All Things Mk5 > Mk5 General Area
K04 Conversion - Looking for opinions & posting my progress/info about the swap
ZoliWorks:
For the past month I've been split between either getting a new K03 or doing a K04 conversion (injectors, intake, sports cat downpipe) so i'd like y'all's opinion.
Long story short, my stage1 K03 is dying because it's constantly underboosting by 0.3-0.4bars. It peaks at 1.4 bars then drops down to 1.1 almost instantly. My mechanic (and tuner) thinks that it's 90% the turbo failing because almost every K03 he's worked with was either cracked internally or had a failing wastegate. We've smoke tested the engine and there are no leaks. DV is new.
Right now the car is stage 1 and it's supposed to push 270-275bhp but realistically speaking I don't think the turbo in it's current state can push more than 230-240.
Mods are as follows:
- R8 coils
- NGK BKR7EIX plugs
- Sachs X-tend OEM replacement clutch and DMF supposed to hold 430nm of torque
Compared to stock, the car is super responsive and allows me to snap around in traffic. When merging, I can floor it and it'll get up to speed fast and kick me back into the chair, which I love. Basically you see a gap, you take a gap. What the car lacks is power in the upper powerband or when trying to overtake on open roads past 100kph. It still pulls better than my stage 3 1.4 Jetta but I feel like I'm starting to want more.
Now as for the K04, would I be sacrificing this snappy responsiveness between 2k and 4k rpm for top end power? or would I retain the same low-down kick that the K03 can deliver to zip around town?
For the K04 conversion I'd go with upgraded injectors, rail pressure valve, sensor and map sensor along with a 200cell cat and an intake. I'm not very keen on a full sports exhaust because I quite enjoy how quiet the car is and would like to keep it that way. I think I've had enough of sports exhaust by driving the 1.4 for 4 years.
All thoughts and opinions regarding the K04 swap are welcome
Below are some graphs of my boost issue with wastegate duty cycle at 95%. Red is requested, green is actual boost.
OllieVRS:
I'm no expert on turbos but wanted to mention a couple things to keep in mind with HP expectations:
- R8 coils do not add more power
- NGK BKR7EIX do not help add more power (at your tuning level):
--- Quote from: ROH ECHT on June 18, 2022, 02:46:21 am ---NGK BKR7EIX are a 5k Ohm restricted plug. You really should consider going back to the 1k Ohm plug (NGK 1675 PFR7S8EG) w/gaps at 0.8 mm, and allow more voltage to pass through the plug when stock as yours is. At stock there's no need to restrict the power for the arc it can generate. Because your combustion situation is not likely to disturb its arc.
--- End quote ---
Not exactly sure how to read your graph, but if this helps, here's my boost (act.) VCDS log from stage 2, intake and 200cel:
EDIT: Also, you're getting mapped and dynoing while running 99 octane, right?
ZoliWorks:
--- Quote from: OllieVRS on March 24, 2024, 04:16:50 pm ---I'm no expert on turbos but wanted to mention a couple things to keep in mind with HP expectations:
- R8 coils do not add more power
- NGK BKR7EIX do not help add more power (at your tuning level):
--- Quote from: ROH ECHT on June 18, 2022, 02:46:21 am ---NGK BKR7EIX are a 5k Ohm restricted plug. You really should consider going back to the 1k Ohm plug (NGK 1675 PFR7S8EG) w/gaps at 0.8 mm, and allow more voltage to pass through the plug when stock as yours is. At stock there's no need to restrict the power for the arc it can generate. Because your combustion situation is not likely to disturb its arc.
--- End quote ---
Not exactly sure how to read your graph, but if this helps, here's my boost (act.) VCDS log from stage 2, intake and 200cel:
EDIT: Also, you're getting mapped and dynoing while running 99 octane, right?
--- End quote ---
I'm running on 100 octane but the map was made for 95 octane. Tuner said making it on 100 it would only add a bit more power but wouldn't behave well if I used anything lower (because i might now always have the chance to tank up on 100 or 99) so he pretty much only makes maps for 95. Also said that running 100 on his 95 map is fine.
As far as dyno goes, the car wasn't dyno-d. Guy took the stock map from the car, modified it then we went for a drive. I've been working with him for a while and he's done so many GTI's he could write a map from scratch.
Plugs and coils, the old ones were dying so I had to replace and these were the cheapest ones. On my 1.4 I've had constant misfires till I switched to this plug and coil combo so I figured it wouldn't hurt here either.
And the graph I sent, that's basically me flooring it in 3rd and then switching to 4th on the highway. Here's an excel log if that helps with anything. 3rd to 4th pull down at the bottom.
https://ubbcluj-my.sharepoint.com/:x:/g/personal/arpad_borbely_stud_ubbcluj_ro/EaMelNr8foZAu2jEjQj2aEUB0sWKGzvO_6McYF4RsmSlxQ?e=chQjX3
This log has less info but has timing
https://ubbcluj-my.sharepoint.com/:x:/g/personal/arpad_borbely_stud_ubbcluj_ro/ESgektv-s7hGrGPq-LW1OMQBbWmIgWbhIMS5MwsuXukIww?e=NpxG7f
OllieVRS:
Your boost does seem to be slightly too low from the requested boost, by a few hundred mbar. So there is definitely an issue with boost somewhere. Mine is at most -150mbar from requested when accelerating fully, usually +-50mbar.
