okay where cool then. sorry about that! i will post up new times monday for you guys

 

I am not tryin to start something here but my truck acted that way until i did my tranny mods. I really had the boat anchor in 3rd thing , but now its great. I wonder if the yank is the reason. Good luck.

 

I have similar mods same shift kit-servo and stall but I have a bigger cam and more weight (z71) SLT also have 3.73 gears. Ive noticed the same thing and am wondering if the converter is locking. But when it comes down to it I think the gearing is just far apart between 2nd and 3rd the transmission isnt geared for fast. Ive heard of some guys that just run the whole 1/4 in first and second shifting at 7k plus. Me personnaly I dont like shifting upwards of 6500 but to each his own and it does work for some people to get thier times down.

Ive also wondered about tuning but I think the majority of it is from a heavy *** truck on top of a crappy tranny with the wrong gearing in the rear and the tranny then you add on a low HP/weight ratio and there you have it, remember GM designs these trucks to tow NOT GO FAST.

If you really want to solve the problem invent a 5 gear auto or install an older vette tranny and start shifting. Someone on here has done it they posted here recently.

 

That definitely sounds like the converter is locking in third gear. I would check that and adjust accordingly with hptuners.

 

In answer to the question on tires and where I am located. The place is Indianapolis, and the tire size is P255/70r16's on factory aluminum wheels. Think that the key is that lock up occurs at the same time it goes into 3rd gear. Need to dive into HP Tuners and delay lock up. Think that converter would allow 3rd gear to pull hard if not into lock up mode at same time.

 

You don't have to spin the motor too high on a bolt-on Z71 to keep it in 2nd gear through the 1/4mile...

Only time I started to think I may have to run it in 3rd gear was after my final N/A tune and I was trapping 97mph. At that point I was just barely keeping it off the rev limiter at 6700rpm... I never shifted above that though.

This is a run through 2nd grear.
http://fatalfoo.com/Movies/F8L%20Z71...14.29_0001.wmv

 

The reason that I did away with the MAF was that I could not get rid of surging up and down at idle, and LTFT would not lean out, it was always rich. So I tuned my truck using HP Tuners to run without the MAF sensor. Also not into running too many RPM's, so will stick with 5,200 rpm shift points. This is a daily driver, so will look for other ways to get my times down, maybe shed some weight off the truck. Has anyone found CalTracs to be helpful on a full size truck?

 

Why did you do a cam if you are not willing to shift your shift points?

My Z71 is my daily driver also. With good springs, and a good tuning I don't see why shifting at 6k would hurt anything. Just makes doing a cam seem like a waste to me.

Where are you from again? Just curious why your truck traps what a stock one traps.

 

Just felt that it was best to keep the rpm's in the powerband of the cam, that is all I am saying. Why wind up the motor to higher rpm's and take a chance of hurting something. The whole point of me putting the cam in was better performance than stock. Not sure why it only traps at the speed that it does, that is why I asked the question.

If your cam peaks out at 5,000rpms, what is the point of shifting at 6,000 to 6,500? Can someone answer me that?

 

Have you dyno'd to ensure that is where you are peaking out at?

Also, even on the stock cam (peaks at 5200rpm) reving it out to 6k and staying in the lower gears longer does indeed improve 1/4mile times. That is why people see a .4 gain in the 1/4mile with the stupid HPP3.

I'm not trying to make you feel bad mate. I'm just trying to understand the logic behind it because your ET and MPH is not reflecting your mods.