Subaru Enthusiasts Car Club of the Sierras

Subaru Enthusiasts Car Club of the Sierras (https://www.seccs.org/forums/index.php)
-   Technical Chat (https://www.seccs.org/forums/forumdisplay.php?f=11)
-   -   Tuning questions (https://www.seccs.org/forums/showthread.php?t=6468)

IheartSTI 2007-12-03 09:45 PM

Tuning questions
 
I am not attempting to tune my own car although I do I have a couple questions about tuning to further my understanding of what my car is doing. I was just reading about ignition timing and I know you can advance/retard timing for better tune on race fuel...but how much? Would it depend on octane and o2 content in the fuel? If it were a cold day at the track would this also become a timing factor? I was hoping I could receive some feedback to help me better understand. Thank you

IheartSTI 2007-12-03 09:54 PM

And when you start messing with ignition timing will the knock sensor still function properly to prevent any disasters?

Dean 2007-12-03 10:49 PM

Race fuel is not required. 91 octane can take a little more timing, especially at altitude.

The knock sensor does little good in open loop/higher RPM where most power is made, so it can't protect you when you need it. This is why logging and the right gauges are critical.

EGT, Wideband 02 and some form of determining HP/torque is how you determine how much timing to use.

There are a bunch of references in a thread I started a while back and haven't gotten back to.

http://www.seccs.org/forums/showthread.php?t=5829

IheartSTI 2007-12-03 11:14 PM

Quote:

Originally Posted by Dean (Post 111098)
Race fuel is not required. 91 octane can take a little more timing, especially at altitude.

The knock sensor does little good in open loop/higher RPM where most power is made, so it can't protect you when you need it. This is why logging and the right gauges are critical.

EGT, Wideband 02 and some form of determining HP/torque is how you determine how much timing to use.

There are a bunch of references in a thread I started a while back and haven't gotten back to.

http://www.seccs.org/forums/showthread.php?t=5829

after reading the information on that thread it explained a lot of things in great detail... thanks

knucklesplitter 2007-12-04 08:36 AM

Quote:

Originally Posted by Dean (Post 111098)
The knock sensor does little good in open loop/higher RPM where most power is made, so it can't protect you when you need it.

This is true, but the rpm threshold where the ECU stops looking at knock can be changed/increased (with Enginuity, Ecutek, etc.)

Dean 2007-12-04 08:49 AM

Quote:

Originally Posted by knucklesplitter (Post 111106)
This is true, but the rpm threshold where the ECU stops looking at knock can be changed/increased (with Enginuity, Ecutek, etc.)

Do you have any references where this has been effective? I was under the impression that at higher load/RPM, the knock sensor was not able to distinguish knock due to the higher background engine noise.

sperry 2007-12-04 09:36 AM

Quote:

Originally Posted by Dean (Post 111108)
Do you have any references where this has been effective? I was under the impression that at higher load/RPM, the knock sensor was not able to distinguish knock due to the higher background engine noise.

The knock sensor is just a microphone. I'm not sure how much control you have over it in the stock ECU, but in the Hydra you can set the rpm cut off as well as the threshold... in that way you can probably bump up the rpm and tweak the threshold to exclude the additional noise but still pick up the knock if it's loud enough.

knucklesplitter 2007-12-04 10:15 AM

UTEC looks at the stock knock sensor all the time and is known to have good detection - lots of settings. They even sell this feature seperately - known as "KnockLite": http://www.turboxs.com/more_info.php?ID=212

In the stock ECU I only know how to change the RPM cut-off, so I dunno how effective the stock ECU's setting are at higher rpm.

Double Phister 2007-12-04 10:58 AM

I have the knocklite. I like the way it is aware of the background noise floor as related to RPM.

IheartSTI 2007-12-04 02:06 PM

I was reading a ecutek thread and a couple people mentioned the knock sensor was nearly ineffective after 5000 rpms. I would think with all the vibrations and abstract noises at high rpm's it would would likely play a factor on how well the knock sensor works. what rmp is a car likely to knock? under high loads or rpms?

sperry 2007-12-04 02:24 PM

Quote:

Originally Posted by IheartSTI (Post 111121)
I was reading a ecutek thread and a couple people mentioned the knock sensor was nearly ineffective after 5000 rpms. I would think with all the vibrations and abstract noises at high rpm's it would would likely play a factor on how well the knock sensor works. what rmp is a car likely to knock? under high loads or rpms?

The knock sensor is quite literally turned off at like 5400 rpms on the stock ECU. The car cannot pull timing between there and red-line because the mic is off.

Knock can occur at any time, but more-so under high loads, which is also when it's more destructive.

knucklesplitter 2007-12-04 03:37 PM

Quote:

Originally Posted by sperry (Post 111128)
The knock sensor is quite literally turned off at like 5400 rpms on the stock ECU. The car cannot pull timing between there and red-line because the mic is off..

Yes, but this rpm is easily tuner adjustable.

UTEC and Knocklite (and Hydra I assume) still look for knock on the stock sensor well above 5400. My UTEC has sensed real knock on my car as high as 7000rpm and pulled timing, flashed the light at me, and logged it. It's one of the few things UTEC does really well. But it is still using the factory sensor.

knucklesplitter 2007-12-04 03:39 PM

Quote:

Originally Posted by R4ND0M_AX3 (Post 111115)
I have the knocklite. I like the way it is aware of the background noise floor as related to RPM.

