Surge on Stage 1 K04 - Cured

[ibizacupra]

surge is'nt common on k04's (std ones), but boost spikes is very very common.. most of them seem to spike >2550

the spike on intial spool is where it will occur tho, so controlling the initial spike will deal with the "out of control" issue.

I had a TT in which had slight surge but only when loaded hard in 6th... and its had all sorts of things tried and it did'nt go away. It was spiking at 27psi boost however!!!!!! but the customer was happy with it at that level

 

[brad1]

What about having a mbc fitted like Sam has had done on LCR, surely clipping the boost spike back will cure the initial surge on the boost spike and it should hold power better. Also give the turbo a longer life? Worth a try?

 

[JamJay]

I've sure considered the MBC but I can't help feeling that it's just a way of masking an issue that shouldn't be there and wasn't there 3wks ago .

I'd love to lug my car up to you Bill to get an MBC fitted if it's the last resort but it's a near on 300mile round trip so as tuners are scarce around here I'll have to take it to AMD or F1 Brighton.

 

[JamJay]

Just had a thought, does anyone think that the MAP sensor tube is a restriction or if I might need to do something with the sensor?

On another note, there was a diagram floating around showing how the MBC is plumbed in along side the N75, anyone able to post this up in here please?

 

[brad1]

The map sensor tube doesn't seem a restriction

 

[traumapat]

could this be anything to do with pressure/flow change at the compressor due to the bigger volume TIP?
In which case would turning up the boost compensate and restore balance?

Total guess

 

[wild willy]

Check your actuator also Jay to see if shes gone slack on you, even better check with a foot pump that she starts opening at approx 4 psi.
Any improvement in the intake flow side of things usually increases peak boost (TIP, Maff tube, airfilter upgrades etc) but not affect surge. The manual boost controller correctly plumbed is well worth it and will enhance your set up. N75 and actuator appear likely culprits at the moment but you really need detailed vagcom logs to proceed with confidence and minimise costs.

 

[Mark300zx]

Shot in the dark but what filter are you running and when was the last time it was cleaned/changed?

 

[JamJay]

Check your actuator also Jay to see if shes gone slack on you, even better check with a foot pump that she starts opening at approx 4 psi.
Any improvement in the intake flow side of things usually increases peak boost (TIP, Maff tube, airfilter upgrades etc) but not affect surge. The manual boost controller correctly plumbed is well worth it and will enhance your set up. N75 and actuator appear likely culprits at the moment but you really need detailed vagcom logs to proceed with confidence and minimise costs.

Does that involve removing it completely? I stuck my hand down there last night and felt the rod (ok that sound perverted) but it was pretty solid, then again I'm no expert.

I'm hunting down a Full Vag-Com enabled laptop as we speak which I hope to have before the weekend. I'll then run block 115 and post it up, what else do you experts need to see?

I've refitted the 007 as that's proven to be working fine, I'll do an ECU reset tonight and I'm considering plumbing the N249 back in.

Shot in the dark but what filter are you running and when was the last time it was cleaned/changed?

Jetex filter FC08001 which is not that old at all, good condition.

 

[csd_19]

Is there anyone near who could lend you a (don't shoot me down for this) BOV to try instead of the recirc?

Just something I've heard mentioned when regarding surge (and I mean the proper surge like you have, not the retard ricers who call flutter surge. Although it is still technically a type of surge )

 

[JamJay]

You mean so that I can blow out the pressure from the system entirely? I'd be game for trying it but not willing to buy one due to the cost and I don't know any local members, I'm all on my own out this way.

I don't think that a DV will have any control over this situation personally as this is happening on WOT when the DV should be completely closed anyhow. If I was to set up a DV to leak partially while on WOT then I'd surely hit limp mode and throw a boost leak fault. I can hear the DV dump each time I lift off so the extra pressure should be escaping each time correctly.

 

[csd_19]

You mean so that I can blow out the pressure from the system entirely? I'd be game for trying it but not willing to buy one due to the cost and I don't know any local members, I'm all on my own out this way.

Yes that's what I was thinking, found a few vids on youtube last night of turbo surge (including the one with the skyline that was posted earlier) and a BOV was mentioned.

My feeling on the surging is that the map now needs to be adjusted to reduce the boost at low revs (in your specific case) where the engine/valvegear cannot digest the airflow the turbo can now move as a result of the big-bore TIP.

On a side note I found an interesting thread regarding surge and what it is etc, bit of an FYI for anyone unsure here

 

[wild willy]

Does that involve removing it completely? I stuck my hand down there last night and felt the rod (ok that sound perverted) but it was pretty solid, then again I'm no expert.

