Tune for boost, tune for timing

So I've been doing some reading and have come to a standstill here. I always understood tuning as tune for the most usable power. Establish a/f relationship, tune boost, fuel, timing, avcs, retune fuel, timing.

 

So you get done tuning boost, and you're targeting boost that's within the compressor efficiency range of the turbo. You target and achieve conservative AFR's, all is well, then comes timing. I've read that tuning for big timing isn't necessarily good for the engine's bottom end, but at the same time too little timing increases egt's and therefore can lead to other failures. How much timing is too much? How much is not enough?(too little?)

Big boost isn't exactly great for the bottom end either. Your on the right track, tune your boost according to the efficiency range of your turbo. Obiviously big boost and big timing won't make your motor too happy so you need to decide where your going to get your power from. Every engine is different so I don't feel you can say XX amount is what you need for timing. As far as EGT's go, Mine never went above 800 degrees once I went catless.

 

I may be wrong but I think lean AFR's might affect EGT's more than a few degrees of timing.

I have no way of monitoring my egt's and yes, if you up the timing gradually and start to see knock, you've reached your threshold and should pull back 2*. But is there a limit as to how low you can go?

I have no way of monitoring my egt's and yes, if you up the timing gradually and start to see knock, you've reached your threshold and should pull back 2*. But is there a limit as to how low you can go?

 

If you retard timing too much then the car's slowness will drive you crazy. Generally speaking, you're not likely to melt anything if you keep the timing such that the car can still haul. The reality is that tuned setups from even the most non-timing-crazy tuners (like Phil @ Element: all boost no timing) where he'll tell you go 10* peak, 17* redline, 30psi or more off a big turbo (with very high octane fuel or meth)... he'll tell you he regularly hit 1000*C EGTs on a stock longblock and never had a problem with the engine... so basically it boils down to this:

 

Run as much boost as you efficiently can. Compare logs in VD at various levels of timing, and when you start to see diminishing returns as you advance timing, pull it back and be happy. If you're knock limited, then replace MBT with knock threshold. Something like 10* and 17* is more conservative than most run at high loads, more so for your 20G. But it depends, two engines with the same tune may net different results.

 

Keep it simple. If you want to have some fun tuning with EGT in consideration, PLX offers a fun gauge/sender/box with 0-5V output you can wire into a TGV sensor. Will help with AVCS, though there is so much out there now for tuning reference of these engines that you don't really need it.

 

*Disclaimer: I am not an expert tuner, so don't listen to anything I have written.

What I'm saying is, I'm running 20psi on my 20g with the process west. This is appropriate for the turbo, yet I seem to be only able to run 10* at peak and 13* at redline. Not sure if I should back down on boost to allow for more timing. It pulls great as it is, AFR 11.1 during peak loads/torque (4300rpm).

my peak loads in 3rd gear are around 3.6g/r

That already appears reasonable, and I'm sure you've logged back-to-back runs to confirm it's not heating up the PW IC and knocking. At 4300rpm the 20G should be really efficient. You could go a couple more PSI around peak torque rpm, but probably not all the way out to redline.

I have logged so much my laptop car charger roasted on me yesterday. I found that the PW is likely too small to keep up with the flow rates of a 20g at 20psi

 

I installed an aem cai yesterday and that seemed to certainly mess with things, had to reduce init wgdc by about 6% and drop the timing to aforementioned values, scaled to match my targets, so 11.1. with the stock intake I was running about 2-3* more timing at peak loads all the way to RL.

Sounds like you need to get you some E85.

save it brooooooooooooooooo

You need hondata.

base + advance

wow...didn't realize how little, that seems REALLY low. I think on pump I ran ~19 at redline on pump. Even if the TMIC cost you 1 or 2 degrees..10 is too low for total timing.

 

This is 93 octane?

to really dial in timing you need to sit your butt on a loaded dyno. With all other parameters already dialed in you can work on ignition timing. You basically go load cell by load cell and increase timing until your peak torque is reached. You'll know this point because advancing beyond it will cause torque to fall off. after one cell is done you move on to the next. Only way to really dial it in throughout the whole power curve.

Do you have your timing compensation per cylinder tables reduced? 05-06's have 2 degrees of advance on cylinder D...not sure if 08's do too?

this is on 93. perhaps my AVCS is a bit too aggressive?

I retared cyl 4 timing to -2*

mine tapers to 0 at 6k rpm, remember i was originally dyno tuned with the fmic and stock intake

Do you know why Subaru adds timing to cyl 4?

I retared cyl 4 timing to -2*

 

Por que? I thought the idea was that since that one is the closest to the knock sensor it should have a little bit of advance. So that it will knock first and be heard by the knock sensor, earlier than the others. In theory you are sacrificing #4 to protect the other cylinders.

 

I would zero it out of leave it slightly advinced (~ 1 degree). All others 0 advance.

 

Anywhoo..I can't imagine AVCS restricting timing that much.