ok so I have a 2008 GMC Sierra RCSB 4.8L

I have done quite a bit of tuning with HPTuners trying to get the throttle to open faster. I've searched and done everything I have read that is supposed to help. And nothing seems to work. I have it going to PE immediately upon stepping on it, PE enrichment rate is 1.0, I've added quite a bit of timing in the 0-3000 rpm range. I've also taken out all the engine torque management.

what's the trick? my truck is trapping nearly 91 mph which is great for just having the tune, but my 60 fts are miserable 2.3+ because it is so slow off the line. I have 3.73's and a locker even.

 

Do you have a short log file showing your truck launching?

 

Try tweaking on the Air flow charge table "not the correct name for it" but it basically dictates how quickly the sensors recognize a change in air flow and temp. There should be two tables try lowering the one that deals with time base numbers by about 10 to 15%.
Also check or log for burst knock and timing tables. If you see any 0’s in the Higher Kpa lower RPM areas gradually increase these checking for knock each time. Also having PE set too low may be causing some isues try around 60 to 80% vs tps. I would also take a good look at my trans tables.

 

this table?

 

also, where might I find your trans tables?

thanks for the help.

 

Yep that table, I bumped it up around 10% or so. Your stock table has the same values that mine did. If you like send me your HPT file stock and what you have now and I can send you some screen shots that may help.

 

send an email to support at hptuners...they have beta testing for the ETC throttle ramp rates... the 5.3s came with 100% from the factory so not much I can do there (Kinda weird though specially since I can hear the throttle body opening gradually.... either way it might work out better for you....

 

I already got that and was very dissappointed when I saw all the 100's in the table! I thought that was going to be my savior.

i suck at saving my logs. I log at the track, make changes and go. I meant to save one while I was there last week but forgot. I can try to get somekind of log this week though.

 

I to have this beta and also found all max values. I plan to do some logging to look further into that issue.

colyneedsv8 Just bump the table up by 10%. it made a diff for me.

 

thanks I'll try it out. I'll post my tunes later also.