Notices

overboost problem?

Thread Tools
 
Search this Thread
 
Old 19 February 2008, 10:22 PM
  #1  
reefsting
Scooby Newbie
Thread Starter
 
reefsting's Avatar
 
Join Date: May 2007
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Default overboost problem?

I think i am overboosting and getting boost cut out. At peak boost it hits 1.25 bar and then cuts, i have done all the usual checks, leaks, clean hoses etc but cannot cure it. any ideas?
By the way the car is a 2000 type RA, full decat and HKS induction.

Also can anyone sugest a good place to get it checked out in the southend area essex

Last edited by reefsting; 19 February 2008 at 10:24 PM. Reason: more info needed
Old 19 February 2008, 10:26 PM
  #2  
STI_Baly
Scooby Regular
iTrader: (23)
 
STI_Baly's Avatar
 
Join Date: Feb 2008
Location: My Workshop, Kent
Posts: 2,588
Likes: 0
Received 1 Like on 1 Post
Default

It sounds like Fuel Cut to me mate, and possibly needs a remap too.

Wait on some of the pro's to give you some more info though.

Goodluck
Old 20 February 2008, 08:24 AM
  #3  
reefsting
Scooby Newbie
Thread Starter
 
reefsting's Avatar
 
Join Date: May 2007
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Default

why would it be fuel cut? Is this linked to the overboost?
Old 20 February 2008, 09:33 AM
  #4  
The rookie
Scooby Regular
iTrader: (1)
 
The rookie's Avatar
 
Join Date: Feb 2006
Location: Warwickshire, UK
Posts: 2,099
Likes: 0
Received 0 Likes on 0 Posts
Default

if it overbbosts beyond the fuel cut limit it will then give an abrupt fuel cut like killing the ignition for about 1/4 of a second - not nice!

The full decat is probably your root cause as that changes the optimal BCS control strategy and on some VF turbo's can give rise to 'boost creep' where the wastegate can't flow enough to keep boost under control.

If its the former, you can cur it by fittinga restrictor in the pipe from the BCS to the intake pipe, for 1.2 bar you will need an orifice of about 1.6mm usually....

Just to confirm you haven't replaced your BCS pipework with silicon hosing, this is slightly larger bore and smoother so flows better than the original stuff, this can then lead to transient overboosting on an otherwise totally stock car.

Simon
Old 20 February 2008, 09:51 AM
  #5  
T5OLF
Scooby Regular
iTrader: (4)
 
T5OLF's Avatar
 
Join Date: Sep 2005
Location: The yorkshire dales - best roads in the UK
Posts: 3,311
Likes: 0
Received 0 Likes on 0 Posts
Default

Good chance it could be the freezing weather if you have not changed anything and it never did it before this cold snap.
Old 20 February 2008, 10:52 AM
  #6  
reefsting
Scooby Newbie
Thread Starter
 
reefsting's Avatar
 
Join Date: May 2007
Posts: 10
Likes: 0
Received 0 Likes on 0 Posts
Default

i have had the problem for some time now and lived with it but its really pi$$ing me of now. It started after i had the inlet pie changed as the old one had started to fall apart, all standard parts were used and then the MAF sensor went about a week later. It went away for a while and has now come back to haunt me.
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Abx
Subaru
22
09 January 2016 05:42 PM
PetrolHeadKid
Driving Dynamics
10
05 October 2015 05:19 PM
T.K
General Technical
10
02 October 2015 11:35 AM
the shreksta
Other Marques
26
01 October 2015 02:30 PM
minguela
Wheels And Tyres For Sale
0
29 September 2015 11:28 AM



Quick Reply: overboost problem?



All times are GMT +1. The time now is 12:13 PM.