Whats safe timining for ls2
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Instructor
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From: KCMO
Whats safe timining for ls2
I have a feeling my tuner is not giving me the best tune I can get. I was thinking I could run a bit more timing with the E85 and cam, right now my tuner has me at 28-29, is this low?? I just thought we could be a bit more aggressive with timing at least 30 but I not sure, any help out there? Any experienced tuners, guys who have seen this setup before or who seen more compression? Any help will be appreciated
Le Mans Master
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From: Tampa FL (formerly Justinjor)
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St. Jude Donor '11-'12-'13-'14
Generally speaking--yes, that's the case. I found that my car like less timing and loads more fuel. The LS3 is very efficient and as such, does not respond well to lots of timing. I only run 21* during peak torque and 24* peak timing at 6000. I had a lot more timing in it to begin with but it seems the more I removed it, and the more fuel I threw at it, the better it responded.
It just goes to show that every car is different and the dyno is a really great tool to establish what your particular car really does and does not like.
Le Mans Master
Joined: Oct 2006
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From: Cumming, GA
What kindof power are you making with the cam and E85? Basic cam specs and compression?
My LS2 doesn't really respond to a ton of timing on 93 octane. We tried adding more and the power started to fall off.
My LS2 doesn't really respond to a ton of timing on 93 octane. We tried adding more and the power started to fall off.
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Burning Brakes
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From: Hartford CT
there is no set number. All LS engines have a fairly effecient combustion chamber design an dont like alot of timing. I remember when we tuned windsor Fords with factory heads, you would see power increases up to 38* BTDC peak timing, ha. most LS engines seem to be happy in the mid high twentys.
If you proceede carefully there is no reason you cant try trial and error on the dyno. Add a little timing until it pings or the power goes flat. My tuner can hear pinging long before the KR kicks in.
Good luck
If you proceede carefully there is no reason you cant try trial and error on the dyno. Add a little timing until it pings or the power goes flat. My tuner can hear pinging long before the KR kicks in.
Good luck
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From: KCMO
My cam spec and current compression is in the title, I making 455-470wrhp right now, I havent dyno since the new tune and before then was putting down 456wrhp with e85 and 102 fast no tune. We had to cancel dyno day this past weekend or I would have new final numbers. The car feels so much tougher after I got it back from the tuner, I would say easily a 10-15 hp gain, but a lot of guys here in the city has commented that it seems my timing numbers were low for e85 and cam, so I thought I would see what you guys(expert corvette guys) knew about it. Thanks @Taken19 I did post this in the wrong section. Thanks guys for your help.
Le Mans Master
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From: Tampa FL (formerly Justinjor)
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St. Jude Donor '11-'12-'13-'14
For starters, your title says nothing about your cam spec etc. It just says "Whats safe timining for ls2"
Second, I'd bet the 'guys in the city' are old school and not familiar with how the 4th generation of the Chevy small block functions with regards to timing requirements.
As I said before, every motor is different and that's what makes the dyno so important. I can tell you that you won't feel a 10-15hp gain on a 460hp motor and if you are feeling a difference in the previous tune, the hp/tq gain will be higher than 10-15whp. Changes in the air quality alone can account for much more than that so if you ran the car in the heat of the day, and then at night, it would feel like it's making more power.
Second, I'd bet the 'guys in the city' are old school and not familiar with how the 4th generation of the Chevy small block functions with regards to timing requirements.
As I said before, every motor is different and that's what makes the dyno so important. I can tell you that you won't feel a 10-15hp gain on a 460hp motor and if you are feeling a difference in the previous tune, the hp/tq gain will be higher than 10-15whp. Changes in the air quality alone can account for much more than that so if you ran the car in the heat of the day, and then at night, it would feel like it's making more power.
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Instructor
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From: KCMO
For starters, your title says nothing about your cam spec etc. It just says "Whats safe timining for ls2"
Second, I'd bet the 'guys in the city' are old school and not familiar with how the 4th generation of the Chevy small block functions with regards to timing requirements.
