Timing and Nitrous

[MidwestSS]

ok how many degrees of timing are people running on a 5.3 with a 150 shot?

... and why

[Botlfed]

ok how many degrees of timing are people running on a 5.3 with a 150 shot?

... and why

general rule of thumb 4 degrees for every 100 shot even though you can safely run 100 shot without a tune, oh and why, so the engine doesnt go boom

[MidwestSS]

ok so what are people's base timing?

[Botlfed]

ok so what are people's base timing?

idk, id hafta look at hp tuners, i think might was 20, but im probably wrong.

[Frenchy]

I know it's not a 5.3, BUT my truck on an 87 tune is running 25 degrees. I filled the tank with 91 and threw a PIG rich 100 shot at it with zero KR. That was on good zero ethanol Shell 91.

[pl4yboy]

I do 2-3 per 100.

[oleshifty]

This thread was actually for me...I was stuck at work. I'm running a 100 shot on my "n/a" tune from nelson. At wot (without spray, with 93 octane, and br7ef plugs) I'm running like 24.5* timing, zero KR. With nitrous, I get zero KR, but get like 5* for 30 seconds AFTER I quit spraying. The plugs look OK (not as good as the old setup) The tips are a little white, the top of the threads are a little black, the ceramic part looks perfect, no color, no spots, etc. I'm getting some random misfires at idle...I've heard that's common with these plugs.


I'm curious how big I can go with this tune. I had timing cut last year (4 or 5*), with a much bigger shot, it was faster on the spray, but a complete dog off of it. I know currently, I can run 89 octane if it's cold and not get any KR. When it was really hot, I got a little KR going up hill on highway at cruising speed (when motor was bogging under load). I put 93 in it and never had a problem. So I'm assuming I could bump up to 25-26* safely (which means I'm currently cutting about 2*).


If people here are running 26-27* all day long, then my tune is probably cutting closer to 3-4*, and I SHOULD be safe to go with a 150-175 shot. If I did this, I would start running torco/racing blend to make octane closer to 97ish.


My current jets are a 28, 51--which puts me right around a 10.5 at wot @ 950psi

I would jet up to a 31, and a 55 or 57

[2boosted]

Sometimes rich AFR are no good in avoiding Knock.

Unless you are racing for pinks.......imho you should stay with 24-22* and 175hp shot+100 oct gas.

Spark plugs 3-4 colder, and non projected tip.

Do scan from passes, and add 1* no more than 25* if no kr is found.

Naz is not that fun when you play on the edge for nothing. Play safe...keep playing....just my 2 cents.

[Frenchy]

Sometimes rich AFR are no good in avoiding Knock.

Unless you are racing for pinks.......imho you should stay with 24-22* and 175hp shot+100 oct gas.

Do scan from passes, and add 1* no more than 25* if no kr is found.

Naz is not that fun when you play on the edge for nothing. Play safe...keep playing....just my 2 cents.

It is however really fun when you're planning on a motor swap shortly

[oleshifty]

i'm not planning on it...but i know it's coming soon. I have too many miles, and beat on it waaaay too much. I already have a spare top end, just need to work on the short block.