Flexiblemouse
Registered User
As I was so badly ridiculed in the remap thread I was just going to log out and never come back to this forum, but I have had PM's asking me how I managed to get stage 1 power for only £20. So I decided that I would come back and explain in detail the process I followed to get from 200hp to 245hp on the stock tune.
First a disclaimer: I am not a mechanic or engineer, I am not affiliated with any tuning companies, nor do I have anything against companies who provide remaps. I did these modifications to my own car, at my own risk, and spent hours researching first. I do not recommend that you do this to your own car, that is something you must decide on yourself, I do not care if you blow up your car attempting this, however if you do decide to do it feel free to message me if you need any advice. Also, and I cannot stress this enough, IF YOU HAVE NOTHING CONSTRUCTIVE TO ADD TO THIS THREAD, DO NOT POST. I don't want to hear about limp mode, how my turbo will blow, how my pistons will melt etc etc because it is a load of crap. Also, this modification was done to a stock 2006 A3 8P with the 2.0T FSI (BWA) engine on a K03 turbocharger, if you have a different spec then your results may differ.
I used a manual boost controller (bleed valve) to control the boost instead of the factory N75 valve. If you would like to read up on boost controllers, go to Boost controller - Wikipedia, the free encyclopedia. If you would like to see how they areHTML.ted and used, visit How To Install A Bleed Valve - YouTube, or Turbo Supporting Mods - YouTube. If you would like one, it seems that one of the best available is available from Go Fast Bits at http://www.gfb.com.au/products/boost-controllers/atomic-single-stage-boost-controller-by-gfb. My budget had already been spent on an upgraded diverter valve (also available from Go Fast Bits) so I bought a budget valve from eBay for £20.
When I was researching modifications, I went to the websites of various remap providers and found that stage 1 made 240-245hp depending on the company. Unfortunately the companies do not usually tell you what they did to get that power, until I came across Unitronic. They had dyno graphs of each stage, and even a small explanation of what constitutes each stage. As you can see at Audi A3 2.0 TFSI stage 1, the information for stage 1 reads "Performance Software Precisely Engineered to Run 17psi of Boost on a Completely Stock Car." If you open the dyno plot for stage 1 you will see that with stock software the torque peaks at 2500rpm. This is because the turbo has spooled up to 8.7psi and the N75 will hold that value until 4500rpm when the turbo can no longer supply enough air to maintain that boost. If you compare the old torque curve with the stage 1 curve, you will see that torque peaks later, at 2800rpm, this is because it takes longer for the turbo to spool to 17psi than 8.7psi. You can also see that the torque stays high until 4500rpm, when again the turbo cannot maintain pressure. Unfortunately with a bleed type valve your torque will drop sooner in comparison due to the wastegate cracking slightly open as boost builds, (to fix this you could fit an electronic boost controller which is expensive, or a ball and spring boost controller from eBay for about £20). If you now look at the stage 1+ dyno graph (254hp @ 19psi) you can see the torque line is now very different to the stock line, this shows that they did not simply add more boost to get there, but that is a more aggressive tune as well. As the stage 1 and OEM lines were very similar you can see that apart from running much higher boost, the tune is not much different from stock.
So 245hp @ 17psi seemed like about as far as I could take my power on the factory tune. I fitted my valve and increased the boost from wastegate pressure to 17psi over a period of 2 weeks. Each time I peaked at a new level I ran a log of a 3rd gear 30mph-redline WOT run, monitoring rpm, load, boost, AFR, timing and MAF values. I would check the log immediately to see if it ran lean at any point, or if the turbo surged at all, as well as to see how much power was produced at the crank. The peak from the MAF can be (appapproximately) converted to crank horsepower by diving it by 0.8 or multiplying it by 1.25. My log at 8.7psi (stock boost) showed a peak of 162g/s which is around 200hp, so far so good. I logged 217hp @ 12.5psi, and 236hp @ 15psi. I stopped there because I noticed I was getting diminishing returns, each new psi gave less power than the one before. This is because the turbo is blowing hotter air (as it is out of its efficient range) and because of the restrictive downpipe (which is why it is changed at stage 2). I needed to find a compressor map for the K03 to see how far I could take things without blowing something up. I finally found a map, and some research done by another enthusiast on the K03 at K03 Compressor Map - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com. I used the blank map and added plots for 10-20psi, which can be found at http://www.audi-sport.net/vb/a3-s3-sportback-8p-chassis/210918-k03-compressor-map-2-0t.HTML. As you can see, the K03 is too small to hold a lot of boost to high rpm which is why the S3 uses a K04. At 17psi and 3000rpm the turbo is getting near to the choke line and will not hold at 17 for long, indeed at 19psi you will be lucky to hold it til 3500rpm. With my car set to 17psi @ 3000rpm in 3rd gear, it spikes to 19psi momentarily in 1st and 2nd gear but that is still below the turbo's maximum wheel speed. All logs checked out OK, the injectors are perfectly happy supplying the extra fuel and did not hit limp mode at all. The forum will not upload my log (something about the format) but here is a screenshot.
As you can see, my peak was 195.83g/s which works out to about 244.8 HP, ignore the 40-60 as I had 2 passengers and a full tank. There you have it folks, and if you are just about to post and flame me, don't bother!.
