TurbochargedBerserker Posted July 16, 2004 Report Share Posted July 16, 2004 So I started basic WOT timing tuning last night. It got the timing tables sorted out with a friend who has been tuning GNs for about 20 years. Basically, I took a *bunch* of timing out of the stock tables. I can't remember the exact ranges, but I took 0.68 g/cyl and up (not all the way up, just to were the stock tables go static), 2200 - 6000 and scaled by .5 (yep that's not a misprint -- newval = oldval * .5) and kinda followed the stock curve. Lower in the table (lower g/cyl) I progressively scaled by a tenth more until I got to .9 from 2200-6000, then did the next higher row by .95, next higher I left stock. Then I smoothed the curves. Above that range (high g/cyl - where the table goes static -- around .84 I think) I scaled the entire useable rpm range by .5. Even this drastic change isn't enough (see below). I then copied the appropriate rows into the base timing in drive table. I also copied the high octane table into the low octane table and removed 4* from every cell 0.40 g/cyl and above. I logged a bunch of light high boost (8psi in first, up to 5200 rpm) wot runs last night, but had inadvertently messed up the PE table (the value some how got written as 1.57 instead of 1.157 - DAMMIT BEN!!) so I was so rich the truck barely moved, but hey, I prefer to think of this as a safety precaution... or something... So I fixed that and fixed the P0101 table (hehe I forgot to do that in the base tune ) --BTW what is a good value to scale that table by? I used 3. Since I very little KR last night and because of the PE screw up, I didn't touch the timing table. Reflashed this AM... Left it in low boost mode to check a couple of light wots (no KR ) and moved on to high boost light wot (no KR) and then medium load, low boost wots (KR < 3 on one) and then a few low boost wots at speed (manually kicked it into third, but it still dropped to second -- surprisingly, not KR derived from the down shift into 2nd) Got some KRs (up to 8*) in the 5400+ range of third, so I have more work to do in the timing table. I know what you are gonna ask... Why did I go back to low boost? Here's what I've learned and what I think: 1) no turbo makes max boost in part throttle or light wot runs, so if your low boost max under these conditions is reading 5 psi (as mine is), med-high load wots will be 7-8psi. This is not boost creep. It is just how turbos work. To get close to max boost in first gear, you have to (a) do a drag launch where your boost is already 2 psi or so, and stand on the go pedal. Anything else will not give you the max boost setting of the turbo. <GN Buddy and Dave at STS> 2) my kit is really going to max out at 7.5 psi during hard wots in upper gears, not 5 psi. I confirmed that this morning. 3) I don't even need to worry about tuning the high boost setting. I am gonna have to do it again in a week anyway ( muhuhahahaha ). 4) Turbo cars make muuuuuuch better power at lower timing and higher boost. <GN Buddy> 5) For each atmosphere of boost that you add (read each 14.7 psi), you effectively double the CI of the base motor. So Ben's target of 15 psi should net him 816 CI displacement. <GN Buddy> 6) Because of 4&5, dropping to total timing of something scary like 8* and running 15psi > 15* and 10psi BY FAR. Tuning WOT is *extremely* fun once you've got a safe base to start from. I loved the pissed off F150 guys Oh, one more thing -- I am totally pegging my EGT pyrometer. It beeps and everything at 5400 rpm. It goes past 1600* by about 1/4 inch and then starts screeching. The sensor is located about 6" past the end of the manifold, but in front of the cats. Gonna check the placement depth this weekend. Those of you who were worrying about the STS not having high enough EGTs to function efficiently can rest easy Link to comment Share on other sites More sharing options...
detjoe Posted July 16, 2004 Report Share Posted July 16, 2004 thanks for feeding my turbo fetish it has been two days with no new news or anything turbo related... I dream about an STS turbo...the look of people checking out the truck and then hearing the turbo...I dream...one day Link to comment Share on other sites More sharing options...
