Notices
Prefabbed Turbo Kits A place to discuss prefabricated turbo kits on the market

begi and boost creep

Thread Tools
 
Search this Thread
 
Old Jul 31, 2007 | 09:46 PM
  #1  
reckless_abandon's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: May 2007
Posts: 93
Total Cats: 0
From: chilliwack, bc
Default begi and boost creep

so on the weekend, i installed the begi downpipe for my greddy kit.
now, i get some scary boost creep. it'll hit 6psi, then creep up from there to about 8 or 10psi.
i've only got the 1.6l injectors, so this can spell disaster.

anyone else get this?
ideas?
Old Jul 31, 2007 | 10:06 PM
  #2  
Snowsurfer03's Avatar
Junior Member
 
Joined: Nov 2005
Posts: 468
Total Cats: 0
From: PA/DC
Default

yeh...it will be fun for a while but if you want to keep her safe you need tuning and more fuel.

trust me! just invest a little in some tuning and it will pay off in the long run!
Old Jul 31, 2007 | 10:18 PM
  #3  
Ben's Avatar
Ben
Supporting Vendor
iTrader: (33)
 
Joined: Jul 2006
Posts: 12,659
Total Cats: 134
From: atlanta-ish
Default

that's a feature, not a problem. get yourself some injectors and/or a hp fuel pump and enjoy.

I have never heard of a boost creep problem with the greddy. It's always a boost droop. Perhaps some porting on the turbo's turbine out would get it flowing better. Where does your WG actuator reference boost signal?
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Old Aug 1, 2007 | 01:35 AM
  #4  
reckless_abandon's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: May 2007
Posts: 93
Total Cats: 0
From: chilliwack, bc
Default

the wastegate has a vacuum line to the turbo housing.
do you recommend just the injectors? or will i need a fuel pump to go with the injectors?
and if so, which fuel pump? i was thinking about getting the 7MGENA supra injectors to be safe. but i'm no expert.
Old Aug 1, 2007 | 01:44 AM
  #5  
kotomile's Avatar
Elite Member
iTrader: (24)
 
Joined: Oct 2006
Posts: 7,537
Total Cats: 42
From: Monterey, CA
Default

I would *think* the Begi would make the boost drop, not creep, since the WG gasses aren't nearly as choked as the "Stock" downpipe..

My Begi just arrived yesterday..

Are you sure you did nothing else to the car that might have caused this?
Old Aug 1, 2007 | 07:50 AM
  #6  
Ben's Avatar
Ben
Supporting Vendor
iTrader: (33)
 
Joined: Jul 2006
Posts: 12,659
Total Cats: 134
From: atlanta-ish
Default

yeah you'd probably be good with the 300cc injectors only. i'm thinking by the time your boost creeps, the ecu is at 90% duty cycle. be safe, get a wideband.

check to make sure that your actuator rod can move feely and the flapper door actually opens fully. like i said, I've never heard of creep on a greddy, only droop, and usually bad droop due to their shitty wg actuator.
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Old Aug 1, 2007 | 09:06 AM
  #7  
Braineack's Avatar
Boost Czar
iTrader: (62)
 
Joined: May 2005
Posts: 80,541
Total Cats: 4,364
From: Chantilly, VA
Default

haha, I was going to say the problem is!??!
Old Aug 1, 2007 | 10:23 AM
  #8  
y8s's Avatar
y8s
DEI liberal femininity
iTrader: (8)
 
Joined: Jun 2005
Posts: 19,338
Total Cats: 574
From: Fake Virginia
Default

you get boost creep because the WG is too small to pass that much gas. it's more apparent on low-boost setups because less exhaust is going through the turbo and more is diverted through the WG.

if you dont want to change the fuel system, port the wastegate.
Old Aug 1, 2007 | 10:50 AM
  #9  
reckless_abandon's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: May 2007
Posts: 93
Total Cats: 0
From: chilliwack, bc
Default

i just checked the wastegate to see if it moves, but i cant get the wastegate flap to open manually. this may be my problem.
Old Aug 1, 2007 | 11:29 AM
  #10  
Joe Perez's Avatar
Boost Pope
iTrader: (8)
 
Joined: Sep 2005
Posts: 34,381
Total Cats: 7,504
From: Chicago. (The less-murder part.)
Default