First a disclaimer: I am not a mechanic or engineer, I am not affiliated with any tuning companies, nor do I have anything against companies who provide remaps. I did these modifications to my own car, at my own risk, and spent hours researching first. I do not recommend that you do this to your own car, that is something you must decide on yourself, I do not care if you blow up your car attempting this, however if you do decide to do it feel free to message me if you need any advice. Also, and I cannot stress this enough, IF YOU HAVE NOTHING CONSTRUCTIVE TO ADD TO THIS THREAD, DO NOT POST. I don't want to hear about limp mode, how my turbo will blow, how my pistons will melt etc etc because it is a load of crap. Also, this modification was done to a stock 2006 A3 8P with the 2.0T FSI (BWA) engine on a K03 turbocharger, if you have a different spec then your results may differ.
I used a manual boost controller (bleed valve) to control the boost instead of the factory N75 valve. If you would like to read up on boost controllers, go to Boost controller - Wikipedia, the free encyclopedia. If you would like to see how they areHTML.ted and used, visit How To Install A Bleed Valve - YouTube, or Turbo Supporting Mods - YouTube. If you would like one, it seems that one of the best available is available from Go Fast Bits at http://www.gfb.com.au/products/boost-controllers/atomic-single-stage-boost-controller-by-gfb. My budget had already been spent on an upgraded diverter valve (also available from Go Fast Bits) so I bought a budget valve from eBay for £20.
When I was researching modifications, I went to the websites of various remap providers and found that stage 1 made 240-245hp depending on the company. Unfortunately the companies do not usually tell you what they did to get that power, until I came across Unitronic. They had dyno graphs of each stage, and even a small explanation of what constitutes each stage. As you can see at Audi A3 2.0 TFSI stage 1, the information for stage 1 reads "Performance Software Precisely Engineered to Run 17psi of Boost on a Completely Stock Car." If you open the dyno plot for stage 1 you will see that with stock software the torque peaks at 2500rpm. This is because the turbo has spooled up to 8.7psi and the N75 will hold that value until 4500rpm when the turbo can no longer supply enough air to maintain that boost. If you compare the old torque curve with the stage 1 curve, you will see that torque peaks later, at 2800rpm, this is because it takes longer for the turbo to spool to 17psi than 8.7psi. You can also see that the torque stays high until 4500rpm, when again the turbo cannot maintain pressure. Unfortunately with a bleed type valve your torque will drop sooner in comparison due to the wastegate cracking slightly open as boost builds, (to fix this you could fit an electronic boost controller which is expensive, or a ball and spring boost controller from eBay for about £20). If you now look at the stage 1+ dyno graph (254hp @ 19psi) you can see the torque line is now very different to the stock line, this shows that they did not simply add more boost to get there, but that is a more aggressive tune as well. As the stage 1 and OEM lines were very similar you can see that apart from running much higher boost, the tune is not much different from stock.
So 245hp @ 17psi seemed like about as far as I could take my power on the factory tune. I fitted my valve and increased the boost from wastegate pressure to 17psi over a period of 2 weeks. Each time I peaked at a new level I ran a log of a 3rd gear 30mph-redline WOT run, monitoring rpm, load, boost, AFR, timing and MAF values. I would check the log immediately to see if it ran lean at any point, or if the turbo surged at all, as well as to see how much power was produced at the crank. The peak from the MAF can be (appapproximately) converted to crank horsepower by diving it by 0.8 or multiplying it by 1.25. My log at 8.7psi (stock boost) showed a peak of 162g/s which is around 200hp, so far so good. I logged 217hp @ 12.5psi, and 236hp @ 15psi. I stopped there because I noticed I was getting diminishing returns, each new psi gave less power than the one before. This is because the turbo is blowing hotter air (as it is out of its efficient range) and because of the restrictive downpipe (which is why it is changed at stage 2). I needed to find a compressor map for the K03 to see how far I could take things without blowing something up. I finally found a map, and some research done by another enthusiast on the K03 at K03 Compressor Map - VW GTI Forum / VW Rabbit Forum / VW R32 Forum / VW Golf Forum - Golfmkv.com. I used the blank map and added plots for 10-20psi, which can be found at http://www.audi-sport.net/vb/a3-s3-sportback-8p-chassis/210918-k03-compressor-map-2-0t.HTML. As you can see, the K03 is too small to hold a lot of boost to high rpm which is why the S3 uses a K04. At 17psi and 3000rpm the turbo is getting near to the choke line and will not hold at 17 for long, indeed at 19psi you will be lucky to hold it til 3500rpm. With my car set to 17psi @ 3000rpm in 3rd gear, it spikes to 19psi momentarily in 1st and 2nd gear but that is still below the turbo's maximum wheel speed. All logs checked out OK, the injectors are perfectly happy supplying the extra fuel and did not hit limp mode at all. The forum will not upload my log (something about the format) but here is a screenshot.
As you can see, my peak was 195.83g/s which works out to about 244.8 HP, ignore the 40-60 as I had 2 passengers and a full tank. There you have it folks, and if you are just about to post and flame me, don't bother!.
