but for a guy who uses his car on track with full range of chassis mods and uses the gears properly the limit could surely be raised. I for one would rather take the extra torque and instead invest in an uprated clutch and gain more mid range. to be honest id not want more than 320ibft, that would be the limit of usability IMO, even on a 'setup' car

Yes, but I dont think thats something that suits everyone. I, for one, like the smooth power delivery more than max peak torque figure. And the track cars I've been involved with, in most cases, easier to drive = faster on the track. Most of us are too ham-fisted to handle the cars that have most potential...

Might be cool to do a race spec version for cars with crazy owners and/or uprated clutches. Left foot braking allowed, "unlimited" torque but perhaps some torque limitation active on 1 and 2 gears (because otherwise the extra torque would just go up in the air in smoke in low gears...).

...All the stuff we could do with our STS units. One map for the road, one for the track.

I actually kinda like that idea.

Edited 15 November, 201015 yr by shark_tech

Yes, but I dont think thats something that suits everyone. I, for one, like the smooth power delivery more than max peak torque figure. And the track cars I've been involved with, in most cases, easier to drive = faster on the track. Most of us are too ham-fisted to handle the cars that have most potential...

Might be cool to do a race spec version for cars with crazy owners and/or uprated clutches. Left foot braking allowed, "unlimited" torque but perhaps some torque limitation active on 1 and 2 gears (because otherwise the extra torque would just go up in the air in smoke in low gears...).

...All the stuff we could do with our STS units. One map for the road, one for the track.

I actually kinda like that idea.

so do i. torque limitation in 1st and 2nd would be perfect as well. then the full beans in 3rd+. not exactly new territory. the likes of mazda and ford have been doing that in the MPS and RS for a while

so do i. torque limitation in 1st and 2nd would be perfect as well. then the full beans in 3rd+. not exactly new territory. the likes of mazda and ford have been doing that in the MPS and RS for a while

We can do torque limitation with any gear on these ECU's if requested, not a problem.

Fascinating reading all of this.

Fascinating reading all of this.

+ 1

Agreed - straight from the horses mouth, thanks Ben and Mikko.

last time i checked timmy

you had a TFSI complete with sachs clutch, and an STS just waiting for some race map amendments

"Just say when"...

last time i checked timmy

you had a TFSI complete with sachs clutch, and an STS just waiting for some race map amendments

"Just say when"...

Stop it now.....

I really need torque limitation on mine. Would help immensely. I'm running REVO code though.

Edited 15 November, 201015 yr by Harry_vRS

Well i said earlier i was completely ignorant about all this stuff, thanks to you gents i now understand a little more about what mapping does "apart from make it faster" and a little bit of the hows n why's. Cheers Fella's very interseting keep it UP

I've been enjoying this thread too!

Interesting to see that the AFR may be a sympton rather than a cause. I should say that fuel trim figures on Block 032 of VCDS seem a bit worse than with Stage 2 where they were both near zero (now -1.9% and 5.1% so still nothing drastic).

I think I will run the car down to JKM to get some diagnostics done and swap out the various sensors as we go in a data-driven way; I don't really want to go down the same route as VRSCarl and swap one thing after another only to be not much further forward. I would probably leave out the N75 for the moment as it's a beehatch to get to.

What I may do before that is get the VCDS cable out and log a few things to include engine load and actual rail pressure again (in case it could show if the fuel pump was 'cavitating' as Ben says). I also have an old MAF sensor kindly donated by Simon. If I see something, I may use the STS unit to take the car back to the old, original Pendle Performance Stage 1 although the demands of that may no show the 'load problem' that a Shark Stage 3 would. It may be futile but worth a shot before spending more money at JKM :p

Here is a graph of Actual/Specied load and N75 taken from one run using the data JKM got with the intial Stage 3 version, if it is of interest / help:

Edited 16 November, 201015 yr by muckipup

would cavitation not result in loads of pits on the HPFP piston itself, which would be an easy fault to find, or am i thinking of a diifferent type of cavitation?

get some logs done dave and post them up :thumbup:

would cavitation not result in loads of pits on the HPFP piston itself, which would be an easy fault to find, or am i thinking of a diifferent type of cavitation?

get some logs done dave and post them up :thumbup:

Had to look up what cavitation was myself but found this definition:

Cavitation is a condition when a liquid, in this case fuel, vaporizes at the pump entry and forms voids or cavities of air. As the bubbles collapse they release energy and force pressure against the pump rotors.

Cavitation is generally is due to fuel temperatures getting too hot or too low pressure feeding the pump - both condition affecting the vaporization point of a liquid.

Anyone used an uprated/aftermarket inline pump?

Happy to post up new logs but I think the RR graph from last Saturday looked much the same as previous ones despite increased power and torque being found suggesting that this problem has been there for a while. In that respect, I have got logs of just about everything from the time I had Keith @ JKM do it.

