Hi all

My vrs is surging under acceleration, I've cleaned the tb, checked the intercooler and pipes and took it for a run with the maf unplugged but it's still doing it,code read it and nothing is coming up, before I take it to the garage to get the turbo actuator checked is there anything else I should check? Any help would be grand thanks Mark

Mark

Put n75 on the list.

Don't want to sound like a chav but I've got an atmospheric dv on my car and it's bolted right onto the metal pipe behind the rocker, so my n75 pipe is off, shameful I no but I love the tiiisssss tiiisssss!

That could also be the problem, these run better with recirculation dv like a properly tuned 007p or better still just the oem diaphragm. Need to see what the blocks are doing to really get to it. When did you have the BOV fitted? The ecu doesn't like losing air that has been measured to atmosphere, try a recirc set up, the forge gives you some tsss but it's got to be set up right and maintained. For low end stage 1 and standard can use green spring maybe with shims, remap stage 1 and just above need yellow spring.

My last vrs had a stage 1 and I was running a splitter R value, it recirculated and dumped atmosphericly, I will put the n75 and std boch value back on and hopefully that makes a difference. Doing my head in it's one thing after another with this car lol thanks YellowCar will keep you posted

Going through a similar phase with mine, mainly maintenance rather than fixing it but even so. Hopefully that sorts it, if not you'll need to get some blocks measured (boost, n75 duty cycle, actuator cracking pressure, maf etc) doing that with recirc stuff fitted will give you a more intelligible baseline to work from. If you get it running right you can either stick with the oem diaphragm (recommend - less hassle, higher reliability) or go for the 007p (get some noise and will perhaps be better if you upgrade turbo in future, but more hassle). Fitting a cone or modifying the airbox and fitting a panel, and a cold feed will also help to give you nice noises and amplify the tsss without the detriment of running issues. Since I fitted my big smic and moved my 80mm cold feed pipe slightly (going into panel in a definned box) my car growls at me. I prefer that kind of noise to the tsss but each to their own. Increasing airflow round the system is what you want, rather than blowing off measured air to atmosphere. Let us know how you get on.

Right that's the atmosphere off and boch and n75 pipe back on, seams to have much more boost now still not convinced the surging has stopped but for now it seams to have gone, maby I'm just being paranoid lol now to hit the list of todo things, back brakes disks and pads, refurbished and fit the back callipers I rescued off a gttdi 4x4 golf, new mesh for the bigmouth (had for 4 week's now), get the reclaimed rust free boot on and fit my rear plate and surround, re spray my grill aggen lol, fit my boost gauge, fit sub and amp, delete side strips, remove the dent in my door, try and find a spoiler in red as mine is pink lol, sure there is more to but first a good service in due thanks YellowCar seams to have worked

Fingers crossed! May also be worth checking actuator pressure because if previous owner was into BOV they may have cranked up the preload on it. To do this unplug n75 (ironically) and log boost 115, should flat line around 5 psi, lower and actuator is weak, higher and if it's a stock actuator on stage 1 or below it's probably got too much preload (nuts on the rod too far up). But if it feels ok run it for a bit until the paranoia subsides and you'll be able to tell more. I'm a bit paranoid about my increased noise, just getting my head around much improved airflow + lower temps= more torque and more noise lol.

To do list is similar to mine, most of my upcoming jobs are low cost (hopefully). Need to change my actuator for my refurbished one though, currently got a pikey mod on it with external springs.

I fitted the atmosferic myself (the shame!) so it should be fine, what's a pikey mod? Low coast is the key like lol, I'm just waiting for the next thing to fail now lol

Pikey mod: an improvised method of improving performance by way of incorporating low cost materials often designed for other purposes, or the manipulation of existing parts (example: drilling holes in things). Also known as a bodge, but considered more as a modification than a fix. Adjective.

I got that from the Oxford English Dictionary.

The list does keep growing, goes something like: mod, mod, fix, correct mod, fix, enjoy, fix, mod etc you get the idea lol.

a pikey mod sounds good to me like lol, yes that's definitely the way it goes like mod mod fix first mod etc lmfao, whilst out for a test spin with the std dv and n75 pipe back on it, jumped over to Fife, before I new what was happening I found myself standing in the middle of a scrap yard!, so I managed to get some dash and boot trim and a solenoid for the petrol cap and some nice badges lol weighed in my scrap pile to so came home 10 bucks up lol

I must be getting old because I feel like I should make my car quieter and stop all the dumping and hissing noises. Is a standard recirculation valve that much quieter than a Forge 007P? I used to run a filter in the wheel arch, which still made a racket, but less so than a Pipercross cone straight on the end of the MAF. Is a standard airbox quiet?

