no hp gains with mods

[BuLoOoSki]

Originally Posted by ross22

The r888 is a heavier tire than stock. I went from BMW 19 inch wheel/tire combo to Apex 18 inch, 305 R888 and the "smaller" wheel, wider tire combo is actually heavier by almost 9lbs per rear wheel. Another thought is spark plugs, how many miles are on the car now vs. initial dyno. If you're past 7K miles on the same set of plugs, it's a good idea to swap them out, especially if you've been making some spirited runs frequently.

He already mentioned that he changed his spark plugs.