Drax240z Posted February 10, 2005 Share Posted February 10, 2005 I wanted to start a little thread where we could exchange some info on tuning, specifically with a wideband. What are your target AFR's at max load? What are your target AFR's at light throttle? What are your targer AFR's at part throttle? I've been shooting for the 12.5:1 area for the most part in all cases, slightly richer under full load (12.0:1 or so) and slightly leaner at lighter throttle (13.5:1). I still feel I am way too rich down low, and up top too, but I still ping occasionally. So what are your tuning targets? Quote Link to comment Share on other sites More sharing options...
clint78z Posted February 10, 2005 Share Posted February 10, 2005 Did you get yours to idle at 14.7:1, my idle was about 14:1. I go from idle all the way over up the rpm line with 14.7. I use a bit of extra gas to transition off idle cell. I think you can go leaner at part throttle. I would Transition from 0.8 bar of 13.2:1 and be 12.7:1 by 1.2bar. 12.5:1 by 1.5bar. Sounds like you could do a little more tweaking while driving on the highway, turn your O2 correction off !! Tweak the fuel map under steady load, tweak the igntion at that point, then set the accelation enrichment so it doesn't stumble. Do the whole map like this, then repeat again. Drastic timing changes can make the car jerky, I have problems tuning very light throttle. Quote Link to comment Share on other sites More sharing options...
Owen Posted February 10, 2005 Share Posted February 10, 2005 I'm using a FAST system and what I learned from various people is that you need to give it what the engine wants. So if you're still pinging, you can cover it with the a/f mixture, or look into other options (different hardware, etc.) I'm at like 15:1 at part throttle cruising. Owen Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 10, 2005 Share Posted February 10, 2005 I was scared so I am running more like 11.5:1 under boost, 15.5:1 for cruise and around 13:1 for part throttle. Around 13:1 for idle also. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted February 10, 2005 Share Posted February 10, 2005 What are your target AFR's at max load? What are your target AFR's at light throttle? What are your targer AFR's at part throttle? Max = 11.5-11.8 any less and I get pinging with 91 octane light load = 15.1-14.5 Part throttle = 13.2-12.8 I idle at about 13.1 or so with 8 heat range, non protruding plugs. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted February 11, 2005 Author Share Posted February 11, 2005 I idle best at about 13:1 with heat range 8 non-protruding plugs as well. I determined best idle mixture pretty much just by using a vacuum gauge. I have a theory that I need MORE timing under boost to prevent ping. I think my ping is being caused by my timing being so late the flame front is moving out the exhaust valve into the manifold. I am using non-projected plugs and running 18*-36* timing, all in by 3000, retarding 1.5* per psi boost. At 10psi that is 21* timing, but with non-projected plugs its probably more like 17* equivalent. Thoughts? Quote Link to comment Share on other sites More sharing options...
clint78z Posted February 11, 2005 Share Posted February 11, 2005 You can probably be more aggressive with timing. Many people get hung up on running a certain psi boost. When they could back off the boost a tad and run more timing to produce more power. You are running a higher compression head correct ?? I would start sneaking in a little more timing in the lower map and work your way up gradually. I think 24 degrees is what I run. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted February 11, 2005 Author Share Posted February 11, 2005 I am running 8.3:1 with an N42 head and turbo pistons. I KNOW there is a lot of power to be gained with my setup still... all with timing honestly. I'm kinda waiting for a special new tool before I really dive into it. (hehehe, made by a company called dyno dynamics) Clint you are running 24* initial with what CR and fuel octane? Quote Link to comment Share on other sites More sharing options...
clint78z Posted February 11, 2005 Share Posted February 11, 2005 Initial timing is 20 deg BTDC, max advance is 40 deg at 3000rpm during cruising. I get pretty good gas mileage with my DFI compared to the ole L jet. Typically I use 87 octane when boosting 7psi, and 91 when going to 12psi. I have alot more playing to do before I turn up the wick to 17 psi. The stock clutch would puke on me !! Did you change your cam over to a turbo one, they have lower overlap to reduce exhaust reversion from high pressure due to the turbine. My self i am getting an oscilloscope, help diagnose problems on other cars and my own when they happen. Quote Link to comment Share on other sites More sharing options...
Bernardd Posted February 11, 2005 Share Posted February 11, 2005 I am running 8.3:1 with an N42 head and turbo pistons. I KNOW there is a lot of power to be gained with my setup still... all with timing honestly. I'm kinda waiting for a special new tool before I really dive into it. (hehehe' date=' made by a company called dyno dynamics) [/quote'] Drax: Where are you finding you're getting the ping? Around 4k or just above? I found that richening the afr's just before and taking an extra degree or two of timing before the knock then bringing more timing back in above 4500 or so got rid of my pinging. Quote Link to comment Share on other sites More sharing options...
