I disabled the cat warm up on my LNF. Now on cold start ups or a startup after sitting for a while, it has a rough idle and I watch the vacuum teeter back and forth like the wastegate is opening and closing.
How can I tune this out?
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I disabled the cat warm up on my LNF. Now on cold start ups or a startup after sitting for a while, it has a rough idle and I watch the vacuum teeter back and forth like the wastegate is opening and closing.
How can I tune this out?
Cam tables help a lot, GMTech has posted some moderate ones that work well cold and warm.
Sweet. Thanks a bunch.
I'll look those up.
I'm slammed at work right now. (My browser with all the forum tabs is up when I go to flash a car at work so sometimes I can't help but look at what's up online!)
Maybe tonight I'll post up some good info on fixing the cold start issues that come up after doing the cat warmup delete. It can be fixed, we've got two Sky's with perfect cold starts and warmups thanks to Chris and Bill.
Hey Chris or Bill, any updates for us? The "Load Damping" still doesn't seem to do much. Didn't you say you had some ign timing tables or load tables in the works for us?
That would be phenomenal, thank you. I found a set of cam tables that you posted but I'm not 100% positive they are the right ones (I think they're warm tables) and I'm doing this on my phone so I can't get the link to the post just yet.Quote:
Originally Posted by gmtech16450yz
Wait on the cam tables I have much better ones. I'll post tonight.Quote:
Originally Posted by Gremlin85
:worship:Quote:
Originally Posted by gmtech16450yz
Here you go, try these. (You too Tom, you might like these better.)
The cam tables I posted in my learn and share thread are pretty aggressive as far as leaning towards power and away from mpg, as Tom mentioned. They also work better on my particular setup because I'm far from stock. These tables I'm posting here work extremely well for power and mileage, just make sure you're particular freeway cruise rpm is the same as where I have the exhaust timing retard in the tables. Watch your rpm and load at 65-70mph and retard exhaust around there, then smooth out around it. You're gonna get a big spike in the table image, that's ok and actually less than stock if you do it right. (not as steep)
Make ALL cam tables for intake match each other, and same with exhaust tables. That means knock, warmup, etc. Make sure ALL idle tables for the particular cams match each other also.
I'll also include a screen shot of some injector and idle tables. I believe these inj timing numbers work better with the cam timing. If you notice on the stock inj timing tables, there's a pretty big retard around the same spots that cam timing is retarded. (Imagine that!) My theory is they obviously want inj timing to match cam timing, and moving inj timing back up along with cam timing works much better. On idle speeds, raise desired numbers in these tables, but also realize you'll need to massage DAL's in those areas to make sure you're not getting any ign timing dump. (For those that don't know, if you request more DAL than is needed at low rpms or idle it will retard ign timing to try to control idle speeds. This is standard practice on many ECM's. The balance between airflow and ign timing is what controls idle speeds, mess one up and you'll mess the other up also.
You may also want to work on the ECT/Ign timing table, if you're still getting fluctuations in the idle, try raising the timing in the specific cell that the warmup is at as far as load, rpm and coolant temp.
Oh, btw, what you felt might have been the wastgate going back and forth is most likely the throttle plate and ign timing hunting up and down because it can't maintain desired idle speeds without overshooting. Try these things first. I guarantee these LNF's can be made to have a nice, normal cold start with a mild fast idle (which is what you want) and enough ign timing to run smooth and quietly. Thanks again Chris and Bill for giving us that tiny little button to turn Cat Warmup off!
http://i841.photobucket.com/albums/z...owerandmpg.jpg
http://i841.photobucket.com/albums/z...dinjtiming.jpg
I'm running a bit more negative intake cam in the midrange for economy, but nowhere near stock. I max around -25*
Wow, thanks. That's way different than what I had.
I, too, had closer to -25* midrange. I'm not worried about gas mileage, I want maximum power.
I'll test these out and see how they suit my needs and wants. I'm thinking they'll be pretty damn decent as they are.
Thanks again! I've always been pretty scared to go too far with these tables.
Maybe Im mixing something up here, but doesnt more timing get better economy not less? So -10* would get more than -25*.
Not on cam timing. What they're doing when they retard cam timing is lowering dynamic compression, which lowers pumping losses. Think about how hard a high compression motor is to turn over vs. a low compression motor. Multiply that by 3k rpm and you'll see why lowering dynamic compression to only what's needed has an effect on parasitic losses. Remember, if you only need 75hp to maintain 70mph, a 100hp motor will do it more efficiently than a 500hp motor will.Quote:
Originally Posted by acesneights
Tom, exhaust cam timing has more of an effect on mpg's than intake. Try lowering your intake retard a little closer to mine and making sure exhaust is closer to stock if you want mpg's. Are your inj timing numbers close to mine? They seemed to really help the cam timing changes as far as mpg's and torque goes.
