Fuse Pull: Low Octane Fuel Fix For L99 and LS3. Reset Fuel Map for High Octane Fuel.

[PQ]

Originally Posted by Screaminz2002

Looked through quite a few pages in this thread but never found a date or production cutoff for this fix. Anyone know what it is?

Nope.

Originally Posted by hamad_311

I LOOOOOVE YOU WHOEVER found out, cuz our sh***y dealer doesnt know a thing.

I was the first here. But everyone here knew about my problem. Many were starting to doubt me. But I got it from Scotts call to me to try it, and he saw a vid posted by D1BADZ where a tuner was puling them just to reset the computer before tuning a car.

Originally Posted by GQ4Life

someone says may 20th 2009

I doubt it. That's only a few weeks after mine was built.

Originally Posted by SonnyakaPig

Here are my numbers. We had really good weather conditions for the dyno today. I'm happy with my numbers.

317.8 HP
336.3 HP/with WCF

342.5 TQ
361.4 TQ/with WCF

Great TQ numbers.

Here's the link to my post in the L99 Dyno #'s thread:

http://www.camaro5.com/forums/showth...56#post1526856 Post number 94

Damn. that's great, but what is WCF?

Originally Posted by Roger Ramjet

The two spark tables, high octane and low octane, show the desired target degrees BTDC that ignition should occur without knock retard. Of course, KR will reduce the timing if detected. What is not visible is the program logic that determines how much KR for how long before switching to the Low Octane table. Also not visible is the logic for how long after KR is NOT present that operation is restored to the High Octane table. It looks like the Low table has 7 to 10 degrees less ignition advance than the high table. That's a significant power reduction.

However, the invisible program logic becomes irrelevant if both tables have exctly the same target spark advance. At that point the computer can shift from High to Low and back again with the resultant power loss only present when knock is actually present. So, by copying the High table values over into the Low table the problem goes away.

By the way, I have looked at the 'Old' factory L99 calibration and the 'New' factory calibration to see what GM did to solve the 'Slow' car problem. The 'Old' cal had a 0 crankshaft pulse count before pulling ignition timing when knock was detected. Meaning that ignition was retarded and power degraded the instant knock was sensed. The 'New' cal has a 4 pulse count delay before pulling timing. So, my guess is that some cars may be running a little lean at some point in the part throttle area or some cars had a too sensitive knock sensor that sent the car into the Low Octane spark table prematurely. My conclusion is for cars stuck in the Low Octane table pulling the fuses will work. But, there may be cars out there that have near constant knock retard working. Continuing KR cars cannot be helped by the fuse pull. All of these conditions can be cured with a tune.

The highlighted is true, true, true.

So then according to your post, this could be why some cars still benefit from this?

[SonnyakaPig]

Originally Posted by GQ4Life

what is WCF?

I think it stands for "weather control factor." I'll look it up and update this post. The dyno shop that I used told me that there is a mathematical formula that they use and they said was standard for somewhat high elevations. I think it adjusts for what the numbers would be at a better elevation. I'll check on this, though.

Edit: So far, this is the only explanation that I found.

Does anyone know if Mustang Dynos are known for giving low, avg, or high numbers?

Also, does anyone know that a "converter spike" is? Does it apply at all to automatics? I was reading on another site that a converter spike can lead to inaccurate torque readings? I think that's what some people were saying?

[SlingShot]

Looking for a straight up answer, does this effect the LS3 Yes or No ?

[GQ4Life]

Originally Posted by SonnyakaPig

I think it stands for "weather control factor." I'll look it up and update this post. The dyno shop that I used told me that there is a mathematical formula that they use and they said was standard for somewhat high elevations. I think it adjusts for what the numbers would be at a better elevation. I'll check on this, though.

Edit: So far, this is the only explanation that I found.

Does anyone know if Mustang Dynos are known for giving low, avg, or high numbers?

Also, does anyone know that a "converter spike" is? Does it apply at all to automatics? I was reading on another site that a converter spike can lead to inaccurate torque readings? I think that's what some people were saying?

mustang dynos are know for reading low.. Dynojets are known for reading high.. But doesnt mean they r all low or high
I do not know about converter spike.. Ive never had an automatic car..

[Scott@Bjorn3D]

Originally Posted by SlingShot

Looking for a straight up answer, does this effect the LS3 Yes or No ?

YES, LS3's also love the fuse pull if they ever had low octane gas.

[TAG UR IT]

According to another GM official, you need to do both the fuse pull and battery disconnect since they are different computer systems. If you are concerned at all, just do it. What in the heck would it hurt to unplug your batter and two fuses over night?!?!

[comm54]

Originally Posted by SlingShot

Looking for a straight up answer, does this effect the LS3 Yes or No ?

+1

And, do we have to disconnect the battery???

And, Why would the fuses pull have to be more than just a couple of minutes??? Every computer or electronic device that I have ever worked on that needed a "reset" to clear a problem, would be "reset" as soon as you removed and restored power to the device = REBOOT?!?

