensor and Random Misfire codes, but runs fine. Greasyman General Miata Chat 2 09-28-2015 11:44 AM
WTB HPDE miata - Texas Voltwings Cars for sale/trade 0 09-27-2015 07:40 PM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 09:31 AM.