Plug change

Larrylu · February 09, 2014, 05:39:43 PM

Just finished installing new SP-534 plugs. I think the old ones look pretty good for 50K. The old ones came out gapped pretty consistently at .040. I had no problems with the install but I did find sort of a mystery with my subsequent test drive. Most of the time my WOT events are from a roll as it's a bit less conspicuous to pull off. I am running a 4+ update which did away with the mystery "Sport Mode" that was present in my previous version of 4+. I did a test on an entrance ramp and the car pulled pretty well... enough to feel some strong torque steer and a good chirp on hitting second and continued to pull strongly in third. My boost was no higher though (12 lbs.) so there goes my hope that the plugs might somehow causing a dial down of boost. Here's where I got real interested. I decided to try a 0 to 60 run using Torque. On an on ramp with no one behind me, I came to a stop. I left it in D and brake rev to 1500 RPM then launched. Car stayed in first. First time that's ever happened to me. Tried it again with the same results. Turned the car off and then back on for another try....same thing. So it shifts ok WOT from a rolling start. From a dead stop WOT it's stuck in first. No I was not in manual, I triple checked. I reloaded my older version of 4+ that has the funky mystery mode. I have a lot of miles on this tune and it has no problem with shifting from a standing stop. In fact I think it shifts crisper and downshifts more reliably than in D. I will redo my test ASAP probably tomorrow.

DJE624 · February 09, 2014, 06:01:15 PM

Very strange Larry. Don't have a clue what it could be. I have been running my custom Stage 4+ for a number of weeks now and haven't had a problem at all. I'll most likely loading a new version Friday when/if I get the pipes put in. I have never seen any mystery/sport mode.

Larrylu · February 09, 2014, 06:56:24 PM

Dave. Weren't you telling me about a tweak to your 4+ that gave some sport mode like functionality? Early on it was called a mystery mode because as it first surfaced no one knew much about where it came from, what it did or did not do and who had it and who did not. Big mystery for sure. Glad I have it to go back to. But what is causing my most recent version to not up shift from a standing start....no clue. Thought I read a few people experiencing shifting problems from a stop and not from rolling but not sure. I hope it's not a tranny issue. Can't wait to run out and test again with my tune change.

SHOdded · February 09, 2014, 07:10:11 PM

Hmmm. PCM may not be picking up the change in plugs? Maybe the car needs to relearn idle? In which case, disconnecting the battery would be worth a shot if this behavior continues.

Larrylu · February 09, 2014, 07:21:01 PM

Idles good. Runs smooth. No error codes. Shifts fine from roll. If I had not decided to do a 0 to 60 run I would not have a clue. Anxious to try now with my old version of 4+. I can't think how this could be related to my plug change???

SHOdded · February 09, 2014, 07:24:39 PM

Ya, I don't understand it either, just brainstorming. Comparison with old 4+ tune will hopefully illuminate the real issue.

DJE624 · February 09, 2014, 08:28:29 PM

My custom tune does have a little trans work.. Firmer, and supposed to drop a gear when shifted into M. I haven't really tested it thoroughly. I know that over 50 when I shift to m, it drops a gear and if you coast, it will drop another. This is meant, I guess to help drop speed after the 1/4. I really need to get the Torque going and do some real testing. BTW, it does have added boost below 2K and above 5K. Dan was able to make these tweaks from when I had a dyno out there last summer. After I get these other projects done, I'll be going to the 3 Bar tune.

black99lightning · February 09, 2014, 08:36:54 PM

Quote from: DJE624 on February 09, 2014, 08:28:29 PM
My custom tune does have a little trans work.. Firmer, and supposed to drop a gear when shifted into M. I haven't really tested it thoroughly. I know that over 50 when I shift to m, it drops a gear and if you coast, it will drop another. This is meant, I guess to help drop speed after the 1/4. I really need to get the Torque going and do some real testing. BTW, it does have added boost below 2K and above 5K. Dan was able to make these tweaks from when I had a dyno out there last summer. After I get these other projects done, I'll be going to the 3 Bar tune.

