More Boost or More Timing Advance?

[imagine3163]

Hey guys, I am wondering from you DSMLink users what you think is more beneficial for you in terms of power. In your experience, have you found that running more boost (20lbs) with more timing retard makes more power, or less boost (15lbs) with more timing advance makes more power? I have also read that the 2gs can make more power from advancing the timing than 1gs can. Is this true or just someones opinion?

Thanks

[Black_Bullet]

More boost gets more power....I run 25psi on my E316g setup on pumpgas with relatively low timing ... At 15lbs you can run as much timing as you can get away with and it would still feel weak compared to the boost im running... Mind you im still getting away with 19 drgs peak timing by redline, what you can squeeze out will be differnt than what I can since different mods different compression... Timing advance needs are different from one car to another, its not an exact science, but for starters just set tha AFR around 11.1 then drop the timing to a low safe amount, and crank the boost as high as your willing to go, then start slowly putting some timing back in by small increments till you get 2-3 degs knock retard then back it off 1 deg and remember, you will naturally be able to get more aggressive with the timing advance the higher the rpms rise, in the lower rpms you will want much less timing. Then once timing and boost are good, lean out your AFR a bit more if you can, and that should be a good tune.

[1992awdlaser]

It all depends on what the car likes. 20psi is not a lot of boost and you should be able to get timing in the high teens depending on what turbo it is and a few other things. Some cars make more power with high boost like 35+ and moderate timing than they do with lower boost like 30psi and a lot of timing. Some are the opposite of that. This is when you will want to be on a dyno or at a test and tune. You will be able to find out what your car likes more.

2g's can make more power from advancing the timing only because they have ridiculously low timing from the factory. A 1g will be pretty easy to make knock on pump gas with any timing advance because they have a very aggressive timing curve from the factory. This is why most 1g guys will try to make more power with more boost before trying to with more timing. So a 2g isn't really making more power from timing advance it is simply making up power that it lost due to the low timing curve the factory put into the ecu.

[Black_Bullet]

Originally Posted by 1992awdlaser

2g's can make more power from advancing the timing only because they have ridiculously low timing from the factory. A 1g will be pretty easy to make knock on pump gas with any timing advance because they have a very aggressive timing curve from the factory. This is why most 1g guys will try to make more power with more boost before trying to with more timing. So a 2g isn't really making more power from timing advance it is simply making up power that it lost due to the low timing curve the factory put into the ecu.

If your trying to run a lot of boost on pump gas the 2g timing curve is actually better in my opinion even for 1gs....Also remember, higher compression speeds up the burn rate so you naturally require less timing.... 1gs have ridicuously low compression so the 1g timing curve is more advanced from the factory for that reason.

[90laserRSfwd]

This is kind of stupid but timing makes power and so does upping the boost. It really depends on your willingness to push your car. A larger spread in boost will make more power then timing alone (like 15 psi with 19 degree's of timing will make more power then 16 psi with say 14 degree's). But your talking about a 5+ psi difference then boost wins, if the tune is correct.

[bluegs03]

This is a great post and helped me a bunch in understanding the relationship you need inbetween boost and timing! thanks

Originally Posted by Black_Bullet

More boost gets more power....I run 25psi on my E316g setup on pumpgas with relatively low timing ... At 15lbs you can run as much timing as you can get away with and it would still feel weak compared to the boost im running... Mind you im still getting away with 19 drgs peak timing by redline, what you can squeeze out will be differnt than what I can since different mods different compression... Timing advance needs are different from one car to another, its not an exact science, but for starters just set tha AFR around 11.1 then drop the timing to a low safe amount, and crank the boost as high as your willing to go, then start slowly putting some timing back in by small increments till you get 2-3 degs knock retard then back it off 1 deg and remember, you will naturally be able to get more aggressive with the timing advance the higher the rpms rise, in the lower rpms you will want much less timing. Then once timing and boost are good, lean out your AFR a bit more if you can, and that should be a good tune.

