Surge on Stage 1 K04 - Cured

[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 ..................................

 

[JamJay]

Ah I didn't know that when you decreased the boost that you still got surge . Definitely points towards a faulty sensor or as Robbie says, map tweak.

 

[Mark300zx]

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

Out of genuine interest could you tell me how this would work?

 

[JamJay]

Just a quick update, checked all boost pips again and still can't find a leak so I reset the ECU and took it for a drive.

The result is that I no longer get surge when going from WOT in 1st/2nd all the way up the gears, the car pulls very hard. However WOT from 3rd, 4th, 5th & 6th anywhere between 2500 & 3000rpm and it will still surge up until 4000ish rpm where it stops surging but feels choked.

Hopefully picking up a full Vag-Com enabled laptop later and boost guage this weekend, will update again soon.

 

[wild willy]

Just a quick update, checked all boost pips again and still can't find a leak so I reset the ECU and took it for a drive.

The result is that I no longer get surge when going from WOT in 1st/2nd all the way up the gears, the car pulls very hard. However WOT from 3rd, 4th, 5th & 6th anywhere between 2500 & 3000rpm and it will still surge up until 4000ish rpm where it stops surging but feels choked.

Hopefully picking up a full Vag-Com enabled laptop later and boost guage this weekend, will update again soon.

Surging from 2500 to 4000 rpm is inline with peak spooling of turbo and could be the result of spiking, the Tip on my car does cause the turbo to work / flow more efficiently and cause higher boost pressures to be realised so the mbc should help with this. Upgrading the car to full stage 2 spec should help also.

 

[t0m]

I reckon you need full stage 2 software. However, an MBC setup properly will probably be cheaper so maybe try that 1st? New N75 too to think about..

 

[ibizacupra]

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.

none of the explains why it was not doing it for 3 weeks earlier with the higher airflow/tip, then it has started to do this........ something else has changed, and its obviously not the tip.

 

[rsmith]

none of the explains why it was not doing it for 3 weeks earlier with the higher airflow/tip, then it has started to do this........ something else has changed, and its obviously not the tip.

?!
ECU adaptations.

 

[traumapat]

?!
ECU adaptations.

Wouldnt a reset sort that?

 

[ibizacupra]

exactly.. if adaption, reset resets it.... BUT, this is'nt what seems to be going on tho

 

[rsmith]

LOL we sure do need some logs, if I was a betting man I would bet map tweaking to win and N75/actuator each way.

 

[ibizacupra]

lol - you and the horses eh Rob

I would'nt bet against ya tho

 

[JamJay]

Hi everyone, I managed to get some block 115 logs for you all. I do not fully understand them but my boost doesn't look that high actually, well the hughest is 2540 which is 10mbar less than the max that the ECU can read. From what I know the left column is requested boost and the right column is actual boost which I would have thought should be the same as each other if everything was ok but as you can see they never match, either requested boost is higher than actual or vice versa so what does this mean?

