Does This Seem Normal?

[XtRmn8]

This may be a stupid question but here goes. When accelerating is it normal for the car to build boost to say 10psi (with a tune) and then drop off as the revs rise while holding the accelerator in the same spot?

For example driving at 60km/h and pressing the accelerator about 2/3 down the cars kick down to 2nd gear (I assume) and hits abut 3500-4000rpm, at this stage the boost gauge says 10psi. If I hold the accelerator in the same spot the car accelerates and revs go up but according to gauge the boost pressure is dropping.

Is this normal or is it a sign of a stuffed solenoid or wastegate actuator?

Its a 4 speed auto by the way and has done this since I got the car. I would have thought that it would hold boost or is this only the case under WOT?

Cheers.

[senna_T]

Completely normal mate, as the rpm rises the amount of torque the motor naturally makes increases, so the need to boost is not required - basically with the higher rpm the load is reduced. that's a pretty rough description of whats happening, but hopefully it makes sense...

Nothing to worry about

[ETM]

That is perfectly normal, when you think about it the burnt fuel is what makes the turbo spin causing boost. As the engines rpm increases it consumes more and more air and therefore the turbo has to work harder to keep the boost level stable. Since you are not applying enough throttle the boost will drop off before the rpm ceases to increase, try it with full throttle and it wont happen untill higher in the rev range where the engine actually consumes more air than the gt3582r can physically supply it and the boost level drops.

[XtRmn8]

Cheers guys

[neo]

with the stock 4sp. do you guys think its safe to floor it at 60km with 10psi tune. as above it drops the a gear and goes like the clappers but is it safe for the box?.

having a stock 4sp myself. if I go to the drags and have a run you can feel it shift at the top of the rev range quite strong. but when you drop it from 60km it feels like it puts alot more strain on the box. I have always tried to keep it off kick down as im warried it mite put to much strain on the box and dammage it?

[senna_T]

try to use the right gear for any full throttle acceleration. If you are going to get up it, use the manual shift mode to select the gear you want then boot it. This will be easier on the clutch packs and hopefully extend the life of your box.

Look into fitting a transmission cooler too, thye go a long way to making the box last