Drax240z Posted February 12, 2005 Author Share Posted February 12, 2005 I am using the stock turbo cam. My ping is right in the area of 4000. Honestly I've taken a lot of timing out, more than I feel I should have to at this point. I will play a little more with it and see. Probably if I richen it up a bit more in that area I can add some timing back in... I run nothing but 94 octane regardless... and I'm not prepared to run anything higher than that. (daily driver and all) What's your CR Clint? Quote Link to comment Share on other sites More sharing options...
Drax240z Posted February 13, 2005 Author Share Posted February 13, 2005 OK, added a bit more timing and really woke the car up. Throttle response is much better. I am 21* at idle now, and ramp up a bit faster. Still have ping around 4000rpm and am going to add some fuel. Interesting tidbit from EFI101: This was on a supercharged Civic B16 IIRC. The difference in output from 9.0:1AFR-19:1 AFR in the same cell: 6ft-lbs of torque. Power is made through timing not through mixtures... (granted this might be an extreme example, but it does raise an interesting topic of discussion) Widebands aren't all that and a bag of peanuts. Quote Link to comment Share on other sites More sharing options...
clint78z Posted February 14, 2005 Share Posted February 14, 2005 By the sounds of things you should not be getting detonation with adequate fuel and conservative spark. Mine is the lower 7.4 CR, but I don't think it would make that much difference. Perhaps you have a cylinder that is running lean, and you are making the other cylinders run richer to make up the total AFR ratio correct?? A somewhat crude test can be done by pulling the injector wire on each cylinder while idling and noting the rpm drop. It will give you a bit of an idea if all are balanced or not. Wideband is useful, however nothing beats good tuning practices and there is ton's of hidden power and drivabilty in the spark map. Probably the most overlooked area IMHO Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 14, 2005 Share Posted February 14, 2005 Widebands aren't all that and a bag of peanuts. It was my take that widebands are for trying to avoid ping, if you want to tune by getting ping and then backing off you shouldn't need one. We'll be waiting for the pics of melted pistons, heh heh Seriously, they help with tuning all areas of engine load and give you some base to tune from, ping could also be your base. EGT could be the base, or all of them if you can afford more equipment. Ping seems to be the worst one to rely on because you may cause damage before you are dialed in. I am just trying to validate my thinking and the dollars I spent on wideband, Quote Link to comment Share on other sites More sharing options...
Drax240z Posted February 14, 2005 Author Share Posted February 14, 2005 Sorry, I'm not saying a wideband is useless. It's a good tuning tool. However, it's not the end all of making power is what I was reaching for. Quote Link to comment Share on other sites More sharing options...
mobythevan Posted February 14, 2005 Share Posted February 14, 2005 Fair enough Quote Link to comment Share on other sites More sharing options...
pparaska Posted March 11, 2005 Share Posted March 11, 2005 Mike Kelly and I were talking lately about EFI and he mentioned that his buddy Jim went to one of the EFI courses (not sure whose) and they said the same thing Clint is saying - there's much more power to be found in getting the timing dialed in than tweaking the AFR too much. Sure, you don't want it pig rich or lean, but worrying about even tenths of a ratio may be putting the blinders on if the timing isn't optimized. Of course, one probably affects the other (as far as having them both optimized) so it's a round robin approach. Quote Link to comment Share on other sites More sharing options...
Owen Posted March 11, 2005 Share Posted March 11, 2005 I agree with this. Some people spend way too much time with getting their actual AFR to match their target A/R. It's an endless circle to me, especially since the wideband isn't even real time, by the time you see data on your laptop or gauge, that mass of fuel-air has already passed the sensor. Reading the plugs is always a good tried and true method, don't forget about that. A high quality EGT never hurt either...to much $$$ though. I'd be more interested in learning what Mike's buddy learned, if he could pass on the info? Owen Quote Link to comment Share on other sites More sharing options...
clint78z Posted March 11, 2005 Share Posted March 11, 2005 As for the actual A/F ratio used if it is 12.5 or 12.8 there will be little difference. What you want to work on is keeping a smooth transition of fuel cell to cell in the fuel map. TPS enrichment and delta map enrichment are quite important for a street car. The big secret in L6 is getting some good timing dialed in just off idle, if you make too big of jump well it will break up, but if you get it right it has awsome throttle response and pull real hard out of the hole. There is a drastic difference in spoolup time to be found if you spend some time working on these cells individually. You have to tweak get one cell close then go back and massage fuel table and enrichments. 1. Dial fuel table close 2. Start bumping a small area in igntion table up by one degree. Drive around in those cells, and note if it is worse or better. 3. Go back to the fuel table, it will be easier tweak the fuel map again now that it is running stronger. Repeat many times. I typically tune the deltaTPS enrichment in lower gears since it takes more TPS to accelrate the car. Repeated runs using lot's of throttle at low rpms will show you what is better and what is not. For deltaMap enrichment tune at highway speed in top gear low rpms, this will blend in the transition between cells in the main fuel map. This is general to most efi system, but should get you in the right direction. Datalogging can be a great feature. Spending time and making small changes tweaking is the way to zone in on a perfect tune. Happy tuning !! Quote Link to comment Share on other sites More sharing options...
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