 

If either of these reversions to standard parts strangle the power/torque in any way whatsoever, then I'll leave the aftermarket bits on. Like I say, I must be getting old...

Std boch is quieter than 007p and std air box (not drilled) is much quieter, did you map your car with the after market parts on? If so you will probably loose some power etc

If you want I will swap you, your after market parts for my std ones lol

I must be getting old because I feel like I should make my car quieter and stop all the dumping and hissing noises. Is a standard recirculation valve that much quieter than a Forge 007P? I used to run a filter in the wheel arch, which still made a racket, but less so than a Pipercross cone straight on the end of the MAF. Is a standard airbox quiet?

If either of these reversions to standard parts strangle the power/torque in any way whatsoever, then I'll leave the aftermarket bits on. Like I say, I must be getting old...

To be fair the oem valve isn't that much quieter than the 007p I ran on the same set up. When it comes to the recirc valves I think it's more about flow that creates the noise. Having a definned box with a panel and 80mm pipe certainly helps. If you run the box as standard you'll still get an audible chuff with the oem diaphragm with a panel filter in there.

What I would say is that a properly tuned 007p is better for requirements with uprated actuator, TIP etc. Oem diaphragm would probably cope fine, but up at that stage 2 range I'd say the forge would cope better. Stage 1 below 220 I'd say there's nowt wrong with oem valve. It's all about how the airflow works for you and your set up and as you know a lot of trial and error is involved. For me nice noises are a bonus but not something I plan for, getting it running right takes priority. I must admit these days it's less about the tsss, and more about the bwwaarrp.

a pikey mod sounds good to me like lol, yes that's definitely the way it goes like mod mod fix first mod etc lmfao, whilst out for a test spin with the std dv and n75 pipe back on it, jumped over to Fife, before I new what was happening I found myself standing in the middle of a scrap yard!, so I managed to get some dash and boot trim and a solenoid for the petrol cap and some nice badges lol weighed in my scrap pile to so came home 10 bucks up lol

Nice work, how was it running?

Nice work, how was it running?

Mutch better lol

Spoke to soon YellowCar, the paranoia was right lol, it's still surging, not as bad or often but definitely still doing it. Going to get it in the garage, totally out of ideas now like, dv replaced with std one, ran with maf off and n75 disconnect and cleaned out my tb, checked boost pipes, new coil packs fitted not to long ago, giving up now lol

Is the car mapped? When my car was relatively standard, I and a pal loaded a map written using Dimsport tuning equipment and we just couldn't get the thing to stop surging. We stuck a standard Leon Cupra map back on it in the end, which, although it was slower, it made a bit more power than standard and didn't surge. Not saying it's the same as your problem, but it could be a possibility.

 

PS. Decided to keep the 007P and Pipercross cone. Will extend the intake so that it is closer to the inner wing and make a heatshield instead, rather than put standard bits back on.

I'm thinking it could be a software issue if mapped. Has it ever gone into limp mode? It does have the right n75 valve on? F is the standard isn't it? If it's the uprated J without the right tune it can surge. Other than that try and get some blocks measured. Not sure who there us near you but a rolling road diagnostics session could be £60 well spent.

 

PS. Decided to keep the 007P and Pipercross cone. Will extend the intake so that it is closer to the inner wing and make a heatshield instead, rather than put standard bits back on.

That's the spirit, think that's the way forward for your set up. Previously I had my cold feed pipe just about at the crash bar being a bit paranoid about water spray and such, but when I fitted the big smic I zip tied and shifted it a bit so it scoops air more from the corner grill I drilled. So rather than it being full frontal in the bottom corner and vulnerable it still scoops rammed air. I now realise how the previous cooler was strangling the car with intake temps and flow, and the intake is now improved. Car sounds pretty nice, gets a proper bwwaarrp on between 3 and 5k revs.

It's not mapped YellowCar, totally std under the hood I'm afraid,

As above mankee no map , your better with the mods imo.

Hate to say it but I think you need to measure some blocks or book in for a diagnostics on some rollers. Were your new coils genuine by the way?

Have a read of this. Reminds me about the actuator or even MAP sensor...

http://forums.vwvortex.com/showthread.php?5246758-COMMON-Question-Boost-Surge-Fluctuation-Flutter

Coils were the recall from the dealer, thanks YellowCar the info was good but now I have even more to check lol doesn't fill me with joy lol

The plot thickens. I have a small port MAP sensor which I changed chasing one of my issues, looks like it was fine. If you cover post you can try it if you like?

I will give it a bash like, I'm defo taking it to my mates garage now lol, will update asap thanks YellowCar