Ok, some of you know I lost a motor a few months back and almost ready to put in the new one with some changes. But I still need to determine WHY I lost the last one. My logs show a lean area high 12's to 13's when it let go on 114 gas. What puzzles me is it pulled and made great power 1st gear thru 3rd gear. It had the lean area and high knock after the shift to 4th. After the shift boost was around .7 bars at 5k rpm were I saw the lean area and knock showed. I made 20+ pulls in the 1/8th mile with NO issues. Also many dyno pulls (30+) with no problems. I will try and post logs below. Let me know if you think this could just be a map problem needing more fuel or could this have been a faulty inj., pfc or what? I dont understand how it was fine in the other gears. The base map looks ok as far as progressive fuel being added with no out of place cells. I would also think high 12's at 5k rpm and only .7 bars would not be to bad but I did tune that area for low 12.2 afr's. Timing was around 23-21 with the next row 19 and so on down.

 

Is there a possibility that you cracked a apex seal on a different, higher boost run? If I where you, I would have the injectors cleaned, and check the fuel pressure. CJ

 

There are many reasons for the possible engine failure. Most of the time it's tuning.

Telling us your running 21-23 degrees of ignition advance at 10psi@5000rpm with an AFR in the 12-13 range
on 114 octane fuel is great. But is anybody on here going to be able to confirm that those setting are optimum?
I don't think so, there is more to it then just PM'ing other members for a copy of their map and plugging it into your EMS.

An efficient way to find your optimum AFR's and ignition advance will require using an engine or chassis dyno with a knowledgeable experienced tuner. Two variables that also need to be taken into account is charge density and the fuel burn rate, both which will effect the tuning. Add in the fact that wideband meters read different from brand to brand things can become pretty confusing for the inexperienced.

If you want to tune the car yourself, I would suggest do as much reading on this topic that you can find. Amazon has a few good reads that will help you understand tuning a little more in depth. The unfortunate things is a turbo rotary is one of the least forgiving platforms to learn on.

 

Higher gears = MORE LOAD on the engine. Your tuning is based on load vrs RPM. Sounds like you weren't loading the engine up enough on the dyno while tunning and in the real world you went outside your tuning boundries for load and went lean. Just smooth out the maps past any load parameters past what you see on the dyno (should have been done from 1 day anyway) and be a bit more conservative with the A/F and timing. I mean are you trying to get that last 0.01 of a secound in the quarter or have to have that last 10~35 HP for dyno bragging rights at the expense of another rebuild?

~Mike...............

 

What was your fuel pressure and how much fuel was in your tank??
John

 

(QUOTE) I don't think so, there is more to it then just PM'ing other members for a copy of their map and plugging it into your EMS. (QUOTE)


Ray, I have asked to see your timing maps just for information and to see how much adv. you run and how you ramp it up. 100% for looking at! Dont worry, I am not a complete idiot. I have "NO" intentions of loading any of your maps or any one else's for that matter. I am asuming that is wht you are refering to.??
Timing has always been very scary for me as I know this can lead to a loss. My car was tuned on the dyno (dyno dynamics) and we chnged the load a few times. Running the max load on the a few fianl pulls. I am learning alot on the timing part and plan to explore this more as I get the correct tools (dual egts) and get back on the dyno.

 

Thats a good point.. I was looking last night a a few logs and started wondering about this. So maybe not a bad idea to pull the car to 4,5,6k rpm +/- before going into boost to hit a few other cells?

 

Very possible... The night before I added a larger gate spring (to help with creep) and a line lock. Went out to test with wrong map loaded. Had some break up on a pull.?? Car seemed fine, idled, drove fine. This could very well be the culprit... But even if this was detenation and started chipping the seal, how could this cause lean spots that I usually did not see?


Again, Ray... I do not want you thinking I am out trying to steal your maps to run. I have asked 2 guys that you tuned to see there timing maps. I explained to both that I was not going to run them...

 

Base is around 40psi and plenty of fuel..