I've got an 05 cav with 5speed. I was playing around the timing, and during the scanning process to see the effect my changes had, I noticed that cruising down the road at 60mph/2300 rpm my advance was staying around 45-49 degrees of advance. There isn't an KR showing in the scan with the exception of a spike that seemed completely random. Afterwards the timing climbed right back up. I'm consistantly running 93 octane, and the only mods are k&n intake, pacesetter header, and 2.5" exhaust.
I'm more used to tuning old small blocks and trying to keep total timing much lower. Do the Ecotecs really like that much timing, or should I back it back down to a more mundane level?
Thanks up front for any constructive input.
it depends really. theres 3 ways to do it really...
- add timing until you see KR, back it down a touch till KR goes away.
- dyno tune it to set the timing where max power is achieved. more timing doesnt always mean more power. there is usually a peak where power drops off or power curve is less desirable.
- add timing, log some performance indicator such as 0-60 times, delivered torque, etc. adjust timing until KR is acceptable and desired performance is achieved.
honestly, the dyno is the best way to go but can get costly. logging a performance indicator on the street is your next best option.
1997 Cavalier Z24 - 15.647 @ 88.02 MPH
phil wrote:I've got an 05 cav with 5speed. I was playing around the timing, and during the scanning process to see the effect my changes had, I noticed that cruising down the road at 60mph/2300 rpm my advance was staying around 45-49 degrees of advance. There isn't an KR showing in the scan with the exception of a spike that seemed completely random. Afterwards the timing climbed right back up. I'm consistantly running 93 octane, and the only mods are k&n intake, pacesetter header, and 2.5" exhaust.
I'm more used to tuning old small blocks and trying to keep total timing much lower. Do the Ecotecs really like that much timing, or should I back it back down to a more mundane level?
Thanks up front for any constructive input.
Even a SBC with alum. heads, with no load (cursing at 60, 2300 RPM) can use up to 40*.......
plug in, and see what you can add, and keep a eye on KR, we all know the eco's aren't the strongest little short blocks out there.
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
Taetsch Z-24 wrote:
plug in, and see what you can add, and keep a eye on KR, we all know the eco's aren't the strongest little short blocks out there.
Chris
lol do you have a major eco vendetta, I say it out of straight curiosity not as a blow.
It seems every post you can you bash ecotecs.
Just stating facts, to much knock, the ring-land will crack.
this is true with all motors, however i think the eco's pistons to be very weak.
(my stock 1992 LG0's piston alone weigh more then the stock L61's rod, wrist pin and piston together.)
Chris
'02 Z-24 Supercharged
13.7 @102.45 MPH Third Place, 2007 GMSC Bash SOLD AS OF 01MAR08
phil wrote:I noticed that cruising down the road at 60mph/2300 rpm my advance was staying around 45-49 degrees of advance.
thats normal. as MAP value climbs, the advance will alter itself to reflect it.
total timing BTDC at WOT is what people usually reference when tuning. the MAP sensor controls the spark advance and as load increases, it'll back timing off (but increase in relation to RPM obviously)
there's a total of 4 spark tables on an eco. Low and Hi RPM tables for reg mode and PE mode. The ecu interpolates between all of them and a multiplier or two before you get the end spark advance.
if you tune for 45* BTDC at WOT tho.. you're going to either lose major power or break something.
DaFlyinSkwir(LS61) /PJ/ OEM+ wrote:
if you tune for 45* BTDC at WOT tho.. you're going to either lose major power or break something.
exactly. a few guys on css.net have played around on the dyno with timing advance at wot with meth injection and they highest they got it where it was still making power was 25 * wot but every car is different and only a dyno will tell.
Quote:
Even a SBC with alum. heads, with no load (cursing at 60, 2300 RPM) can use up to 40*.......
ok, that made me laugh.....the first thing that went through my mind was Jay doing the scene from Jay and Silent Bob Strike Back.
I know I've got 27 degrees of advance on mine. Pretty much for every degree I added it seemed to pull a lil better and smoother up to that point, I went to 31 just to test it and it didn't seem to gain anything above 28, this is all based on feel. But as chris stated the eco ringland is very weak, I would not suggest pushing it too far considering the stock pistons I pulled from my motor back in December could be dropped from about 8 inches up and the ringland would shatter right off the piston.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
phil wrote:I'm more used to tuning old small blocks and trying to keep total timing much lower. Do the Ecotecs really like that much timing, or should I back it back down to a more mundane level?
