Guy at the track said my shift points were killing my 1/4 mile times

So I've been running my '18 5.0 with a mild tune and intake, thinking I was shifting right at 6500 rpm for max power. This older dude with a built Lightning came over after a pass and told me my truck was falling flat on its face past 5800. I argued with him for a minute but he showed me his datalogs and I was like okay fine. I dropped the shift point to 5600 and took a full 0.3 seconds off my ET on the next run. Curious if anyone else has found their truck makes power way lower in the rev range than the dyno sheet claims?

3 comments

3 Comments

david3717d ago

Wait, are you sure your shift points were the only thing that changed? That 0.3 seconds is a huge jump from just dropping the rpm by 900, makes me wonder if your tune or intake is actually choking up top more than you thought. A lot of those mild tunes just shove timing at the top end without looking at the intake airflow, so the motor might be making good numbers on a dyno with a fan on it but falls off hard when it's actually pulling air down the track. You might wanna log your MAF readings or look for a better intake that flows past 5800 if you wanna keep revving higher in the future

mia74817d ago

Never thought about it that way, but @david37 you might be right about the intake choking.

bettywood9d ago

Used to think any drop in rpm was just about the gearing, but @david37 you're making me rethink the whole setup. That 0.3 seconds makes way more sense if the intake is choking and losing power up top, not just from shifting earlier. Gonna have to watch the MAF logs closer now and see where it really falls off.