New project needs some tuning help
Thread Starter
Teching In
Joined: May 2020
Posts: 23
Likes: 1
New project needs some tuning help Hey all. I just picked up a 2003 Yukon, stock 5.3 (stock cam, etc), FIC 775 cc injectors, Precision wastegate and blowoff valve, GM 2 bar map, a Trick turbo kit, with what looks like a 7875-ish turbo, walbro 320 lph pump. 4l60e with shift kit and a 2500 rpm stall. The previous owner did what he called a "safe" tune, but he admitted he is not a tuner. This rig has an aem wideband that is not tied into the ecm yet. I am also not a tuner and trying to learn, just bought HP Tuners to get some data and download the current tune. My short term plan is to swap in a 4l80e and some kind of boost control and get it properly tuned either locally or via email.
If any of you seasoned tuners would care to take a look at them and give me any ideas of what I am dealing with, I would really appreciate it.
If any of you seasoned tuners would care to take a look at them and give me any ideas of what I am dealing with, I would really appreciate it.
That tune needs to be tossed out and start over fresh. The fuel injector data is wrong, causing the VE table to be wrong, causing the spark tables to be wrong, etc. The current tune has so many baked in errors that it would be immensely easier to start over fresh from a factory tune. That combo should be very easy to tune once you start with accurate data. It would be beneficial for you to do a lot of reading in the gen3 section of the hptuners forum. Also, I believe a member here who goes by Chopperdoc did a series of youtube tutorials with info that would benefit you. Having a stock cam and a smallish stall converter will eliminate most of the problems people commonly run into tuning, as most of the stock tune will already work perfectly well. You will need to input ALL of the correct injector data that FIC supplies in an easy to use spreadsheet that will be copy/paste into your file. Verify the part number on the 2bar MAP and input the correct offset values. Convert the file into HP 2bar sd. After that you have to fill in the above 100kpa section of your now 2bar VE table with plausible numbers. Once that is done, you can start the actual tuning process. There are numerous guides on how to do that.
Thread Starter
Teching In
Joined: May 2020
Posts: 23
Likes: 1
Thanks for taking a look. It seems like this thing is pig rich. The afr gauge reads "10" quite often, which is as low as it goes. It's probably running richer than 10:1. I have the correct connectors coming this week to make a pig tail so my wideband can be connected to the ecm. I may be better just taking this truck to a local tuner to get it done.properly but I'm sure they will want a wideband logging in HPT. Do any of you guys do remote tuning (I'm not expecting for free).
Also, I think the injector table is close to what FIC provides
Also, I think the injector table is close to what FIC provides
Thanks for taking a look. It seems like this thing is pig rich. The afr gauge reads "10" quite often, which is as low as it goes. It's probably running richer than 10:1. I have the correct connectors coming this week to make a pig tail so my wideband can be connected to the ecm. I may be better just taking this truck to a local tuner to get it done.properly but I'm sure they will want a wideband logging in HPT. Do any of you guys do remote tuning (I'm not expecting for free).
Also, I think the injector table is close to what FIC provides
Also, I think the injector table is close to what FIC provides
