zachm89

iTrader: (16)

Well I figured since I have HPTuners I'd give tuning a shot on the 03 SSS I just picked up. The truck is bone stock other than a Vararam CAI and a Magnaflow muffler. Starting off I just wanted to adjust tire size, remove the speed limiter and reduce the amount of both engine and transmission torque management. I went out and logged the truck on the stock tune before messing with anything and at WOT I was seeing upwards of 8* of KR which I thought was kind of crazy for a pretty much completely stock truck.

Went back to the house and saved the log and pulled the stock tune, saved a copy of it and started working on the torque management and speed limiter. I followed some simple instructions I found on the HPT forum to remove all torque management, but used my own values to reduce it by 75%. Then uploaded the new tune file and went out for another log. This time I saw no KR at all at WOT, the shift from 1-2 felt a bit sluggish but I know I'm going to have to either add a vette servo or some more tuning work to fix that issue. But overall, the truck felt like it pulled much stronger than before. I also noticed though that with the stock tune, the commanded AFR was 14.68, but with my modified tune the value for commanded AFR was gone in the scanner.

Now, I don't know if something that I modified in the engine torque management is the culprit for the missing AFR value or not, because other than clearing codes, shutting off rear O2s or loading in a custom tune, this is the first time I have ever messed with HPT on my own. For peace of mind until I got some insight from someone more knowledgeable, I loaded the factory tune back in the truck before going to bed last night and kept my foot out of it on the way to work this morning. I did have a few instances passing other cars on the highway at about 1/2-3/4 throttle that I saw about 2* of KR this morning however so Id like to try and figure that issue out along with making sure my values for torque management are acceptable for a stock trans.

Thanks in advance!

FFDP

iTrader: (2)

Post your tune and log file.

What fuel do you run?

Knock on 87 is pretty much always normal. Run 89 or 91 to be knock free with a good tune. Shift times and shift pressure can be adjusted without the need for a corvette servo. Also be aware that your factory driveshaft is not rated for speed above 100mph, do so at your own risk. Driveshaft failure are not something you want.

zachm89

iTrader: (16)

I'll post them tonight when I get home from work. And I'm running 93 octane fuel. As for the driveshafts, I know they aren't rated for a whole hell of a lot. I'm not going to be cruising the highway at 100+ all the time, I just hate knowing there's a speed limiter in place.

Thanks for your input

madmann26

iTrader: (7)

There are a handful of tables that can institute knock at weird or unwelcome times.

as FFDP suggested, post your tune. Alot of us tune ourselves.

Atomic

iTrader: (42)

That speed limiter is there for your protection, mainly from driveshaft failure and tire failure. I'm not saying dont remove it, but just be aware of its purpose.

The factory knock sensors are very sensitive usually, so the KR you pick up may or may not be "real". A good way to test this is to put in a tank of good gas (100+ octane) and see if its still there or not. If it is, then its probably false, but if it goes away it was probably real.

I do remote tuning under my sponsor account, Atomic Performance, if you are interested in having someone hold you hand so to speak along the way.

zachm89

iTrader: (16)

I keep meaning to post the stock and my modified tune files but I have been getting home late a lot this week and have been going straight to bed. I will try to get them posted up today. I actually went back and reviewed the two logs again, one from the factory tune and the one from my modified tune and the knock retard was there in both of them, not just the stock tune like I had originally thought. So Im hoping it is just false knock but Ill keep digging deeper until I figure it out.

Thanks!

zachm89

iTrader: (16)

Im well aware of the dangerously low performance abilities of the stock driveshafts, no worries there. It's more of a mental thing for me with the speed limiter, I just don't want it there. I definitely plan to keep speed to a safe level with or without the speed limiter.

Ill do some looking around and see if there is anywhere near me that sells 100+ octane fuel. Im sure there has to be somewhere so if I find some Ill give that a try!

I also know that you do tuning and are a sponsor, which is why I have been hesitant to contact you for "help" since you do this as a business and I didnt want to seem like I was trying to get tuning help for free from a sponsor/tuner. You tuned my buddy Jon's truck, single turbo black SSS out of Idaho and he has told me about your work. Ill definitely be in touch for some hand holding, haha.

Thanks!

zachm89

iTrader: (16)

Okay, tune and log files have been added to the original post. The first file is the stock tune, second file is the log of the stock tune. Third file is tune with modified engine and trans torque management reduced and speed limiter raised and the fourth file is the log of that tune. The fifth file is the same tune as my modified TM one, but with PE adjusted as well as shift points/times adjusted. The last file I have not been able to take a log of yet but it's messed up anyway because the truck bangs off the rev limiter before it shifts so that one can be ignored lol.

Thanks!

FFDP

iTrader: (2)

Per the fuel trims you are way lean at WOT, +20-23 on the trims and the o2 sensors seem low around 860's. Ideally those are around 920-940 as a guess even though fuel tirms are something you trust 100% of trhe time.

Do you have a wideband on there?

I'd make sure your MAF sensor is clean, that you have zero vacuum leaks and that the screen on the MAF sensor is in good shape still. Or put the stock intake back on there and see if the fuel trims improve. Overall throughout that log file the trims are positive a lot of the time.

For future logs, add injector pulse width for both banks and TPS to your logs. Always good stuff to watch, for sure because the stock 25lb/hr are barely big enough for the 6.0's.

zachm89

iTrader: (16)

I don't have a wideband nor do I have the factory air intake. On my to do list is to ditch the vararam intake and go back to a factory air box with just an airaid intake tube. Ill disassemble and check out the MAF this weekend as well as check for vacuum leaks.