Dan's Build

Dan Carter

Supporter
I'm bringing my P0606 ECU code story back under my build blog. Received the new ECU and installed it Friday. Downloaded the stock file and sat down to make a comparison to the tune currently on the car. Unfortunately to get to this point, I had 3 tuners do their thing, and each was “recommended”. The first two tunes were questionable post-delivery, because the car never ran right. The 3rd tuner (Ed Gomez, Pro Edge Tuning
www.ProEdgeTuning.com) is the guy Allan uses for all his builds. Ed lives in the NE and travels to do all the tuning for a company in Tallahassee FL that still builds Trans AMs ($184k and up) and I got to visit the company while Ed did some tuning for me (really nice cars). By the time Ed got my tune, the other two guys had made changes, but we had no way of knowing who did what.

The jury is still out on should you/can you change the stock GM throttle table without bricking the ECU, and there is a lot of discussion on tuning forums on the subject (note, GM says do so at your own risk). Anyway, I broke down and bought the HP Tuner reader/writer and even thou I lack the skills to change the tune, I can at least read it, download the tune and run the car to watch the engine data, which has made the purchase worthwhile. BTW you don’t need to buy any credits ($50 each, 2 required) to download tunes, review and record engine data, only to write to the ECU. Now, I found a lot of changes to the tune I have compared to stock, and many probably not required, to include the throttle table. I sent both the current tune and stock files off to Ed, who will review and send back a tune that is his alone without any unnecessary former changes left behind. HP Tuner software lets you review and compare two tunes and visually show the differences for review, a great feature.

Not certain it makes a difference, but I noted that the GM part number for the original LS3/480 ECU and the current one is different (new one is the 331part), but both are listed for the crate motor application. As soon as I get the file back, upload the tune I will start driving again and can report back if the code comes back, which will be chasing a ghost, but I’m hoping all will be OK.

More to follow.

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GM keeps changing part numbers on the engine controller and crate engines - the last one I bought was superceded above the prior one - not sure why the effort on their part to do it

Hope it works out; I know how painful it is to chase gremlins and hope like hell the solution of replace everything works!
 

Ken Roberts

Supporter
My GM Tech2 scan tool has a section in it devoted to the GM Performance engine control. See if you can find someone locally that can hook one up for you.
 

Dan Carter

Supporter
A new window development. Earlier in my build I conducted a product test on making a Frit for the door/rear windshields. At that time, I did not conduct a pull test and I did not complete a time test to see how well the selected Krylon (molecularly bonds-“riigghhttt”) would hold. Well now I know what time has yielded. In the picture below note the bubble look in the black frit along the rear window. The Krylon has let go of the Poly. I have taken the drivers window off using a windshield wire pull cutter, very slowly making sure I didn’t cut into the paint.

In the second picture I did run a pull test with two new Frit experimental products……epoxy primer and Raptor truck bed liner…...that’s right truck bed liner. The red tab is used in pulling car dents with a slide hammer, so I ran the poly in two sections, one epoxy primer and the other bed liner. Both tape edges are superior after pulling blue pinstripe tape off.

Next a pull test. While priming both “paints” with windshield primer, I noted that the primer was able to take the epoxy primer off the poly (that’s not supposed to happen), but the primer did not phase the bed liner. Both products gave an excellent black Frit from the front BTW. I then ran window urethane for about 7 inches and stuck two each red tabs into the urethane and allowed them to dry for 2 days. I used my slide hammer and aggressively pulled on each tab. They all held. So why are three missing, glad you asked. I went to failure on the next pull test. Off to get my vice grips…….grab hold and pulled until it pulled loose. If that window is being pulled with the force I was using, then bolts would be the only way to hold it to the car. I nearly snapped the poly in two with the last tab. When they did let go, it was the union of the tab to the urethane and not the “paint” to the poly. So, I’m going to use the Raptor bedliner this time. Will UV cause a breakdown, probably not as the bedliner is the same in my pickup and its been on for 12 years roughly. Raptor is thin so its not a super thick Frit. I’ll glue the window in again this week. Are we having fun yet?

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Joel K

Supporter
Thanks for sharing Dan, who would have thought of bedliner for a frit, Just wondering how you came up with that approach.
 
