LSx questions

[68GMCCustom]

1) what amount of total timing would one expect to see on a tuned & high lift cam'd up 6.0 LSx? vs stock?

2) what size wire is required for a 1 wire alternator hookup? I've noticed that during WOT...if I stay in it I smell an electrical burning type smell. Before increasing the size of that wire I even got smoke in the cab under WOT....yet all is fine at most all other power levels.


Thanks!

[BR3W CITY]

Not sure about the wire, but as far as timing; 26-32. Far over 30 not good, far under 25-26 means your leaving something on the table, something is pulling timing, or timing has been intentionally pulled due to a problem.

[Clyde65]

On the alternator wire, are you speaking about the wire that goes directly to the starter? I use an 8 guage wire on my all stock 4.8, however I have an alternator that pumps out well over the "rated" 110Amps, this is why I put the 8 guage wire in.

Hope this helps you.

It seems to me after I read you post again, the smell is coming from the ignition wire from the starter to the switch, have you checked this? Maybe you have a short but it currently isnt enough of one to cause any issue until demand goes way up. I would suspect the ignition switch also, especially if it isnt an OEM or stock one, aftermarket switches blow.

[69gmcc10]

Gauge of wire depends on 2 things. 1) how many amps the cable needs to carry and 2) how long the run is.

85-105 amp alternator needs 8 ga cable up to 7 feet to flow at its full potential. After that it needs 6 ga cable up to 10 feet and 4 ga for any reasonable length beyond that.

Regardless, I would run a 3 wire set up to protect from over charging. I am sure you are aware how easy they are to wire up, but here is a page that does an awesome job of summing it up:

http://bob_skelly.home.comcast.net/~...ternator1.html

[Clyde65]

Good Info 69GMCC10!

[Hart_Rod]

Originally Posted by 69gmcc10

Gauge of wire depends on 2 things. 1) how many amps the cable needs to carry and 2) how long the run is.

85-105 amp alternator needs 8 ga cable up to 7 feet to flow at its full potential. After that it needs 6 ga cable up to 10 feet and 4 ga for any reasonable length beyond that.

Regardless, I would run a 3 wire set up to protect from over charging. I am sure you are aware how easy they are to wire up, but here is a page that does an awesome job of summing it up:

http://bob_skelly.home.comcast.net/~...ternator1.html

+1. Also, I would not feed my fuel pump through the factory body harness. It should have a fused/circuit breaker power supply from the battery or starter post, depending on which one is closer.

[68GMCCustom]

Great info on alternator all....thanks, and for wiring diagrams too! I'll have to do some wire tracing on the ign. switch. Hartrod I am running a Painless Circuit Boss (7 circuits) for all my "new" circuits to keep them off the oem wiring until I repaint the truck...and do a complete rewire. Fuel power comes off the efi stand alone harness and has its own relay.

Brew those total timing numbers seem low? are they for boosted app or n/a? I thought I saw 40* (or maybe even 45*?) while watching my Aeroforce ScanGauge, while hooked into OBDII, coming from my stock LS2, in my TBSS in coasting conditions. Under 30* seems really low? Weren't SBC's like 32-36* or more for total timing?

I asked because my LY6's current tune has as much as 50*?

[BR3W CITY]

Originally Posted by 68GMCCustom

Brew those total timing numbers seem low?
I asked because my LY6's current tune has as much as 50*?

Low? Hell no, 32 was me putting some room on each side of those numbers. Most LS motors like 24-29*. The "add timing till it knocks" style of tuning doesn't jive on these motors, and each motor will act a little different. I've seen some LS2 corvette's KILL with about 25*.

In some cases, tuners will get less-than-expected power levels from a combination or tune, then try to add like 35* timing to make power, and chase the timing with fuel. What this ends up with is a tune that runs more dangerously, is less efficient, and doesn't make more power than the same tune done differently on lets say 26*

Turbo cars on stock blocks are in the 10-14* range.

I don't think the thing would even run on 50*

[68GMCCustom]

This was in light cruise or decelerating conditions as read by my scangauge. Maybe its giving me bad info as I know I've seen numbers in 30's and 40's in similar conditions on my LS2 with oem tune?

Guess I need to get the laptop out and log with HPT to see what I'm really getting.

[BR3W CITY]

Its possible that you looked at in while in DFCO, (fuel cut on decel). In that case, its possible that the tune is throwing 30's at it, trying to burn off the tiny bit of fuel thats present in DFCO. The reason for doing this is to eliminate backfire/popping from the unburnt gas (and trying to protect the CAT in doing so. )

[68GMCCustom]

I'll look at the LY6 in my '68's tune, and check the TBSS LS2's tune and see what they show.