Upgraded 9 to 13 speed, MPG takes a dump

http://www.youtube.com/channel/UCZ08qn4z5TC5je7Bxo6hLSQ
Step by step video instructions to that post by the guy that wrote it , they are listed backwards start at the bottom 1 6 then up to 2 6 ect.

 

Here's my 2 cents worth on this topic,it takes more horsepower to turn a 13,15,and 18speed trans,than a 9,and 10 speed,guys correct me,if I'm wrong on this!

 

If I understand you blsqueak, you noticed decreased mpg after hooking up airlines to the valve on the back of the transmission? So, before you did this, you were running in 12th gear as your top gear. You are now able to use all 13. Don't get too hung up on the mpg benefits of running low rpm's unless you can maintain your desired speed while using the same or less fuel that was required to run the shorter gear (more torque) and higher rpm. Your manifold temp and manifold pressure gauges are a good way to tell. If you are having to pull higher manifold pressure and heat to maintain your speed, you are using more fuel to do the same amount of work. Like someone suggested, leave the splitter button alone, drive it like you did before not using the top hole for a week or two, and see if you get it back. If I misunderstood, this reply should be treated as the ranting of a crazy person.

 

What gear 12 or 13 is your RPM's the same before you did the conversion?

Why are you doing backwards progressive shifting? Shift the low side at low rpm's and as speed increases increase rpm with each shift. You should have less time between shifting gears on the low side than the high side.

 

Doubt the tranny made any difference.

 

With that many miles,I hope you've ran the overhead,if not that should make a big difference. Also may want to think about servicing the trans & rears.