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Dan Carter

Supporter
I want to say it’s talent, but that would be BS...lol. I have been using this Raptor product for a lot of other car projects and have been impressed with its project flexibility. It’s also tintable so I have used it to protect vulnerable parts for debris damage. It has worked well and after being hit hard many times it never lets go. So the idea just struck me, try it. I rolled it onto the back side of my test piece and while it appears to be thick, it’s really not. It grips like no other test I have done, so why not, but once again time will tell I guess, but confidence is high. I know this time that 80 grit sandpaper will not take it off poly, so it has to work. Fingers crossed.
 

Dan Carter

Supporter
Many if not most of us gear heads focus a lot on mechanical things to solve problems (at least I do). Anyway, I ventured off into a new world by attempting to learn as much as I could about the tuning process, so I ordered a tuning school course. Wow, there are so many ways to screw up your car it isn’t funny, but I did learn there is a very systematic way to approach the tune based on the modifications made to an engine.
I’m certain there are some of you much more experienced at this stuff so be nice to me with this post. I’m sharing because I recall two things, I’ve come across that may be of benefit to those of us using the LS3/480 with GM hot cam and have or will experience stalls and hard hot starts. (BTW stock table pictures in this post). When your time comes to tune your car, ask your tuner to look at these two items and see what they think (they may very well say it’s a load of crap…so be it), but it did work for me, so here we go:
  • I recall some of us were having HOT start issues, and an occasional stall while driving/decelerating. Look at the following table from the tune (RPM vs Temp vs Spark). Note the spark at the higher temps 212+ (yes that’s hot) are set at -10 to retard the engine. The school house will tell you this can be a problem and to reset these values to in this case to 5 degrees to help eliminate issues with a hot start. I can only tell you it solved my problem.
1575319077748.png

  • The second discovery is addressing the stall problem some of us have experienced. There is a table called the throttle follower airflow step-up whose purpose is to control the throttle bodies closing after letting off the throttle rapidly (aka rapidly taking your foot completely off). It adds air based on the throttle closure to prevent stalling. Anyway the school house says to add 1 gram/second for occasional stalls and up to 2 grams/second for more frequent stalls. Again, I can only add that it worked for me.
1575319106141.png


I spent a ton of money on three tunes prior to ordering the home study course and have my own HP tuner now. Be warned, that the system works best with a wide band 02 sensor and its best to buy the systems that work directly with the HP tuner for logging wideband for WOT tuning. However, for me fixing the low-end street driving portion of the tune gave me the car I wanted to drive, not the race tune provided by the stock GM version. With so much at stake on this project, I recommend you consider having your own tuner (pro version) and take the beginners course. If nothing else, you can speak the language and analyze any tune you pay for. I’m discovering that some tuners do things that IAW with school protocol, deviate from a systematic tuning method. The interdependencies between ECU settings is huge and merits your understanding IMO.

I am stunned me how two completely different approaches to the tunes I have can vary so much and still provide a relatively descent drive……it hurts my head.
 

Joel K

Supporter
Many if not most of us gear heads focus a lot on mechanical things to solve problems (at least I do). Anyway, I ventured off into a new world by attempting to learn as much as I could about the tuning process, so I ordered a tuning school course. Wow, there are so many ways to screw up your car it isn’t funny, but I did learn there is a very systematic way to approach the tune based on the modifications made to an engine.
I’m certain there are some of you much more experienced at this stuff so be nice to me with this post. I’m sharing because I recall two things, I’ve come across that may be of benefit to those of us using the LS3/480 with GM hot cam and have or will experience stalls and hard hot starts. (BTW stock table pictures in this post). When your time comes to tune your car, ask your tuner to look at these two items and see what they think (they may very well say it’s a load of crap…so be it), but it did work for me, so here we go:
  • I recall some of us were having HOT start issues, and an occasional stall while driving/decelerating. Look at the following table from the tune (RPM vs Temp vs Spark). Note the spark at the higher temps 212+ (yes that’s hot) are set at -10 to retard the engine. The school house will tell you this can be a problem and to reset these values to in this case to 5 degrees to help eliminate issues with a hot start. I can only tell you it solved my problem.
View attachment 102499
  • The second discovery is addressing the stall problem some of us have experienced. There is a table called the throttle follower airflow step-up whose purpose is to control the throttle bodies closing after letting off the throttle rapidly (aka rapidly taking your foot completely off). It adds air based on the throttle closure to prevent stalling. Anyway the school house says to add 1 gram/second for occasional stalls and up to 2 grams/second for more frequent stalls. Again, I can only add that it worked for me.
View attachment 102500