And, could this cause me to LOSE 40hp??? We dyno'd a group of cars yesterday, 5 stock LS3's, 3 cars pulled from 373 to 384 rwhp, 2 cars pulled 343 rwhp...WTF??? Could the timing tables cause that much difference?

PLEASE HELP!!!
:flag2:

[GQ4Life]

Originally Posted by comm54

+1

And, do we have to disconnect the battery???

And, Why would the fuses pull have to be more than just a couple of minutes??? Every computer or electronic device that I have ever worked on that needed a "reset" to clear a problem, would be "reset" as soon as you removed and restored power to the device = REBOOT?!?

And, could this cause me to LOSE 40hp??? We dyno'd a group of cars yesterday, 5 stock LS3's, 3 cars pulled from 373 to 384 rwhp, 2 cars pulled 343 rwhp...WTF??? Could the timing tables cause that much difference?

PLEASE HELP!!!
:flag2:

yea.. timing be way lower will lower HP alot

not knocking u on the pulling fuses for just a couple of minutes. Most things have stuff that will quickly drain the remaining power.. I use to on my old car disconnect or pull fuse to reset car. it only took like 5 seconds
though one time my computer froze.. we couldnt get it to shut off so we flipped the switch in the back.. nothing happened.. then we unplugged it.. and it still was going. Monitor was still showing screen and harddrive was still spinning.. this happened for over a hour..
I say it was possessed by ghost

[PQ]

Originally Posted by TAG UR IT

According to another GM official, you need to do both the fuse pull and battery disconnect since they are different computer systems. If you are concerned at all, just do it. What in the heck would it hurt to unplug your batter and two fuses over night?!?!

Good enough for me. And you're right. I can't think of a good reason NOT to do it. Espec, if you think there's a problem.

Originally Posted by SlingShot

Looking for a straight up answer, does this effect the LS3 Yes or No ?

Of course it does. It's basically the same engine.

Originally Posted by Scott@Bjorn3D

YES, LS3's also love the fuse pull if they ever had low octane gas.

Yup. Well, the older ones anyway.

[Roger Ramjet]

Originally Posted by GQ4Life

what is WCF?

I think they mean 'Weather Correction Factor'. This is normally referred to as 'Correction Factor' or Cf. If you want to get the most accurate dyno measurements, write the weather conditions (temp, humidity, & baro pressure) for each pull. Then do the corrections later yourself. There are several correction equations out there but I think the SAE is real world most accurate.

Try this:
http://www.anycalculator.com/enginehorsepower.htm

[Roger Ramjet]

I have posted this before but this may be a good place to repeat:

It is not necessary to wait at all to do a reset if you use the 'Down-Power' method to bleed down the keep-alive power for the ECM.
Disconnect both battery cables.
Touch both battery cables together a couple times.
Reconnect the battery cables.

[Roger Ramjet]

Originally Posted by SonnyakaPig

Also, does anyone know that a "converter spike" is? Does it apply at all to automatics? I was reading on another site that a converter spike can lead to inaccurate torque readings? I think that's what some people were saying?

It ONLY applies to cars with a torque converter (i.e. automatics). Since a torque converter multiplies torque and a chassis dyno measures wheel torque (HP is calculated from torque), higher than engine torque can be indicated. This condition is the worst when there is a large difference in converter input RPM vs output RPM. That is when the torque gain is the greatest.

These cars have a very low stall (1500 RPM) torque converter with a lockup clutch system. Dyno converter spike should be little if any.
The dyno pull method I would use is:
Do Tap mode and throttle as necessary to get into 4th gear (that gear is the closest to 1:1).
Reduce throttle to get to minimum pull RPM desired.
Then quickly go WOT.

[GQ4Life]

Originally Posted by Roger Ramjet

I think they mean 'Weather Correction Factor'. This is normally referred to as 'Correction Factor' or Cf. If you want to get the most accurate dyno measurements, write the weather conditions (temp, humidity, & baro pressure) for each pull. Then do the corrections later yourself. There are several correction equations out there but I think the SAE is real world most accurate.

Try this:
http://www.anycalculator.com/enginehorsepower.htm

oh SAE.. thats the correction factor i know but some dynos dont have SAE..
yea I got a dyno one time and it was way low compared to my last one.. but then guy did some correction factor shit and it came out sounding more right.. he said this is the real reading

[PQ]

Originally Posted by Roger Ramjet

It ONLY applies to cars with a torque converter (i.e. automatics). Since a torque converter multiplies torque and a chassis dyno measures wheel torque (HP is calculated from torque), higher than engine torque can be indicated. This condition is the worst when there is a large difference in converter input RPM vs output RPM. That is when the torque gain is the greatest.

These cars have a very low stall (1500 RPM) torque converter with a lockup clutch system. Dyno converter spike should be little if any.
The dyno pull method I would use is:
Do Tap mode and throttle as necessary to get into 4th gear (that gear is the closest to 1:1).
Reduce throttle to get to minimum pull RPM desired.
Then quickly go WOT.

Good info.

The guy who dynoed my car did it his way in 4th gear as well.