[NEVL666]

So I've tried the magnet trick in the air box, I've removed the snorkel and sock (now refitted), taken out the resonator/muffler from of the top of the air box .. but nothing makes the surging disappear all together.
Again this morning I experienced very noticeable surging under hard (not foot down) acceleration on the way to work.
I have the Solo cat back with the resonator fitted, and today I was running the stock air box with the flap removed and the top air box resonator removed. I feel it is worse with the snorkel/sock fitted, meaning there's not so much air getting into the air box compared with the larger opening on the engine side with it removed.

The engine is at operating temp as I've been on the road for 20 mins when I notice it, and just prior to it happening I've been driving at 60km/h for around 2-3kms.

What is causing this on/off power surge under acceleration? I'm presuming it's wastegate, but why is it so noticeable and so bloody annoying? Does anyone else have it this bad? It's definitely taking the fun out of driving this in a spirited manner. I'm so pissed with this I'm almost (stress almost :wink ready to take it to the dealer.

 

[velociraptor]

I have noticed minor surging in 3rd gear under heavy accel. I have noticed it more in warm damp weather than cooler dryer weather here. I don't have a heavy foot during my normal commute and do not notice any surging when shifting at 2500rpm. My only performance mod is Injen CAI. I did notice less surging after going to the Injen but it was not eliminated completely.

All my comments are anecdotal since I have taken no steps to fully document all conditions when surging occurs.

 

[nvyseal]

I think the OP has an Auto Trans.

I also have this problem with my A/T, but not all the time, some days I can push the throttle and get nothing, other days I get takeoff, all at operating temps

 

[mwil028]

did the sensor mod and I have it nailed down. You just nudge the pedal and it revs absolutly no hang ups. But my car still does the "wave"

 

[NEVL666]

I have no hangups or hesitation issues. This is a surge that happens to me after sedately driving along the road for some kms, then want to open it up on a certain piece of straight road.
I talked to the service manager at my dealership and he says it's most probably the fuel I'm using. I have to admit I buy all my fuel from the same place because it's cheap as I get 7c back per liter. I'm going to fill up next time with Shell and maybe try the next grade up and see if that makes a difference.

 

[velociraptor]

I have no hangups or hesitation issues. This is a surge that happens to me after sedately driving along the road for some kms, then want to open it up on a certain piece of straight road.
I talked to the service manager at my dealership and he says it's most probably the fuel I'm using. I have to admit I buy all my fuel from the same place because it's cheap as I get 7c back per liter. I'm going to fill up next time with Shell and maybe try the next grade up and see if that makes a difference.

i have experienced the surge with different brands of gas. BP, speedway, other generic. always regular, though.

 

[velociraptor]

I'm tellin' ya, until there's an ECU tune, the APS is the most effective way to address the throttlling issues.

Agree with the part of your comment regarding a tune resolving this but do not see how the APS would resolve the surge I am seeing... no surge in first or second at same RPM but it shows in 3rd, don't know about 4th+ as I generally do not want the reckless driving charge that will come with those speeds... That strikes me more as a software issue.

 

[nvyseal]

I have no hangups or hesitation issues. This is a surge that happens to me after sedately driving along the road for some kms, then want to open it up on a certain piece of straight road.
I talked to the service manager at my dealership and he says it's most probably the fuel I'm using. I have to admit I buy all my fuel from the same place because it's cheap as I get 7c back per liter. I'm going to fill up next time with Shell and maybe try the next grade up and see if that makes a difference.

Exactly like mine, at speed, with your foot on throttle, and you give it more gas, it does nothing, then you keep pressing down harder and eventually it takes off

 

[cruisn76]

How about turning off the ESC and see if it still happens

 

[velociraptor]

How about turning off the ESC and see if it still happens

No difference. I turn it off when the roads are dry and that is also the only time I really accel hard.

I will try to nail down more specifics of when my surge occurs and see if I can find any pattern.

To -X-, I want to better determine the symptoms and conditions to what I am experiencing before making any changes to try to fix it. I do not disagree with what you say, though.

 

[Dmilinare]

Auto or manual doesn't matter, the sensor on the accelerator pedal can still be adjusted to compensate for the lagging/surging. Just be prepared to spend a good bit of time unless you get lucky the first time. It took me 5 hours of tryfails before I found a setting I liked.

My suggestion is to find the exact center postion for the upper right screw and start there. Rotate the sensor to the right to increase the idle RPM, left to decrease. Once it settles after starting the car, lightly blip the throttle and see if it settles higher that 700 RPM.

Does anyone have pics to show where this sensor and the screws to adjust are?

also what is APS?

