It’s been a while but I thought I would update the thread with the latest developments.
The 3R break in went well and the clutch functions as advertised. Still can’t believe how easy the car is to drive with that.
So apologies in advance for the looooooong update and possibly a lot of irrelevant information to some!
The persons that followed my build also know that I added a Killer Chiller as well as a vFiz system with a few sensors to monitor temps etc. Another feature of the vFiz was the ability to hook up and monitor boost on the DIS. Took me awhile to get that all hooked up and even longer to record and analyze exactly what boost the car was making at different rpm’s but eventually got around to it.
The Stage 1+ kit is advertised as making between 7/8-9Psi if I am not mistaken. And that is spot on if you live at sea level. For the educated it’s also general knowledge that a blower is belt driven and therefore fixed in relation to the crank pulley so unlike a turbo car altitude will have an impact on peak boost. All things that never crossed my mind until I did a 3rd gear pull and recorded the actual boost. Wow, what an eye opener and a bit of a shock to the system to say the least. I have a table that show and compare boost at different rpm’s and will try and get that loaded, however for some reason I am battling to get photos loaded so will look at that later.
So back to the Boost recorded with the stock Stage 1+, 4.48” JHM Pulley. I have boost figures up to 8500rpm but for the simple reason that I don’t normally want to ever rev that high I am going to stick to 8000rpm which is where I would like to be most of the time. So at 8000rpm I recorded 0.34Bar / 4.93psi. Keep in mind I am sitting at an altitude of 5740ft so really no surprise there, well now that I understand how blowers are affected by altitude. That was not my original reaction though. Initially I was quite disappointed but also excited realizing what a difference the low boost of 4.93psi made to the car. Next thought was ok, how do I get to or as close as possible to 9psi and will the blower cope with that etc. A lot of things went through my mind at the time and was a bit at a lost as to where to start. I reached out to certain people, some of them on this forum as well as JHM, thanks to all of you, to kick around a few ideas and then decided on a plan of attack which was quite aggressive but I decided to find the limit and then adjust down from there.
Ordered a 3.33” Vortech pulley from Summit Racing, installed and went for a cool early morning drive and right of the bat I threw a belt under acceleration, sigh! Back home, replaced the crappy belt with a Gates one and went out again a few days later. Belt stayed on but the max I could get was 6500 rpms and the belt would start to slip. Tried a few other pulls and also gathered some VCDS logs to check Lambda etc but 6500 was the highest rpm achievable due to belt slippage. Logs at least indicated that fueling etc was good. By this stage I have already ordered another Vortech pulley from Summit Racing, this time a 3.60” as well as new 34mm Turbosmart Diverter. Figured I had a 25mm diverter installed so decided to replace with a slightly bigger one just to be safe. Swapped the pulleys, had endless problems with sourcing the correct size belt and to make things worse I couldn’t get hold of any Gates ones so just went with what was available! At the same time I also replaced the tensioner pulley with the same type, old one felt a bit notchy and sticky, so decided it’s a good idea to replace. Belt stayed on under acceleration and I could get to 8000rpm but as soon as I get off the gas the belt will jump off and shred. I was stuck and out of ideas. Only good thing was we manage to gather some more logs and again all the results were showing the tune and HPFP’s were good to support the additional required fuelling. The belt situation was worrisome though and I started looking into that, no fun driving a car that throw belts so I had to get that resolved. I already knew the tensioner pulley is a potential contributor but wasn’t convinced it was the primary cause. From the word go my suspicion was the new Vortech blower pulleys because initially that was the only thing that changed. I had the smaller 3.33” pulley on hand so pulled out some measuring tools and compared the offset etc. with the JHM pulley. I found there was a small difference in offset and that was later on confirmed by someone more qualified with advance precise measuring tools. Ultimately there is a difference of exactly 0.4mm between the Vortech and JHM Pulleys. The other main difference was the absence of the 3mm lip around the outer edges of the Vortech pulleys. That offset was small but I didn’t want to take any chances so I had my local machine shop manufacture me a 90mm / 3.54” size pulley with the 3mm lip and correct offset. With that sorted I could scratch the pulley off as a suspect but even though it was a step in the right direction it didn’t solve my belt problem. I still had belts jumping off when I get off the gas suddenly at 8000rpm! Talk about paying school fee’s!!!
