496 BB

This may be a super retarded question, as I may be too, but when folks say their timing is set at say 15* (just picked a number here) at what point does that mean? I know I have mine set pretty conservative and didnt want to mess with it until I got traction issues at least somewhat lined out as I recently have. Now Id like to start adding small amounts and checking on the plugs. Issue is Im not sure where to actually start adding as in do I add at X amount of Rpm and Y amount of boost and interpolate from there or what? I feel below boost is good but feel rpms climb rather slow in boost. I have checked with a timing pointer and piston stop method that I am right on the money with the Holley set at 20* static timing. Also on a quick side note does this plug suggest I can add some more? I assume 2* or so. They been in there for a month or longer with street driving too. Ive only seen around 19psi testing thus far (for last week and only on the streets).

Sorry for big *** pics. Couldnt figure out how to make thumbnails for some reason.

3 window

iTrader: (1)

Pump gas? E85? Meth? Need a little more.

496 BB

**** my bad. Yea its E85, no meth. MATs never get above 140 unless its super hot out and hot lapping and then its well below 200. Have a MAT map built to take timing out starting at 200.
Gen 3 LQ4 SBE but all gone thru, cleaned and put back together. Cleaning pistons and all
Rings gapped around .032 (some were bigger than others but minimum was .030)
BTR stage 2 cam
10.5:1 CR or so. Milled .020 or so off these when I redid em before I put em on
799 heads w/ LS9 GM gaskets (I think thats what they were.... whatever the most popular ones are for turbo LS)
Head studs
Trunion kit
7875 turbo
Holley Tx
Twin 450 Holley pumps
1500 injectors
Sniper sheet metal type intake

Runs good. Have had it Dynoed but went for driveability more than max power at that point. That was in January. Now Im ready to start adding to get some more speed into it. Wasnt worried about it before as I still had stuff to work out on it. Put down decent numbers even on low boost and that timing map above. AND a trans that was slipping with a converter that flashed too high. Thats all fixed now.

rpturbo

iTrader: (47)

I'll have to look over your timing map when I'm not on my phone. The down low timing ( below boost up to say 2psi ) should be basically N/A. You don't say how much boost your currently running, or how much you may want to turn in it. My thought is your going to be rod limited. I've been kinda curious what timing others run on gen IIIs myself.
A friend of mine has a similar combo, lower CR. In that, we have 12# in it, and run 15* on E. I have no doubt it will take more, to me the cautious part is on the shift. I know lots of guys have experience with this and I know every combo is different, but other than the basic rule of 28, I haven't seen much sharing. I'm curious if anyone would chime in on how much timing your running or pulling on the shifts.

3 window

iTrader: (1)

Just mine, but I don’t pull timing until 6 psi, then it’s about .75° per psi after that. Peak torque is roughly 5200 so I pull a couple extra from 5200 to about 5750 then ram it back in. I’ve got Gen IV rods and also run E85. If you’ve got a converter that’ll stay away from peak torque on the shift return, don’t even bother pulling any there. This is just my opinion. I’m sure others will chime in.

496 BB

I understand I need to add more but my issue is where on my 2D table do I start and finish? Do I just add a certain number somewhere and have Holley fill in the rows and columns from there? Thats whats messing me up. Its all linear and smooth now unlike a 1d table would be. I know Im making this more confusing but once I get it I will understand. Still a learning process for me and I rode the short bus to school.

Also what would peak tq timing be max and at what psi level say on your setup 3window?

So when RPTurbo you say your friend has 15* at 12psi is that the same across all rpms? Or is it like my 2d table pictured above? Im trying to figure out at what rpm is everyone saying they have X amount of timing. Or maybe other ecm's are 1d unlike mine.

Im running up to 20psi atm. So basically if I get a 0 boost number and a 20 psi boost number and a 3k rpm and a 7k rpm number I can figure it out most likely from there (Ok maybe not but I will damn well try).

Thx for bearing with me.

rel3rd

iTrader: (43)

Just my 2 cents, but just a 3k and 7k number may not really help.
Most people subtract a little bit of timing at peak torque.
I run a very similar combo, also on E85. But I try to cap boost at 15-16psi.
I have roughly 24* timing, @2psi, but only run like 13 degrees at peak torque (4300-4400ish on mine), and then immediately ramped up to 18.5-19*. My shift extension is about 800rpm, give or take (shift @ 6500/down to 5700), so RPM-wise, I stay well above peak torque on 1-2 and 2-3 shifts.
So, my timing curve (for comparison sake), in basic terms, is 24*, ramped down to 13* at peak torque, then ramped back up to 18-19*

Like this, is how mine is...
24*@113kpa (2psi) and 2900rpm (on 2 step)
Ramped down to...
13*@167kpa (9.8psi) and 4300rpm (peak torque)
Ramped up to...
19*@210kpa (16psi) and 5300-6800rpm

I can't help with the graphs and tables, as I use HPTuners, but this is how mine runs best, according to ET slips. Never been on a dyno.

I'm 100% NOT suggesting you go out and run 19* of timing, lol, but it looks like you're maxed at 12-13* @ 20psi and E85 should allow a bunch more timing, especially leading up to your max boost, although it looks like you are very conservative on the timing numbers all over.

496 BB

I get what ur saying. I just didnt know if it was ok to just type in a number across the board or not since mine is smoothed across it. I get where peak tq and where it needs to come out.

rel3rd

iTrader: (43)

I would never just have a flat number from Point A to Point B.

496 BB

How does this look? Thanks!