Jump to content

Transmission after Exhaust Upgrade

stever1986

Recommended Posts

stever1986 Enthusiast

stever1986

Posted
Posted

Ok so my truck has only 400 miles on it. I am trying to get more miles on this thing so I can get it broken into and hopefully get the transmission to smooth out a bit. I put a magnaflow exhaust on the truck at about 390 miles (same pipe size and also the same exit configuration) and now I notice how lazy and confused the transmission is at times. I think it was doing this when I bought the truck but b/c the truck was so quiet I never noticed a lot of the transmission as it has been shifting somewhat smooth. Now with the exhaust, I can hear the truck shift from the exhaust note and now can really tell how this tranny wants to have a mind for it own. Obviously there is a lag at initial throttle and then you press more on the pedal to then have to back off when the truck all of a sudden after 2000 RPMS gets like a small turbo boost. Then during light take off, its a lag then a boost, then shifts in 2nd, small lag and a boost, then shifts into 3rd then it clears up. If I am heavy on the pedal I will get a delay where it hangs into 1st gear at a high rpm before it shifts. Same for 2nd. However when it is doing this, You do not really feel it that much until you are watching the RPMs to see it. Truck still gets up to speed just fine.

 

So again could it be b/c I have a magnaflow at 400 miles and it still learning?

 

Could it be that It was like this when i first bought it before the magnaflow but b/c the engine and exhaust we quiet, i never noticed it

 

Sorry for bad spelling / grammar . Typed from my cell

00Silverado4x4 Senior Enthusiast

00Silverado4x4

Posted
Posted

The transmission you have is a learning transmission. It takes several miles to "learn" your type of driving. I'd give it some more time to get used to your driving. 400 miles is very much time.

02suburbanZ71 Senior Enthusiast

02suburbanZ71

Posted
Posted

If you are not happy with the shifting you can always get a blackbear tune and make that truck scream!

MikeNH Senior Enthusiast

MikeNH

Posted
Posted

To keep it from being too busy in town, I drive in M4 or M5. Helped out a lot with it constantly shifting.

Spurshot Senior Enthusiast

Spurshot

Posted
Posted

Your transmission isn't lazy. The programming is designed for a balance of fuel economy and normal driving. Operating higher gear (low rpm) loads the engine up and requires more throttle for the equivalent acceleration or maintaining speed than lower (higher rpm). This raises BMEP and therefore fuel economy. There's a balancing act, of course. Too much lugging is annoying to the driver, too much rpm is detrimental to fuel economy. Performance oriented people will want to get a custom tune that changes the transmission shift logic/schedule.

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,840
    Total Members
    8,960
    Most Online
    appletrav
    Newest Member
    appletrav
    Joined

  • Who's Online   0 Members, 0 Anonymous, 432 Guests (See full list)

    • There are no registered users currently online

  • Latest Articles

  • Posts

    • newdude
      2 speed transfer case optional now?

      By newdude · Posted

      This is a 1/2 ton thing ONLY.  All HDs 2020-2026 have the two speed transfer case, with Autotrac as an option.     1/2 tons 2019-2026, regular 4x4s come with a single speed case (no 4LO!), and trucks with Z71 ordered, or all Trail Boss trucks come with the 2 speed case.  2 speed case is also an option on WT, and is also standard on High Country.  
    • newdude
      Different requirements for oil filters?

      By newdude · Posted

      2013 5.3 still to this day calls for the PF48 filter.  Which as a 15psi bypass pressure.     There is a TSB, 17-NA-157 that talks about the PF-63 and PF-64 filters which have a higher bypass rating of 22psi.    TSB HERE - temp.xml   "Beginning in 2012, the oil pumps began to regulate main gallery feedback instead of pump out pressure. This means that the oil pump now does not begin to regulate until pressure is built up to the main gallery. This change reduces the amount of time it takes to provide oil to the engine bearing and lifters during extreme cold start conditions.  Main gallery feedback oil pump control systems are present on the following engine families which use Spin-on oil filters: Small Gas Engine (SGE), Large Gas Engine (LGE), High Feature (HFV6) Gen2 and Small Block Gen5 gasoline engines. These engines with the main gallery feedback oil pump control systems are factory built with an ACDelco® oil filters"   It also calls out what engines use those filters.  The gen 4 small blocks were not on that list (LMG, LC9, L9H, L92, L94, L20, L96).  Gen 5 small blocks use the higher pressure filter.          That all said...   Your 7045 Napa filter is the PF63 equivalent, with 22psi bypass.  You are already using the higher bypass pressure filter.  You CAN keep using it, you don't technically have to use it though.  
    • Grumpy Bear
      Different requirements for oil filters?

      By Grumpy Bear · Posted

      Do you know WHY the filter relief setting was increased to 22 psig?    When the new system goes into the second stage the pump volume ramps up considerably. It was found that the 15 psi filter bypass setting put the filter in bypass on a warm engine when the second stage was activated. Raising the filter bypass setting forced the filter to do what it designed to do. Filter. Preventing debris from circulating during high load, high rpm operation.    So next question is how did GM find this out? VLOM/lifter failures and a deep dive by Melling Corp.    Last question. Is it required? Look at it like this; a motor may be equipped with a rev limiter. But it only works if the set point in reached. That 22 psig setting only matters if the pressure differential across the filter media exceeds 15 psig during normal warm operation. Second stage kicks in around 3000-3500 rpm.    I can't answer your question because I don't know you and how you use the truck. But I think there is enough information here to let you decide for yourself. 😉
    • Coastie05
      give me some tips to make my truck look better

      By Coastie05 · Posted

      Go back to OEM wheels. 
    • newdude
      2020 Trailboss 6.2 replacement

      By newdude · Posted

      Probably not their first rodeo, so it should go as planned most likely.  Typically the service manager or tech doing the swap will put some seat time to shake it down after they get it all put back together.  We usually put 50-100mi before we hand them back so if something happens, its not after you get it.  A coolant leaks, oil leaks, a ground left off or loose, vibration, etc.     The new engines so far have been good?  There's been a couple that have popped out there again (the replacement engine) but most have been okay.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...