Custom Pulley
http://audirevolution.net/addons/albums/images/457562341.jpg
https://lh3.googleusercontent.com/JrqRBEow0XNl47R5Z-Loz9HC5STM4p6Mi9e8a5OmGKN1d1Pk-cR05lH77BobbzMxfJb_8R21-SvD6ryh8f21E84YMeeeVmhBB3FvnuPIwePpB6AWMwiKdBftKNj6iQcGqi86wK8edPRMS_6Xkz4Wu562-DEW7EWFrfeFBiofUoOeLJ7cJt8htEV10mjUrVSn6VKHa35hL1huy939RzATUtST_VXE93-jRnMpGvJmQ5jOtOgQEMnOMQRJ3cMpzeRDC9fL04aX75qxcccQ0fxg3EWmKNtmQGYhOH2IMfk5ilsZD-WFlfIlQYiPT8moLmBtbfwFrUmY4-k4O8HhLyiiKWuB-q41Jof9_1u87IaLta_bozZjLazH5mbxJaR68mOLIgaGvvhs9jrlsWQ6rBl_16LWp92esIzE6z9V45cIvidwHNuRxzJgnAkSCPiMmIYGgEEQrYCNBdygw3ru9i0PYIOFWzMTMbtrzBB_Xq3Y4pl7dgROhw8gXmkFmYt7yfgab3e-8jx_TXCk4J-RC4GNPzLf7_6OunMDQMmF1cCBy1rOGc-2_tS51mtLJvmOZauiD62wN3dcYPKxrcu2LxNO1kAiBmDZaiAYno6wharVo3fM4gbZyyucouMQ_cADlOQlyDliwjmd5QfxodJ73G_ClDhe=w742-h988-no
https://lh3.googleusercontent.com/VAKfHidgJQj3SEPLMGVZcB7fSCRvYALLuCUvnphQLyEA3HEwq8rCdHOayG8qX7k9DPfORa1OyV34dvmenDlPzkV_QdeJu56mXCcp3O8RhsIIS9vsiFtkb7BTsgIPqGhIoAFh3BUUBt-Ho49pjUo24AbFKHc1HmxAeTrd4OeqBnXZq0YrTkhvu0XmcHWBP79j8_VpuNsqkUAODe6t6djl5mkrWHTBtua6POGnSx44zHfQupB_hGjEd_V-5W2nXw5mnSeaB_Fp2PB8ztTTb7aCSPwAP-oOP8bbQoBDIKu3mscM7FZHadT-MaUeQxBHcMLPgIjSeRRxHbJ4_xOSML6A6X6TH9OdKpFi15iOrJRXwqTiqtviK3t3dsgxZU6Pan7wxYJOBvG2Zb4iDwY-aeSZ2OemWbEPEn1G1jSHuNYSzQhVM7-XFfbgq0-6Sq1Qqf6w4SyU3Exwit5M9z1vk-W1XIqHk8hBudmFAP3bt1kUh3kDbLoMyD4akjAJJ9p53jH3cLPV47D9OKwsMpcBCSBnJqkMCG9AjGV0BFq88z0R9JJeSjBn6GNgV4MbULODeoEK8_KSeAD-DUlxMm9tByRmLiZnCp2nkNG96kD4oI38PVI7LcWQjfY31PkcJnzRWe7y1_EsGwkmBcC6cken_ngVxY0P=w1318-h988-no
Trust me when I say I can swap a belt on the car out with my eyes closed and without taking off the bumper! No problem!
Knowing there is something else I looked further and found another interesting link on the net where some knowledgeable blower guy described my exact same problem and apart from pulley offsets he pointed me in a direction that I never thought of namely the diverter. Basically saying centrifugal blowers will throw belts when getting off the gas suddenly at high boost during high rpm pulls, exactly my problem! The reason, with the throttle body valve closing suddenly and with the blower still spinning at high rpm, too small or non functioning diverters will basically create excessive back pressure which will stall the blower wheel from spinning due to the compressed air not being diverted fast enough and that sudden jerk causes the belt to jump off because the crank pulley will still drive the belt at high rpm. Sorry, simple description but go Google and read for yourselves if interested.
So onto the diverter I went. Pulled the old one because I did order a bigger 34mm one! Damn, turned out I already had a 34mm diverter installed so decided to keep the old one in place and sell the new one. For some reason though I decided to check the installation instructions and discover according to Turbosmart my diverter was installed the wrong way around? I was sure I installed as per JHM instructions so went onto my blower instructions and pic’s that came with my kit and sure enough I had it installed as per their instructions and pictures. Not knowing any better I send them, Turbosmart, an email to query and the response came back confirming that their instructions are correct and I should not install the other way around! The above story about the high boost and small or non functional diverter now made more sense to me. Well it suited my problem so I am sticking with it. Knowing that Turbosmart, well I read their documentation, supply three type of spring tensions I checked the new with the old and sure enough it’s different. I decided to keep the softer spring that was in the JHM supplied unit but decided to first check the diverter functionality before swapping everything out. Hooked up my vacuum pump and the old one wouldn’t hold vacuum, new one would hold vacuum until I release. Swapped the springs and now the old one with the stiffer spring wouldn’t even open with same vacuum pump. Not sure why but it seems that not only was it hooked up the wrong way around it was also possibly defective. Went ahead and installed the new one with the softer spring as per their instructions. Also check the 2nd smaller diverter closer to the blower and that was ok. Went ahead and trimmed as much as possible from the vacuum lines to keep overall line lengths as short as possible.