Also remember that it's most useful to subtract ambient atmospheric pressure when talking about boost numbers, 1000mbar, e.g. my peak boost boost is 16 psi/1.1bar in my graph.
As for octane, I think mapping on that is equally at fault for the disappointing performance.
In Ireland we only have 95 octane, so if you want more octane here you have to use octane booster. So nearly everybody maps on 95 octane. Back when my car only had a cold air intake it was measured 184hp stock, then 225hp stage 1 (on dyno). When using measuring engine torque in KW via VCDS later, I estimated adding expensive octane booster to make the octane 99 only raised HP by 8-10hp on my 95 map. But the car felt a lot more responsive, and the timing was less retarded so the engine sounded more aggressive. Adding the 200 cel sports cat and another mapping raised the 95 octane power to 235hp, so max 245hp with octane booster.
Online tuners give their numbers for mapping on 98/99 octane, so if you see 'Stage 1 250hp or Stage 2 275hp' they are talking about the car running on a 98/99 map, that can't run 95. Nobody ever gives numbers for 95 octane mapping unfortunately. So if you're making ~230-240hp on a 95 map (on 99 fuel) that's probably realistic numbers.
If I had easy access to 99 octane, I would map for only 99 octane. And I would expect my stage 2 to be ~275hp. '270-275bhp' is a fantasy for stage 1 with no engine mods, your tuner may be overestimating to make his map sound better than other tuners.
Only way to know how much power it's actually making is to go to a real dyno. If that's not an option, you can log Mass Air Flow g/s (act.) and Engine Torque Nm (act.) in VCDS next time you do your log, that can *estimate* hp, but it can be inaccurate.
ZoliWorks:
--- Quote from: OllieVRS on March 25, 2024, 12:05:13 pm ---Your boost does seem to be slightly too low from the requested boost, by a few hundred mbar. So there is definitely an issue with boost somewhere. Mine is at most -150mbar from requested when accelerating fully, usually +-50mbar.
Also remember that it's most useful to subtract ambient atmospheric pressure when talking about boost numbers, 1000mbar, e.g. my peak boost boost is 16 psi/1.1bar in my graph.
As for octane, I think mapping on that is equally at fault for the disappointing performance.
In Ireland we only have 95 octane, so if you want more octane here you have to use octane booster. So nearly everybody maps on 95 octane. Back when my car only had a cold air intake it was measured 184hp stock, then 225hp stage 1 (on dyno). When using measuring engine torque in KW via VCDS later, I estimated adding expensive octane booster to make the octane 99 only raised HP by 8-10hp on my 95 map. But the car felt a lot more responsive, and the timing was less retarded so the engine sounded more aggressive. Adding the 200 cel sports cat and another mapping raised the 95 octane power to 235hp, so max 245hp with octane booster.
Online tuners give their numbers for mapping on 98/99 octane, so if you see 'Stage 1 250hp or Stage 2 275hp' they are talking about the car running on a 98/99 map, that can't run 95. Nobody ever gives numbers for 95 octane mapping unfortunately. So if you're making ~230-240hp on a 95 map (on 99 fuel) that's probably realistic numbers.
If I had easy access to 99 octane, I would map for only 99 octane. And I would expect my stage 2 to be ~275hp. '270-275bhp' is a fantasy for stage 1 with no engine mods, your tuner may be overestimating to make his map sound better than other tuners.
Only way to know how much power it's actually making is to go to a real dyno. If that's not an option, you can log Mass Air Flow g/s (act.) and Engine Torque Nm (act.) in VCDS next time you do your log, that can *estimate* hp, but it can be inaccurate.
--- End quote ---
The car definitely feels mapped and it's a big improvement over stock but it doesn't quite run how it should. Tuners here claim 260hp for a stage 1 map, on 100 octane presumably.
The problem is that I can feel it boost then it dies off quite fast so it's definitely meeting the expected boost early on but it cant maintain it. I suspect the wastegate or the N75.
The tuner is a friend of mine so he was my first choice. This being the first car he mapped for me, I cant say if the map is good or not. I haven't dyno-d my car because this buddy is mainly a mechanic/car electrician and donesnt have a dyno and it would have cost 180 euros at a different tuner. A stage 1 map would have cost me between 500 and 600 euros so I was quite happy when he offered to do it for me for 200. (He normally makes maps for 350). He did offer to put a different map on the car just to try but said it's unlikely to change anything since he thinks it's a turbo issue.
I went for a run and measured G's and torque; The first one is a 3rd through 4th gear pull, the second is a 2nd through 4th gear pull (60-180)
Navigation
[0] Message Index
[#] Next page
Go to full version