I just updated the inj window tables yesterday evening. I'll see how the mileage goes. Looks like around 24 mpg on 60% ethanol right now. Hoping for dry roads to flog it a little. Very rainy spring here. If I get out of work tonight I'll post the cam tables up. They will look familiar to you except the highest load column. I have the best luck with the stock tables so far greater than 200% load.
Here's my cam & boost tables with DAL's at 255 in the highest load columns & a bit more above 5k in small steps. Pretty flat 24-25 psi boost in 3rd & 4th with the 50* IAT2 range, .898 PE Lambda. Should give a few guys a fair starting point.
Remember I'm pretty well bolted up so it flows 32 lb/min VE in the upper midrange with stock MAF tables. Never got over 125 to see how 5th pulls. lol.
http://www.hptuners.com/forum/attach...1&d=1303344216
Here's the PE, DAL's and timing. All 4 timing tables the same.
Use GMTech's Inj Window tables and have fun. I've noticed that the Commanded PE lambda runs .007 richer in the table when logging than commanded in the tune so .898 is truly .891. YMMV.
http://www.hptuners.com/forum/attach...1&d=1303345172
are you keeping your malt table at 100% all across? did you limit the torque in 4th and 5th to tame the boost spike or save the clutch?
MALT is 100% from 2500 rpm up. Torque limit in 4th & 5th is to clamp boost under load at ~24 psi or it would see 26 psi in those gears. I has no clutch slippage. SPEC Stage2+. :D
Holy timing!
God i wish I could run E85 :(
Meth is coming in soon, though. I think that'll help a little.
My pathetic timing...
http://www.hptuners.com/forum/attach...1&d=1303356287
That's 3-4* more than I could run on 93.
This is good info for others too, not just Iam Broke...
Hey Tom I think we can get you to 28mpg with a little more massaging. You're our mpg mule so it's all up to you to test out mileage theories! It sounds like you have a nice freeway commute to get solid results with. My son is getting around 24 and I'm getting 21 or so with about a dozen speed runs per tank. We're both running E47.
Here's some ideas...
Try either advancing your intake numbers or retarding the exhaust more right around that freeway cruise area. Your overlap numbers are closer than stock and I don't think you're getting as much EGR effect as you can. Remember, copy the exhaust table to the intake by "special- add" to see what the overlap looks like. (Obviously you don't want to leave the tune file like that, just don't save when you're done looking at overlap.) Basically you want to keep the intake and exhaust numbers similar, or even have the exhaust more retarded than intake for more cylinder charge exhaust dilution. (we're just talking about freeway cruise areas for mpg here.)
Another thing that will help a lot is ign timing. We can't do a direct comparison of our timing tables because I'm using a different approach than you for the E tune. I have pretty aggressively advanced main tables, but I also advance based on IAT quite a bit. The IAT add and multiplier tables give you more control over when you're adding timing with the E or in my case, Meth. It also gives you more safety when IAT's get too high, you can make sure you're timing isn't too crazy unless intake temps are safe. Look at your timing drop below 2500-3500, it's pretty steep. It can take a bunch more timing down low, and that's where you're at freeway cruise too. Advance the crap out of it down there, or at least smooth everything out more by increasing. Another thing I do with the 4 tables is don't just pick one table to use and make the others the same, I do a series of copy/pastes between the 4 tables to make sure you're using all of the HIGHEST numbers of all 4 tables in every cell. The tables all have cells that are higher AND lower than the others, so just using one will mean there are spots that you're loosing advance. (Sorry if any of this is old news to you in particular Tom, I know you've figured out a bunch of stuff on all of this. I'm using your tables as an example for others and also so I can pass along some of the things I've learned. In other words, we have very different approaches on some of this stuff and that means we've learned lots and can learn more from each other!)
Here's another thing I noticed... Your "torque/gear" tables can be tweaked more I think, I also use those tables with great success to control boost. I learned long ago that it's VERY useful to be able to control boost per gear. If you lower boost by DAL's or MALT's or now with the actual boost tables to eliminate the boost spike, you're sacrificing boost in lower gears to keep the spike away in higher gears. What I've done is reduced torque/gear severely in the upper gears also, but ONLY around the 3700rpm boost spike area. Once you're past that area, like 4k or so, you can go back to full 100% in every gear. That is unless you want to control traction of course. Same with down low, I'm at 100% up until 2500rpm or so.
