Timing….again
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Timing….again Ok I know this has been beaten to death about how much timing to pull with how much spray. My issue is that I see “stock timing” literally all over the place! Searching the net I see 24-28° and even some more or less here and there. I had a tune on my 2000 corvette when I got it so I don’t know what stock was. I had a respected tuner since note that early stock ls1’s had a lot of timing and mine should have been 28°. He has since done a mail order tune and his tune removed 4° at WOT from 3k onward from 28°. I did not pull my plugs (br7ef), to check as I don’t track and it’s just a street car running a 100 shot occasionally from a roll. I could find a place and do a launch to 1/8th mile mph if necessary to check plugs but I’d probably have to leave in a hurry and not have time to pull over after an immediate shut down 😆 With all that said is there a max timing I should have it set at other than my 26°? I have hptuners arriving any day now so I’ll be able to monitor KR and log but I prefer safe. I also have an ln2000 I can pull more timing while spraying if necessary. Don’t think I’ll spray a 125-150 but it’s not off the table either. I’ll also be picking up a wide band. Thanks!
Ok I know this has been beaten to death about how much timing to pull with how much spray. My issue is that I see “stock timing” literally all over the place! Searching the net I see 24-28° and even some more or less here and there. I had a tune on my 2000 corvette when I got it so I don’t know what stock was. I had a respected tuner since note that early stock ls1’s had a lot of timing and mine should have been 28°. He has since done a mail order tune and his tune removed 4° at WOT from 3k onward from 28°. I did not pull my plugs (br7ef), to check as I don’t track and it’s just a street car running a 100 shot occasionally from a roll. I could find a place and do a launch to 1/8th mile mph if necessary to check plugs but I’d probably have to leave in a hurry and not have time to pull over after an immediate shut down 😆 With all that said is there a max timing I should have it set at other than my 26°? I have hptuners arriving any day now so I’ll be able to monitor KR and log but I prefer safe. I also have an ln2000 I can pull more timing while spraying if necessary. Don’t think I’ll spray a 125-150 but it’s not off the table either. I’ll also be picking up a wide band. Thanks!
There is really no set timing amount to pull based on shot size.. The old "2° per 50 hp worth of nitrous is kind of crap" and can put you in a bad spot. The timing a motor wants/needs is dependent on fuel and the heads. A more efficient head/combustion chamber will need less timing as compared to a less efficient head.
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I think I’m going to do like said and put the timing back to stock at what I believe is 28°. If anyone has an earlier LS c5 and could verify that would be great. I’ll use the lnc 2000 for retard purposes however what gets me is the starting point. I know the old 2° per 50 rule is kinda crap but at least it was a baseline of sort. Having mine setup for 24° sounds safe to me but it may not be. Some say you can’t tune nitrous on a dyno and in don’t have a place to make a run and immediately pull over to check plugs. Maybe at some point I can get to the track but without all of that how does one know? Measuring KR could be a disaster waiting to happen. Idk, I’m open of options lol.
edit: I’ve noticed a shift in tuning since the last time I ran nitrous (like 20 years ago). Looks like things are less timing and leaner now. Is there an afr that I should be aiming for? General of course. 12.5?
edit: I’ve noticed a shift in tuning since the last time I ran nitrous (like 20 years ago). Looks like things are less timing and leaner now. Is there an afr that I should be aiming for? General of course. 12.5?
Last edited by Boogsawaste; Aug 27, 2024 at 05:17 PM.
I think I’m going to do like said and put the timing back to stock at what I believe is 28°. If anyone has an earlier LS c5 and could verify that would be great. I’ll use the lnc 2000 for retard purposes however what gets me is the starting point. I know the old 2° per 50 rule is kinda crap but at least it was a baseline of sort. Having mine setup for 24° sounds safe to me but it may not be. Some say you can’t tune nitrous on a dyno and in don’t have a place to make a run and immediately pull over to check plugs. Maybe at some point I can get to the track but without all of that how does one know? Measuring KR could be a disaster waiting to happen. Idk, I’m open of options lol.
edit: I’ve noticed a shift in tuning since the last time I ran nitrous (like 20 years ago). Looks like things are less timing and leaner now. Is there an afr that I should be aiming for? General of course. 12.5?
edit: I’ve noticed a shift in tuning since the last time I ran nitrous (like 20 years ago). Looks like things are less timing and leaner now. Is there an afr that I should be aiming for? General of course. 12.5?