speedy Posted July 16, 2004 Report Share Posted July 16, 2004 Glad to here the tuning is going ok. How do you like HP tuners?Is it hard to learn?Im thanking about getting HP tuners. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 16, 2004 Author Report Share Posted July 16, 2004 The biggest problem with tuning is the lack of reliable knowledge. Every one pretty much tells you to go search through 4-5 sites that just has guys like me posting there. Almost everything I've found on the websites proved incorrect for my truck -- things like move this table up by .98 and that will take the LTFTs this direction -- which proved to be exactly backwards... The things I've seen that were correct were incomplete -- statements like "scale the such and such table" with no idea what range the scale should be, etc. It's been slightly frustrating but I do tech stuff for a living and have a very reliable debugging method. I got the best and most reliable info from the GN guy. My advice on self-tuning is to get a couple of books and talk to a some guys who are local to you that might be willing to help. Otherwise, get your hip waders out and wade on in Link to comment Share on other sites More sharing options...
m396 #00-011 Posted July 16, 2004 Report Share Posted July 16, 2004 The best advice on tuning would be to go slow, and take your time. Understand the change you are making first, will go along way towards safegaurding your engine. Once you boost is maxed out, up the timing until you get knock, then back it off slightly. It's good to periodically check it too, to make sure things stay stable. BTW, to adj LTFTs you would increase the IFR table to drive LTFT's positive, decrease the IFR table to drive LTFT's negative. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 16, 2004 Author Report Share Posted July 16, 2004 Yah, I'm done with part throttle - what I was specifically refering to was some advice on VE adjustments that just didn't work no matter how I shook it My biggest tuning advice would be to start from the stock tables. Keep your other tunes for comparisons, but start stock and step one thing at a time. My chain was: 1) scale the IFR table for 44lb injectors 2) get LTFTs negative for FTCs 6-14 (again by scaling the IFR table) 3) follow a bunch of weird advice about VE table and better low end torque... 4) go back to the stock VE table 5) figure out what timing I needed 6) set my tables and check for part throttle kr 7) figure out the AFR at WOT that I wanted 8) adjust my PE table accordingly 9) log, log, log (read FLOOR IT BABY!) that's where I"m at A lot of my frustration came from having too small of an air cleaner and from not realizing that turbo tuning is not supercharger tuning, and also from not being able to get straight answers from tuners or from folks who've spent a lot of time studying PCM behavior. Also from the attitude you see on a lot of the tuning sites from people. Most of my questions that got answers got answered by SSS.com members on other forums. I completely disagree with the sentiment that you can learn everything you need to learn by searching through a million posts on tuning websites. Most of the answers are just... Link to comment Share on other sites More sharing options...
m396 #00-011 Posted July 16, 2004 Report Share Posted July 16, 2004 Yah, I'm done with part throttle - what I was specifically refering to was some advice on VE adjustments that just didn't work no matter how I shook it My biggest tuning advice would be to start from the stock tables. Keep your other tunes for comparisons, but start stock and step one thing at a time. My chain was: 1) scale the IFR table for 44lb injectors 2) get LTFTs negative for FTCs 6-14 (again by scaling the IFR table) 3) follow a bunch of weird advice about VE table and better low end torque... 4) go back to the stock VE table 5) figure out what timing I needed 6) set my tables and check for part throttle kr 7) figure out the AFR at WOT that I wanted 8) adjust my PE table accordingly 9) log, log, log (read FLOOR IT BABY!) that's where I"m at A lot of my frustration came from having too small of an air cleaner and from not realizing that turbo tuning is not supercharger tuning, and also from not being able to get straight answers from tuners or from folks who've spent a lot of time studying PCM behavior. Also from the attitude you see on a lot of the tuning sites from people. Most of my questions that got answers got answered by SSS.com members on other forums. I completely disagree with the sentiment that you can learn everything you need to learn by searching through a million posts on tuning websites. Most of the answers are just... Well, the good ones at tuning, turned it into a business. ;) Hence, why there isn't so much free info going around. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 16, 2004 Author Report Share Posted July 16, 2004 Boy I sound bitter, eh? Really I am not. I am really tired however. Yah, the good ones turned it into a business, and there are some really helpful amateurs around. There are also a lot of people who are just repeating what they read or heard, and quite a few who are using their knowledge in order to feel superior. And a lot of myths going around. You have to be a skeptic when wading through all this. If it doesn't make sense when you think it through, it probably is bs. Just be prepared to solve every problem yourself. If you go into it with that attitude the helpful people just become frosting on the cake. Link to comment Share on other sites More sharing options...
