Steve,

The Borderline Knock tables were SCT first recommendation but it didn't work for locking the timing. In other words so it would be WYSIWYG with what the Advantage software showed. Exceeding the timing was not the problem in warm temps with my truck. It was pulling timing.

FYI, SCT would rather you run the one tune the way it comes out and only worry about the MAF tranfer and A/F. At least that was the attitude of the guy we were dealing with.

 

The original tune I got from SCT had the timing ramped too high in the borderline knock table and my truck detonated bad. I changed the spark in the borderline knock and it was fixed.

Interesting that the SCT rep. told you not to worry about the other parameters. I deal with Ryan and Bryan from SCT and they know that I had to change my spark parameters for our crappy CA 91 octane. They had no problem with that. As a matter of fact, they gave me some info. on torque converter lockup changes, intercooler turn on changes, and a variety of other things I could change.

Your right about the maf transfer and a/f, it's essential to get those right.

Steve

 

Steve,

This was not Ryan or Bryan. The guy didn't say don't worry about the other parameters. It was the attitude that this is the way the software is setup and you wanting to command the timing the software shows on the screen is just not right (so to speak). I'm not the one calling SCT. It's my dyno shop. They know more about Cobras than Lightnings but they are learning fast.

I know the Max Allowed table had to be involved in getting the 18 degrees of timing from 1250 rpm to redline for the race tune.

 

Spark strategies are set up the way they are for a reason. Just because they are dependant on IAT2, EGR, A/F, knock sensors (N/A to Lightning), etc. does not mean they are "moving around on their own". They are modified because things other than just load and rpm effect knock.

The maximum spark timing allowed is the least of any of the available tables under most circumstances.

DO NOT ignore IAT2 when determining spark! Either you'll risk detonation or set your base spark too low and lose performance.

 

The only solution other than locking down the timing was to cheat it by adding 2 degrees of timing. That would have put it at 21 degrees at the top of the gear. I did this with Extreme tune for a few days just to get 18 degrees at the top of the gear. What do you think would have happened in cool weather? Boom with 21 degrees of timing in cold weather when I wouldn't want more than 16 degrees of timing.

I didn't just pull this out of my a$$. I have been datalogging this truck for years using many different tunes and I have a stack of timeslips that would choke a mule. I've done more than my share of homework on what works and what doesn't work.

I know the theory of a cooler charge should allow you to add timing hence the intercooler and that's how the SCT and Chipmaster software act much like the stock tuning. That's all fine and well with a stock truck at low boost and low factory timing.

The reality of it on a boosted up L with advanced timing is quite different. In the hot weather the air is thinner producing less boost. The temps will be higher after the intercooler but the lower boost more than offsets this allowing more timing to be added. When it gets cold and you suddenly have 2 extra pounds of boost from the weather if you're running the warm weather tune get ready for some detonation at the top of second gear with it getting worse in Drive. This happens with a locked down tune like the old Superchips programs. What do think is going to happen with a program trying to add more timing when the IAT2 reads cooler? BOOM!!! How many times have we read about this happening when it get cold.

With all this being said you could run a tune that is dialed back enough to be fine in cold weather but it will run like a turd in the heat. We won't get into how much this will cost you at the track.

When I see timing tables on the software screen and I get totally different values when datalogging that makes me uneasy. I was checking my IAT2 temps, intercooler operation and several other things just to find out everything was working properly.

 

LTNBOLT,

Has the max allowed table worked for you? It doesn't for me in all cases, I've still seen more than what I put in as max allowed in certain cases.

As far as the adding timing in cold weather, you can zero that section of the table out if you want so no timing is ever added due to air temp. I would not recommend reducing or eliminating the timing retard due to high temps just to make sure you get as much timing as you want. That is a safety issue and a guy may run into detonation. Better to fix the air temps than eliminate the retarding of the timing when the IAT2 exceeds 150 degrees.

There is also a spark adder table in regards to A/F; on the stock 03 tune any richer than 11.7 would start adding timing, more the richer it got. They also have a spark adder for A/F to change the max allowed, which would override your max allowed table.

I would really like the story on the max allowed table. If it's truly max allowed then you could limit your max timing there and never have the cold weather problems, as long as you don't allow the other tables to override it.

Jody

 

When it gets cold these motors tend to make WAY more power than they do at warmer temps. Some of the motors that go BOOM break rods but show zero signs of detonation.

Some modified trucks have detonation in the summer but not the winter and some have it in the winter but not the summer. This is a tuning issue (tables and adders), not a strategy issue.

Don't expect to see your timing match the tables, you'll be disappointed. You'll need to monitor many tables and other parameters to determine the full spark picture.

 

Jody,

Mine is a CUX2. I don't think it's as user friendly as newer programs. I'm not using the Pro Racer Package. This is a tuner that has the full meal deal. I was just looking over their shoulder when changes were being made or where they veiwed changes made by SCT. They made it happen but it didn't go quietly.

When I was running a RWTD Diablo tune it pulled 1 degree of timing for no good reason. It was in the mid 60's outside and IAT1 & 2 were plenty cool. James couldn't believe it. He finally locked it down to get the timing we were after.

This truck is one of those factory freaks that loves timing. It feels completely flat if it doesn't have 2 degrees more timing than the average L needs for the same mods.

 

A broken rod end sticking out of a hole in the block is a pretty solid sign of detonation.