[soldave]

Originally Posted by Black_Bullet

More boost gets more power....I run 25psi on my E316g setup on pumpgas with relatively low timing ... At 15lbs you can run as much timing as you can get away with and it would still feel weak compared to the boost im running... Mind you im still getting away with 19 drgs peak timing by redline, what you can squeeze out will be differnt than what I can since different mods different compression... Timing advance needs are different from one car to another, its not an exact science, but for starters just set tha AFR around 11.1 then drop the timing to a low safe amount, and crank the boost as high as your willing to go, then start slowly putting some timing back in by small increments till you get 2-3 degs knock retard then back it off 1 deg and remember, you will naturally be able to get more aggressive with the timing advance the higher the rpms rise, in the lower rpms you will want much less timing. Then once timing and boost are good, lean out your AFR a bit more if you can, and that should be a good tune.

Just curious to know, what do you class as relatively low timing?

[Black_Bullet]

Originally Posted by soldave

Just curious to know, what do you class as relatively low timing?

For a 7:8 compression ratio, and my turbo size and my mods, I think my timing advance is lowish.
Peak timing is fine for pump gas, but thru the midrange Im as low as 10-15 degs thru half my powerband and even
the stock 2g timing map ramps up a little higher in that area even with their higher compression.
My timing doesnt get decent until the higher rpms which due to more revolutions per min you will naturally need more timing, and plus the boost falling off on the 16g, Im able to ramp up the timing really fast after 6k and its peaking at 19degs a little after 7k.

Ideal timing for what im after is closer to MBT. My race gas tune is already at 15degs of timing by 4000rpm, with a peak of about 24degs by 6500rpm. Were speaking roughly 5-7 degs more timing from 4k to 6k with about 5 more degs peak timing.... Massive difference on how the car feels, and pulls.

I cant wait to get e85, then id be running that race gas tune daily on the street with probably as lean as 11.9- 12.1 afrs on the current 24-25psi I run now. Thats mid 11s all day on a 16g for me...

[delta448]

7:8 compression ratio

I'm not flaming, and I'm sorry to nitpick on such a great post, and thread for that matter, but this is a pet peeve of mine. I'm sure it is a typo in most cases, likely this case too, but I've seen this extensively done on this forum and it really drives me crazy.

Ratios are correctly expressed with a colon separating the value compared to 1, not as the decimal point in the significant value. If a compression ratio is 7:8 that would mean you are decompressing a volume of 7 into a volume of 8.

To express a CR correctly, you should write it as a volume compared to 1. Example: if you have a compression ratio of seven point eight to one, you write it as 7.8:1, which basically says in mathematical expression that you have 7.8 times more volume above the piston at BDC than at TDC. Or in a gear ratio of 4.5:1, that the driving gear makes four and a half revolutions for every revolution of the driven gear.

[wishihadatalon]

Originally Posted by delta448

I'm not flaming, and I'm sorry to nitpick on such a great post, and thread for that matter, but this is a pet peeve of mine. I'm sure it is a typo in most cases, likely this case too, but I've seen this extensively done on this forum and it really drives me crazy.

Ratios are correctly expressed with a colon separating the value compared to 1, not as the decimal point in the significant value. If a compression ratio is 7:8 that would mean you are decompressing a volume of 7 into a volume of 8.

To express a CR correctly, you should write it as a volume compared to 1. Example: if you have a compression ratio of seven point eight to one, you write it as 7.8:1, which basically says in mathematical expression that you have 7.8 times more volume above the piston at BDC than at TDC. Or in a gear ratio of 4.5:1, that the driving gear makes four and a half revolutions for every revolution of the driven gear.

Gee smarty pants

[Black_Bullet]

Originally Posted by delta448

I'm not flaming, and I'm sorry to nitpick on such a great post, and thread for that matter, but this is a pet peeve of mine. I'm sure it is a typo in most cases, likely this case too, but I've seen this extensively done on this forum and it really drives me crazy.

