Hey guys, got some progress to report. I'm back up to 1.7bar of boost on my Alkycontrol setup. Posting the message I put up on my blog on TeamFC3S this afternoon:

http://forum.teamfc3s.org/showpost.p...&postcount=224

Back to 100% today. What I did was create two maps -- BDCBP72 and 72A. I built 72 based off of BDCBP57, my last known 100% gasoline only map, and re-tuned it from there to low-mid 11's:1 AFR's from bar 16 to 22 (approx 7psi to 14psi of boost). I wound up adding about 8% across the board to achieve this. I also verified that the wideband is indeed working well under load. I think what may've happened to throw me off was both the failure of the pump (due to possibly race gas making its way into the system) as well as the failure of the older L2H2 wideband sensor I had. I feel confident, after today's re-tuning, that the older sensor was accurate under load. What changed during the time that I was testing up until today, besides the introduction of the brand-new L1H1 wideband sensor, was the dramatic drop in ambient air temps. I originally started this experiment at the tail end of the summer time season when it was still fairly hot outside. But, during the time these past couple of weeks that I was doing testing of the alcohol system as well as ripping apart the manifolds and looking for any possible air leaks, the outside temps dropped here significantly. They're sitting between the 40's and 50's most of the time. Normally, this wouldn't be an issue for an EFI system, but since I relocated my IAT sensor over to the LIM to measure drops in charge temps when the alcohol sprays on, I disabled any corrections factor that it would otherwise provide if the sensor were located in the proper position. I think the drop in temps was significant enough to throw my original maps off (8-10%) to the point where everything was running leaner everywhere. Part of today's efforts were to re-tune anything in vacuum and in boost to reflect the air temps outside directly as opposed to relying upon a corrections factor from the air temp correction map. If I continue with this approach, then it will only run richer as the air temps warm back up. Otherwise, it will require slight retuning of the fuel curves and the placement of an IAT sensor back in the factory location w/ the use of that corrections map.

After I re-tuned the original map (ran it up to about 1 bar), I removed 25% of fuel out of bar 22 and above. From there, I went to the spring rate of boost (about 6psi; 7psi out in this colder weather) and retuned that particular fuel bar by leaning it out slightly for the inception of alcohol (about 12% from what memory serves). Re-linearized from there to bar 22. Reduced a bit of fuel at bar 15 to help with transition of 100% fuel into 75% fuel / 25% alcohol. It's seamless. From there, all I did was adjust gain by going immediately to 1bar (max setting on Low on my boost controller) and then inching it up to verify the stability of AFR's. Gain is set to about 4.25-4.3 as it stands now.

I got it up to almost 24psi today (23.9psi) with AFR's in the solid 11's across the board. EGT's reflect the same as they always have. TurnOn point on the controller is at 9:15-9:30 position. Initial is set at 12 o'clock noon, straight up. The alky system hits 30psi by about 10.5-11psi of manifold pressure. Whatever suspicions I had about the M15 nozzle being too small for this setup have been squashed. Duty cycles are still in the high 40's to low 50's percentile ranges under the highest load points. I'm having a slight fluctuating problem with the boost under heavy load. I may need to put a restrictor pill on the IN line to the PROfec's solenoid as I believe it's being overwhelmed under higher loads.

I'm experiencing some moderate breakup under load but I'm not sure what this is. The IAT's are dipping as far down as the mid 70's*F at the very high end of boost so I don't believe there's a heat problem. The only other thing I can think of is perhaps the plugs are getting hot, but why they didn't do that during my initial 22-25psi tested is beyond me. It may be something else but it feels like spark is either blowing out, breaking up, or misfiring due to being too hot. I may try a set of R6725105's at some point in the leadings to see if the problem persists.

B

 

try a colder range plug, the meth tends to cause ignition breakup at higher boost levels so a colder plug or auxiliary ingition box may be required to help prevent it.

 

that's great news that you are back in the game Brian.

i am sure the AI community especially appreciates the details you have always provided re your tuning process.

i do think that as more AI rotaries tune up to mid 20s boost that we are going to see alot less theoretical threads and more nitty gritty threads as you have always provided.

along w some new hp numbers...

great to see you back.

howard

 

Thanks, Howard.

B

 

Hi Karack,

Where did you get or derive this data from? Reason I'm questioning it is because I didn't have this same problem a few weeks back when running the same and slightly higher loads. It ran quite smoothly. Had it had any kind of breakup or hesitation, I certainly would've noticed it and written about it in my blog early on.

B

 

Sometimes it's mile enough that you don't notice, I guess that's the preference for some tuning on a dyno you can get breakup and will see it straight away. Get 10 or 10.5 plugs and it will disappear.

 

So, ya think the plugs are getting hot?

B

 

I get similar problems when i swap to new plugs. Once they get a few miles ( about 200 miles) the misfire disparears.

Scott

 

ask the meth guys that have been running alky for years and they will tell you they generally run colder plugs to keep the break up away, that or they have ignition systems that could kill a small child.

 

Think so mate.

 

i don't believe it is the spark plugs getting hot, the reverse is actually true, the intake charge condensed is blowing the flame out in the plug, a colder plug will have a hotter spark but they also do more work and have shorter lifespans.

don't quote me, that is just something i remember hearing on the subject but it seemed to make sense.

 

Good to hear, Brian.

Hopefully I'll be right there with you in a month or so.

 

+1 you are correct

 

Maybe I'm dumb but I still don't get it. Could you elaborate?

B

 

how do the plugs look? i run the 10.5 #6725 and they have always looked cold. darkish.

i do need to do some additonal leaning, advancing igl and raising boost. if they still look cold i will go to 10s.

howard

 

If he is getting flame blow the type of spark plug ngk 9 or 10.5 etc doesn't matter, he would need a better ignition system that would provide a better spark to resolve the blow out issue. I don't own the car so don't really know for definite, but I don't think BDC has a blow out issue.

 

maybe not but tossing in some colder plugs only takes a couple seconds, worth a shot to see if it helps IMO.

 

I'll give it a try in the next few weeks.

B

 

Tapped on 1.8bar's door this afternoon. Took several videos. Have a peek, folks.

http://forum.teamfc3s.org/showthread...264#post555264

B

 

Hey, I got to ride in that! Haha.

 

did new plugs help with the break up issue?

 

I don't have any hesitation anymore. I am not sure what it was. It's running very well. Haven't changed the plugs.

B

 

i did notice on the dyno that with the mixtures if you are a bit rich it will cause a break up feeling in the power curve, once i leaned it out to the 11:1 range it completely went away, i am still using 9's all around. could have just been a rich condition bogging feeling if you were still making adjustments.