Base Timing

How much timing is everyone getting away with under high loads up top? I am finishing up tuning my boost and MAF, so I will soon start increasing my timing. Looking at some of the maps on romraider it seems that for pump gas that most people are running 12-14 degrees under high loads above 6.5K. Since I am running a larger turbo (TD05-20G) I don't think I can can away with as much timing. I just wanted to hear what everyone is running since I am currently only running 6-7 degrees:p

 

Thanks

It's pretty common to run around 12 degrees at peak torque and 18 degrees at redline, regardless of turbo. Plus or minus 3 or 4 degrees. Approximately. It just seems to work out that way.

 

At high boost (or rich AFR), you'll be closer to the low end of that range (e.g. 10 at peak tq, 16 at redline) and at lower boost (or lean AFR), closer to the higher end (e.g. 15 to 22). If you have a bigger turbo you'll be hitting those at higher loads than a small turbo would.

 

If you're using pump gas, the way to find the limit is to increase slowly until you find knock, then subtract a couple degrees. You'll start to knock before you reach max torque, so forget what you might have read about adding timing until output stops increasing. For our motors, that only works with high octane (race gas, E85).

Thanks. For the different timing values (12 degrees at peak torque and 18 degrees at redline) is this at peal load?

 

Here is what I plan on running once I get my boost finished.

Peak torque and peak load are the same thing for the most part. Your timing curve should be lowest at peak load and timing should increase with rpm piston speed. Is this total timing or just your base timing table? *I always hate to assume anything*

 

Dave

I can't really say anything without knowing what cells you're actually hitting during a pull, and what your AFR is. A picture if the fuel table would help, especially if your actual AFRs match the fuel table fairly closely.

Good call! See attached.

NSFW, I hit around a load of 3.3 under WOT. My AFR's track the map now that my MAF is dialed in.

Any opinions?

The fuel table is a bit richer than I prefer, but that's no big deal. Experts disagree about that kind of thing, and different setups respond best to different tuning. The shapes of those tables look reasonable, but it's hard to say much more than that.

 

I can't mentally add the base timing to the total timing and contemplate the results based on two tables of numbers.

 

A table that shows total timing would be more informative.

 

A total-timing table with a line drawn through it showing the cells you hit in a WOT pull would be even more informative.

 

Basically you'll want to know how many additional degrees of timing you could add, at 4-5 points along that line, before knock starts. And you figure that out through experimentation. When you know, you're done tuning timing. At least, you're done tuning timing for that amount boost and for that fuel table.

 

A good data log would also be informative since it would show total timing, AFR, load, RPM, and knock activity. And the first consideration in evaluating a tune is basically just, "does it knock?"

I recently did some 3rd gear pulls and had to cut my timing back due to winter gas. During the fall I was a around 20 degrees of total timing near redline and now I am at 18 degrees. Some thoughts into my total timing table would be very appreciated

any comments?

We/he want(s) to know what loads you are hitting when you do a WOT pull.

How about some logs?

 

This. Pictures of tables aren't very informative when we can only guess which cells you're actually hitting.

 

My guess is that you have room to turn up the boost.