TurboSmart BOV
Not the best pic but clear enough to show the correct vs incorrect fitment. The factory example on the left is how my Stage 1+ TurboSmart Bov was installed. Clearly incorrect as can be seen from the instructions. Simple fix though around 10-20 mins.
https://lh3.googleusercontent.com/33rXMAZjQBpcvV2wNBUxGR_KHGAhsGyiQtFaRcENKxeag8ldR_ohFRZJBykbm62-AB9H0BBox_RlHYtCO4jij__R6mLLpaBaDc5zBFbB-G0aZAecrKTLTiteEWBSTPm0MZa8K0aFlw2U9je-POLtWbCdhgpllxiU0KEFJDQaZ0CO0bYZbB8Lo3blknCCZBV7Z2ZMZEJpS30qC-vk0wsCMf23FNWOnwZn1h3zervJwLY2d1ZWuuUcw1zlqwJqyAMnJ-yhEbUyHSMATxxu9U3vOiqDkjfT4qTuSxPnbfJA7AsfGGKjWNps7uvFhIcsSrBbLSdPP9JvoQx5Ss-8M5XjgG7AIj0P9lxwrw99jr8cwlyUX8t63tFApe0RG6MUmsGZ97XH7krGxu6YUTKhR56o0yVEwAYlxC5XSt5S24bPWoosWYlm62rfbyg7s2VbmEYJTKUOB-v9xAs0l1YXFQ6lP1LUh6kHJnhWqMJn-TUEg90lS39FZ19J6CW3yNHQwpcmu_bC8Mk0LN7t3AKZ45wcPELeEmE4WYQRRs6k2lMh3HT8iXpxTeqIcRBABxKtylHFpJU_XwVwoEull1TNBrzf-Y3kDnqJ1uWSxKlRUELVAf-PIGfOwXz1JxmQLoUbB_JPkT4Dgl6LdJo7mqLd6QUkbCI7=w640-h360-no
Turned out the new tensioner pulley was also toast, “MADE IN CHINA” junk and had to replace again. Not many options so found a 2nd hand OEM pulley at an Audi breaker yard as a temp fix.
Got all hooked up and installed and went out for some testing. So far so good, belt is staying on and all things seem to indicate that the problem has been resolved. Last test was to do a dyno pull because that would normally throw the belt as well but went through a few pulls without any issues so I am confident the problem has been solved.
With the belt problem solved I could go out and record some 3rd gear pulls. This is how the smaller pulley stacks up against the original one.
Power at the wheels are now as follows, pulls done at same operator. Perhaps important to keep in mind that the previous high of 428whp was recorded in Winter vs now midst of summer with 30+ Degree Celsius ambient temps.
4.48" Pulley: 315wkw / 428whp
3.54" Pulley: 360wkw / 489whp (90mm Pulley)
So not sure what that will equate to at the flywheel I guess around 600hp give or take??
The important bits are the 4.48" Pulley peak of 4.93psi @ 8000rpm vs same @5500rpm for the 90mm Pulley
And then the 8.41psi peak @8000rpm for the 90mm Pulley
Below a boost comparison between the 4.48 & 3.54"(90mm) Pulleys during a 3rd gear pull. Also recorded the Time of Day, Ambient Temps and the different sensor temp readings.
https://lh3.googleusercontent.com/-Q58Op9aqbzhy7J-u6iymhR5l7v95NohUSaZRiAwrL2MBb-rLvECroi-JV_WEQYBoRoPNhMceQSHhrFvWlWYFfPtG7WjbYlu4rxpc1CaWD8ZS5-HmHjgpIFAON3OC9TBIJwNK6FmDZQ8k4sD5JT4QcE_UPomApnVlB7khqKJOUiL2pa7ZNzd26uHP6TBgGSnSfYyf-lnwEC2TFKMM8xIkrulSqYO62MxSCP8Zpqzciv4IsoAJp_ZqQzJORvYi0LT9eehHu3H7Vwb1Xb7qFb6CywzQPaOLccclzrulCD20uNhK6mXRcietv1-sOLxt__Cqj9hN06RUdKDzdWEeOkkrD9jFao3wKByx3mxsWY3jLdlBMaNxIj3JkAlR2_t1VUwgD0dY7SHsSjraPbXx2hlAvU9pttPi_xXdlViKMXzlbRW0VXbnmwCbL3WR9uJhN-9Mb9yBNUrngdIbikNemsRlA-hi8S_isiWf4MLFi-9nMdEraOgRDbIH_Dj5vw7PcXlxgaFj6j7J2oN_05P2BHb9JwmF0yk52g1eDrSDBGETOqtBMagGZkCDVtdRhcMbT0i6VB7J-u0oOjefzZnQ6docdJY4XONUpr0U9FehpC2e94kJiDDqd1JM0TIL_WDNVK8IELoVDt8pFRmifsfohCdH42y=w1318-h988-no