T4 Boost level

[BobbyV]

Know I know a t4 standard boost a 0.9bar, mine usually is between 0.9-1.0 but in 5th gear it shoots up to 1.2bar. I have a decat and panel filter, causing engine management light to stay on but is it normal to boost at this level?

[puntodan]

Originally Posted by BobbyV

Know I know a t4 standard boost a 0.9bar, mine usually is between 0.9-1.0 but in 5th gear it shoots up to 1.2bar. I have a decat and panel filter, causing engine management light to stay on but is it normal to boost at this level?

You checked for a boost leak?

[t4 tony]

have a look at the actuator arm, see how much thread there is behind the locking nut, if there's none left or very little there's the problem.

keep in mind that the car is breathing better so there's less back pressure on the turbo so it will spool up better.

[960kg]

Originally Posted by BobbyV

Know I know a t4 standard boost a 0.9bar, mine usually is between 0.9-1.0 but in 5th gear it shoots up to 1.2bar. I have a decat and panel filter, causing engine management light to stay on but is it normal to boost at this level?

......if you had a cat. and four turns from standard on the actuator arm for the wastegate you would be pulling the same boost as i am about 1.2....17 to 18 psi and mine will pull that at 120mph ,i have been at that for 2yrs ...it does not spike and then drop as the speed goes up.......you must not go above 20psi as it is detrimental to the standard engine the boost is detrimental but not the power it produces if you have the larger turbo for more BHP then the boost is about the same with no ill effects........as T4 tony says you are probably pulling that boost at a higher speed because the exhaust is more efficient at those revs. but you are also burning more fuel as the O2 sensors are not calibrating the fuel correctly at lower speeds that is why your light is on , bad emmissions!!......so you can still pull the higher boost with a cat. as mine and be fuel efficient.....at WOT the O2 sensors are open loop and not in the game so that does not matter but when you slow up that is when the fuel economy comes into play......

[BobbyV]

Thanks for the replys, what you are saying makes sense. Im going to get the car custom maped so that should sort the sensors etc out. No boost leaks as I recently did a whole check on the system. Plenty of tread left on the arm, i noticed this today for the first time so gonna keep my eye on it, tbh i hardly ever floor it in 5th and not worried about the extra boost, you guys have told me what i expected. Cant wait for the map, hoping to get over 250bhp. Besides that im just waiting for my strut brace and new grill. After that not sure what will be next.

[beemer]

Dont forget to update us with who what and where after your remap as I for one will be interested in the results

[BobbyV]

will do pal, theres bit of info on t5d5 forum on remap places but alot of them are a bit far for my liking as i want a custom map with a rolling road so will be sourcing a place near me but will keep you updated nonetheless. Theres a fella called Don North of Watford whose meant to be good, not far from you but cant vouch for him myself

[t4 tony]

don at kalmar union do you mean ? he dose the mte soft wear, thats what i would go for. and i'm near middlesbrough