Auto's are for pansies
Join Date: Dec 2008
Location: Brownsboro, TEXAS
Thanked 191 Times in 139 Posts
Maunal Guys w/ or w/o tunes
My truck has two things it does that I think is slightly odd, and I was wondering if all manuals do it, or if it's the tunes, or what.
1) With the 250 tune, in first gear, I run the RPM's up to about 2500 on a side road to help warm the engine on cold mornings. Sometimes, I push the gas above 2500, say around 2700, and no matter how much I let off the gas from that point, the RPM's keep going up, until I take my foot all the way off, resulting in a jolting deceleration. It's like the truck really wants to go above 2700. I have feathered the gas at that threshold RPM before, and it still climbs at a pretty fast pace. It does it in second too, but not near as bad.
2) The trucks are resistant to stall. If you idle in first gear, the truck will stay at 750 RPM's no matter what. I've tested it on hills without hitting the gas. I've tested it with a 3k trailer without hitting the gas. Now, I learned a trick the other day, if you hold the brakes to keep the RPM's between 500-600, the engine will fight back (trying to get back to 750 again), and with my 250 tune, it dumps smoke like a train in this phase. It works in all gears, but best in second gear, so you're going about 4 mph just flooding the road with smoke, like an insect repellent truck. If you let off the brakes and let it get back to 750, it acts fine when you hit the clutch. But if you just hit the clutch when you're below 750, the RPM's jump to over 1200 and waits a few seconds before coming down. I assume that's the engine's reaction to going from one second trying to boost speed and the next not having any resistance. I know the smoke is tune related, but the jump when the clutch is hit is what I'm wondering about.
'10 F350, CCLB, SRW, 4x4, 6 speed, 2.5" AutoSpring front leveling pucks, 37 x 13.50 x 18 Toyo's, 18 x 9 XD Diesel's, Road Armors front/rear