IAT Spark Advance Correction Table Gen IV LS2 2005 Corvette

Hello, All.

I'm a relative newbie learning the tuning process and have made great strides on my 2005 Corvette 6.0L LS2. By great strides, I mean that by reading lots of posts here over the past couple of months and getting my IFR, Base Idle RAF, VE, MAF tables, and most of my spark tables adjusted and dialed in using the techniques posted here, I've been able to get my car to pass the Colorado emissions test which I failed four times previously before I decided to take ownership of how my car runs and purchased and installed HPTuners and a PLX wide band sensor. I'm not trying to throw my tuner under the bus here, but since I did all the work myself to do my heads, cam, headers, exhaust, and intake upgrade myself, I wanted to learn more about the tuning process and take the loving care that a performance car owner/enthusiast has to optimize and make their car run in accordance to their personal standards which may or may not align with other people's expectations. My AFR % Err histograms and my STFTs on the logs I've done (about a 9+ iterative logs), show that everything is pretty much really dialed in now, my idle is the best that it has ever been, and I passed my emissions and am good for another two years here in Colorado. :yay: Not only do I have a sense of pride and accomplishment of doing my own wrenching to do the hardware upgrades, I now have the sense of self-satisfaction of knowing that I'm learning how to tune my car! :cool: I can't believe how much better my car runs and how much better it is to drive!

However, in my quest to make the most of my $ spent on all my upgrades, I have a question about my IAT Spark Advance Correction table. I've posted a screen shot of my current settings and wanted to get other, expert opinions on it. My impression is that it is overly aggressive and I'm leaving HP and performance on the track. The upgrades I've done to my car are as follows: Trick Flow As Cast 220cc heads, FAST 102 intake, ported stock throttle body, 230/234, 114+2 cam. Kooks 1.75" headers with hi-flow cats midpipe, Flowmaster II catbacks, and Halltech Venom II C6 CAIS. The car currently runs in an OL/CL config with LTFTs turned off. I used SDtuning methods to get the VE dialed in and did the appropriate configs to get the MAF dialed in. I also monitored KR and adjusted my HO, LO Spark tables accordingly. But, I think my IAT Spark Advance Correction tables are too aggressive and wanted feedback from other on this. I'm interested in other's opinions. I've attached my latest HPL and HPT files for reference.

Thanks in advance for your feedback!

Attachment 53331

the hptuners book "tuning the right way" has this to say about your iat table- "Do not adjust the numbers very low past 131f column as you are more likely to encounter detonation at these higher temperatures." if you do make changes to higher iat temp columns, you should definitely log data with iats at these warm temps and verify no knock activity.

Tuning the right way wasn't written by anyone at hptuners.

I don't understand that comment. It has hptuners name on its cover and sold on hptuners website?

It's written by Bob Morreale of the tuning school. Last I knew he was not affiliated with hptuners. He simply developed a complimentary product.

Quote:

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Originally Posted by AutoWiz

the hptuners book "tuning the right way" has this to say about your iat table- "Do not adjust the numbers very low past 131f column as you are more likely to encounter detonation at these higher temperatures." if you do make changes to higher iat temp columns, you should definitely log data with iats at these warm temps and verify no knock activity.

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Sounds like a common sense approach. I probably won't have many more hot day opportunities here in CO to get the IAT up that high to do some data logs, but I'll definitely stay on the conservative side until I verify. The reason I asked for feedback is that my table (as programmed) seemed to be a lot more aggressive with respect to timing retard than other tunes I've looked at here on the forum and other websites. I've done quite a few data logs thus far and have been able to eliminate KR in a lot of different rpm/map cells, I just need to work in the high temp and WOT areas now.

That table just pulls timing (or adds it at cold ECTs) to modify the Main Spark Timing Table (High and Low).

Basically, set your spark timing to MBT (if possible) with your Main Spark Table(s) and take note of what your normal IATs are.

use the IAT modifier table to reduce spark timing under hot IAT conditions to prevent preignition.

Simple as that, really.