Mrr23...Hptuners part 2
This is a discussion on Mrr23...Hptuners part 2 within the Computer & Tuning forums, part of the LSx Technical Help Section category; Wanted to get an update from you to see how you're coming along on your car. I really haven't had ...
09-12-2007, 10:35 PM #1
Mrr23...Hptuners part 2
Wanted to get an update from you to see how you're coming along on your car.
I really haven't had an abundance of time the last month or so to play with mine but I did get some time in last weekend and a little this week. Got my ve done and now I'm working on the MAF table which should be good to go in 1 or 2 more logs.
I also finally started to tackle the shift points. I've had them fairly conservative up until now. It's been shifting at 5900 rpm. I'm gonna raise that up a couple hundred rpm. The 2-3 shift won't be much problem but the 1-2 is proving to be a pain. I don't really get enough traction on the street in first to run it up to the redline. I've given up completely on trying to launch it. Even letting the car roll in first then slowly getting into it to WOT the tires end up spinning. There's definitely worse problems to have and I'll get a few good shifts in there before it's over with. I'm gonna lower my tire pressures way down and try it that way next. I have Nitto's with only a few hundred miles on them so it's not like they're bald. I forsee going to 15" tires at some point.
09-14-2007, 04:02 PM #2
i finally got into SD tuning for the VE tables. went pretty well on the first three shots. almost got it finalized. got into a surging issue again on the third tune up. for giggles, i put my over/underspeed idle spark correction tables back to stock. fixed the surging right off the bat. almost ready to plug the MAF back in.
shift points, i changed mine to 6500 rpms and raised the mph tables 3 mph. i noticed, in the track logs, the 1-2 shift was happening at the right mph, but not the right rpms. i think the PCM relies more on mph over rpms for shifting. started playing with shift pressures on a couple other cars. doing good.
after i'm done with the statewide gathering i'm hosting, i'll start my MAF tuning.
09-14-2007, 08:47 PM #3
Glad you got your surging issue beat. I'm about ready to plug the maf in and put my new O2's in but to be honest the cars running good right now and I'm kinda hesitant to do it. Not sure what the cars gonna run like after everything is plugged back in.
Back in the day ( ls1edit days) I talked to Nogo about shift points. He used the mph for the 1-2 shift and rpms for the 2-3 and 3-4 shifts so that's the way I've been doing it ever since.
I saw a post by Russ K on shift firmness that I tried in the GTO and liked so much I changed the bird over too.
Using the "shift pressure" table he puts zero's in the 0ft/lb column and 40 in the 640 ft/lb column then clicks Interpolate Between Horizontal Bounds. Copy that table and click on "undo changes" then paste special >add. I really liked how that worked out. I did both my cars but am gonna go 0-50 on the bird due to the extra stall I have in that one.
09-14-2007, 08:53 PM #4
For shifts, the MPH must be met BEFORE the RPM and then it will shift. If the MPH is X, and X occurs at 6600 RPMs, you command the shift at 6000, and your limiter is set at 6400, your car will hit the limiter. If you then zero'd out the MPH, you'd get your shift closer to the commanded RPM, which will put you back under your limiter. Many times I have stubborn "built" trannies, and it has helped before to use and leave zero'd out MPH tables. Just what I have seen.
09-14-2007, 08:57 PM #5
yeah, both have to be met. I've never tried zeroing out the mph table because I've always read that it may cause the tranny to hunt for shift points if the mph and rpm aren't somewhat close to where they should be.
09-18-2007, 11:28 PM #6
ran a 12.1 @113 on this current tune. AFR was pretty good through the run. I did see a little lean spot. Had 4 degrees of KR during all my runs though. When I would stage the car my AFR would go lean then when I launched KR would go to 4 degrees and work it's way down throughout the run. I'm trying to find the root cause of that now. I'm assuming it's due to it going lean while staging the car up and it's a transient problem I think. I'll post my log as soon as I transfer it over to my desktop from the laptop.
09-19-2007, 05:25 AM #7
i've seen that KR problem on a couple of vehicles i've been playing with. i've isolated it to the rich/lean and airflow mode tables. depending on which airflow mode you are in, it changes the point where the switch point is from rich to lean. i had a car with a serious issue of stumbling and poor idle. kept noticing how lean it was at idle. no matter how much i added fuel, it kept taking it away. reason why is the computer is trying to get to the switch point for rich/lean at the given airflow mode.
i'm going off memory because i don't have my stuff with me.
airflow mode 1 has a switch point of 445 mV. so, the computer leans the mixture out until it reaches the switch point. with aftermarket cams, this is too lean at idle. i ended up raising the table 200mV.
try that and see if the lean condition goes away at idle. if the lean condition gets resolved, the knock problem will cure itself. the knock is from too lean of a mixture.
09-19-2007, 08:14 AM #8
I'll try that this weekend. Just add 200 mv to that whole table?
Here's another issue I'm having that I posted at hpt's site but still haven't really gotten a good answer as to what's causing it.
Anytime I crack the throttle while cruising around the car goes a little lean for a few seconds and anytime I let off the gas the car goes a little rich for a few seconds. Doesn't have to be hard acceleration either. Any throttle changes at all result in the AFR swinging one way or the other. This also does it when at WOT. On the shifts the car jumps lean for just a second. There's also a delay going into and out of PE. I'm wondering how much of this stuff is directly related to me running OLSD and will go away when I go back to CLMAF.
09-19-2007, 09:12 AM #9
i added 200mV to the entire table.
sounds like transient fueling. something i'm not daring to touch.
09-19-2007, 02:45 PM #10
yeah, I was thinking about this on my way into work tonight. I'm in OLSD so adding to that particular table wouldn't do anything for me. I'll play with the transient tables and keep you updated if I learn anything......or blow the car up trying.
09-19-2007, 04:46 PM #11
well dang it. guess that won't work then. now, there is a minimum injector pulse width reference.
09-21-2007, 06:02 AM #12
finished up my SD tune. morning logs showed about 6% rich. afternoon logs showed about 6% lean. so, i'm pretty much right in the middle. just got through turning the MAF back on and dialing the idle in. time for some driving logs.
09-21-2007, 06:05 AM #13
09-22-2007, 07:03 AM #14
Mrr23, when your done tuning with those cars, when can you help me with mine? Spoke last time, but nothing concrete!
09-23-2007, 05:27 AM #15
up to you.
09-24-2007, 02:52 PM #16
HECK NO MAN, its up to you!! LOL!! I'll wait til your done working out your bugs. Besides, awaiting for my longtubes to come in! Ill let you know bub, thanks again!!
09-24-2007, 04:38 PM #17
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