Again, not trying to pick on your tables Tom, you know a lot and yours are better than most. Advance the crap out of midrange load and low rpm ign timing, dial in more cam overlap and oh, I just thought of one more thing... Decel DAL's. I've never seen anyone mess with the rest of the DAL table, 99% of tuners just change the 2 far right columns. Why? It's a big table with lots of throttle mapping control. I don't think there's a single cell in my DAL's that's stock! So here's my thought as far as optimizing mpg's, try lowering coastdown DAL's a lot, like maybe 50% even. What this does is makes sure you're getting into DFCO more often, and also even if it's not in DFCO, you're burning less fuel with a smaller throttle opening. You can drop the numbers quite a bit until 1250rpm or so. Work on the 10-19.9% columns. This will also help on exhaust burbling or backfiring. Here's another one, MAF correction table on decel- those same areas have a HUGE effect on coastdown. Again, I never see anyone changing those areas to improve driveability or eliminate backfiring, etc.
Damn, sorry to ramble guys! Hope there's a few tidbits of info for somebody in there!
Really?
I'm suffering some dreaded phantom KR all over the place still. Some pulls I'll see 0.00 and then another will see 3.0. Midrange will be clear across the board but as soon as I'm done with a pull and just driving around, I get KR like crazy. Sometimes as much as 4.2 in the midrange.
I'm checking into the position of the knock sensors themselves and also to see if there is any metal on metal anywhere (dp, intake, etc.).
Just rainy weather and not a lot of time is keeping me from getting under the car.
I'm actually in the middle of completely re-doing my DAL table to increase in air load rather than starting high and slowly dropping off. Almost seems backasswards with how they set it up. I understand 400-1000 deal with idle but the rest is just strange.
Also, one thing that BYT, Tom and I had touched on in the past was making similar changes in all ign timing tables rather than just utilizing the int max/exh max table for all. Works well.
I will say that I've tried a multitude of different int/exh cam table configurations and found that I like the stock tables best. However, my car is 100% stock. So for me, by increasing overlap with my terribly restricted exhaust, I believe I'm doing more harm than good at this point, until I open it up with a catless DP and resonator delete.
FWIW after going back to stock MAF cal and setting my MAF correction to all 1's and dialing in my Inj constant, my STFTs look stellar and LTFTs sit at zero. Even with the crazy swings in temps here in the desert, fueling stays consistent. I've also manually calculated better fuel mileage as well. Before, while using the MAF tables to correct, I was getting a best of 23.5-24mpg(Even with the warm temps). I'm now sitting between 26-27. Crazy thing is, my DIC mileage has stayed pretty accurate too but the instant fuel mileage is definitely skewed. I run 1:1 by the way.
Thanks to everyone for being so open and sharing your thoughts and theories. When I'm finished with my DAL, MALT, WG, etc. I'll post it up.
Hey T-ManQuote:
Originally Posted by T-Man
You're right, the DAL's are backwards down low, you definitely can make them ramp up like they should.
On the timing maps, I kept the tables different and added the same values to all 4 tables like you mentioned, but awhile back I ditched that idea. I found that having all 4 tables the same keeps the timing WAY smoother. There are cells in the 4 tables that are very different and when the cam is moving back and forth the timing can jump around too much. The secret is like I said above, start with one table, copy and past the second table to it. Save the file, compare to what you started with and zero out any cells that show that you've retarded timing. Save that file, go to the next table, copy and paste it into the first one again and repeat the process. Obviously what you're trying to do is taking all of the HIGHEST numbers from all 4 tables and putting them in one. Once you've got one table with all the highest values, copy paste that table into all the other 3. Make sense?
One word of caution here, if you're on pump gas make sure you're not getting KR.
On the cam timing thing, try the tables I've posted above, with the injection timing tables also. There ABSOLUTELY are gains to be had with cam timing, even on a bone stock motor.
Here's some cam timing and logging info from my old notes guys, it might be helpful here...
Subtract 10 from entire intake table and add 6 to entire exhaust table.
COPY EXHAUST TABLE TO INTAKE TABLE BY "SPECIAL-ADD". THIS WILL SHOW OVERLAP.
NEGATIVE NUMBERS MEAN OVERLAP IS GETTING CLOSER, POSITIVE NUMBERS MEAN OVERLAP IS GETTING WIDER.