How so?
A "typical" SBC 350 would run 12°-16°@idle with a mechanical curve to about 36° ramped to be "all in" by 3000 rpm.
So if your highway cruise rpm was 3000, you would be at 36° because of mechanical advance and then adding another 7°- 10° with vacuum adavnce on top. So your typical SBC cruising advance at around 3000rpm is actually 43°-46°... nearly the same as the eco and your eco is running leaner.
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protomec wrote:at around 3000rpm is actually 43°-46°... nearly the same as the eco and your eco is running leaner.
Nearly the same? Have you really looked at the eco tables? Just looking at the the main spark tables, the highest spark advacne is 41* and that's from 4400 to 6000 and only 20 kpa. Normal driving spark is in the mid 20's, w/ wot spark being 20 in the high octane table and 16 in the low. And if your IAT's are too high expect to have a lot of that spark taken away from you, to the tune of pulling about 3 and up degrees if the iat is above 111 at wot, sounds like a lot of fun huh.
On a side note, I guess I never really looked at the stock tables all that much, seeing the 41 in there made me think for a minute, is it possible to run more than 27* and have power gains? I know I've discussed this w/ Vega a bit, but I'm just not convinced that I'm at the max spark for my car.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
Skunk wrote:protomec wrote:at around 3000rpm is actually 43°-46°... nearly the same as the eco and your eco is running leaner.
Nearly the same? Have you really looked at the eco tables? Just looking at the the main spark tables, the highest spark advacne is 41* and that's from 4400 to 6000 and only 20 kpa. Normal driving spark is in the mid 20's, w/ wot spark being 20 in the high octane table and 16 in the low. And if your IAT's are too high expect to have a lot of that spark taken away from you, to the tune of pulling about 3 and up degrees if the iat is above 111 at wot, sounds like a lot of fun huh.
On a side note, I guess I never really looked at the stock tables all that much, seeing the 41 in there made me think for a minute, is it possible to run more than 27* and have power gains? I know I've discussed this w/ Vega a bit, but I'm just not convinced that I'm at the max spark for my car.
Only the dyno will tell my friend, prove css.net wrong and help further org knowledge of OUR ecotec.
Skunk wrote:
Nearly the same? Have you really looked at the eco tables?
No, I am not looking at the tables, nor have I.
I was only commenting on his statement in his 1st post...
phil wrote: I noticed that cruising down the road at 60mph/2300 rpm my advance was staying around 45-49 degrees of advance... I'm more used to tuning old small blocks and trying to keep total timing much lower.
Notice he says 45-49 is way higher than what "old small blocks" run. My comment is that it isn't.
I wasn't commenting on Eco tables at all.
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I've never gotten much benefit out of running that much timing with the 350's I've built. Base timing of 8deg, mech of 20 max, vac of 10 max. Seems like 38 total to me. My math could be wrong though. Now, that's always been 9-10:1 compression cast iron headed small blocks. Anything more than that things didn't seem to get any better.
I just find it hard to take a face value that aluminum 4 cyl engines and fuel injection can allow for an extra 6-12 degrees of timing. But this is my first experiment into this platform.
I was just checking to see what the most reliable timing advance is recommended on these motors. I've been more adventurous with my projects and fun trucks because I didn't need them to be on the road. My cav is my daily however, and I really don't want to cause damage through ignorance. Damage through beatings, floggings, or trying to break something in order to replace it with out asking permission from the wife is completely different.
20°???
I know of no one using that little on any 1950's designed V8 and making any real power,
phil wrote: I just find it hard to take a face value that aluminum 4 cyl engines and fuel injection can allow for an extra 6-12 degrees of timing. But this is my first experiment into this platform.
old design engines are slugs. they required much more timing advance their lack of breathing ability and fuel mixing.
Modern engines usually require much less timing because they fill the cylinder better and keep the fuel/air better mixed
These statements apply more to WOT operation. At light throttle, much more timing can be, and is, used because the limited air available won't cause enough pressure to detonate.
But typically, a 4v engine will usually run 6-12° less advance than a 2v old design engine. So no, an "aluminum 4cyl" will not typically run 6-12 more.
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