Is your knocklite using the factory sensor, and if so how is it connected - spliced or what?

IheartSTI 2007-12-04 08:10 PM

So today i was doing some logging and i ran into a problem... my car just went to high idle and would not let me throttle. I just got a tune from i-speed but I am not sure how accurate the tune was because it was emailed to me. (I have the EcuTec) here are some reading i got while logging maybe someone could tell me what my car is doing.

Minimum Maximum
Primary wastegate duty cycle: 83.1

Manifold absolute pressure: 2.0 27.1

Manifold relative pressure: -11.6 13.3

ignition timing: -8.5 45.0

knock correction: -13.0 5.5

Fuel Injection #1 Pulse width: 0.77 18.43

air/fuel sensor #1: 0.75 1.40

Advance Multiplier: 1.0 1.0

atmospheric pressure: 13.6 13.6

mass air flow: 1.99 238.16

air/fuel correction 1: -25.0 25.0

air/fuel correction 3: -51.6 -43.8

air/fuel leaning #1: -1.6 1.6

air/fuel sensor #1 current: -1.38 1.75

air/fuel sensor #1 resistence: 25.0 39.0

rear o2 sensor: .005 1.015

CPC valve duty ratio: 0.0 100.0

tumble valve position sensor right: .34 4.24

tumble valve position sensor left: .3 4.24

accelerator opening angle: .0 100.

throttle motor duty: -62 77.

fuel pump duty: 0.0 100.

roughness monitor cylinder #1: 0 0

roughness monitor cylinder #2: 0 0

roughness monitor cylinder #3: 0 1

roughness monitor cylinder #4: 0 1

so i am not sure what this all means and if it looks good or bad... feedback please

IheartSTI 2007-12-04 08:12 PM

the first numbers are minimums and the second are maximums

sybir 2007-12-04 09:58 PM

Email tuning scares the living shit out of me.
Even scarier is that I-speed isn't demanding logs so they can evaluate and send you a new map, no matter what. It should be an ongoing development and review process. I didn't think Bill was that lazy (he used to tune pretty lean, but was a conscientious guy), or are you just checking with us in addition to talking to him?

Just my 2 cents.

IheartSTI 2007-12-05 09:16 AM

well i am calling him back today and letting him know i am emailing my logs. Hopefully with more information he will be able to tune more accurately. But as of now my car wont boost more then 12 psi

IheartSTI 2007-12-05 09:18 AM

btw... the reason i did internet tuning is i am currently living in north idaho and need to be able to get my car back to reno in 2 weeks. hopefully i can get a better tune down there

GST Mike 2007-12-05 09:28 AM

I have not logged with that setup for a while but the fact that is shows at some point that you ran -8.5 degrees of timing and -13 degrees of knock correction would have me a little concerned.

Mike

IheartSTI 2007-12-05 10:29 AM

Quote:

Originally Posted by GST Mike (Post 111176)
I have not logged with that setup for a while but the fact that is shows at some point that you ran -8.5 degrees of timing and -13 degrees of knock correction would have me a little concerned.

Mike

I just emailed the guy at i-speed my logs and we will see what will come of the situation. So far they have been good to me.

sperry 2007-12-05 10:30 AM

Quote:

Originally Posted by GST Mike (Post 111176)
I have not logged with that setup for a while but the fact that is shows at some point that you ran -8.5 degrees of timing and -13 degrees of knock correction would have me a little concerned.

Mike

+1. That's the motor trying to protect itself. You probably don't want it making more than 12 psi of boost if it's already knocking. In fact you should probably just reflash it with a low-boost, low redline "safe" map and baby the car until you can get it back to civilization and on a dyno for a custom tune.

IheartSTI 2007-12-05 11:12 AM

Quote:

Originally Posted by sperry (Post 111180)
+1. That's the motor trying to protect itself. You probably don't want it making more than 12 psi of boost if it's already knocking. In fact you should probably just reflash it with a low-boost, low redline "safe" map and baby the car until you can get it back to civilization and on a dyno for a custom tune.

haha back to civilization... that was great.

IheartSTI 2007-12-05 11:17 AM

Quote:

Originally Posted by sperry (Post 111180)
+1. That's the motor trying to protect itself. You probably don't want it making more than 12 psi of boost if it's already knocking. In fact you should probably just reflash it with a low-boost, low redline "safe" map and baby the car until you can get it back to civilization and on a dyno for a custom tune.

i talked to the guy at i-speed and he said the +1 is fine... when it gets to 30+ then i have a problem.

sperry 2007-12-05 11:38 AM

Quote:

Originally Posted by IheartSTI (Post 111184)
i talked to the guy at i-speed and he said the +1 is fine... when it gets to 30+ then i have a problem.

Huh? "+1" means "I agree"... it's not a reference to the data.

100_Percent_Juice 2007-12-05 12:23 PM

Quote:

Originally Posted by IheartSTI (Post 111184)
i talked to the guy at i-speed and he said that my ROFL settings and my WTF meter is fine... when it gets to OMFG then i have a problem.



All times are GMT -8. The time now is 05:43 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
All Content Copyright Subaru Enthusiasts Car Club of the Sierras unless otherwise noted.