Zero would mean overlap is the same as base setting. (?)
Make a custom pid for intake and exhaust, subtract 10 from intake and 6 from exhaust and that will make numbers in logs match numbers
in editor. Exhaust lower than intake means less overlap, Intake over exhaust means more overlap.
-1 in cam timing table equals 10.8 in logs.
10 is actually zero in logs.(intake cam only)
Exhaust cam runs at 0 when at idle.-6 in table equals 0 in logs.
cam tables switch from normal to idle when rpms drop to 800, even when coasting.
Lots to digest, like most of us I do see a bit of random KR in the light to moderate load & rpm ranges at times, mostly seems to show up after stopped at a light for a minute or two when taking off. Happens with no apparent rhyme or reason so I was leery to jack the midrange timing up more. If I get time this weekend I'll try the GMTech approach to get more advance in there. I know some of the midload areas are 6* or more under stock on a few tables. Always room to experiment some more.
Some great information. I feel I am getting an even better understanding of everything, thanks to all the contributions of tips, tricks and facts.
I jinxed myself, though... I decided to log my KR a bit more this morning and everything looked "normal" until I was half-way through my morning commute.... I was getting SEVERE KR EVERYWHERE! Midrange, WOT... everywhere. *sigh*
Reducing all the timing back to stock and starting over. I'll try GMTech's way... I'll try anything at this point.
Ugh, I can't wait until my meth kit arrives so I can mess around with that.
Funny, I just ordered a meth kit for mine this morning. Gotta clean them valves. lol.
Nice! Mine should be on the way as well. Bought a new one (never installed) from a member on CSS.net.
Oh, and just to update on the original reason for this thread:
The cam timing and injector tables worked FLAWLESSLY!
Thanks again! No more cat warm-up noise crap. Just a nice, smooth, slightly elevated idle on cold startup. Perfect.
I've found that I will get some kr after DFCO with either bliping the throttle to up shift or when taking off from a light before the commanded lambda has returned to 1. Wish we had control of that as I can only assume its more for cat protection than anything?
Rich knock or is this another tip in limiter as part of cat protection?
From what I remmber if you disable DFCO with all zero's in the table the Lambda never leaves 1.0 after a stop. It'd be a tradeoff but worth a test on the KR issue. You'll have to disable a code or two after long decels though. I used to pop one once in a while for the rear 02 I think.Quote:
Originally Posted by T-Man
On your intake cam cold idle set to +10.0 in all cells. I do the same with the intake cam warm idle as well. Exhaust cam idle leave at -6 in all the cold and warm idle cells. You also can smooth out the lumps in the cold and warm cam tables. I posted some that work well in the other thread.Quote:
Originally Posted by Gremlin85
Quote:
Originally Posted by gmtech16450yz
This helped me a LOT thank you! I've been gone to long and now that I'm back Im doing as much reading as I can to try and catch up. lol
So it made sense to you I take it?!Quote:
Originally Posted by Pandion
Yeah anyone that hasn't set up a custom pid for cam timing in the logs isn't showing timing properly. Or at least what they're seeing in the logs would be hard to relate directly to what you're commanding in the editor. Setting up a custom pid will make seeing cam timing changes and overlap very easy when logging. And for anyone thinking "there's nothing to be gained going from stock cam timing" (that was a comment I got quite awhile ago)- that's total BS. Cam timing is HUGE. I first learned about ignition timing on a '67 Mercury Cougar, and I first learned about cam timing on a Datsun 240Z. Those two things, of course along with fuel mixture, are where power is made or lost. Period.
Yeah that made sense to me. Now I just gotta figure out the PID thing lol. I'll get it though. I'm a super noob to this stuff but I think I pick it up pretty quick. If it weren't for this forum I prob would never have bought HPT in the first place though.
I first learned about engines on my 72 Nova. Built the engine myself following a build book. I was pretty proud at the time considering I was only 15.
Played with the timing tables today, picked all the highest cells in the GMPP file under 120% load from all four tables, kept pasting in the highest ones & smoothed it out. Ended up with 6-8* or so more in the cruise rpm & load areas. I'll load them before I leave work at 9p. If it doesn't knock all to hell it should help up the cruise mpg some.
My cruise is between 2k & 3k from 40 - 60% load. Here's the table and the difference from what I posted earlier.
http://www.hptuners.com/forum/attach...1&d=1303432438
Hey Tom, try this... 3k rpm @ 120% load- there's an 18 in that cell. Starting from that cell, select all the way to full load and down to lowest rpm, you should have a 5x9 box of cells. Add 3 degrees to all of those. You're still way low in those cells.
