$42 Tuning Questions??

[devind]

I am very new to the tuning game and I have been in the process of tuning my Jeep with a 355 Chevy with Vortec heads and mild comp cam
http://www.compcams.com/Company/CC/c...x?csid=98&sb=2.
Here’s a link to my original post when I first came on board it has more details on the actual build of my Jeep and it’s motor
http://www.gearhead-efi.com/Fuel-Inj...-proram-issues

I had Dave w of Old School EFI tune a chip for me after having issues with TBIchips.com.
Dave has done an outstanding job getting all of the issues I was having fixed and has the Jeep running very well now.

However during this 7 month process I have learned a lot with a BIG thanks to Dave W and this forum.

I just recently bought a burn 2 from Moates so that I could burn my own chips if I needed to make small changes. Plus it just made sense to be able to burn my own chip rather than mailing them back and forth. Not to mention I believe I have caught the tuning bug and plan to continue to learn and try to increase my knowledge for future projects. I am now thinking about buying the Auto prom and selling the Burn 2.


Back on subject and my main question today has to do with the setting of the distributor’s base timing.

On my current tune I have to distributor set between 9 and 10 degrees BTDC (With anything less than 7 degrees the motor just falls on its face under acceleration).
With the base timing in the bin set at 0 and the spark bias set at 9.84.
Also I have double checked the balancer to make sure that it has not spun. The mark is reading perfectly on 0 at TDC. In addition I have added a knock sensor to the system that I originally didn't have.

I have spent some time with the timing light and have compared the timing at various rpm levels against what I am reading off of the crank and what Tuner Pro is reading. I even tried to manipulate the map reading with a hand held vacuum pump while trying to read the timing. But I didn’t have much luck because as soon as I would release the vacuum to the map sensor the motor would flood due to ecm seeing a load and start adding fuel.

But consistently the crank readings are what Tuner Pro reads plus the 9.5 degrees set at the distributor.

I have also compared the spark advance history table to what is programed in to the main SA table and they are consistent minus the 9.84 degrees of spark bias.

With all this said it runs great and there are not any issues. Like I said earlier Dave w has done a great job tuning it for me.

I have come to the understanding with tuning like most things in life there are more than one way to skin a cat. Therefore tuners have different methods of tuning to reach the same goal of a properly tuned motor.

But with me trying to learn how to tune and understand the process I get confused when I read threads where Eagle Mark is very adamant about not running any advance timing with the distributor due to it throwing the injector timing off with the spark timing.

I want to make it perfectly clear, I am not trying to throw anyone under the bus or call anyone out on whose tuning method is better than the others.
I am just trying to better understand it all and hopefully in the end see what the pros and cons are to the different methods.