Originally Posted by reckless_abandon
i just checked the wastegate to see if it moves, but i cant get the wastegate flap to open manually. this may be my problem.
If it is still connected to the WG canister it is *very* difficult to operate manually. For a device that's designed to actuate on only a few PSI, the diaphragm in that canister is surprisingly stiff. This is not indicative of a problem.
Old Aug 1, 2007 | 08:17 PM
  #11  
reckless_abandon's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: May 2007
Posts: 93
Total Cats: 0
From: chilliwack, bc
Default

that makes sense.
i havent tried to move it while disassembled.
Old Aug 1, 2007 | 10:44 PM
  #12  
wildfire0310's Avatar
Senior Member
iTrader: (1)
 
Joined: Jun 2006
Posts: 761
Total Cats: 1
From: Outside of the Loop-ATL
Default

Originally Posted by kotomile
I would *think* the Begi would make the boost drop, not creep, since the WG gasses aren't nearly as choked as the "Stock" downpipe..

My Begi just arrived yesterday..

Are you sure you did nothing else to the car that might have caused this?
Like Y8s said, boost creep is caused because off opening the exhaust. Its normally only a problem on small turbo on larger engines running low boost. Supra have that problem really bad with stock turbos. Running just a full exhaust 3' on a 7mgte supra without any other mods will cause a boost creep of 9 psi before setting back to stock 6psi. DSM have the same issue hence the reason for the 34mm wastegate "mods".

The only cure for boost creep is to port the wastegate.... well that or just turn up the boost...but yea
Old Aug 1, 2007 | 11:24 PM
  #13  
Agent935's Avatar
Junior Member
 
Joined: May 2006
Posts: 70
Total Cats: 0
From: Portland, OR
Default

I've heard of the same problem on FDs when you get a downpipe or pull out the cat. Their solution is like y8s said, porting the wastegate.
Old Aug 1, 2007 | 11:40 PM
  #14  
Joe Perez's Avatar
Boost Pope
iTrader: (8)
 
Joined: Sep 2005
Posts: 34,381
Total Cats: 7,504
From: Chicago. (The less-murder part.)
Default

Originally Posted by reckless_abandon
that makes sense.
i havent tried to move it while disassembled.
If you have a hand-operated vacuum pump which has a port on the exhaust, you can connect the outlet of the pump to the inlet of the WG canister and make enough pressure by hand to actuate the diaphragm.
Old Aug 2, 2007 | 08:18 PM
  #15  
reckless_abandon's Avatar
Thread Starter
Junior Member
iTrader: (1)
 
Joined: May 2007
Posts: 93
Total Cats: 0
From: chilliwack, bc
Default

what is involved in porting the wastegate? and should i get a professional to do it?
Old Aug 2, 2007 | 09:11 PM
  #16  
Ben's Avatar
Ben
Supporting Vendor
iTrader: (33)
 
Joined: Jul 2006
Posts: 12,659
Total Cats: 134
From: atlanta-ish
Default

I would say if you have to ask, let a pro do it.

I have always wanted to do this:
http://www.gpopshop.com/portpolish.html
(minus the exterior polish that is)

I'd bet the gains are as worthwhile as they claim.
__________________
Chief of Floor Sweeping, DIYAutoTune.com & AMP EFI
Crew Chief, Car Owner & Least Valuable Driver, HongNorrthRacing

91 Turbo | 10AE Turbo | 01 Track Rat | #323 Mazda Champcar

Originally Posted by concealer404
Buy an MSPNP Pro, you'll feel better.
Old Aug 3, 2007 | 02:01 AM
  #17  
kotomile's Avatar
Elite Member
iTrader: (24)
 
Joined: Oct 2006
Posts: 7,537
Total Cats: 42
From: Monterey, CA
Default

Is it just take off turbine housing, radius the corners, polish?
Old Aug 8, 2007 | 02:56 PM
  #18  
kotomile's Avatar
Elite Member
iTrader: (24)
 
Joined: Oct 2006
Posts: 7,537
Total Cats: 42
From: Monterey, CA
Default

Another question: I have the stock 1.6 injectors on mine now, but with a 190HP. Vortech FMU is untouched, so 12:1 disc. If I bolt on my Begi DP and get boost creep to, say, 8 psi, will I run lean?

And another: If I bite the bullet and get the AEM EBC.. will it help to control the creep?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
84
Apr 12, 2021 04:21 PM
StratoBlue1109
Miata parts for sale/trade
21
Sep 30, 2018 01:09 PM
tazswing
Race Prep
20
Oct 3, 2015 11:04 AM
Trent
WTB
2
Oct 1, 2015 12:15 PM




All times are GMT -4. The time now is 05:19 AM.