 

[VTBoost]

NEVL666, I suggest you try the $30 DIY SRI. http://www.velosterturbo.org/forum/veloster-turbo-diy/1748-30-diy-short-ram-intake-sri.html

Nothing I've done with the stock airbox has completely gotten rid of the surging /wave issue for an extended period....it always comes back. Adding an SRI or CAI seems to get the best results regarding reducing the wave, as long as you don't mind the noise that's associated with this mod.

 

[velociraptor]

NEVL666, I suggest you try the $30 DIY SRI. http://www.velosterturbo.org/forum/veloster-turbo-diy/1748-30-diy-short-ram-intake-sri.html

Nothing I've done with the stock airbox has completely gotten rid of the surging /wave issue for an extended period....it always comes back. Adding an SRI or CAI seems to get the best results regarding eliminating the wave, as long as you don't mind the noise that's associated with this mod.

CAI did not entirely get rid of this problem for me.

 

[VTBoost]

CAI did not entirely get rid of this problem for me.

I agree, it's not 100% gone for me either, but much much better in my opinion.

 

[velociraptor]

You need to do some datalogging if you really want to figure it out.

I suspect that judging by my success with kicking up the voltage/idle, there might be voltage oscillation going on, caused by some kind of fucked up conditional triggers that make no sense.

Then again, a lot of stuff about this car makes no sense.

Figuring out Torque in the hopes it will let me capture the behavior in a graph over time.

 

[NEVL666]

i have experienced the surge with different brands of gas. BP, speedway, other generic. always regular, though.

So this last weekend I filled up with mid-grade 89 octane gas to see if I could tell the difference. I filled up from as empty as I was willing to go, and after running it for some miles I have the following observations:

1- the engine idles a whole lot smoother
2- the acceleration from standstill is also way smoother
3- the Solo exhaust note at idle is deeper
4- the engine seems to have more power at all speeds and I can feel it by not having to press on the gas as much
5- the surging I was experiencing seems to have finally gone away
6- it's gonna cost me more to fill up :dread:

The car feels like it did when I first got it four months ago, so either the tank was originally filled with a better grade or make of gas, or I've just been filling it with crap ever since .
BTW, the 89 I filled up with this time is from the same gas station I always get my 87 from.

Interesting tidbit for Canadian drivers:

Grades of Fuel, Gasoline

Most Canadian gas stations carry 3 grades of fuel. Each of the 3 grades of fuel is formulated to offer good performance and fuel economy. Your vehicle owner's manual will recommend the right octane level for your vehicle.

87 - Regular unleaded gas contains a minimum octane level of 87, which is suitable for many types of cars. At many gas stations, renewable fuels with up to 10 percent Ethanol are included in the regular fuel grade. Stations providing Ethanol blended fuel, often referred to as "E10" will have this indicated on the pumps.

89 - A step up from regular unleaded is mid-grade gas containing an octane level of 89. If your engine knocks or pings, you may want to step up to this level or higher. If the noise persists after filling up with higher octane a couple of times, you should have your vehicle checked. At locations supporting renewable fuels, 89 octane fuel or "mid-grade" may contain up to 5% Ethanol.

91 - The highest octane rating fuel is ideal for high performance vehicles, particularly those with Turbochargers.

 

[matt6g72]

I haven't put anything but 91+ in mine. Still get surging. Like the post above, a tune is necessary.

 

[Cinderblock7881]

I still think the surge is just to be blamed on the fact that the WG is controlled by a solenoid, so it fluctuates more than a pure mechanical system would, especially at less than full throttle, where the turbo may be wanting to push max, but the ecu says no and has to constantly cut the boost off.

 

[silverarrow27]

This whole surging issue imo is a boost leak problem. It's such a common issue with forced induction. It could be anywhere from a leaky bpv, wastegate, boost solenoid, and/or ic piping or couplers.

Update: Just noticed that cinderblock7881 and I posted at the same time and I did forget that the stock ecu normally does have a fuel cut off when hitting certain boost on most cars as he mentioned.

 

[cbrmale]

I know what NEVL666 is describing and it doesn't seem to be the stumbling and carrying on that manual transmission cars suffer from; it's an uneven slightly-surging acceleration at heavy throttle openings, mid-range revs in higher gears. I have experienced it three or four times and I have run my turbo automatic on 95RON since new. Based on my findings so far NEVL666 may still come across surging now that he is using higher octane petrol (I assume he's now using something close to my 95), but it won't happen very often. Of course his car will go better because the VT seems to be optimised for higher octane petrol, although we do pay more per litre.