Ratios are correctly expressed with a colon separating the value compared to 1, not as the decimal point in the significant value. If a compression ratio is 7:8 that would mean you are decompressing a volume of 7 into a volume of 8.

To express a CR correctly, you should write it as a volume compared to 1. Example: if you have a compression ratio of seven point eight to one, you write it as 7.8:1, which basically says in mathematical expression that you have 7.8 times more volume above the piston at BDC than at TDC. Or in a gear ratio of 4.5:1, that the driving gear makes four and a half revolutions for every revolution of the driven gear.

Your right, I have typed it out right and wrong plenty of times , I will make sure I correctly express the ratio next time, thanks.

[daren_p]

Like has been said it can vary in certain cases but the norm is most increase in power from boost, then timing & then air/fuel ratio. I have never tested this on a dyno but with my car, the butt dyno confirms this. If I lean the car out from 10 to 1, to 11 to 1, the butt dyno doesn't really notice much of a change. If I up my timing from 15deg to 20, I can feel a difference. If I up my boost from 15psi to 20 psi, I feel a big difference. Looks like you run the 3052 as well, I find right around 20 psi it starts to wake up nicely. Currently run 25 psi daily, ~11.1 with about 19 deg of timing, & this seems to work well for me (running meth injection).

[green92gsx]

I find power to be made with boost first, a/f ratio 2nd, then timing. I've done all kinds of different timing sweeps with not much or any mph increase at the track.

[95GSXracer]

The statement that timing makes power is only half correct. Timing just allows you to make the power you should relative to the amount of fuel/air you're burning. Increasing beyond that point will cost you power, and eventually parts. To increase power potential, you need to increase air/fuel flow. The easiest lever here is boost. The tricky part comes in when adding boost requires dropping timing as a bandaid (in other words, more than you would have to drop it due to charge density increase, which doesn't cost you any power). This is where you need to be on the lookout for diminishing returns.

I agree that the 1g timing curve is crap. I always swap it out for the 2g curve which makes much more sense, has less built in assclownery from the factory, and works much better. Timing is a much bigger lever than AFR, up until the point of diminishing return, which is easy to spot on the dyno. AFR should fall within a pretty narrow window (not be used as a bandaid), and within that window, the effect on power is rather small.

[gsxrtalon]

Great thread. I would like to see some numbers on the dyno provideing some definite answers to this and maybe tuning our cars would be one step easier.

[Black_Bullet]

Originally Posted by 95GSXracer

The statement that timing makes power is only half correct. Timing just allows you to make the power you should relative to the amount of fuel/air you're burning. Increasing beyond that point will cost you power, and eventually parts. To increase power potential, you need to increase air/fuel flow. The easiest lever here is boost. The tricky part comes in when adding boost requires dropping timing as a bandaid (in other words, more than you would have to drop it due to charge density increase, which doesn't cost you any power). This is where you need to be on the lookout for diminishing returns.

I agree that the 1g timing curve is crap. I always swap it out for the 2g curve which makes much more sense, has less built in assclownery from the factory, and works much better. Timing is a much bigger lever than AFR, up until the point of diminishing return, which is easy to spot on the dyno. AFR should fall within a pretty narrow window (not be used as a bandaid), and within that window, the effect on power is rather small.

I love the way you explain things! I could have the same information stored in my head and would not have said it to were it made perfect sense like you just did !

[wishihadatalon]

Originally Posted by Black_Bullet

I love the way you explain things! I could have the same information stored in my head and would not have said it to were it made perfect sense like you just did !

Agreed.

[JayRolla]

I agree also that the butt dyno doesnt feel much from different afr's. I run 11.3 afr and have tuned to 12.1 and feel really no difference, maybe just a little. Add some boost, then timing and you feel a big difference.