Boost problems

R

rox

Member +
Hi,

i made a thread recently about my engine managment light coming on under full boost due to boost creep this was about a week befoe xmas when every morning was about -2 very cold so i assumed it was that that was giving the extra boost!

now i know its still cold now but it is deffinatlky warmer as the car isnt frozen up with a cm of ice every morning, but now!!!! the same thing is happening but i am actually hitting the fuel cut and its jolting the car round like mad from about 5.5k! why would this problem be getting worse? as i could redline it a few weeks ago and only the light would come on with no fuel cut yet now i cant get all round with my foot planted??????

any help will be gr8!!

cheers
 
C

CMR

Member +
Get some throttle control on your right foot or dont drive the car if you cant use half throttle. Repeated fuel cut hitting is not good and can cause long term engine damage.

It is still very cold outside and the turbo will be sucking in more denser air, if you havnt got a boost gauge.. get one asap so you can decide what to do next.

edit; Also to explain why its jerking now, if you have a glanza the engine light comes on before it cuts the fuel, and if you go over the MAP voltage then you get the lurch / backfire... I dont think GT's are the same, as soon as the light comes on in GT's you hit fuelcut I think.
 
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R

rox

Member +
yea i knew the light came on before the fuel cut thats why i wasnt overlly concerned as i know these engines and turbos are very prone to the boost creep. but now it is actually hitting the cut which is obviously very bad. i have been feathering the throttle so as not to hit the fuel cut etc but i just want to stop it!!!!

no new modifications to the car and yea i have a hks boost guage fuel cuts at about 0.9 bar
 
C

CMR

Member +
What mods do you have though?

Is the gauge setting at 0.7 then slowly creeping to 0.9 or does it instantly boost upto 0.9?
 
durmz

durmz

Member +
port wastegate, adjustable actuator from toby, or a hks unit, or get sum fuel mods and run the extra boost i spose lol porting wastegate usually works and is cheapest option
 
R

rox

Member +
not alot of engine mods just a cat-back system of unknown origin blitz blow off and adjustable actuaator. yea gets to about 0.7-8 and creeps up to what looks to be very close to 1bar!!!!
 
durmz

durmz

Member +
if youve got an adjustable actuator ide recomend winding it out abit to lower the boost, or get wastegate ported, i fitted a decat, boost creeps like mad, got it going in for clutch and wastegate proting friday, should fix both probs im hoping
 
J

JDubz

Member +
Personally id just go with an external w/g as it will be better in the long run. And if you do future mods ur gonna have to uprgade at some point anyways! Plus it sounds awsome! lol.
 
R

rox

Member +
yea not got a load of cash for external wastegate plus can you fit an external one to the stock turbo setup? i imagine you need to change manifold etc?

so how do you go about porting the internal one?
 
durmz

durmz

Member +
yea, man fitting an external wastegate to a near standard setups like putting race tyres on a milk float, where the bloody point, if you take the cat off and look into side of the turbo u can see the turbine and next to it is the penny flap which covers the wastegate, the standard size of that is 22mm, the most people have recomended on here is porting out to 23.5, which doesnt sound alot, but can be very effective as it increases the area quite greatly, if you do want to do this the once only and ure thinking of putting more mods on, you may want todo what some have done and really get involved, taking the whole turbo out and porting the wastegate inlet and fitting a bigger penny flap, therefore meaning u can make the hole bigger, but ide only recoment going for 23.5 mm with sumthing like a dremel or die grinder, wack a cloth in the hole, grind it out, pull cloth out, away you go ;) hope this helps
 
R

rox

Member +
is there a guide anywhere etc for this? when using the dremel dont you have to be fairly accurate to get a snug fit with the larger flap your adding?
 
C

CMR

Member +
You only need to take a mm off the edge, dont do it too much or the wastegate flap wont cover the hole.

Ideally its best to take the turbo off, but I guess it can be done on the car, take the cat off put a cloth in, shave a mm or two off the wastegate, pull the cloth out with the shavings.. cat back on, job done.
 
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