Look at it this way Tom, if GM thinks those numbers are ok for 91octane pump gas, they'll certainly be fine for your E60 mix.Quote:
picked all the highest cells in the GMPP file under 120% load from all four tables
Actually, you should be good for at least an additional 5-10 degrees above stock in those areas running E60. If you're getting KR, it's gotta be false.
I have a few thoughts about this whole KR issue these LNF's have, since it's such a problem this might put things in a little better perspective...
Anyone consider ditching the whole knock retard system on LNF's running any amount of Ethanol? I pretty much have for quite awhile now. If you feel confident enough in your timing tables, and you're running anything over 40% Ethanol, you're not gonna get any real KR. If you do, something is very wrong because it's very hard to get true knock on even that little Ethanol. For those of you running pump gas, if you go too far on timing not only will you get KR in your logs, you'll HEAR it. So guess what? For decades and decades we tuned igntion timing by ear, and if you knew what you were doing it worked pretty darn good. Why keep looking at that KR in logs and trying to fix it when it can't be "fixed", at least not by retarding timing. Trust your tune, keep your timing tables reasonable and either ignore the KR or turn off the system.
Here's what I've done, I've taken "Max Knock Retard vs. RPM and dropped it down drastically. I've kept at least a degree or two just so I can still keep an eye on it somewhat, but in the lower cells I've turned it all the way to zero. How many LNF's will show a TON of KR on a cold start at 600-800 rpm? Lots. Does anyone really think it's knocking in that situation? No way. I zeroed the 400 and 800rpm cells long ago for that reason.
Here's the big warning- DO THINGS LIKE THIS ONLY IF YOU KNOW WHAT YOU'RE DOING AND ACCEPT THE RISKS! I would say pretty confidently though, if you're on stock timing tables and you're running anything over 40% Ethanol, there is no way you're gonna get any real knock. If your logs are showing KR on Ethanol, you have about a 90% chance it's false, or at least not caused by ignition timing. If this were an LS motor, or any other GM ECM, I wouldn't recommend or even consider this. There are so many ways to deal with knock sensors in say, the E38 ECM's. If we had that kind of control over these Bosch ECM's we could fix a lot of these KR problems. Unless these ECM's are just stupid and don't have that kind of knock learn, sensitivity, retard decay, etc, tables in them. DI is so much different as far as KR goes than normal port injection anyway. I'm seeing LNF tuners richen the cr#p out of people's tunes trying to fix KR, instead it just makes things worse. Absolutely the wrong approach on a DI motor.
Food for thought. Just don't PM me with bills for broken pistons, I won't pay them.
lol. Changes accepted, I ran that much advance down low on the stock plugs last winter and vaporized #2, might have been a cracked center insulator out of the box though.
Time to go load it and drive.
Went out tuning tonight. Trying to get a lot of things in check... I was really concentrating on my timing and I think I'm getting A LOT of FALSE KR... Here's what I'm talking about...
You can see where I am, I command 12.5* there and its giving 12.5*.... only it says theres 3* KR...
http://www.hptuners.com/forum/attach...1&d=1303445067
I've reduced my timing so much because I kept seeing KR. :banghead:
.82 Lambda? Damn dude you'd be better off if it was .92! Keep that between .88 to .92.Quote:
Originally Posted by Gremlin85
Seeing KR but not getting it actually reducing timing is common on these. It's not normal, believe me. This Bosch ECM is so weird on stuff like this. Look at any other GM ECM and you can clearly see KR numbers exactly taken away from desired timing. For example, if you're showing 5* KR, and you're commanding 20* in your tune, you'll see 15* in the log. The other thing about tuning most any other motor is if you get 2* KR, you reduce that cell in the editor 2* and you'll never see that 2* KR in that area again. It's not that precise obviously, but pretty darn close. On this LNF, you can see 2* KR and reduce timing till you're blue in the face and the car barely runs, and you'll still get that damn 2*! Or maybe it will just go away on it's own without doing anything, only to come back in another spot at 5*!
Sucks seeing these low timing numbers, these motors REALLY need better fuel to run good. Hopefully with the gas prices back up we'll see more E85 stations popping up.
Yeah, definite tradeoff. I remember messing with that table... It's probably false kr. I enjoy my DFCO :DQuote:
Originally Posted by Iam Broke