ok so I have looked around and cant find anything on this particular issue.

I have a 2009 bravo t jet 150 had it for 2 years I have had a few problems mainly with gearbox but I love it so ive stuck by it. Anyways its been remapped nothing crazy..

I have a cone air filter and I'm not sure if its this causing the issue.. anyways let me explain so I'm driving at 40mph in 5th cruising along and the only way to explain it is it feels like you are speeding up slowing down speeding up slowing down all the while my foot aint moved... I thought it was in my head but the instant consumption also changes with the motion.. sorry for the long story but anyone else experienced this.

Donnybob1985 said:

ok so I have looked around and cant find anything on this particular issue.

I have a 2009 bravo t jet 150 had it for 2 years I have had a few problems mainly with gearbox but I love it so ive stuck by it. Anyways its been remapped nothing crazy..

I have a cone air filter and I'm not sure if its this causing the issue.. anyways let me explain so I'm driving at 40mph in 5th cruising along and the only way to explain it is it feels like you are speeding up slowing down speeding up slowing down all the while my foot aint moved... I thought it was in my head but the instant consumption also changes with the motion.. sorry for the long story but anyone else experienced this.

Click to expand...

Sounds like the remap could be causing this.

I have similar issues with my 1.9jtd 16v 150hp motor, it has been remapped too and to be honest - i think they have over done it.

I can be in 2nd, 3rd or 4th tickling along and as soon as i hit 2500rpm, you can feel the turbo surge a little and i havent even moved my foot on the loud pedal! thsi tells me that the remap that has been done is just wanting to full boost at certain revs or allows the turbo to spool more, using the full throttle is fine and the turbo is up to full boost almost immediatley and nearly all the time!..

Get it checked, im taking mine for a power run in a week or so - then next month im having it remapped again but proffesionally, not by some jokers who did this before (if it was jokers lol, it was done before i bought the car and i only know it was done by speaking to the previous garages that has done work on it...)

I felt something similar yesterday with my t-jet. I immediately thought about this post.
The problem with mine is a defective wastegate control solenoid N75 (new one should be coming tomorrow).

The thing is the n75 valve is not working correctly so the boost is not optimal.. there are spikes.. even at constant load. So more boost more power.. more acceleration.


I would say you have something similar.

It doesn't loose it's boost, its smooth and constant with the foot down, you only feel the surge if plodding, like I have tapped the loud pedal a tiny bit... you can hear the wastegate too... sounds very healthy

i think it must be the cone filter I have as I hear it sucking in air and its not constant its like taking fast breaths if that makes sense.....

It still looks like a problem with the way the turbo is regulated.. the most obvious place to start would be a graph of the intake pressure, boost pressure and the wastegate solenoid command.

That way you will see if the boost does not respond immediately to the actuator command.

I found a video on youtube which I cant post due to the lack of posts I have made but this is the title if anyone wants to hear/see it. Compressor Surge - On throttle
its the top result.

My car does exactly the same noise as this..... no one seems to know what was the cause of this sound. Any ideas?

Yes, that is the issue i had when i connected the westagate actuator solenoid wrong.
https://www.fiatforum.com/grande-punto/449451-120hp-vl36-turbo-surge-flutter.html
Basically your actuator is not opening the wastegate.
the turbo is spinning at max rpm... nothing slowing it down...except for the ECU that will limit boost by
1. not opening the throttle plate all the way ( it is limited to something like 20-30 %)
2. after a certain RPM 4k-4.5k it opens the diverter valve.

The same thing will happen if the solenoid is dead, wires not connected, the turbo actuator diaphragm brakes, or if the wastegate is physically stuck closed.

It is definitely NOT GOOD, and does cause damage to the turbo.

could it be the map and filter and now the standard actuator cant handle it? if so do I get the forge actuator with yellow spring?

what map what filter??
Your problem is that the wastegate is not opening, a stiffer spring will only make it harder to open.
First thing to do is to check if the actuator solenoid is correctly connected like i posted here

then check the solenoid is working by using 2 wires on the connections and blowing through the solenoid.