Notices
General Technical
Sponsored by:
Sponsored by: CARiD

why would my car stop making as much boost? Mappers Please :)

Thread Tools
 
Search this Thread
 
Old 14 January 2008 | 06:13 PM
  #1  
Ian's Avatar
Ian
Thread Starter
Scooby Regular
iTrader: (10)
 
Joined: Jul 2005
Posts: 7,845
Likes: 1
From: Cambridge
Default why would my car stop making as much boost? Mappers Please :)

my car normally runs around 1.5 bar on full boost (sometimes a little over/under)

readings from defi boost, apexi commander, apexi avcr

went for a drive today, and after a hardish launch, it only made 1.35 bar

drove a few more times and it strugled to get to 1.4 bar most of the time at 1.39

i know its not the air temp

what else could i check.

the only thing i have changed is the centre section and back box of my exhaust.

from a blitz nur spec system to a unknowen brand 3" titanium one.

but it was running the normal 1.5 bar of boost with the new exhaust on.

what could it be, or i can check?


took these readings off the commander

boost 1.39
knock 11
injection D 92.0 %
reves 7068
ing T 49 deg
air flow 4645

if it helps


thanks
ian
Old 14 January 2008 | 08:03 PM
  #2  
Ian's Avatar
Ian
Thread Starter
Scooby Regular
iTrader: (10)
 
Joined: Jul 2005
Posts: 7,845
Likes: 1
From: Cambridge
Default

ok just been out again, and all seams fine i think

these were taken off the commander

boost 1.53
knock 18 (abit high, only went this high on this set of readings)
I D 98.2%
rev 7522
I T 49
Air flow 4710

this seams normal now, i did put some more v-power in.

any ideas?
Old 15 January 2008 | 01:04 AM
  #3  
Jolly Green Monster's Avatar
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Joined: Jan 2001
Posts: 16,548
Likes: 2
From: ECU Mapping - www.JollyGreenMonster.co.uk
Default

you mention launch so I presume the first time out you were looking at lower gear readings and gunning up through the gears..

ie. full throttle in 1st to redline, then change to 2nd and take to high rpm then third etc.. you won't build as much boost doing this as if you say are at 3000rpm in 3rd and floor it.. due to the load on the engine in 1st being lower and then the rpm being higher and the turbo strugglnig to produce the air /boost quick enough etc..

or something else if the tests were identical?

Simon
Old 15 January 2008 | 04:25 AM
  #4  
Ian's Avatar
Ian
Thread Starter
Scooby Regular
iTrader: (10)
 
Joined: Jul 2005
Posts: 7,845
Likes: 1
From: Cambridge
Default

hi simon,i that is when i first noticed it, but when i took these readings there were in (both same gear) but can not remember if it was 2nd or 3rd, from low reves start

really strange as it has never done it before.

would a exhaust leak cause it?
Old 15 January 2008 | 09:57 AM
  #5  
Welloilbeefhooked's Avatar
Welloilbeefhooked
Scooby Regular
iTrader: (3)
 
Joined: Sep 2003
Posts: 3,577
Likes: 0
From: Sheffield
Default

Injection duty 98%? Surely thats bad.
Old 15 January 2008 | 01:25 PM
  #6  
Ian's Avatar
Ian
Thread Starter
Scooby Regular
iTrader: (10)
 
Joined: Jul 2005
Posts: 7,845
Likes: 1
From: Cambridge
Default

they are 550 with 3.5 bar fpr
Old 15 January 2008 | 01:29 PM
  #7  
banny sti's Avatar
banny sti
Scooby Senior
iTrader: (68)
 
Joined: Oct 2004
Posts: 16,598
Likes: 22
From: Type R
Default

What are you idle vacuum readings once up to temp?

Banny
Old 15 January 2008 | 01:59 PM
  #8  
Ian's Avatar
Ian
Thread Starter
Scooby Regular
iTrader: (10)
 
Joined: Jul 2005
Posts: 7,845
Likes: 1
From: Cambridge
Default

anything from -420 to -480

they normaly are the -420 to -440

but when it was not making boost the other day, it was the -480
Old 15 January 2008 | 02:35 PM
  #9  
Jolly Green Monster's Avatar
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Joined: Jan 2001
Posts: 16,548
Likes: 2
From: ECU Mapping - www.JollyGreenMonster.co.uk
Default

Originally Posted by Welloilbeefhooked
Injection duty 98%? Surely thats bad.
no, he is just maxing his injectors at high rpm..
Old 15 January 2008 | 05:07 PM
  #10  
Welloilbeefhooked's Avatar
Welloilbeefhooked
Scooby Regular
iTrader: (3)
 
Joined: Sep 2003
Posts: 3,577
Likes: 0
From: Sheffield
Default

Originally Posted by Jolly Green Monster
no, he is just maxing his injectors at high rpm..
So its ok to have them that high for short durations? No danger of sticking?

Curious thats all.

Wayne.
Old 15 January 2008 | 05:23 PM
  #11  
Jolly Green Monster's Avatar
Jolly Green Monster
Former Sponsor
iTrader: (4)
 
Joined: Jan 2001
Posts: 16,548
Likes: 2
From: ECU Mapping - www.JollyGreenMonster.co.uk
Default

no real danger of sticking.. the only danger is when the injectors exceed 100% ie. the recorded value is a peak of 100% but the engine wants more fuel..

Never seen a problem running up to high 90s at redline etc.. as there is therefore enough fuel supply to cover the needed fuel.

Simon
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Iqy7861
Engine Management and ECU Remapping
22
12 October 2015 09:21 AM
ossett2k2
Engine Management and ECU Remapping
15
23 September 2015 09:11 AM
ossett2k2
General Technical
9
13 September 2015 09:35 AM
alcazar
Other Marques
9
09 September 2015 05:42 PM



Quick Reply: why would my car stop making as much boost? Mappers Please :)



All times are GMT +1. The time now is 08:26 PM.