You guys do know that the stock tach/speed or inaccurate, right?

I can 'visibly' rev my engine to 9000 - which is obviously wrong since I have the stock ECU which cuts fuel at 8600. Also, vtec kicks in where? 5800rpm stock? Mine appears to be more at 6000-6100.

That is 3.5%-4.5% error in that rpm range.

The speedo is just as inaccurate. 3% or so. Also, tire size will change the speedo as well - 205/50-15 is 1.7% smaller in rolling diameter than the stock tire size (195/55/15), 195/50-15 is 3% smaller. So you're speedo will show an even higher speed if you run a 205/50 or 195/50 tire: add that on to the basic estimate that the speed is already 3% off. You're looking at 5-7% already!

You may be showing 150mph on the stock speedo.... but without GPS or some kind of external measuring device, it's REALLY hard to know how fast you are actually going. Given the excel sheet that Trey (or clayton?) put together (which shows mph per 100 rpm given tire size, gear ratios and FD), we are able to show how fast we *should* be able to go at redline in 5th gear... but I'm not sure any of us really know if we can hit the fuel cut in 5th gear. We might be slightly drag limited at that speed, but who knows for sure?