WTF is wrong with my car. AKA why is my boost so saggy V2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


DIY Turbo Discussion greddy on a 1.8? homebrew kit?

Reply
 
 
 
LinkBack Thread Tools
Old 11-16-2013, 09:27 PM   #1
Senior Member
Thread Starter
iTrader: (1)
 
gorillazfan1023's Avatar
 
Join Date: May 2010
Location: Harrisburg, Pa
Posts: 582
Total Cats: 8
Default WTF is wrong with my car. AKA why is my boost so saggy V2

I previously had a thread, "Why is my boost so saggy". Which didn't yield any results. I concluded that my wastegate (Internal) was defective. Thirdgen was kind enough to let me use one he had. Excited by the thought that I would finally have power for more then a few hundred rpm I slapped it on and went for a datalog...Attached are the disappointing results that followed.

Basically I still can't hold boost.
I have;
-Switched turbos
-Switched manifolds
-Gone to a bigger exhaust
-Installed VVTuner (tried changing the settings and am currently running it on the base DIY supplied map)
-Moved my wastegate line from post throttle plate to the coldside of my intercooler
-Switched wastegate cans

I'm at all loss now. Short of an EWG and EBC. As you can see in the log it hits ~11psi by 4500 then drops to ~5.5 by redline.

Any suggestions would be appreciated.
Thanks,
-Patrick
Attached Files
File Type: msl new wastegate3.msl (700.0 KB, 42 views)
gorillazfan1023 is offline   Reply With Quote
Old 11-17-2013, 12:59 AM   #2
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,186
Total Cats: 2,582
Default

I assume boost leak test yielded absolutely zero leaks?
18psi is offline   Reply With Quote
Old 11-17-2013, 09:34 AM   #3
Slowest Progress Ever
iTrader: (26)
 
thirdgen's Avatar
 
Join Date: Oct 2007
Location: The coal ridden hills of Pennsylvania
Posts: 5,806
Total Cats: 183
Default

I'm thinking it could be that internal wastegate flange. Ditch that and go EWG.
thirdgen is offline   Reply With Quote
Old 11-17-2013, 10:24 AM   #4
Senior Member
Thread Starter
iTrader: (1)
 
gorillazfan1023's Avatar
 
Join Date: May 2010
Location: Harrisburg, Pa
Posts: 582
Total Cats: 8
Default

Quote:
Originally Posted by 18psi View Post
I assume boost leak test yielded absolutely zero leaks?
Correct. As far as I could tell I couldn't hear or feel any leaks. I even used a stethoscope.
gorillazfan1023 is offline   Reply With Quote
Old 11-18-2013, 09:53 AM   #5
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,092
Total Cats: 90
Default

Is it possible that his turbo has such a massive wastegate flap that you need a stronger iwga spring to hold it closed against the exhaust pressure?
Leafy is offline   Reply With Quote
Old 11-18-2013, 11:12 AM   #6
Senior Member
Thread Starter
iTrader: (1)
 
gorillazfan1023's Avatar
 
Join Date: May 2010
Location: Harrisburg, Pa
Posts: 582
Total Cats: 8
Default

Quote:
Originally Posted by Leafy View Post
Is it possible that his turbo has such a massive wastegate flap that you need a stronger iwga spring to hold it closed against the exhaust pressure?
I guess it's possible. I have this style waste gate. 5 Bolt to 2 5" V Band Turbo Downpipe Wastegate Adapter | eBay

It appears to be sealing fine just can't hold boost, I was hoping the new actuator would fix it, but it did not.
gorillazfan1023 is offline   Reply With Quote
Old 11-18-2013, 11:23 AM   #7
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,092
Total Cats: 90
Default

Grab a weak extension spring from from the hardware store and see if that helps the sag?
Leafy is offline   Reply With Quote
Old 11-18-2013, 12:12 PM   #8
Senior Member
Thread Starter
iTrader: (1)
 
gorillazfan1023's Avatar
 
Join Date: May 2010
Location: Harrisburg, Pa
Posts: 582
Total Cats: 8
Default

Hmm I could try that. Not sure how I'll hook a spring up. Also don't know if it matters but I couldn't even maintain 5psi
gorillazfan1023 is offline   Reply With Quote
Old 11-18-2013, 12:17 PM   #9
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,092
Total Cats: 90
Default

Quote:
Originally Posted by gorillazfan1023 View Post
Hmm I could try that. Not sure how I'll hook a spring up. Also don't know if it matters but I couldn't even maintain 5psi
Just hook it up between the rod on the wg flapper (where the iwga connects) and the bracket for the iwga (or the barb fitting on the iwga).
Leafy is offline   Reply With Quote
Old 11-18-2013, 12:35 PM   #10
y8s
2 Props,3 Dildos,& 1 Cat
iTrader: (8)
 
y8s's Avatar
 
Join Date: Jun 2005
Location: Fake Virginia
Posts: 19,038
Total Cats: 407
Default

have you done a "disconnect the boost control" test?

in other words, if you pull all the vac lines off the wastegate actuator and do a run (KEEPING YOUR EYE ON THE BOOST GAUGE TO PREVENT BOOOOM), does it build fast or slow?
y8s is offline   Reply With Quote
Old 11-18-2013, 12:54 PM   #11
Senior Member
Thread Starter
iTrader: (1)
 
gorillazfan1023's Avatar
 
Join Date: May 2010
Location: Harrisburg, Pa
Posts: 582
Total Cats: 8
Default

Quote:
Originally Posted by y8s View Post
have you done a "disconnect the boost control" test?

in other words, if you pull all the vac lines off the wastegate actuator and do a run (KEEPING YOUR EYE ON THE BOOST GAUGE TO PREVENT BOOOOM), does it build fast or slow?
Haven't tried, but I will. I had boost cut set at ~15psi and cranked the rod full tight once and I did hit it.
gorillazfan1023 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 01:15 PM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 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 01:25 PM.