As I said before, every motor is different and that's what makes the dyno so important. I can tell you that you won't feel a 10-15hp gain on a 460hp motor and if you are feeling a difference in the previous tune, the hp/tq gain will be higher than 10-15whp. Changes in the air quality alone can account for much more than that so if you ran the car in the heat of the day, and then at night, it would feel like it's making more power.
Second, I'd bet the 'guys in the city' are old school and not familiar with how the 4th generation of the Chevy small block functions with regards to timing requirements.
As I said before, every motor is different and that's what makes the dyno so important. I can tell you that you won't feel a 10-15hp gain on a 460hp motor and if you are feeling a difference in the previous tune, the hp/tq gain will be higher than 10-15whp. Changes in the air quality alone can account for much more than that so if you ran the car in the heat of the day, and then at night, it would feel like it's making more power.
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Yea but he is running E85. The GM race tune has LS2's running about the same on race fuel.
You know I hate to be the one to say this, not really
This is where a load bearing dyno comes into play. You can actually what your torque numbers and be able to figure out where you make the most torque at and go from there. The is no replacing the proper tools and that includes a proper dyno.
You know I hate to be the one to say this, not really
This is where a load bearing dyno comes into play. You can actually what your torque numbers and be able to figure out where you make the most torque at and go from there. The is no replacing the proper tools and that includes a proper dyno.
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Every car is different. I just ran a CTSV with the LSA and it loved fuel on the top end, more than where I would like to see it but it's hard to argue when it keeps making more power while your feeding in the fuel.
Instructor
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I have an ls2 with un-milled and un-ported ls3 heads and a small cam and it loves timing, it was gaining right around 5hp and 3tq every two degrees the tunner and showed no sign of knock, he stopped at 29 degrees though.
Le Mans Master
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From: Tampa FL (formerly Justinjor)
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St. Jude Donor '11-'12-'13-'14
Exactly Justin. Dyno is the only tool for this job.
Also, regarding the 5hp/3tq gain for every 2* of timing...I can't speak for everyone, but that's not a very good return for the the risk involved in my opinion.
Cylinder pressures(load on the motor) go up exponentially for every degree of timing added. I'd rather have much a much safer motor with 4* less timing and give up 10whp/6tq then push it to the ragged edge and risk damaging the motor. The risk/reward just isn't there for those minimal gains.
Just my $.02 though
Also, regarding the 5hp/3tq gain for every 2* of timing...I can't speak for everyone, but that's not a very good return for the the risk involved in my opinion.
Cylinder pressures(load on the motor) go up exponentially for every degree of timing added. I'd rather have much a much safer motor with 4* less timing and give up 10whp/6tq then push it to the ragged edge and risk damaging the motor. The risk/reward just isn't there for those minimal gains.
Just my $.02 though
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From: KCMO
Exactly Justin. Dyno is the only tool for this job.
Also, regarding the 5hp/3tq gain for every 2* of timing...I can't speak for everyone, but that's not a very good return for the the risk involved in my opinion.
Cylinder pressures(load on the motor) go up exponentially for every degree of timing added. I'd rather have much a much safer motor with 4* less timing and give up 10whp/6tq then push it to the ragged edge and risk damaging the motor. The risk/reward just isn't there for those minimal gains.
Just my $.02 though
Also, regarding the 5hp/3tq gain for every 2* of timing...I can't speak for everyone, but that's not a very good return for the the risk involved in my opinion.
Cylinder pressures(load on the motor) go up exponentially for every degree of timing added. I'd rather have much a much safer motor with 4* less timing and give up 10whp/6tq then push it to the ragged edge and risk damaging the motor. The risk/reward just isn't there for those minimal gains.
Just my $.02 though
I agree, all gains are not worth it. I want to stay in a safe zone and enjoy the car. Dont want a max out ***** to the wall tune just from what I know(which isnt much) I thought 30* was a starting pointing with my mods but obviously I am wrong.