Did they send you an updated tune, or did you change something that necessitated a change? I ask as I've been running the same 4+ for well over a year now and have never asked or gotten any revisions? I guess I should ask for revisions for my offroad DP's. Should be here next week.

DJE624 · February 09, 2014, 08:42:05 PM

I don't believe there are any revisions to the Stage 4+. I got the tweaks because they had done my dyno there and they had a good feel for my car. I did just get a revised tune for the off road pipes and TStat. They are on my MyCal waiting to be loaded when I get the work done. Hopefully by Friday.

black99lightning · February 09, 2014, 09:02:08 PM

Quote from: DJE624 on February 09, 2014, 08:42:05 PM
I don't believe there are any revisions to the Stage 4+. I got the tweaks because they had done my dyno there and they had a good feel for my car. I did just get a revised tune for the off road pipes and TStat. They are on my MyCal waiting to be loaded when I get the work done. Hopefully by Friday.

I just sent them an email requesting updates for my offroad downpipes, SCT tuner.

DJE624 · February 09, 2014, 09:23:26 PM

Cool. I know it will turn off the O2 sensors so you don't throw a code and maybe tweak it for the higher flow you're gonna get.

Larrylu · February 09, 2014, 09:51:04 PM

Here is my perspective on 4+. I got it and installed it as soon as it was released. Short time after installing and enjoying mightily, I happened to accidentally drop it into manual without intending or noticing. The only thing I noticed was the new icon in my display of a car going downhill. Never there before. I described it to BPD and he recognized it right away and said his car had that functionality also. Here is what that new functionality is. When stock, M meant paddle shift. No paddle no shift. It would hold a gear and bounce off the limiter. With my new 4+ my car in M will shift itself. A bit firmer than D. I think it downshifts more aggressively also. Once a paddle shifter is touched the stock manual function takes over. No paddle touch and it shifts itself. No 6th gear, and more pronounced engine braking. No numbers in the display either....just says M. I thought the source of my new functionality was my new 4+ tune and I started trying to figure out why some of us with 4+ had it and some did not. Never did figure out exactly how or why. LMS never shed any light on it but several weeks later I got an email from LMS rep saying that he was sending me an updated 4+ file and when I loaded it my car going down hill (grade assist) icon was gone and so was the new functions. Back to normal shifting. I kept my old file though because I really liked the new features. Now I hope that by going back to that tune my up shifting from a standing start will be back and it will be good to have my funky grade assist "Sport Mode" back.

DJE624 · February 09, 2014, 10:04:08 PM

OK Larry. Now that you mention it, when driving and shifting into M, I get the car on the hill light. Then, when I click the paddle, it shows a gear number. Dan said something about doing this for somebody. He wanted me to test and see what I thought. Like I mentioned, I haven't really tested it yet mainly because the weather got bad . I think somebody didn't like it and he took it off. He said he would take it off mine if I wanted him to but I don't know yet. I'll try it out a little bit more when I go to work later and let you know what happens.

bpd1151 · February 09, 2014, 10:06:43 PM

Quote from: Larrylu on February 09, 2014, 06:56:24 PM
Dave. Weren't you telling me about a tweak to your 4+ that gave some sport mode like functionality? Early on it was called a mystery mode because as it first surfaced no one knew much about where it came from, what it did or did not do and who had it and who did not. Big mystery for sure. Glad I have it to go back to.

It may have been termed a "mystery mode" but it turned out to be nothing more than merely a programming matter.

It is (or was) simply a "grade assist" mode.

This option was inadvertently turned on during some of the (at that time) ongoing tune revisions being performed by LMS.

It has since been isolated and turned off.

If it reappears, you may (I stress may) be running an older revision. I would inquire directly with LMS.

This is what the icon appeared as, on those '10-'12 model year's of SHO's:

From what I understand, using this mode, did nothing more than change shift points, and eliminate 6th gear IIRC. IDK..... been a few years.

Larrylu · February 09, 2014, 10:22:08 PM

I suppose it's conceivable he may have turned it off for me. I never said I didn't like it. I was just asking questions. Actually I like it. Isn't the whole idea of a tune "simply programming details". I like knowing what is going on and why whenever possible. When there are no answers I usually feel like asking more questions.