Freeway speeds, VTA, and 02Clamp - Page 2 - 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 12-13-2006, 01:58 PM   #21
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

I never had a bucking problem VTA, only an engine cutting out problem.
Braineack is offline   Reply With Quote
Old 12-13-2006, 02:02 PM   #22
Elite Member
iTrader: (14)
 
Join Date: Mar 2006
Location: Edmonton, AB
Posts: 4,921
Total Cats: 0
Default

Maybe what you call cutting out and what we call bucking are the same thing?
jayc72 is offline   Reply With Quote
Old 12-13-2006, 02:16 PM   #23
Miotta FTW!
iTrader: (24)
 
Splitime's Avatar
 
Join Date: Jun 2006
Location: Chicagoland, IL
Posts: 4,295
Total Cats: 26
Default

Get rid of the AFM?
Splitime is offline   Reply With Quote
Old 12-13-2006, 02:46 PM   #24
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

Quote:
Originally Posted by jayc72 View Post
Maybe what you call cutting out and what we call bucking are the same thing?

no. i mean 0rpms are hard to mistake.
Braineack is offline   Reply With Quote
Old 12-13-2006, 03:11 PM   #25
Elite Member
iTrader: (14)
 
Join Date: Mar 2006
Location: Edmonton, AB
Posts: 4,921
Total Cats: 0
Default

Quote:
Originally Posted by braineack View Post
no. i mean 0rpms are hard to mistake.
Ok, your car is busted.
jayc72 is offline   Reply With Quote
Old 12-13-2006, 03:28 PM   #26
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

no, it's why a huge vacuum leak on a metered engine sucks.
Braineack is offline   Reply With Quote
Old 12-13-2006, 03:41 PM   #27
Senior Member
iTrader: (2)
 
SamS's Avatar
 
Join Date: Jun 2006
Location: Wisconsin
Posts: 1,254
Total Cats: 7
Default

...literally :gay:
SamS is offline   Reply With Quote
Old 12-13-2006, 07:22 PM   #28
Senior Member
 
Join Date: Apr 2005
Location: NAS Oceana/VA
Posts: 759
Total Cats: 0
Default

Lol
getsidewaysd1 is offline   Reply With Quote
Old 12-17-2006, 06:45 PM   #29
Elite Member
Thread Starter
iTrader: (7)
 
samnavy's Avatar
 
Join Date: Apr 2006
Location: VIRGINIA BEACH, VA
Posts: 6,020
Total Cats: 175
Default O2 Clamp Installed!

Well, I just went for a nice little jaunt to test out the O2 clamp just installed. My freeway cruising jerkiness seems to be about 50% gone. At 75-80 though, I'm still in that grey area where a breath on the pedal takes me from -10vaccum to 8psi in an eyeblink. I honestly think that the turbo is spooling and making positive pressure while the manifold is still in vaccum and the boost is just going straight out VTA. I can hear the turbo wind up and can modulate the gas to keep the BOV open. I can hear both working at the same time... my record is about 6seconds, during which time, the car will jerk like crazy (but a lot less now due to the 02Clamp).

Olderguy's instructions say don't adjust the little brass screw on the clamp unless I've got a voltmeter. Can I adjust it a little bit pretty please if I mark where it was when I started just to expiriment? If so, what am I looking for in response. Is moving that little brass screw going to do something I can feel.
Also, it comes set to "clamp" at .5psi... any reason I should want it to wait until more boost to clamp.
What should I be trying to feel wrt driveability to "tune" the thing... or is most of it stuff to mess with on the dyno?
samnavy is offline   Reply With Quote
Old 12-17-2006, 06:54 PM   #30
AFM Crusader
iTrader: (18)
 
olderguy's Avatar
 
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,438
Total Cats: 84
Default

You can increase the boost pressure setting by turning in the allen screw on top of the switch clockwise. I run mine about 1-1.5psi so that I don't hit clamp at high speed cruise.

Changing the voltage to the ECU during clamping should be done with a digital voltmeter. It is set to send a pretty lean signal. Counterclockwise will make the signal more rich, but it is very sensitive.
olderguy is offline   Reply With Quote
Old 12-17-2006, 09:57 PM   #31
Senior Member
 
Join Date: Dec 2004
Posts: 1,450
Total Cats: -1
Default

Yeah, I can guarantee you're turbo's producing boost at freeway speeds and spitting the excess out the bypass valve. I can clearly hear my bypass valve venting on the freeway...it's built into the compressor housing (recirculating) and it makes quite a bit of noise at those speeds.
bripab007 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
elesjuan's mediocre 95 Miata adventure (google fiber edition) elesjuan Build Threads 8 02-16-2016 09:36 PM
3rd Time's a Charm...hopefully. zephyrusaurai Meet and Greet 2 09-28-2015 11:59 PM
Got bad Crank Angle Sensor and Random Misfire codes, but runs fine. Greasyman General Miata Chat 2 09-28-2015 11:44 AM
Nb transmission 100$ MN Laurent Miata parts for sale/trade 5 09-23-2015 09:04 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 06:11 PM.