It felt like almost none, I can say it's a LOT quicker to spool than my Volvo was. Not that you can compare but it's crazy. Just barely stepping on the gas 2k rpms you hear what sounds like a mix between a supercharger whine and a turbo. Vit has seen all the logs and he would be able to pinpoint how quickly it spools better than I. I'm just aware that it capped out the stock MAP so I haven't tried to pass anyone or anything like that really in fear of doing it again. It's like a quick snap back when it happens
Also buy FlashPro already! It's worth it just to have if you ever need a tune for any reason!