Turbo Surging, what to do?

I noticed on my way back home my turbo started to surge. It happened in 4th gear while WOT before max boost. It would hit 20 and go back down to 17 and up again and repeat. I had a tune a few months ago from SS.

To fix this, do I need a retune? I heard maybe tightening the wastegate arm would help, but I have no idea how to do this. What would cause my car to start surging?

 

Ok that is not really surging, that is related to the wastegate and how the ebcs is dealing with the boost. Surging is when the turbo wheel actually is forced to stop and kinda gulps air. Surge is the situation when the compressor "spits out" more air than the engine can swallow, which causes a backup of air at the intake and it actually creates reverse-flowing pressure waves that can be very damaging to the turbo. I think this is usually cause when there is not enough exhaust gas to drive the turbine wheel OR when the bpv or bov does not open early enough causing a back up in the system... Surging is bad stuff!

Talk to Scott. I am sure it is just some WGDC that need fine tuning due to the cold weather. You might be able to fix it with the wastegate actuator arm, but not really sure on that. Sounds like either WGDC or Turbo dynamics tables need adjusting.

 

thanks for the tip. I had no idea what this situation is called and it happened long ago before too. I called it "surging" and nobody explained that what I was talking about was not surging.

 

Put some zip ties or hose clamps on all the vacuum lines connecting to the waste gate actuator. I had the same problem and it turned out to be a tiny tiny vacuum leak. You should give it a try. Or even better replace all those lines with fresh ones.

Mike

 

stock Boost controller ?
SS can fix that easily

Did you add anything or mess with the BCS lines ?
dont rig it !

 

It's possible I don't have the stock controller, I did add new lines for the stock BOV since I put a Turbo XS on once and accidently ripped that line. SS did add one or two zip ties also.

 

I have noticed the same thing.....I was thinking it was weather related as well...so i'm curious to see the outcome of this

 

I do get a lot more aggressive with the "intake-air-temp wastegate duty compensation" but sometimes in the really cold weather some setups will still have a little trouble keeping the boost down. Obviously the cold air is WAY more dense than the warm air, and trying to make it run full boost in the heat of summer, but no more in the cold of winter, sometimes they overshoot a touch. Just give me a call and we can setup a time for me to put more aggressive air-temp compensation in it.

SS

 

The Siegel has Spoken

 

indeed....

 

would u expect this to happen if u switch to a big intercooler without tuning?... or is the temperature difference in the later case not significant?

 

I personally did not see any huge boost peaks when I switched to my bar and plate from the factory one. I did get a slight increase to where I was supposed to be running with the cobb stage 2 ots map though. But I did not see the boost fluctuations that he is describing, it just went to where it was set and stayed there.

 

i didn't experience anything either... in fact i do experience some hesitation if i stomp the gas before it starts pulling... i believe its running a little rich because of all the piping :dunno

but no surging yet

 

cooler air allows you to run leaner and more timing

pressure is pressure the Engine dont know what brand or IC you are using, but it does know when its available

 

Thats not always true, blanket statments like that blow up cars.

Richer mixtures will usally allow for more timing.

Lean is Mean but Fat makes it till the end of the track.

 

I had a similar thing happen the past few days, right after the car is warmed up I will put it in 5th with WOT, the boost seems to shoot up higher than normal then drop. I try to replicate it after this happens, but it won't do it again. Is the car not fully warmed up? I notice it happens when it is around 40 degrees or lower outside. Any thoughts?

 

hey Scott, mine does this too. Is this something that you can fix easily?

 

educate me which blanket statement will blow up car ?

 

i think matt meant that adding more pressure isnt always the best.

 

maybe ?
never said add more pressure

car can easily handle more pressure (to an extent) if there is enough fuel and dont det.

 

I would say the car's ECU learning.

 

im not a tuner im sure our onsite pros will have the answer

if it was my car
i would finetune WGDC and turbodynamics
most tuners have zeroed out the boost compensation(intake temp), i dont
timing is also effected when water temp is not at norm op temp.

if i were you i wont do any WOT before water temp gets to 120F, colder days the water takes longer to warmup

 

For the cars that I tuned that overshoot in the cold, I can make your intake air temp wastegate compensation more aggressive... Assuming it's not mechanically limited, that should help.

Siegel

 

I think I found the problem, the turbo is not surging, my clutch is slipping. Time for a new clutch.

 

I'll see you at lunch one day this week. Are you around this week?

 

You do not want to zero out the IAT compensation. When it gets hotter you want the car to run less boost/timing.

 

i'm around. how's tomorrow?

Siegel

 

mine's doing it again. But the simple solution is not go WOT.

 

^^ Thats no fun though.....

 

I'm busy today, I'll call you tonight to see what your week looks like