Do you have the UNI, K&N or the AFE filter??
I have the UNI. hole cut in cowl. I noticed a pretty significant peak drop. I had the 10 plate in, slightly foward before the scotty II. I could hit over 1500* in 4th gear, not sure how much over though cause thats all my gauge reads.
With the Scotty and plate in same location, 4th was right around 1400*, so I saw at least 100* reduction.
Now that I have more fuel and different turbo, the scotty works even better I think. I love it. I wish it was even louder.
--Jeff