Its simple Jay, just pull the vac tube off the n75 that gores directly to the actuator and connect it to a foot pump and slowly activate the pump and observe the pressure the actuator starts to move at.......job done.

 

[Mark300zx]

Or turn down the actuator if you want to ease the symptoms?

 

[JamJay]

Its simple Jay, just pull the vac tube off the n75 that gores directly to the actuator and connect it to a foot pump and slowly activate the pump and observe the pressure the actuator starts to move at.......job done.

I'll give this a go and let you know what happens , thanks.

Or turn down the actuator if you want to ease the symptoms?

Am option but just masking the problem really, I don't surge if I drive normally so if I need to use the car then this is what I'll do. Thankfully I don't NEED the car at all, it's just a toy.


I just want to take this opportunity to thank everyone for getting involved in this, it pretty much sums up SCN and you have no idea how grateful I am. I know the problem is still there but with your help I hope that I get to the bottom of it soon .

Again, thank you

 

[ibizacupra]

could this be anything to do with pressure/flow change at the compressor due to the bigger volume TIP?
In which case would turning up the boost compensate and restore balance?

Total guess

it did'nt do until 3 weeks after it was fitted.
tip is'nt why...
boost control and maf (under reading now fixed) most likely culprits..

when he's got the boost gauge on we will know more
something changed a few weeks after.. and n75 control is now most likely now maf has been replaced and reading healthy numbers again.

 

[Markypoo]

Hi Bill its Mark here with the black TTR came to you on Monday
Been trawling the net and found this thread and been chatting to Jason for the last couple of days as having the exact same trouble with mine.
Have tried standard N75 (although running a new J valve now as it had a J valve fitted prior to the problem and yes Bill 27psi is high)
N249 delete, new MAF endless logs that show nothing except when logging the MAF
My car has a Vagcheck map FMIC all silicon hoses and ran fine like this for 2 years before this problem so like Jason Im eager to get to the bottom of it
If anybody could throw any light on this problem I'd be really greatful
Cheers
Mark

 

[rsmith]

Guys from my point of view its pretty simply, this is a great mod for sure, but peeps are just firing it on there car unaware of some possible side effects, 1.Surging 2.Injectors maxing out due to the increased air flow.

For sure sometimes other factors come into play(n75,MAF, leaks etc...) but if they were working before the mod its pretty unlikely they are the problem.

All turbos have a surge line as seen on there compressor map, the previous TIP's whether OE or the likes of forge keep the turbo operating safely to the right of the surge line i.e pressure ratio and volume, now with this new TIP this line is moved further to the right, so crossing the surge line is more of a possibility.

You need to have your MAP's tweaked to compensate for this, running lower duty cycles lower done in the RPM range should suffice.

To absolutely rule out other components, just put your old TIP back on or someone post up there Airflow, boost and duty cycle logs so we can pin them against the compressor map of the K04-023.

Thats my 2 cents.

 

[JamJay]

Hi Mark, welcome along! Between us it looks like we've tried most of the likely culprits and solutions are becoming thin on the ground. There may be more than one thing that causes this surging, what fixes yours might not fix mine and vice versa but I hope that I am wrong and this is a linked issue that is solveable by replacing one part, then anyone else with this issue can do the same. It's just a shame that we are the test pilots for this more or less and it's in our hands/bank balance to fix it. I'm going to get the logs/results of the boost guage up ASAP and then I guess try changing the N75 like you did just in case but I'll let Bill and some of the veterans on here cast their views on them and suggest some solutions . It's likely that my lods will be nigh on identical to what you will have been seeing so the 'fix' will likely be the same.

I can't stress how good the 3" TIP is and I do not think that this is the cause otherwise we'd all have the issue, I believe it's just me and Sam so far and Sam cured his with MBC. I will fit an MBC to kill this off if need be but like Mark I would love to get to the bottom of this and find out which part of the engine has caused it as neither of us had the issue, both had a remap for 2yrs and no issues.

Robbie you may well be right and if that's the case I'll Stage 2 the car and explain my issue befroe they do it, they should then hopefully be able to reign it in.

One thing I'll throw out there is that not all of these K04 engines are equal, there have been some real spikey ones, ones with much higher power than expected and others that just read low all the time. I know that Mark doesn't have a 3" TIP but his figures are impressive already, 280bhp? for a K04, with the TIP then a lot higher perhaps so maybe we both have two very spikey, high reading K04's...look at my Stage 1 logs lol, 226g/s.

 

[Markypoo]

I dont have the 3" TIP I have a Forge TIP and the car ran as it is problem free for at least 2 years until recently, no other mods fitted before the fault. Bill did all the logs on Monday on mine and all was ok, right mine is boosting at 27 psi with the J valve but still get the problem with a standard N75 boosting at 22psi ..................................