Safer to run more boost less timing?
Timing vs boost.
Airflow (CFM) is what makes power. Application should determine boost level to an extent. I run less boost and more timing in road racing, but drag racing and street duty you can normally go the other way. Octane (lets say 92) will determine alot as do the mods that are helping or hurting VE. For instance here are 2 dyno sheets on my car on the stock 2.0L. (Its not dyno logged on the 531 run but it was also 29psi for reference-
This was on the stock intake manifold (531whp) and 10* of timing at 7750. It wouldnt take more without knocking and would misfire on the dyno at more boost. On the street it was fine and didnt have any knock or any misfires.
The next 2 power plots are after the Magnus with the inital tune. The 542 is still at low timing and 92 octane. I then was able to add 3* of timing more less globally but since the engine was stock I only added it out the top to control torque. EGTs didnt change from either one, but the pulls are only 10 seconds or so on the dyno so it didnt have too much chance to heat up radically.
On a side note though you can add more boost without knock but without more timing not necessarily be making more power-
All these pulls were at 11* of timing out the top with the exception of run 37 that tickled 12 for a second.
Airflow (CFM) is what makes power. Application should determine boost level to an extent. I run less boost and more timing in road racing, but drag racing and street duty you can normally go the other way. Octane (lets say 92) will determine alot as do the mods that are helping or hurting VE. For instance here are 2 dyno sheets on my car on the stock 2.0L. (Its not dyno logged on the 531 run but it was also 29psi for reference-
This was on the stock intake manifold (531whp) and 10* of timing at 7750. It wouldnt take more without knocking and would misfire on the dyno at more boost. On the street it was fine and didnt have any knock or any misfires.
The next 2 power plots are after the Magnus with the inital tune. The 542 is still at low timing and 92 octane. I then was able to add 3* of timing more less globally but since the engine was stock I only added it out the top to control torque. EGTs didnt change from either one, but the pulls are only 10 seconds or so on the dyno so it didnt have too much chance to heat up radically.
On a side note though you can add more boost without knock but without more timing not necessarily be making more power-
All these pulls were at 11* of timing out the top with the exception of run 37 that tickled 12 for a second.
Evolving Member
Joined: Mar 2010
Posts: 323
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From: Behind a laptop in FLA
What turbo was that?
Looks like a 35r ish spool. What was you mivec at up top.?
I normally max out the mivec until about 6500 on ix's
Last edited by BillSpec; Nov 2, 2010 at 04:06 PM.
Evolving Member
Joined: Mar 2010
Posts: 323
Likes: 0
From: Behind a laptop in FLA
i can tell more boost = more compressed air so there are more heat.
but i thought more timing means more cylinder pressure for longer. You are exposing the engine to heat for a longer period. More ignition timing means higher in cylinder temps.
boost > timing as long as the turbos in its efficiency range still. Only to a certain extent tho. Theres a way to determine the best combination based on how much hp you gain per degree vs psi. fuel also plays a huge roll of course.
Timing vs boost.
Airflow (CFM) is what makes power. Application should determine boost level to an extent. I run less boost and more timing in road racing, but drag racing and street duty you can normally go the other way. Octane (lets say 92) will determine alot as do the mods that are helping or hurting VE. For instance here are 2 dyno sheets on my car on the stock 2.0L. (Its not dyno logged on the 531 run but it was also 29psi for reference-
This was on the stock intake manifold (531whp) and 10* of timing at 7750. It wouldnt take more without knocking and would misfire on the dyno at more boost. On the street it was fine and didnt have any knock or any misfires.
The next 2 power plots are after the Magnus with the inital tune. The 542 is still at low timing and 92 octane. I then was able to add 3* of timing more less globally but since the engine was stock I only added it out the top to control torque. EGTs didnt change from either one, but the pulls are only 10 seconds or so on the dyno so it didnt have too much chance to heat up radically.
On a side note though you can add more boost without knock but without more timing not necessarily be making more power-
All these pulls were at 11* of timing out the top with the exception of run 37 that tickled 12 for a second.
Airflow (CFM) is what makes power. Application should determine boost level to an extent. I run less boost and more timing in road racing, but drag racing and street duty you can normally go the other way. Octane (lets say 92) will determine alot as do the mods that are helping or hurting VE. For instance here are 2 dyno sheets on my car on the stock 2.0L. (Its not dyno logged on the 531 run but it was also 29psi for reference-
This was on the stock intake manifold (531whp) and 10* of timing at 7750. It wouldnt take more without knocking and would misfire on the dyno at more boost. On the street it was fine and didnt have any knock or any misfires.
The next 2 power plots are after the Magnus with the inital tune. The 542 is still at low timing and 92 octane. I then was able to add 3* of timing more less globally but since the engine was stock I only added it out the top to control torque. EGTs didnt change from either one, but the pulls are only 10 seconds or so on the dyno so it didnt have too much chance to heat up radically.
On a side note though you can add more boost without knock but without more timing not necessarily be making more power-
All these pulls were at 11* of timing out the top with the exception of run 37 that tickled 12 for a second.
Evolved Member
iTrader: (11)
Joined: Oct 2007
Posts: 1,430
Likes: 1
From: Connecticut / Massachusetts U.S.A
Bink, do you monitor EGT? It's tough to make big power, particularly on pump, on a Black without running hotter than 1650F. I would imagine that the guys putting down 600 whp are way past that. The key to not cooking the turbo is limiting the high EGTs to short bursts so that the components don't actually reach those temperatures.
And yes, I have an EGT probe in runner #2.
When she was getting tuned on the dyno it was 94 ambient in the room, I *believe* it reached 1800. Which I wasn't all that thrilled about. However, on the street I couldn't replicate that temperature. Obviously, that was due to the increased airflow.
-Bink
Last edited by binky; Nov 2, 2010 at 08:52 PM.
EDIT: thread should be closed.. Aaron already answered it. 
I didnt bother to read all pages or I wouldn't have posted anything.
EDIT x2: well I just failed. I went to edit my own post and quoted it instead.
I didnt bother to read all pages or I wouldn't have posted anything.EDIT x2: well I just failed. I went to edit my own post and quoted it instead.
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