3rd Generation Specific (1993-2002) 1993-2002 Discussion including performance modifications and Technical Support Sections.
Sponsored by:

boost creep ?

Old Feb 24, 2008 | 02:11 PM
  #1  
tafkamb2's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
 
Joined: Jun 2007
Posts: 484
Likes: 1
From: florida
boost creep ?

Hey guys,
I just changed out my tired turbos for some not so tired turbos and I ported to waste gate first I did everything including taking that metal out so it can open more. My question is I have a DP and intake on the car with the stock cat and stock intercooler should I still be getting boost creep? One more thing how important is it to put the outside heatshield on the turbos there being a real pain so I don't feel like putting them on lol.
Last question I read somewhere that sense we only have on waste gate it really doesn't matter what boost controller you use, like you don't need a twin turbo boost controller is this true?
Reply
Old Feb 24, 2008 | 02:23 PM
  #2  
dgeesaman's Avatar
Moderator
Tenured Member: 20 Years
Liked
Loved
iTrader: (8)
 
Joined: May 2002
Posts: 12,313
Likes: 27
From: Hershey PA
You should be fine with a single boost controller. A second one will give you adjustment of the precontrol. If your transition is smooth there is no need.

You should not see boost creep with any part of the stock exhaust installed. If you install a midpipe you may see creep, but the first priority in upgrades would be to 1) control your boost and 2) install the intercooler.

Dave
Reply
Old Feb 24, 2008 | 05:01 PM
  #3  
tafkamb2's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
 
Joined: Jun 2007
Posts: 484
Likes: 1
From: florida
Im pretty much trying to stay stock right now while I get my other engine built up. Im going to make a V mount when i get the other engine together. Another question just to make sure I heard the stock ecu is good for 12 psi is that true?
Reply
Old Feb 24, 2008 | 05:08 PM
  #4  
dgeesaman's Avatar
Moderator
Tenured Member: 20 Years
Liked
Loved
iTrader: (8)
 
Joined: May 2002
Posts: 12,313
Likes: 27
From: Hershey PA
No, you'll be constantly bumping off fuel cut.

11psi is as far as I'd go.

dave
Reply
Old Feb 24, 2008 | 09:44 PM
  #5  
tafkamb2's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
 
Joined: Jun 2007
Posts: 484
Likes: 1
From: florida
Thanks I'll just leave it at the stock psi.
Reply
Old Mar 9, 2008 | 02:17 PM
  #6  
Silver7even's Avatar
Full Member
Tenured Member 15 Years
 
Joined: Feb 2003
Posts: 83
Likes: 1
From: Colorado
What exactly is boost creep? I would appreciate a definition, or some links. Is it a static condition, or does is increase with time, long term, or over a pull?? Thanks
Reply
Old Mar 9, 2008 | 02:29 PM
  #7  
tafkamb2's Avatar
Thread Starter
Senior Member
Tenured Member 15 Years
 
Joined: Jun 2007
Posts: 484
Likes: 1
From: florida
Boost creep is when your car gains extra psi of pressure while your boosting. Its really bad on our cars because when you change a couple of parts such as the intake and exhaust it lessens the restrictiveness of those parts so much that it allows the turbos to spool more and create more pressure, and sense they fuel cut off is at 12 psi its not hard to hit that.
Reply
Old Mar 9, 2008 | 02:47 PM
  #8  
Silver7even's Avatar
Full Member
Tenured Member 15 Years
 
Joined: Feb 2003
Posts: 83
Likes: 1
From: Colorado
Originally Posted by tafkamb2
Boost creep is when your car gains extra psi of pressure while your boosting. Its really bad on our cars because when you change a couple of parts such as the intake and exhaust it lessens the restrictiveness of those parts so much that it allows the turbos to spool more and create more pressure, and sense they fuel cut off is at 12 psi its not hard to hit that.
Thanks, so it is a static condition, once the mods have been performed, right?
Reply
Old Mar 9, 2008 | 03:26 PM
  #9  
Mahjik's Avatar
Mr. Links
Tenured Member 20 Years
iTrader: (1)
 
Joined: Aug 2001
Posts: 27,595
Likes: 43
From: Kansas City, MO
Arrow

Originally Posted by Silver7even
What exactly is boost creep? I would appreciate a definition, or some links. Is it a static condition, or does is increase with time, long term, or over a pull?? Thanks
Start here:
https://www.rx7club.com/3rd-gen-archives-73/boost-creep-control-26389/

Some more info here:
https://www.rx7club.com/showpost.php...6&postcount=22
Reply
Old Mar 9, 2008 | 08:48 PM
  #10  
dgeesaman's Avatar
Moderator
Tenured Member: 20 Years
Liked
Loved
iTrader: (8)
 
Joined: May 2002
Posts: 12,313
Likes: 27
From: Hershey PA
Originally Posted by tafkamb2
Boost creep is when your car gains extra psi of pressure while your boosting. Its really bad on our cars because when you change a couple of parts such as the intake and exhaust it lessens the restrictiveness of those parts so much that it allows the turbos to spool more and create more pressure, and sense they fuel cut off is at 12 psi its not hard to hit that.
What you're talking about is just overboosting. Install an adjustable boost controller of some kind and it will be fixed. A few mods can create overboost.

Boost creep is when no boost controller can control boost, and under heavy load there is no maximum boost level. It just keeps increasing until you lift. Boost creep is caused by exceeding the venting capability of the wastegate.

Dave
Reply
Old Mar 9, 2008 | 09:19 PM
  #11  
Silver7even's Avatar
Full Member
Tenured Member 15 Years
 
Joined: Feb 2003
Posts: 83
Likes: 1
From: Colorado
Thanks to Dave for the definition of creep. Here is a shot of my overboost situation, this is not creep, but overboost (right?). This boost reading of 90 equates to about 16.5lbs of relitive boost in Denver, 1 mile above sea level.

Two questions:

Is this 16.5lbs of boost equivalent to ~ 13.5lbs at sea level?

Will a spring and ball work as a mechanical boost controller?
Reply
Old Mar 9, 2008 | 09:32 PM
  #12  
Silver7even's Avatar
Full Member
Tenured Member 15 Years
 
Joined: Feb 2003
Posts: 83
Likes: 1
From: Colorado
one more WOT example
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Shainiac
Single Turbo RX-7's
12
Jul 17, 2019 02:20 PM
Jeff20B
1st Generation Specific (1979-1985)
73
Sep 16, 2018 07:16 PM
Bauer778
3rd Generation Specific (1993-2002)
10
Nov 4, 2015 04:42 PM
zxrazorxz
3rd Generation Specific (1993-2002)
2
Sep 14, 2015 07:21 PM
High_Carb_Diet
Power FC Forum
1
Sep 5, 2015 09:07 AM


Thread Tools
Search this Thread

All times are GMT -5. The time now is 08:38 AM.