MK5 Golf GTI
All Things Mk5 => How to Guides / Troubleshooting => Topic started by: razor1199 on September 10, 2019, 05:58:24 pm
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Hello,
I have a little problem with my car, it's after Stage 1 map.
It had great stock result, it could even loose traction on 3rd gear on dry surface, it has lasted for couple days, after I felt something has gone.
Stock file: great result 204,5 HP, 297Nm
(https://i.imgur.com/YB7c7qfl.jpg)
After Stage 1:
(https://i.imgur.com/yvz04U9l.jpg)
After something "broke":
(https://i.imgur.com/oy7GZ5zl.jpg)
I lost 10HP and 50Nm.
Things I have replaced:
- DV
- Spark plugs
- MAF
- Cam follower
Nothing changed :(.
I've done some VCDS logs. 4th gear WOT starts from 17.03 time stamp of column B
https://drive.google.com/file/d/1smgs5WDgQuOACW_2IW22jZIDfoCcVi5d/view
2nd measure: (more specific about air)
https://drive.google.com/file/d/1IyHPCPwMFg2N4ejjaDhzB-KtpzCzAP84/view
I did also log fuel pressure, trust me, what is requested from ECU that is provided by HFPF (so I don't think it can cause any problem)
Any suggestions?
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I am no master at reading logs, some things make sense, others not so much! I'ts not knowing what some of the values "should" read to know if they are out or not.
So my following could be way out and the figures might be perfectly normal. But.. in your second log at full throttle you're getting max duty cycle from the N75 valve and on the next run your getting mid figures from N75, which at full throttle is should be back up at 94 ish i think it is. Either something is retarding and pulling it back or you have a dodgy N75 valve?
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The difference in temperature, pressure and any heatsoak will easily account for a loss of 10HP
The loss of Torque is because you're hitting peak Torque higher up the rev ranger, which can be explained by a number of things - less load/quicker run, or more likely and visually evident - starting the run higher up the rev range, so it will take longer to load up the car and build up the boost. There's also a difference in the measured/estimated mechanical loss which will account for a change of peak HP numbers
Loosing traction in a straightline, in the dry and in 3rd gear at your power and torque level? says to me you either have other issues or sh*t tyres. I have more power & torque than you and get next to no spin in second gear
I'll take a look at the logs but to be honest I think you are chasing a ghost and the car is fine
*Edit* Checked the logs - from what you've logged the car looks 100% happy and healthy for a safe Stage 1. Go and enjoy it
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Peak MAF figure in your second log puts it at 237hp, which is only 6 less than your 3rd dyno run before corrections, so I agree with Dan, I don't think there is much to worry about here. It's only about 5% less. It's an analog/organic device, not a computer. You will never get exactly the same result when dynoed on different days with different temps and ambient pressures.....and let's not even go there with different dynos :grin:
I don't like that big dip at 6000 on your second run. Did the dyno operator explain what that was? Unlikely to be wheelspin at that speed. Is it a DSG?
Another thing to consider is the engine ECU will always adapt down. After a fresh map is uploaded, the first couple of runs always give the highest hp figures. Over time it adapts down, so 5 - 10% less after a few months isn't uncommon.
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Adapts down.
Do things ever adapt up? My car had a new lease of life months after it was mapped. The well respected place made a huge issue about different types of fuel and mentioned timing pull (new one on me but always happy to learn) a number of times.
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It will never adapt over and above the initial map upload and initial run. Fuel quality is critical on these for achieving numbers and keep timing pull to an absolute minimum
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Adapts down.
Do things ever adapt up? My car had a new lease of life months after it was mapped. The well respected place made a huge issue about different types of fuel and mentioned timing pull (new one on me but always happy to learn) a number of times.
Nope. The engine is tuned for MBT (Mean Best Torque) at the factory which is then set as the base map. It can't advance over that for obvious reasons. The ECU will always try to protect the engine from over advancing and over fuelling. I often read of some tuners adding more advance to the base map, but I do wonder how much of that is then pulled out again by the ECU. It's not wise to exceed the timing VW set at the factory.
Anyway, I also experience inconsistencies with mine and I do wonder if it's fuel quality related. I religiously use V Power but as it's the most expensive fuel at the pumps, I do wonder if it 'goes off' due to so few people buying it?