for the past week i have really started to learn some rather interesting timing traits. currently i have been working on low end timing to get rid of cam surge which i must admitt have been very sucessful! my car will pull itself up to 1100 rpm and just roll right along even up hill.. when first fired up the car i could barely get moving from a stop without giving myself whiplash and/or killing it. i have noticed too much timing is just as bad as too little in killing throttle response and too much doesnt always mean you see KR... i didnt at least.

now im at a point where i want to tune for WOT and part throttle but i have no idea how to go about this. i do realize you want to aim for the highest vacuum or lowest KPA/in Hg but they fluctuate around so much i have found it almost impossible to do accurately and when i have pulled or added timing in a particular RPM/KPA range... i feel absolutely no difference in the car or see it in knock retard. i do however get quite a bit of KR at low RPM high map when i try to accelerate in 4th-6th gear around 1500-2500 rpm and have pulled tons of timing out without seeing any reduction in that KR so maybe its false? basically i am wondering if there is any formula out there that calculates timing? givin cam specs, KPA, RPM... it would spit out the more efficient timing for that area of the map. i have found a few degrees adjustment down low gives the car more torque off the idle so i can only imagine what the "correct" timing will do in the right high to mid KPA/RPM ranges.

if anyone is interested i could send them my file. the cam is a 224/230-110 LSA. my base tune came from Bryan Herter of PCMforless.com.... its a good tune but mail order is only a crap shoot and a decent place to start.

 

click HERE for the file.

 

Brad- if you get a chance will you email me a vid of your car at idle? I want to hear this thing.

 

Export the log file to CSV for excel and do an average... there you can: either see paterns or simple enough see the lowest average.

 

Whats this CSV thing

 

ttt

 

Comma, Separated, Value..

Its a way of exporting it thought plain text so Excel will recognize it and then separate into different colums and rows..

 

I wouldn't worry so much about the timing tables as I would be about your AFR at WOT. If you look at a table showing timing vs. cylinder pressure, the difference in pressure produced is very little off of best timing either way (too much or too little). however, when you take out like 10 pts, then the power reduction becomes significant and of course if you add too much there is absolutely no benefit there. You are running a more efficient engine now with the cam. I would even venture to think that you can pull timing and be in good shape. When I wideband dynoed, I went in with 2 deg reduction in WOT timing across the board - all RPM's and still pulled the no's I did. In fact, my 3rd and 4th run, my AFR was a bit off and I ran 13.3:1 and others there said I had knock on those runs. So I know I am pretty much at max timing right now.

As for WOT tuning, you need to have your AFR correct and the only way to do that is to get your BLM's right. Disable your PE mode and run the car throughout the range including high RPM runs. This will show if your BLM's are off. Mine were off by up to 9% and I had to modify my MAF table to get them right, but they are dead on now.

This needs to be done or else you could run lean (I was until I did this) and getting knock that way.

Just my opinion. Trying to help.

 

How do you disable PE mode?

 

http://web.camaross.com/forums/showt...hreadid=143169

I explain it here.

 

IF AFR is safe worry about timing.. the faster you get to full timing the faster it will reach peak cylinder pressure and the more "momentum" it will have and the more power it will create...

 

LT1edit would not let me set my "MAT Threshold" to 255. The most you can go is 150, and that did not disable the PE mode as far as I could tell.

Anyone else know how to disable PE mode?

Ryan