I spent a ton of money on three tunes prior to ordering the home study course and have my own HP tuner now. Be warned, that the system works best with a wide band 02 sensor and its best to buy the systems that work directly with the HP tuner for logging wideband for WOT tuning. However, for me fixing the low-end street driving portion of the tune gave me the car I wanted to drive, not the race tune provided by the stock GM version. With so much at stake on this project, I recommend you consider having your own tuner (pro version) and take the beginners course. If nothing else, you can speak the language and analyze any tune you pay for. I’m discovering that some tuners do things that IAW with school protocol, deviate from a systematic tuning method. The interdependencies between ECU settings is huge and merits your understanding IMO.

I am stunned me how two completely different approaches to the tunes I have can vary so much and still provide a relatively descent drive……it hurts my head.
Dan, I give you a lot of credit to learn all this stuff. Hopefully it pays off with a very drivable car. Sounds like you have made some good progress.
 
I have had two guys tune my car so far. The first was an out and out fail due to issues with the engine itself. The second tune got it to run strong in the mid and upper ranges, although I could use a crispier throttle response off of idle. Recently the mileage has gone south from 26 mpg highway to sub- 10 mpg highway (supercharged 700 HP). I am told it is most likely bad oxygen sensors, new ones on the way - we will see. I now have the guy I trust the most looking at the tune. He being the guy who tuned all my road race bikes and is just now branching into car tuning. So far he has very little good to say about the HP Tuners software, very user unfriendly. And this coming from a guy who deals with Motec based electronics regularly.

Really looking forward to what we find out.
 
Thanks for this information Dan and awesome you took this on yourself. I have a good buddy with HP Tuners and while he's tuned a few of my LS engines with a typical basic tune (cars always felt so much better afterwards), I wasn't interested in doing it to this car.... I don't really care about HP gains, just more driveablity like you. Armed with this info, one day I'll drive the car to him and give these changes a shot on mine unless he suggests otherwise. I also plan to get the idle bumped up a bit per Allan's suggestion which should let the car idle much better without surging when the AC kicks on.

My stall issues is mainly at idle or very low RPMs, sounds like yours is more WOT?
 

Dan Carter

Supporter
Del
My stalls were street driving stalls mainly when coming to a stop. They were very inconsistent hence very hard to isolate. When I read about this in the school books, I made their recommended adjustment and it seems to have stopped the problem. I too am mainly tuning for street drive ability, so that has been my focus. I’m no master tuner, just tired of not understanding enough to ask the right questions.

What has been the most challenging is comprehending the collateral impact of one adjustment will have on another aspect of the tune. That is why I appreciate the systematic approach used by the school house. I’m plodding along and reading the material a third time while practice tuning with the assistance of the school, so it’s a pretty good deal.
 
Del
My stalls were street driving stalls mainly when coming to a stop. They were very inconsistent hence very hard to isolate. When I read about this in the school books, I made their recommended adjustment and it seems to have stopped the problem. I too am mainly tuning for street drive ability, so that has been my focus. I’m no master tuner, just tired of not understanding enough to ask the right questions.

What has been the most challenging is comprehending the collateral impact of one adjustment will have on another aspect of the tune. That is why I appreciate the systematic approach used by the school house. I’m plodding along and reading the material a third time while practice tuning with the assistance of the school, so it’s a pretty good deal.
Good to know and sounds pretty similar to mine. Sometimes when I'd come to a stop with AC on the RPMs will start jumping around and if I don't blip the throttle it'll continue to do it until it finally dies. Last week when I was driving around, weather was MUCH cooler and didn't need the AC 24/7 so when I'd come to a red light I'd flip the AC off. Put ~70 miles on it doing this and never had it act up. It does make sense a slightly higher idle could cure it as well, I also think a higher idle could make it a bit easier to take off from a stop.
 
Thanks for sharing your harrowing experience with tuning your excellent build for driveability. I love your pioneering spirit to tackle the tuning process which can be such a black box to the uninitiated.
 
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