	Group A:	'115			
		RPM	Load	Absolute Pres.	Absolute Pres.
	TIME				
MARKER	STAMP	 /min	%	 mbar	 mbar
	0.01	2080	13.5	990	1010
	0.49	2040	13.5	990	1010
	0.91	2040	13.5	990	1010
	1.4	2000	13.5	990	1010
	1.8	2000	15.8	990	1000
	2.22	2040	61.7	1300	970
	2.62	2080	85.7	1930	1050
	3.02	2200	98.5	2090	1200
	3.42	2280	114.3	2120	1360
	3.82	2400	131.6	2150	1560
	4.32	2560	160.9	2230	1900
	4.73	2720	191.7	2230	2290
	5.13	2880	191.7	2240	2540
	5.53	3080	191.7	2260	2540
	5.93	3280	191.7	2260	2540
	6.33	3440	191.7	2280	2540
	6.75	3640	191.7	2280	2540
	7.24	3880	191.7	2290	2540
	7.64	4040	191.7	2290	2540
	8.04	4200	191.7	2280	2540
	8.44	4360	191.7	2270	2530
	8.86	4480	191.7	2260	2460
	9.35	4680	191.7	2240	2360
	9.75	4840	191.7	2230	2230
	10.27	5000	191.7	2240	2230
	10.67	5120	191.7	2230	2220
	11.07	5240	191.7	2220	2230
	11.47	5360	191.7	2200	2250
	11.88	5480	191.7	2190	2220
	12.38	5600	185.7	2170	2170
	12.87	5760	188	2140	2120
	13.29	5840	182.7	2120	2120
	13.67	5920	176.7	2110	2180
	14.09	6000	172.9	2110	2130
	14.49	6120	179.7	2110	2130
	14.98	6200	181.2	2110	2060
	15.5	6320	172.2	2110	2090
	15.9	6400	170.7	2110	2110
	16.3	6440	169.2	2120	2080
	16.79	6520	164.7	2110	2100
	17.21	6600	168.4	2100	2070
	17.61	6680	163.9	2110	2110
	18.01	6720	160.2	2110	2130
	18.42	6800	163.9	2120	2130
	18.9	6840	171.4	2120	2050
	19.32	6920	149.6	2130	2160
	19.72	6960	156.4	2120	2050
	20.12	7040	139.1	2130	2200
	20.52	7080	150.4	2120	2120
	20.92	7120	140.6	2120	2240
	21.32	7160	157.9	2130	2110
	21.72	7200	168.4	2130	2180
	22.13	7240	143.6	1440	2370
	22.63	7120	12	990	1570
	23.03	7080	14.3	990	1190
	23.44	7000	12	990	1110
	23.84	6920	12	990	1060
	24.26	6800	12.8	990	1040
	24.75	6560	12.8	990	1030
	25.15	6440	12	990	1030

I've been unable to fit my boost guage today as I can't get the wiper arm off to give me access to the hole to feed the pipe through uder the plastic panel under the windscreen

 

[elviscat]

Hi m8, I had what sounds to be exactly the same problems your having, turned out to be my actuator!!

Make sure it is set right, or not gone altogether.

 

[Markypoo]

With a faulty actuator did this throw up anything unusual in Vagcom logs?

 

[wild willy]

Yep, as expected from 2280 - 4360 rpm your boosting too high, this will give you the perception of surging and not good for your rods either. Simple fix.... get the mbc fitted to cap the boost to 1.45 bar max and the car will be run better than ever. The free flowing tip is allowing the car to boost better but needs a little triming back as above. Your stage one map is killing top end performance though as its only requesting 1-1.1bar latter in the rev range when the car is capable of running more. REVO stage 2 is highly recommended here if going for a generic map as it can request up to 1.3 bar at the red line which most stage 2 maps don't.

 

[JamJay]

Thanks Willy, the question still remains though, why is it doing this? I'm thinking that it's the map now TBH and the mods that I've stuck on since it was mapped (TB exhaust, Jetex, 3" TIP) have just exceeded the capabilities of the generic Stage 1 AMD.

How does my N75 look from those logs, can you tell?

So what do you reckon, stay off WOT at low revs, fit a FMIC and take it down to AMD for a Stage 2? There are a few members on here with the same mods at me on Stage 2 with none of my issues and no MBC. Tom, if you happen to read this, would you mind logging block 115 on your VCDS for me so I can compare?

I can feel the car choking at higher revs, feels slow now but if the boost is low then would be expected.

 

[wild willy]

The more efficiently you modify your car the more efficiently boost is going to be generated and during peak spool your going to overshoot boost a little. I would say Jay that mechanically you have no problem with your car other than it is struggling to deal with the overboost. The surging could be the result of the stock intercooler struggling with flow maybe. If you want i can send you out a mbc to try in the post, the mbc will cure your problem i'm sure.

 

[JamJay]

Thanks Willy, a great help. I'd love to try an MBC but I have NO idea how to plumb it in to work with the N75

 

[elviscat]

Have u or anyone adjusted the actuator? In my humble opinon, make sure this is setup right. If this is done up to much or is unable to operate this will give you your problem!!