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Since I’m green with hptuners I’ll probably leave the tune alone until I’m a little more confident and just pull another 2° with the lnc2000. I’ll work with my tuner too to get my feet wet. Thanks for the help!
Not sure I get the logic here. You have a device to pull timing when nitrous is active. Yet you are driving around excessively retarded and pulling more timing? Why do you want it at 24*? Where did you pull that number from?
Most of the standard LS stuff Is happiest around 28*. It will vary the more you rev it and “upgrade”. But I don’t think you want to drive around 24*, then pull 2 more degrees? If you run decent 91-93 octane, I’d set it at around 28* from 5k to redline. Pull 2* with the n20 activation and call it good. You are likely costing yourself 15-20+hp with the current setup. If you wanted to be super conservative. leave it at 28* NA and pull 4* with the N20... then read a plug and bump timing back in it until the plug ground strap reads happy.
Most of the standard LS stuff Is happiest around 28*. It will vary the more you rev it and “upgrade”. But I don’t think you want to drive around 24*, then pull 2 more degrees? If you run decent 91-93 octane, I’d set it at around 28* from 5k to redline. Pull 2* with the n20 activation and call it good. You are likely costing yourself 15-20+hp with the current setup. If you wanted to be super conservative. leave it at 28* NA and pull 4* with the N20... then read a plug and bump timing back in it until the plug ground strap reads happy.
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Teching In
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Not sure I get the logic here. You have a device to pull timing when nitrous is active. Yet you are driving around excessively retarded and pulling more timing? Why do you want it at 24*? Where did you pull that number from?
Most of the standard LS stuff Is happiest around 28*. It will vary the more you rev it and “upgrade”. But I don’t think you want to drive around 24*, then pull 2 more degrees? If you run decent 91-93 octane, I’d set it at around 28* from 5k to redline. Pull 2* with the n20 activation and call it good. You are likely costing yourself 15-20+hp with the current setup. If you wanted to be super conservative. leave it at 28* NA and pull 4* with the N20... then read a plug and bump timing back in it until the plug ground strap reads happy.
Most of the standard LS stuff Is happiest around 28*. It will vary the more you rev it and “upgrade”. But I don’t think you want to drive around 24*, then pull 2 more degrees? If you run decent 91-93 octane, I’d set it at around 28* from 5k to redline. Pull 2* with the n20 activation and call it good. You are likely costing yourself 15-20+hp with the current setup. If you wanted to be super conservative. leave it at 28* NA and pull 4* with the N20... then read a plug and bump timing back in it until the plug ground strap reads happy.
Anyway I just finished my VE table and going to scale the MAF next. I’ll more than likely bump my timing back to stock and use the lnc2000 to just take 4° when spraying. I have to find some time to hook a meter up to it to verify it’s pulling timing as it does not log it. The ECM doesn’t know that it’s modifying timing which is a little annoying but nothing to write home about.
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Verdad Gallardo I'd log the total timing and verify. There are many parameter that change timing. So while it may state 17*on the map for the 01+, I can’t imagine that’s the actual total number. I’d assume other tables come into play and add to that 17* base number. IE coolant, IAT, maf loads etc. 17* is likely the base timing it reverts to if there is a problem. CEL etc. Where the older models didn’t have that ability.
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Right I can’t imagine that 17° is total and I’m sure like you said it’s modified by something else. Mine is stupid haha. I do log timing and will have to go over those too. Life is so busy anymore it’s crazy. I only ran 2 bottles of nitrous and I’ve been sitting on one now with like 3lbs left. It’s $16/lb here so it’ll be a while until I fill it anyway. Thanks for the help too. Appreciate it.