rceron

This has probably been mentioned before but I thought it might be worth reiterating. Today, while X-mas shopping with a buddy I discovered that I was getting some light detonation when I got on the throttle in a higher gear than I should have been (i.e., slightly lugging the engine). Typically, I only drive around with myself in the car, but the combination of another passenger, traffic, not knowing where I was going, conversation, etc I found myself in the wrong gear one or two times when seeking some acceleration. Being lazy I didn't shift accordingly and discovered that some detonation would occur. After discovering this I carefully (what ever that means) and purposefully repeated the action and watched the knock sensor on the PFC. Well, the readings were off the scale (something like 180). Lessons: watch gear selection and add fuel in other areas of the fuel map.

BTW, the maps I have are rich enough for full WOT runs, thus no detonation or obscene knock readings, but this was new. So, I plan on adding 3% or so more fuel to certain cells.

Just a reminder that fuel should not just be added in the mid-high rpm and boost levels.

Hope this was helpful to some.

Ramon

Boost

this just happened to me recently too. though i think my engine is gone. The car had really started to get kinda sluggish, so i thought i'd rev it out a bit. maybe clear out some carbon deposits and the fuel system (car always seems happier after a nice hard drive). I was driving over to my girlfriend's house givin' it some gas here and there. Then i just started cruisin in 5th and came to a hill/overpass and gave it just a little gas to get up the hill and notice the knock went VERY high on the PowerFC. i was like WTF?, but just drove easy the rest of the way to her place while watching the knock (nothing un-normal). on the way home from my girlfriend's place i try to nail it in 5th to see if it reads a high knock again. it didn't but fealt slow compared to normal. i then throw it into 4th and nail it from 4K and let off at 5K after i see a high knock. hmm, wtf is goin on? so i keep on driving and the car still makes decent power just feels like not as much. i get off the highway, pass a few lights and finally come to a stop at which point i notice the idle is bouncing.

i still haven't looked the car over except to check if the map sensor hose was still attached since it was late the night it happened.

rceron

Yesterday I spent some time with the PFC and added fuel to the cells where this might occur. Of course, no one should or does drive in this manner, but occassionally you might make a mistake by not paying attention. If I purposefully try to lug it with load I now only get knock readings of about 100. Much better than before. Again this shouldn't matter for all intents and puroses but I just wanted to be sure.

BTW, its a new street ported engine.

Wade

iTrader: (1)

I have found this is the case with my modded car, plus a nearly stock car. Below about 3k RPMS and with boost, the car runs pretty lean (I have a wideband lambda meter) with a stock ECU. Chuck Westbrook just found the same thing with his Power FC and a wideband.

We also found on my car and a nearly stock FD that lugging the engine will cause it to knock. I added about 16% fuel in the boost maps of my PMS to get the a/f into the 11.X:1 range just to try to help the problem. It seems to have helped, but I don't actively try to make it happen anymore either.

Also, it is just a good idea to try to avoid lugging the engine, too, whether you have extra fuel added at high boost/low RPM or not.

Just supporting this discussion,
Wade

rceron

Thanks for the confirmation. Well, it turns out that I may have been too late to discover this nuance and now my 1500 mile engine may/probably lost an apex seal. Then again it could be something else entirely. Not to be an alarmist, but please be careful. And, of course, no one drives the rotary in this manner, but should you occassionally allow someone else (e.g., wife, friend, cousin, etc.) to drive your car then this is a very real problem.

Demonstrating as much patience as I can with the rotary...

Happy holidays

cewrx7r1

iTrader: (2)

More news about this problem!

Comparing the stock PFC timing map to my mods PFC map for columns 8, 9 and 10; and for rows 16 - 20: there is more advance in that area for my mod map. This helps my non-seq develope more power there but by 4000 I am already at max boost. A seq will be at max boost even sooner.

I have periodically had my J&S light up briefly between 4000 and 4500 rpm. I think the mod base map is too lean and has too much advance in this region.

I have added a little more fuel in this area and plan to retarded the timing a little. When I finish my linear O2 testing, I plan to work on the ignition maps.