6.2 LS3 timing

[StoneJohnson001]

How much advance are some of you adding and where? I was thinking about 3000 RPM and up adding 5 - 7 deg, but was looking for some input first. I'm running 93 octane (for what that means today). The car is a G8 GXP to answer any weight questions. I wonder if I could have found something lighter, like a Suburban?

Thanks, Mark

[Sneakyws6]

Nope Wont Work, The Factory Tables In That Area Of The Map Are 19° And Right Now With 22° In My Tables I Still See Up To 2° Or Kr At Times.

The Lsx Engines Dont Need Alot Nor Do They Tolerate Alot Of Timing, 24° Is Usually The Absolute Max For A Stock Engine.

By The Way I Have A 2009 G8 Gxp As Well....

[69lt1bird]

Hmmm, that's pretty funny. I have the L92 heads/L76 intake on my 6.0 iron block engine and I can run over 30* with no knock. You probably have other tables pulling the timing.

[Mep_q8]

a friend of mine was on the dyno the other day, and we coudl've easily pulled of 29* of timing, but it was only a gain of 2-3hp, not worth it to be honest.. would rather keep the engine out of any possible knock later down the road...

richen ur mixture to a 12.5 and see how much you'd be able to pull off

[Sneakyws6]

Hmmm, that's pretty funny. I have the L92 heads/L76 intake on my 6.0 iron block engine and I can run over 30* with no knock. You probably have other tables pulling the timing.

Sorry but I have street tuned my GXP and you wont be able to run anywhere near 30° of timing on the LS3 in the GXP.

I guess go ahead and make sure you are running 93 as you will be seeing KR...

[Blackdevil77]

Is the L76 similar in the amount of timing you can use?

[madvette08]

Typical the LS3 like low timing, and the same goes for the L76. Higher then 25 degrees net a small hp increase and have seen reduction in torque numbers. Around .68 g/cyl and 3000 rpm above for wide open throttle timing.

Ian

[69lt1bird]

The times in my sig where ran with that timing. I used to work at SPO headquarters and the GMPP engineer on the LS3 crate engine program ran ALL of them at 27*, that was the sweet spot.

[LSX378]

The times in my sig where ran with that timing. I used to work at SPO headquarters and the GMPP engineer on the LS3 crate engine program ran ALL of them at 27*, that was the sweet spot.

Interesting stuff. Which cam was that with? Isn't there a couple different cams for the crate motors other than the production item?

[69lt1bird]

The crate engines with the hot cam and ASA cam.

[69lt1bird]

One of them they put on dyno for durabilty testing for 20 hours at WOT, the rods/rod bearings etc looked great still.

[Phil'sC5Vette]

Typical the LS3 like low timing, and the same goes for the L76. Higher then 25 degrees net a small hp increase and have seen reduction in torque numbers. Around .68 g/cyl and 3000 rpm above for wide open throttle timing.

Ian

I drove Ian's car last week, and I have to say it feels just as fast as my Heads and cam C5. Actually a little better and that pissed me off lol.

Listen to what he says

[CactusG8]

I drove Ian's car last week, and I have to say it feels just as fast as my Heads and cam C5. Actually a little better and that pissed me off lol.

Listen to what he says

Whom ever said 24 max wins. I actually get my best times with the following spark.

at .68 cylinder fill and above.

up to 4400 rpm 24 degrees

at max torque 4400, 4800, 5200 21 degrees

from 5600 on up 23 degrees of timing

I can go to 25 or so at top end. No knock. Just because it does not knock does not mean it is making more power. At the track it shows no kr with 25. But it slows down. And that is with a rich 12.3 afr and TR6 plugs to make the cylinders a little cooler.

The engines and heads are so efficient that the burn happens quickly. Only when your heads are inefficient is the burn slower and you need more timing. But go ahead run them at 26 plus and go slower.

[CactusG8]

Whom ever said 24 max wins. I actually get my best times with the following spark.

at .68 cylinder fill and above.

up to 4400 rpm 24 degrees

at max torque 4400, 4800, 5200 21 degrees

from 5600 on up 23 degrees of timing

I can go to 25 or so at top end. No knock. Just because it does not knock does not mean it is making more power. At the track it shows no kr with 25. But it slows down. And that is with a rich 12.3 afr and TR6 plugs to make the cylinders a little cooler.

The engines and heads are so efficient that the burn happens quickly. Only when your heads are inefficient is the burn slower and you need more timing. But go ahead run them at 26 plus and go slower.

I just ran my fastest time last night with only 21 degrees of timing. At inaugural night at Wild Horse Pass with a DA of 1550 I ran 11.65. At 4800 to 5200 rpm 20 degrees of timing. Then to red line only 21. That is with 91 octane E10 which is now all across the country. So you definitely do not need a lot of timing with ls3 engines.

[MikeOD]

I run my heads/cam LS3 right around 24 degrees too...it doesn't like any more. Running 93 octane and TR6 plugs.

I have added quite a bit just off idle, but that was for light load surging with the cam...up at higher airflow my timing is very close to stock.

[THE CHAD]

you guys are right ,as we all know the later model L76/L77/L98/LS3 etc don't need a lot of timing to make the power/torque that you are after, my L76(exhaust only) only runs 18-19* at W.O.T and then my LS1 h+c/manifold etc only runs 21* at W.O.T even with E10 which with that fuel didn't do boo with 22* W.O.T but made more power/torque with a richer LAMBDA of 0.86 so as the boys have explained why run more timing if it DONT MAKE A DIFFERENCE, but as I always say each to their own

[CactusG8]

you guys are right ,as we all know the later model L76/L77/L98/LS3 etc don't need a lot of timing to make the power/torque that you are after, my L76(exhaust only) only runs 18-19* at W.O.T and then my LS1 h+c/manifold etc only runs 21* at W.O.T even with E10 which with that fuel didn't do boo with 22* W.O.T but made more power/torque with a richer LAMBDA of 0.86 so as the boys have explained why run more timing if it DONT MAKE A DIFFERENCE, but as I always say each to their own

Funny. I just got the car back. LS3 with lunati voodoo stroker 416 crank and rods. Wiseco domed pistons with valve reliefs. About 11.3 to 1 compression. A smaller Rick Crawford/Lunati custom grind. 223/235 112 straight up. .625/.626

It seems like it wants more timing. I go on the dyno the Friday after next Friday. We will see then.

[MikeOD]

That's a completely different animal now being a 416 though.

[CactusG8]

I agree. But I would not think it would want more timing with more compression. But then again I will see this Friday as sometimes you think something and the dyno proves you wrong.

[Area47]

23-23.5 for pump gas bolt on ls3/l92 engines maintaining the factory curve. 24-25 for mild cam setups to slightly make up for compression loss. More efficient heads require less ignition timing to make power.