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Mk5 General Area / Re: K04 Conversion - Do you ever regret it? How is it for daily driving?
« Last post by ZoliWorks on Yesterday at 05:37:17 pm »Many options there, your final biggest option is probably worth more than my whole car
Up to you what path you go down, but as the HP increase the money required to get more HP exponentially increases, if you get what I mean.
If you're talking about upgrading pistons, keep in mind how much time and money that that full engine rebuild will cost too. Factory pistons are fine up to 350hp according to others on this forum.
If I do go down the route of forged piston rods, I might as well get the pistons themselves. My other mechanic pal who I collaborate with recommended that I replace my pistons if I do take the engine apart. A set of forged pistons should only set me back somewhere between 800 and 1k while I've seen rods as low as 700. But this is very far away tbh. I just want to get the car back up and running, putting down that 300-310hp.
And yeah, the more HP I want, the more I need to invest, which is why I think the K04 basic might be a good middleground. I'll get better middle and top end, more HP but will lose low down responsiveness all for under 1.2k, the price of an OEM K03. Anything more than this will turn this car into a money pit. I'd be fine with injectors and the fuel pump if I can safely push the engine to 350hp that way but I've heard a lot of mixed opinions. Some say stock rods should not be pushed beyond 330hp but I think it's the torque we need to limit. 500nm might be too much on stock rods. Maybe they can take 450?
On another note, I wonder if the S3, ED30 or other k04 engine's pistons and rods fit a BWA cause I can get a complete ED30 engine from the UK for under 1k
You don't necessarily need the S3 intercooler upgrade, but performance will suffer if you're doing more than just 1 pull from traffic lights, due to heat soak. Essentially as the heat from the extra fuel being burnt can't dissipate fast enough, the car automatically reduces power to contain the heat. E.g. the first dyno run will get you a high number, but the second much lower. Or on a race track the car will lose performance after a few turns. I wonder what @breeze thinks about this. He also has a good point about torque, you may have to start revving higher when driving after upgrading. But that's down to personal preference whether you prefer balanced torque through the whole rev range or more high end torque and less low end.
Summers we get upwards of 35c here so I'll deffo make good use of the intercooler. My general driving style keeps the engine above 2.5k at all times so I should be good. Spoke to my tuner who says he drove in both k03 and k04 tuned cars and that there isn't that much difference down low. I'd want a turbo that is balanced throughout the power range but I think that's what the K04 is. If I want instant response, I might as well get a diesel
Downpipe costs money, but it's a good HP value upgrade after the turbo. It normally gets 15hp extra on stock cars (on high octane maps), it got me 10 extra hp on 95 octane. Not to mention my 200 cel cat really improved the exhaust note of mine even with the rest of the exhaust being stock, it sounds like a fancier raspy race car engine rather than the boring 4 cylinder that it is . Mine is from MPDevelopments UK, €600. It does cause a check engine light which has to be coded out by your tuner though. Haven't put it through an emissions test yet, but I've kept the original downpipe just in case.
I've read that 200 cell cats wont trigger a check engine light but that's the least of my worries, we'll code it out. Passing emissions is the important part to me! I'm hoping for the same result; Improved sound, something more sporty, not your generic 4 cylinder family car but not as loud and as much drone as a full sports exhaust. Plus at 1/4th of the cost.