MustBBrent Posted July 17, 2004 Report Share Posted July 17, 2004 Good for you! Don't wait for me! I'll catch up. Link to comment Share on other sites More sharing options...
BenKey Posted July 17, 2004 Report Share Posted July 17, 2004 the value some how got written as 1.57 instead of 1.157 - DAMMIT BEN!!) What did I do? I never gave any advice for tuning. I assume you monitor your O2s in addition to your ltrims? I didn't care for the gauge like display of the hpt. If it were me, I would use a line type graph that show history. If you do log, maybe you can go back and replay any way you want? The line graphs allow you to silmutaneously see what's going on on all your PIDs, vice only seeing what was there for that instant, then it's gone. Link to comment Share on other sites More sharing options...
MN C5 Posted July 17, 2004 Report Share Posted July 17, 2004 FWIW Lower Ignition Advance Equals Higher EGT Readings... It will also get you into boost sooner Link to comment Share on other sites More sharing options...
deezel Posted July 17, 2004 Report Share Posted July 17, 2004 Thanks for the report. Please keep us updated. You have to be a skeptic when wading through all this. If it doesn't make sense when you think it through, it probably is bs. Just be prepared to solve every problem yourself. If you go into it with that attitude the helpful people just become frosting on the cake. Thats a good attitude to have. I followed your "tuning chain" list above almost exactly - minus step one for me. Link to comment Share on other sites More sharing options...
vette dude Posted July 17, 2004 Report Share Posted July 17, 2004 I am by far not an expert, but i was always under the imopresion that in a turbo aplication you wanted to decrease boost and raise timing at the upper RPM range??? Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 17, 2004 Author Report Share Posted July 17, 2004 the value some how got written as 1.57 instead of 1.157 - DAMMIT BEN!!) What did I do? I never gave any advice for tuning. I assume you monitor your O2s in addition to your ltrims? I didn't care for the gauge like display of the hpt. If it were me, I would use a line type graph that show history. If you do log, maybe you can go back and replay any way you want? The line graphs allow you to silmutaneously see what's going on on all your PIDs, vice only seeing what was there for that instant, then it's gone. It's your fault none the less, Ben! I decided everything this week should be blamed on you since you're going on vacation. Sound reasoning, eh? I log to a data file and parse it up later. I do monitor 02s as well. I do run with the gause thing open, but only for the 'quick glance' at KR feature. Link to comment Share on other sites More sharing options...
TurbochargedBerserker Posted July 17, 2004 Author Report Share Posted July 17, 2004 FWIW Lower Ignition Advance Equals Higher EGT Readings... It will also get you into boost sooner Ahhh.. Thanks, man. I didn't know that about the EGTs. It does explain why I never rang the bell before though. I'd thought I was just never on it long enough. I have liked looking at the boost gauge and seeing max boost almost right away. The lowest RPM I've noiced full boost was 3k. I followed your "tuning chain" list above almost exactly - minus step one for me. Hey Deezel, did you get anything useful from the VE table or was that the 'minus step'? I am by far not an expert, but i was always under the imopresion that in a turbo aplication you wanted to decrease boost and raise timing at the upper RPM range??? The only way I can see to decrease boost in a certain RPM range is to lift your foot. Waste gates are just fancy spring driven valves. I suppose with an electronic controller that was beefy enough, you could write a program to monitor RPMS and adjust the boost limit, but I've never heard of one. Plus, I think the reasoning above would still apply (the boost you'd sacrifice to run more advance would rob more power that the advance would give you). Link to comment Share on other sites More sharing options...
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