What happens to vac controlled items under boost? - 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 03-19-2007, 02:18 PM   #1
!!! NOT CONFIRMED !!!
Thread Starter
 
Join Date: Feb 2007
Location: Thunder Bay Ontario Canada
Posts: 60
Total Cats: 0
Default What happens to vac controlled items under boost?

Things like cruise control, power brakes etc. Do we have to put in a one way valve so it does not damage these items? Thanks for the replys
Kenny is offline   Reply With Quote
Old 03-19-2007, 02:24 PM   #2
I'm Miserable!
iTrader: (1)
 
Join Date: Oct 2005
Location: Columbia, SC
Posts: 858
Total Cats: 0
Default

you'll never brake in boost, unless you have really weird driving habits.

Dunno about cruise.

Edit: You *will* want to address your PCV system though.
SloS13 is offline   Reply With Quote
Old 03-19-2007, 02:25 PM   #3
Elite Member
iTrader: (13)
 
Join Date: Dec 2006
Location: Taos, New mexico
Posts: 5,703
Total Cats: 237
Default

Quote:
Originally Posted by SloS13 View Post
you'll never brake in boost, unless you have really weird driving habits.

Dunno about cruise.

Edit: You *will* want to address your PCV system though.

What do you mean?
Fireindc is offline   Reply With Quote
Old 03-19-2007, 02:37 PM   #4
Senior Member
 
Join Date: Dec 2004
Posts: 1,450
Total Cats: -1
Default

Well, if you routed your PCV breather hoses incorrectly on a car with forced-induction, you could introduce a bunch of pressure into the crankcase, break-down rings, blow seals, etc.
bripab007 is offline   Reply With Quote
Old 03-19-2007, 03:16 PM   #5
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

the brake booster line has a check valve from the factory.

throw in a one way check vavle on the cruise and charcol cansiter. i believe the msm has a few others on select lines.
Braineack is offline   Reply With Quote
Old 03-19-2007, 04:23 PM   #6
!!! NOT CONFIRMED !!!
Thread Starter
 
Join Date: Feb 2007
Location: Thunder Bay Ontario Canada
Posts: 60
Total Cats: 0
Question

The check valve will work for the brake, cruise and charcol cannister for sure and yeh braking under boost would not be likely. I would anticipate that the cruise will drop off if you were cruising and started up a hill because boost would eventually exceed the vac and cruise lets go... correct?

The whole PCV system is what got me thinking about it. I have read several threads and there seems to be a couple of opinions on how to do it. There is a PCV check valve coming off the valve cover to the intake manifold which under boost should close, so that seems straight forward. The other line coming out of the valve cover on OEM goes into the intake just before the Throttle Body however that would not work with FI as you do not want boost in the crankcase so what is the "final" wisdom on what to do with this line? Some people have said to vent it to atmosphere with a little filter, others said to run it to the intake side of the turbo around the air filter and there seems to be another version although I cannot remember what it is????
Kenny is offline   Reply With Quote
Old 03-19-2007, 04:32 PM   #7
I'm Miserable!
iTrader: (1)
 
Join Date: Oct 2005
Location: Columbia, SC
Posts: 858
Total Cats: 0
Default

Quote:
Originally Posted by Kenny View Post
Some people have said to vent it to atmosphere with a little filter, others said to run it to the intake side of the turbo around the air filter and there seems to be another version although I cannot remember what it is????
Another option would be route PCV to catch can (to accumulate oil) then to intake side of turbo (after mafs)

OR - PCV to catch can to atmosphere.

You can make a catch can out of just about anything
SloS13 is offline   Reply With Quote
Old 03-19-2007, 04:35 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,900
Total Cats: 1,792
Default

or valve cover straight to intake, the end.
Braineack is offline   Reply With Quote
Old 03-19-2007, 06:50 PM   #9
Junior Member
 
Join Date: Dec 2006
Posts: 85
Total Cats: 0
Default

Quote:
Originally Posted by Braineack View Post
or valve cover straight to intake, the end.
That's what I did.
t25miata is offline   Reply With Quote
Old 03-19-2007, 08:03 PM   #10
Junior Member
 
Join Date: Sep 2006
Location: E.City NC
Posts: 81
Total Cats: 0
Default

I left my PCV valve alone and ran a hose off the other side of my valve cover to a catch can with a mini air filter on it
yadayada is offline   Reply With Quote
Old 03-19-2007, 10:25 PM   #11
Elite Member
iTrader: (4)
 
Join Date: Sep 2006
Location: Charlotte, NC
Posts: 3,054
Total Cats: 8
Default

When I turbo'd my non-turbo ka24de 240sx I had no problems with cruise control and I made no changes to the system. Didn't add a check valve or anything and the car would go into boost when on cruise control if I was going up a hill.

Maybe the nissan system is different than Mazda's but I had zero problems leaving it alone.
Efini~FC3S 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 59 12-15-2017 09:00 PM
Raleigh: Fiberglass headlight scope, 1.6L ECU, AFM, Hardtop latches, more bigmackloud Miata parts for sale/trade 13 09-22-2017 01:34 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 01:15 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM
"Chimney Ethanol" E100 MiataGarage Engine Performance 5 09-30-2015 12:04 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 03:44 PM.