Drove 157 mile today to get me car remapped. Drop it of at tracktive at 940 and was given gavins car to go into notts for a meal with a freind. At 145pm set of after not getting any call, i arrive to find the car still away and hang around a half hour. They returned we bad news the car will only boost up to 1.1 bar for a few secounds before dropping off to .8 even with the waste gate by passed. talk to toyauto and he seems to think the waste gate/ turbo (Hoping it is as it new and has never been over running speed), But tracktive seen to think by the way it boost up quickly but drops isnt the sign of a waste gate failiurthat would boost up slowly as the pressure slowly builds we engine rev, (i believe ). tracktive seen to think the engine has a air flow problem somewhere or a blocked exhaust have anyone heard or come across teh same problem.

things that have been done
most small bore vac hoses has been replace
engine rebuilt by toyauto
afm removed
air con removed cat removed
blitz bc added
recycl dv
i do get a bit of oil back from the hose that return to the hose between afm (if fitted) and turbo that we get through the air intake side ????

_________________
st185 c/s No 2801
mongoose ex
stage 3 turbo
forged pis
K&n induction
baily recur dv
aussie decat pipe
blitz boost controller
Nemesis ecu

When i am at home my wife is my right hand
When i am at work my right hand is my wife

I'd go with Ians suggestion of a dodgy wastegate especially as everything else is virtually new. It is not uncommon for the wastegate spindle to expand when it gets really hot and start sticking in the housing. You wouldn't necessarily be aware of this when accellerating as there is will be lots of exhaust gas flow to build boost initially. After a few seconds as you go from wide open throttle to cruise then the exhaust gas leak around the slightly open wastegate will show itself as a drop in boost pressure.

This happened to mine and the only way to tell for sure is to pull the downpipe off and see if the actuator/spring is pulling the wastgate fully closed.

You can also use the 'bicycle pump' test to confirm that the actuator is doing its job under boost although by the sounds of it this part of the equation seems to be working OK.

HTH

_________________
Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Another vote for the most likely item to be the wastegate.

Testing as Don suggests is a good method

_________________
Kris
95 ST205 - slept for 10 years, now waking up...
Avensis
http://www.gtfours.co.uk
_______________________________________
Turbocharging - the replacement for displacement

hmm,
1) check your boost gauge at idle to see if you are getting a good healthy vacuum of circa 500mmhg? If not then you have a loose hose or such like.
2) check your dump valev if you are running one is correctly plumbed in and is venting only during gear change.
3) test wastegate operation by removing the downpipe, attaching a bicycle pump to teh main line into the actuator (the pipe form turbo to actuator) (ensuring you have blocked the VSV) (it is also good practice to attach a boost gauge into teh line to monitor actuation pressure) Pump slowly until the actuator audibly cracks off its seat and monitor the pressure. Do not exceed 1.5 bar pressure onto actuator. Check wastegate is physically off its seat on the turbo turbine housing. Remove pressure line to the actuator and ensure the wastegate quickly returns to its seat without any fouling.

The only exhaust restriction I have heard of is a Cat falling apart and clogging the exhaust. It is posisbel but unlikely as you have removed the cat. How was teh cat on removal??

Good luck m8

_________________
JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

thks for the advice according to tracktive the accuator work ok and all hose's are well sealed as he went round them all with a propain toucjh (unlit) while engine running and got no increase in revs. The cat was removed complete and is in good condition as far as i can see into it. i willbe talking to xs purformance later today as they was a problem with a accuator when i got the new turbo. But like i said before this is something that could have been a problem for ages as the boost have never gone above 1.1 bar and normally run at .8. i will take all advice willing and try anything to sort the problem out


thks again nik

_________________
st185 c/s No 2801
mongoose ex
stage 3 turbo
forged pis
K&n induction
baily recur dv
aussie decat pipe
blitz boost controller
Nemesis ecu

When i am at home my wife is my right hand
When i am at work my right hand is my wife