well I'm a corvette guy looking for advice. I just started tuning on my own. I got my BLM's very close on my 89 corvette. I wanted to see what I can do to improve the spark table. My motor is modded. AFR 180 heads, as&m runners ported intake and plenum, flat top pistons, ZZ4 cam, and long tube headers. tuning the fuel trim seemed simple enough but the timing table just seems a little overwhelming. The table is already modded from mail order.

 

Do you have any spark adders like power enrichment advance still in the tune adding to that table?

the lower rpm lower lv8 cruise areas may be too much timing, i usually see less than say a stock arap bin for stock vette heads. Afr's usually take alot less

If no adders to the pe mode spark then wot might be a touch low at peak hp, say 4000 on up. It might want 32-34 but thats gonna need track or dyno to verify

 

Try doing some smoothing on the tables first. 40+d may be a bit much.

 

The pe Spark adders have been zeroed out

 

Ok I played around with the timing table. Let me know what ya think.

 

Also, if there's a spark timing vs coolant table like in the $8D code, probably want to zero that out as well. In $8D, it'll start subtracting off timing at various coolant temperatures.

 

In $6e there is coolant compensation vs load. Where you seeing knock counts before your new tables. You can use the knock counts as a guide for timing curve. There is a ecm forced knock so it’s normal to see a few knock counts.
You can also improve your cranking time bye adding values to the 1-8 of the crank pw multiplier vs ref pulse table.
Glad the Accel base finally showed up

 

 

The zz4 is a easy cam to dial in the int/blm with tpi maf.
You might want to read this for additional help with your new cam. Great information.
https://www.thirdgen.org/forums/atta...air-flow-tuned

 

Yeah I have had the ZZ4 cam for years now. I ordered the lingenfelter 211/219.

 

 

Well I took it for a drive and logged it. Had some knock counts around 3300 rpms and up in the high lv8. I knocked down the timing there a bit to 33. I need to drive it more and see more of what it’s doing. But I think I can up the timing some more at the cruising levels since I saw no knock counts.

 

Unless you were having knock issues at the lower loads, you should put those areas back to the original higher values.

RBob.

 

My 9.6:1 350 with cast iron Vortec heads in my Express van when I was running the tiny 300 HP Vortec marine cam liked as much as 50* of timing at 3,200 rpm without load and running 70 mph the cruise timing was in the 38-42* range at 2,400 rpm and 50 kpa.

 

Yeah kinda got to play with it. The 48-80 lv8 area might be ok with 30-36 deg. My 383 liked 35 ish but was 11:1 comp on pump gas but a big cam.

 

Yeah I actually thought about it and I did change it back. I’m going to adjust the table by watching the knock counts.

 

Well I’ve done some logging and also put my stock table back in. The only issues I’m haveing is with the high lv8 when I mash the throttle and after 3200 rpms I start getting knock counts like mad. I’m starting to see why my tuner had the values so low right there in the first place at 29.88. So I knocked all that down to 30 d. I need to swap chips when time permits and drive it again. I hope I’m not getting false knock from somewhere.

 

so I was poking around at the power enrichment section on tuner pro and found this table. looks like it gets leaned out around the same rpms I start seeing knock counts. could this be my culprit?

 

Do you have a WB O2?

Just looking at the table doesn't really say anything. You'd need to see what the actual AFR is via a WB O2. But if you're indeed running lean, that can cause knocking, yeah...

In the absence of a WB, what you could do is richen it up by a 1 point on the PE AFR and see if that helps. You still won't know what the actual AFR is, but at least it'd be a clue that you're likely on the lean side of things...

 

No I do not have a WB. But I do want to get one. Money is tight at the moment. Not sure when I’ll be getting one. Any suggestions on what brands to look at for a WB? Do I have to get the gauge or is there a way to use it on tuner pro? I’m a newbie but a fast learner. Tuning is very new to me. Always been on the mechanical side of cars.

 

Innovative or aem make good wb kits.
I don’t know of a adx for $6e already setup for a wb
But here’s a how to.
http://support.moates.net/logging-a-...h-tunerpro-rt/

 

Have not see this table before. what xdf are you using. I have the older 6e expanded xdf and power enrichment is a percentage increase adder vs rpm in one table and vs coolant temp in another

 

I have not seen this table before either. Looks like the values need to be inverted...

- Rob

 

I got my xdf and adx from scott hansens site. the ones on his site actually save as the right file. I don't know why but all the ones from tuner pro or gear head I can only save as text. maybe because I'm running windows 7 maybe.

 

I didn't see it brought up, I personally like to have all the cells around my idle area at the same spark advance. The 400 cells I bump up in case it starts to die it can kinda catch itself. That really helps to keeps the idle from wandering for me. Granted the ZZ4 cam isn't big and hard to tune, just a suggestion that works for me.

 

Not sure how that one works but you can test it with a wideband o2 or try using the narrowband voltage as a guide

 

well just an update. I purchased a wideband just need to pull my front y pipe and get the bung welded in. also did my 211 cam and accel base intake swap ditching my ported stocker. I did some logging and even before I swapped everything I kept getting random lean spots up to 132 blm in my log. could not seem to get it dialed in. well I already planned on putting in a stronger fuel pump in anyway. did that yesterday. now the lean spots are gone. actually slightly rich 122-126 blm. my fuel pump was an airtex pump changed in 09. wonder if it was going bad. I put in a deatschwerks DW200 fuel pump.

 

I got my wide band hooked up. I had this table set for 13.80 and wow my actual AFR was like 10.50. glad I got it now the real tuning begins.

 

As others have alluded, that table doesn't exist as the XDF shows it. With the values shown it will be very rich.

RBob.