[JamesM3M5]

Updated in the newest post, scroll down...

I'm at VIR right now with my 335 and I am getting limp mode 30FF boost pressure too low. Running Procede Rev 3 for years, never a problem. When the motor cools down a bit, boost works but overshoots badly then drops to compensate. With the Procede off, it only builds a couple psi and I get a 30FF. With the Procede on, I get boost overshoot until I think the wastegate seizes due to heat then I get low boost and a 30FF.

I suspect worn turbo wastegate shafts, but has anyone seen this problem with a bad solenoid? I'm at the track with tools but no spares unless I take them off another running car.

[JamesM3M5]

Here's a screen cap of a log in 3rd gear. Cruising normal throttle to full throttle. The boost maxes out at 21psi which triggers a throttle closure along with a dump in the Boost Control DC. Boost setpoint is about 14.5psi running the 7-29 autotuning maps. Log is included, change file extension to .csv to view in Vishnu analysis or in spreadsheet format.

[JamesM3M5]

I am getting new turbos, so I just wanted to show what happens when the wastegates stick. I could hear the exhaust note change once the car didn't build boost once the exhaust was very hot. I pulled in, shut down, and restarted then headed back out on track with only about a 30 second cool-down time. The sound leaving the pit lane was definitely more raspy like one or both wastegates were stuck open not pushing exhaust through the turbos. Driving around sedately on the street then getting into boost doesn't cause a problem, only does it when pushed hard for a bit. It got so bad that even after a cool-down I could replicate the exact problem after only 3-4 decently hard pulls on the street.

Stock builds very little boost then throws the half-engine and 30FF. With the Procede on and car warmed up, it builds boost normally. Once the turbos get really hot, that's when I got the severe boost overshoot.

[Ilma]

Sounds about right.....I am getting a bit of jerky throttle at first few throttle applications.

Press pedal......nothing happens for a second or so.....then sudden jerk into boost.

Goes away for me after a few passes but I suspect it's a sticking wastegate cam.

Yours is much more extreme though.

How long has your car been presenting this behaviour?

[JamesM3M5]

Just started on the second session on Saturday. However, it was acting up back in November when I was last at VIR, I just don't recall the exact behavior. You just don't get the chance to really push the car hard on the street without getting severely reckless.

[JamesM3M5]

So I replaced both turbos. The wastegate shafts were definitely worn, but nothing beyond what I've seen on some other old turbos.

Then I let them break in for a couple of weeks and took the car to Summit Point for the weekend with the National Capital Chapter. What a blast! No turbo issues whatsoever now. Didn't change anything but the turbos and related gaskets. Just running a stage 1 tune the E9x M3s didn't stand a chance. There was that pesky Ferrari Challenge 430, was pointing him by before track-out. I was happy to be passed by that dude, what a gorgeous looking and sounding car!!