03 NB FM2 Turbo Loss Of Power - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 11-04-2015, 01:47 AM   #21
Elite Member
iTrader: (15)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 8,797
Total Cats: 248
Default

Quote:
Originally Posted by Chowcow View Post
I'm not only getting boost lag, but I'm getting a huge loss of power.

I'm set to boost at 11PSI and can only hit 3PSI max now.

So the down pipe connection doesn't explain my symptoms?

...bah...
For the most power and best spool, remove downpipe from turbo. This will get backpressure as low as possible.

So no, an exhaust leak after the turbo does not explain your problem. See my other post for what to check/look for.
patsmx5 is offline   Reply With Quote
Old 11-13-2015, 05:18 PM   #22
Junior Member
Thread Starter
 
Join Date: Jan 2012
Location: Calgary, AB
Posts: 151
Total Cats: -11
Default

Update:

So I just had time to look at my downpipe and its fully connected. It just looks off.

When I was under the car, I was tapping around and noticed that my cat has a rattling noise (you can hear this when you drive too). I'm guessing my car went bad-- but I've only had it installed for less than 5k km (FM cat). I've heard when you run the car rich you can ruin the cat, but the only time the car is extremely rich is under boost (10.5-11ish).

Could a clogged cat cause the symptoms I'm finding? My car smells like gas and won't boost past 3PSI. I also find it hard to drive it past 100km/h as it'll rev up to 4-5k RPM but I can hear a huge "pshhhhhhh" -- leak noise (not boost).

I've looked for boost leak and haven't found anything to support that hypothesis yet.

Can this be explained by a clogged cat?
Chowcow is offline   Reply With Quote
Old 11-13-2015, 09:32 PM   #23
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 3,878
Total Cats: 344
Default

Yes, a cat would cause that. The exhaust is highly restricted by the clogged/broken cat, so you get a lot of back pressure. This means it runs rich, which is why you're smelling fuel, and it limits power and turbine spool.

FM was selling metal-core cats for a long time, but they had a lot of in-warranty failures on them, so they have since been replaced by ceramic-core ones. These are more restrictive, but have longer life.

--Ian
codrus is offline   Reply With Quote
Old 11-13-2015, 11:59 PM   #24
Junior Member
Thread Starter
 
Join Date: Jan 2012
Location: Calgary, AB
Posts: 151
Total Cats: -11
Default

Quote:
Originally Posted by codrus View Post
Yes, a cat would cause that. The exhaust is highly restricted by the clogged/broken cat, so you get a lot of back pressure. This means it runs rich, which is why you're smelling fuel, and it limits power and turbine spool.

FM was selling metal-core cats for a long time, but they had a lot of in-warranty failures on them, so they have since been replaced by ceramic-core ones. These are more restrictive, but have longer life.

--Ian
Any idea if FM offers a warranty on the Magnaflow cats they sell? I guess I'll give them a ring and see what they can do.

I'll post up the results once I remove the cat and test the car.
Chowcow is offline   Reply With Quote
Old 11-14-2015, 12:28 AM   #25
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 3,878
Total Cats: 344
Default

Quote:
Originally Posted by Chowcow View Post
Any idea if FM offers a warranty on the Magnaflow cats they sell? I guess I'll give them a ring and see what they can do.

I'll post up the results once I remove the cat and test the car.
It probably does, although it may have expired. Definitely give them a call and ask.

--Ian
codrus is offline   Reply With Quote
Old 11-14-2015, 12:52 PM   #26
Elite Member
 
DNMakinson's Avatar
 
Join Date: Jan 2013
Location: Seneca, SC
Posts: 2,709
Total Cats: 269
Default

Quote:
Originally Posted by Chowcow View Post
I've heard when you run the car rich you can ruin the cat, but the only time the car is extremely rich is under boost (10.5-11ish).

Can this be explained by a clogged cat?
Why so rich? Seems most folks run 11.5 - 11.8 at most.

See post 3 in this thread.
DNMakinson is offline   Reply With Quote
Old 11-23-2015, 06:59 PM   #27
Junior Member
Thread Starter
 
Join Date: Jan 2012
Location: Calgary, AB
Posts: 151
Total Cats: -11
Default

Update:

It's not the cat. I pulled it and drove without it. Same old power loss.

I've fabbed up a boost leak tester and found that a leak is happening where the IAT inserts into the silicon pipe (FM2 kit- 2015). The leak is happening from the conduit from which the IAT mounts into on the silicon pipe. So I've thrown on RTV around it to hopefully cover the boost leak. I'll update when I get to drive it.
Chowcow is offline   Reply With Quote
Old 11-23-2015, 09:47 PM   #28
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,207
Total Cats: 2,587
Default

silicone coupler + rtv + metal sensor sounds like the biggest bucket of failure this week
18psi is offline   Reply With Quote
Old 11-24-2015, 02:49 AM   #29
Elite Member
iTrader: (2)
 
Join Date: Jan 2007
Location: Los Angeles, CA
Posts: 8,782
Total Cats: 119
Default

Quote:
Originally Posted by Chowcow View Post
Update:

Compression test came out a bit low: 145-140-145-140.

=.
For a factory VVT motor I think your compression is dogshit
Faeflora is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Replacement clutch disc for FM1, or something else altogether? matthewdesigns Suspension, Brakes, Drivetrain 1 10-10-2015 03:07 AM
Complete BEGI S3 NB Kit, Full Enthuza 3" Exhaust, ACT HD Clutch, MS2 PNP, Wideband kronikker Miata parts for sale/trade 17 10-06-2015 11:18 PM
MS3 Basic Connection Issues EErockMiata MEGAsquirt 6 09-24-2015 10:49 AM
starting issue Johnny Tater Engine Performance 3 09-23-2015 07:10 PM
Miata Newbie hdizzle Meet and Greet 8 09-21-2015 11:08 AM


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 02:44 PM.