Hi guys, what does the total initial timing end up being on a stock 350 TPI? The reason I ask is I had a chip burned for me by someone who had the equipment, just to get my radical setup running enough that I can burn my own chips later. Since I'm running a flat tappet cam that lopes quite a bit (10-12" vac idling) I had him set the chip up such that, in closed loop, I have 22 degrees initial timing (total, when I set the timing to 6 btdc it ends up being 22 when the computer is controlling). This was the optimal base timing when I was running this setup carb'd, I'm just wondering if I got a little carried away using this much base timing with a TPI setup. The car drives great with the TPI, but I can't monitor what the knock sensor is doing yet.


EDIT: Please stop using that ISP to post your car's picture in you signature as it attempts to place spy-ware cookies on people that veiw you post. Thank you. Glenn91L98GTA.

 

Off the top of my head, 22° doesn't seem excessive.

Download TunerPro, and you can browse a bunch of stock calibrations yourself to compare.

 

Thanks guys. Glenn, villanova.edu is my university's website. This is the first time anyone has complained about it. I'll move my sig pic just for use on this board.

 

Thanks 327_TPI. As I said, on the stock SD AUJP bin for the L98, the amount of timing is between 20*-24* betweeen 600-800 rpm when fully warmed.

There is also a "Spark Coolant Bias Table" the can add as much as 6* of timing, as well as remove 4* of timing based on your coolant temp. When the car reaches the typical operating temperature of 180-200*, the bias is 0.

Which system are you using on your TPI? MAF or SD? The values I gave above are for the SD system. I haven't check the various MAF systems as there is 4 different variations and a lot of different bins for each variation. But I suspect they are all fairly close to the range I gave for the SD version.

 

Glenn, I'm running a MAF tpi setup. Sounds like I accidentally came up with a setup that is pretty normal. Thats good to know.

 

The next question is, what you like it to do.

 

I had to bump up my timing to over 30deg at idle 850rpm otherwise me headers where glowing!

https://www.thirdgen.org/techbb2/sho...hreadid=246142

 

Most of the stock chips aren’t quite that high in the normal spark table, usually 15-18* in most areas, but the ARAP and a few others get to the 20’s in some cells.

To be honest, best that I can tell, the only reason to stay that low is emissions (lower idle timing make for hotter exhaust which runs cleaner on an emissions test), and I run most of my chips with all the cells in the table raised up to at least 22 or 24* (anything lower then that gets set to that number). Hell, we got tired of chasing low speed drivability problems on my brother’s car and finally just locked out the timing at 34*, all the time, everywhere, and it’s finally happy (could probably use some “vacuum advance,” but it happily chugs along getting 24mpg on the highway which seems adequate for a blown, 10 second car on slicks).