If there is anything in particular that I should be focussing on, I can post up logs of that and then go out with the VCDS and see if it is the same.

So far, I have been thinking about:

• MAF sensor (which always seemed to read low but cause or effect?)
  
• In-tank fuel pump or HPFP (as noticed a very occasional 'fuel rail pressure low' as a pending DTC when going in to clear another unrelated code)
  
• MAP sensor (coz it gets mentioned now and again and "boost control" was mentioned as a possible issue by JKM
  
• Remap (seems much less likely given Tim's car)
  
• ITG intake (doubt it but it is a difference with Tim's set-up)
  
• Sensor on HPFP
  
• N75
  

Edited 16 November, 201015 yr by muckipup

Is it possible to log the in-tank pump? Maybe log that against requested/actual rail pressure and go from there.

Muckipup

I changed my N75 recently and it took under an hour on the drive using a jack. That time includes a cup of coffee too The valve costs less than £20 and you have to remove the boost hose from the turbo for easy access. Once thats done it is a simple task of undoing the vw clips for the vac pipes and two screws that attach the valve to the engine.

Matt

Edited 16 November, 201015 yr by 56OctyVRS

Is it possible to log the in-tank pump? Maybe log that against requested/actual rail pressure and go from there.

I'll look into that Ian. There will be nothing monitoring the pump itself as its a contant thing but I forget if there is a pressure sensor on the low-pressure side.

Muckipup

I changed my N75 recently and it took under an hour on the drive using a jack. That time includes a cup of coffee too The valve costs less than £20 and you have to remove the boost hose from the turbo for easy access. Once thats done it is a simple task of undoing the vw clips for the vac pipes and two screws that attach the valve to the engine.

Matt

Cheers Matt, that doesn't sound to bad at all. My N75 duty cycle seems to log ok and I was going to leave it to last but that was bwecause I thought it would be about the same price as a MAF. What were your symptoms of a failing N75?

My N75 duty cycle seems to log ok and I was going to leave it to last but that was bwecause I thought it would be about the same price as a MAF. What were your symptoms of a failing N75?

Unfortunately its impossible to see a failing N75 from logs.

The duty cycle is the control duty cycle from ECU, not the actual valve duty cycle. There's no feedback loop on the actual duty. When N75 starts to fail, it begins to respond a bit slower, sometimes causing such problems as we're seeing here.

Unfortunately its impossible to see a failing N75 from logs.

The duty cycle is the control duty cycle from ECU, not the actual valve duty cycle. There's no feedback loop on the actual duty. When N75 starts to fail, it begins to respond a bit slower, sometimes causing such problems as we're seeing here.

Ahh, thanks Mikko. I will move the N75 up the 'to do' list as I investigate what's going on.

Can you offer any advice as to what the best way to investigate what you are calling 'load control'?

My car kept getting a P0299 fault code where it was under boosting for a split second and them making the required boost. I changed all the "normal" things like diverter valve, PCV etc and none made a difference. I changed the N75 to the lastest revision and no more fault code.

Ahh, thanks Mikko. I will move the N75 up the 'to do' list as I investigate what's going on.

Since its just about impossible to test the N75, and failing valve is very common on these cars and often causes such behavior as we're seeing in your dyno runs, I would change that before doing anything else.

Since its just about impossible to test the N75, and failing valve is very common on these cars and often causes such behavior as we're seeing in your dyno runs, I would change that before doing anything else.

Thanks Mikko!

56OctyVRS - do you remember the part number for the Octavia 2 N75? I can see the one for the Mk1 cars only

well N75 sounds like a plan then. i presumed it would be really awkward being by the turbo. good news.

Dave if you post up the last set of logs, then once you get a new set of logs after map updates we can see the differences.

in hindsight, it would have been handy to have ran your car with timmys MAF sensor on the recent jkm RR day. that way you could compare top the RR day on the 5th that we went to.

Which is exactly where you don't want it. That's what will kill clutches and cause massive IAT hikes which will actually lose power. OK for one dyno run, not so great on the road.

Just to add a little backup to this, one of the guys on the recent RS Tuning RR day had a scirrocco 2.0 TSI with a map that had a very violent torque spike at 3.5K RPM from 300 to 325 lbs/ft then back down again within 200rpm band, he was complaining that the map, had wrecked his clutch and that it was slipping at motorway speeds in 6th, before he found the spike he had stated the problem at this point in the rev range and the RR confirmed it, had it not had the 25Lbs/ft spike it would have most likely been okay, it had only covered about 20K miles. tpo quote pirelli ' power is nothing without control' and with engine mapping this rule should be firmly applied as Ben has stated.

BTW this was NOT a shark Map but a well know american company who now has very limited UK representation!

Edited 16 November, 201015 yr by The Skud

.

BTW this was NOT a shark Map but a well know american company who now has very limited UK representation!