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

Safely running boost creep?

Thread Tools
 
Search this Thread
 
Old Jan 8, 2018 | 03:14 AM
  #1  
Aramir's Avatar
Thread Starter
Full Member
 
Joined: Aug 2015
Posts: 103
Likes: 4
From: Auckland, NZ
Safely running boost creep?

Hey guys, im in the middle of pulling my motor, as im replacing the clutch and installing a 3in full exhaust. Ive read about the boost creep people experience when theyve put in a larger exhaust and i was wondering if my power fc is able to adjust for the increase in boost to run it safely, or is porting my wastegate an absolute must?
Reply
Old Jan 8, 2018 | 04:23 AM
  #2  
kensin's Avatar
Put it in the microwave!
Tenured Member: 15 Years
Liked
Loved
Community Favorite
iTrader: (22)
 
Joined: Jul 2009
Posts: 1,568
Likes: 35
From: CA
with a full 3inch exhaust a ported wastegate is pretty much standard.

the amount of air is just too much for the tiny wastegate. even with a boost controller. its best to port the wastegate no matter what.
since your motor is out. its pretty wise to do so.
and i also suggest you pull the injectors and have them sent out for service. RC dose a great job and like 24$ per injector ?
changed the orings while your at it. heck, do the fuel lines too. test your coils since your already there. the list goes on but lets not get too ahead of our selfs lol
Reply
Old Jan 8, 2018 | 09:36 AM
  #3  
IRPerformance's Avatar
Sponsor
iTrader: (41)
 
Joined: Apr 2003
Posts: 11,347
Likes: 321
From: NJ
You cannot adjust for boost creep. The only thing you can do is tune for the boost level it creeps to providing your fuel and ignition systems can keep up. That being said, I strongly advise against running a full 3" exhaust on a twin turbo car unless you port the wastegate and even then it sometimes isn't enough to stop the creep completely. Temporarily you can add a 2.5 or 2.25" restrictor plate in the exhaust to try and prevent the creep.
Reply
Old Jan 8, 2018 | 10:11 AM
  #4  
DaleClark's Avatar
RX-7 Bad Ass
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (56)
 
Joined: Jan 2002
Posts: 15,622
Likes: 2,724
From: Pensacola, FL
There is actual creep, where the waste gate can't keep up with flow, and there's the stock boost control system running away with boost.

If you have the engine out, take the time and port the waste gates. Isn't that hard and won't take you very long. I would also research boost control, either using a Datalogit and MAC solenoids or an aftermarket boost controller.

Dale
Reply
Old Jan 12, 2018 | 06:11 PM
  #5  
Aramir's Avatar
Thread Starter
Full Member
 
Joined: Aug 2015
Posts: 103
Likes: 4
From: Auckland, NZ
Thanks for the replys, my next question is which wastegate am i acutally porting?
Reply
Old Jan 13, 2018 | 01:13 AM
  #6  
kensin's Avatar
Put it in the microwave!
Tenured Member: 15 Years
Liked
Loved
Community Favorite
iTrader: (22)
 
Joined: Jul 2009
Posts: 1,568
Likes: 35
From: CA
Open the flapper on the second pic and then enlarge the hole
Reply
Old Jan 13, 2018 | 06:53 AM
  #7  
bajaman's Avatar
Constant threat
Tenured Member 20 Years
 
Joined: Jul 2001
Posts: 4,968
Likes: 39
From: near Wichita, Kansas
Originally Posted by kensin
Open the flapper on the second pic and then enlarge the hole
Is there a write-up on this anywhere? Drawing/specs?
Reply
Old Jan 13, 2018 | 08:50 AM
  #8  
DaleClark's Avatar
RX-7 Bad Ass
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (56)
 
Joined: Jan 2002
Posts: 15,622
Likes: 2,724
From: Pensacola, FL
There may be. The principle is you want to open the hole up underneath the flapper but still have enough material for the flapper to seal to. Really you only need 1-2mm of lip around the hole to seal up to the wastegate flapper.

Also, just a small amount of porting makes a pretty substantial difference.

Dale
Reply
Old Jan 13, 2018 | 03:59 PM
  #9  
Aramir's Avatar
Thread Starter
Full Member
 
Joined: Aug 2015
Posts: 103
Likes: 4
From: Auckland, NZ
yeah i was thinking that would be the case, what is the function of the other gate? looks like it redirects gas through that spacer chamber to the other turbo or something?
Reply
Old Jan 30, 2018 | 11:20 AM
  #10  
dburks10's Avatar
Junior Member
Tenured Member: 15 Years
iTrader: (1)
 
Joined: Aug 2010
Posts: 19
Likes: 0
From: DFW, TX
In general, is porting the wastegate worthwhile if you already have the engine out?
Reply
Old Jan 30, 2018 | 11:28 AM
  #11  
IRPerformance's Avatar
Sponsor
iTrader: (41)
 
Joined: Apr 2003
Posts: 11,347
Likes: 321
From: NJ
Originally Posted by dburks10
In general, is porting the wastegate worthwhile if you already have the engine out?
If the motor is out and you plan to run a full exhaust on twins you might as well port the wastegate.
Reply
Old Jan 30, 2018 | 08:27 PM
  #12  
existanzrx7's Avatar
Just Boosting
Tenured Member 20 Years
iTrader: (8)
 
Joined: Mar 2004
Posts: 1,125
Likes: 7
From: Chy-Town
Here's a pick that can help you when porting. Be careful not to port too much the flapper still needs to seal.
Attached Thumbnails Safely running boost creep?-img_4380.bmp  
Reply
Old Jan 31, 2018 | 11:48 AM
  #13  
cloead's Avatar
sold--no longer in debt
Tenured Member: 20 Years
Liked
Loved
 
Joined: Dec 2002
Posts: 1,659
Likes: 11
From: Cleveland, Ohio
Originally Posted by Aramir
Thanks for the replys, my next question is which wastegate am i acutally porting?
might want to replace/fix whatever is showing all of those cracks in it
Reply
Old Jan 31, 2018 | 04:17 PM
  #14  
Sgtblue's Avatar
Urban Combat Vet
Tenured Member: 20 Years
Liked
Loved
Community Favorite
iTrader: (16)
 
Joined: Oct 2003
Posts: 12,160
Likes: 983
From: Mid-west
Originally Posted by cloead
might want to replace/fix whatever is showing all of those cracks in it
Those cracks are common/inevitable and on every used set of twins I've seen. And I've seen alot worse. You can't practically do anything about them. As long as they don't extend beyond the gasket they're usually not an issue.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
TheAnalogKiddd
2nd Generation Specific (1986-1992)
5
Oct 17, 2002 12:38 AM
jackc
3rd Generation Specific (1993-2002)
8
Nov 25, 2001 02:02 AM
badass7
3rd Generation Specific (1993-2002)
7
Sep 24, 2001 09:12 AM
rmani
3rd Gen Archives
11
Aug 29, 2001 01:56 PM




All times are GMT -5. The time now is 02:37 PM.