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Old 04-10-2003, 11:19 AM   #101
sdseagles
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Quote:
Originally posted by dan avoN7
I must have read it wrong or something. So just be at complete stop in third gear. Start going forward at around 2500rpm while braking to build boost while only moving at 2500rpm and do this for 5 seconds. Is that correct? By not pushing to hard on left foot you mean not braking to hard so u dont bog?
I may be mistaken, but I don't think you have to start from a stop in 3rd gear. I think you can start in first and drive without boost until you get to 3rd gear, then do the above steps. That's why you need a long road with little to no traffic. Someone correct me if I'm wrong
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Old 04-10-2003, 11:57 AM   #102
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Quote:
Originally posted by trhoppe
Ok, stupid question.

Can we just do this WITHOUT resetting the ECU? Lets say Im on my way to an autox and just want to make sure the multiplier is good to go. Will doing this trick max it out,or does the ECU have some kind of failsafe built in, where this only works right after a reset.

-Tom
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Old 04-10-2003, 12:14 PM   #103
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My guess would be that if you've been driving around for a while you've already reached the peak multiplier and would not have to do this reset anyway. This is just a way to speed up the learning process of the ECU for someone who just had a reflash.
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Old 09-02-2003, 08:18 AM   #104
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I just did this with my new COBB reflash, so a bump to the top.
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Old 09-05-2003, 09:27 PM   #105
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I'm going to try it tomorrow and will let you guys know what my butt dyno says.
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Old 09-05-2003, 09:27 PM   #106
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Old 09-06-2003, 07:55 AM   #107
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Quote:
Originally posted by dbrier
I just did this with my new COBB reflash, so a bump to the top.
And?
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Old 09-06-2003, 09:19 AM   #108
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Worked great. The car had lots of power right away.
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Old 09-09-2003, 05:44 PM   #109
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Wow - I read most of this thread.... And i have ECUtek and i reset it on occasion due to the extreme heat I get here in Florida - I have never done this but will very soon (Cool night) - My car always is a bit sluggish after resetting..... Bump this forever...

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Old 09-09-2003, 10:33 PM   #110
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Seeing this thread again got me thinking a bit. Doesn't this "trick" pose a potential problem? Say the ECU has backed off the IAM to 12 or 8 due to external conditions. Then you cruise around on the fwy or drive up a slight incline in 4th or 5th at ~3k RPM holding 3-5psi for 5 seconds or so. Now the ECU bumps up the IAM to 16 when it shouldn't. The real question is why in the world does the ECU choose to bump the IAM based on a low load cruise condition??

-- Ed
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Old 10-23-2003, 10:22 PM   #111
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I have a few questions.
1.-How many degrees of correction will the stock ECU allow once it learns? And how long does this take?
2.-Also, I have no boost gauge. So, will simply holding the revs at 2500 for 5 seconds in third gear produce the desired effect?
3.-What do I do after the five seconds? Do I need to continue on
at low boost for any period of time, or should I floor it to see if it worked?
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Old 10-24-2003, 01:47 AM   #112
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Default learning

Hi all-

In doing this little trick, you aren't making the ECU do anything that it doesn't want to do at all. You are just adding a little load to the engine to accelerate the learning process slightly.

From lots of times doing this, while watching the ECU advance multiplier and looking at the live data, here are some thoughts:

1.) after you reset the ECU, just drive normally for a minute, to take it from the advance multiplier of 8 up in the right direction.

2.) If you have a hill nearby that you can drive up in third or fourth gear, do so. Not necessarily starting on the hill - it doesnt matter. Just don't bog the car, keep the revs above say 2500 or so. Use the rev band as you would in normal driving. This does literally the same thing as the left foot braking trick.

3.) If you don't have a hill nearby, then use the left foot braking trick. You don't want too much pressure, just enough to feel a little drag on the car, requiring you to add a LITTLE more gas to compensate. Just a bit. do it for about 10 seconds, somewhere between say 2500 and 4000 RPMs (not set in stone). You can do this a few times if you like, no worries. You don't need to keep doing it though....

Thats it. No need to do anything else. Just drive normally. Don't worry about resetting every week, a happy car will usually stay right up there... unless you get some bad gas. Maybe good to try right before a competition like an autocross. The car will hold the advance multiplier each time you start it (no need to re-do this trick).

Most people new to LFB (left foot braking) use way too much pressure, as the left foot isnt used to this drill. Try modulating the brake with your left foot as you come up to a stop sign that is safe... teach it to stop the car basically, it will wake up as a more controlled input device

We still like to leave the advance multiplier at 8 on our ECUs, and let the car learn.

Regards,
Ken
Rally Performance
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Old 10-24-2003, 03:02 AM   #113
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thanks.
How long does the ECU typically take to learn under normal circumstances?
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Old 11-05-2003, 08:59 PM   #114
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It worked fine for me...the engine learned very quickly and the car felt more responsive.
Thanks, Micah
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Old 11-05-2003, 10:24 PM   #115
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Default Yo

1. Is it always better to reset the ECU then try the "Vishnu Reset" method or does it matter if we've already been driving for 200+ miles then try the method?

2. If knock does occur wil it just reduce the multiplier?

3. How many times/cycles will we need to perform the 5-10 sec runs at 2500 rpm+ w/ 2-5psi?
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Old 11-05-2003, 11:25 PM   #116
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Default Re: learning

Quote:
Originally posted by Rally Performance
Most people new to LFB (left foot braking) use way too much pressure, as the left foot isnt used to this drill. Try modulating the brake with your left foot as you come up to a stop sign that is safe... teach it to stop the car basically, it will wake up as a more controlled input device
Regards,
Ken
Rally Performance
LMAO your not joking about that!
i used to race karts for 10 years, then one day i decided to LFB at a auto'x. without thinking my left food stabs the breaks and i go skidding off course.most drivers automatically condition the left foot to push down as hard adn as fast as the can( pushing in the clutch)

i agree that you should practice this a few times in a nice wide area at lower speeds first .

Tom
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Old 11-06-2003, 05:23 PM   #117
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I still have an issue with this whole behaviour of the ECU. Basically I see this "trick" more of as a flaw. The problem is that the ECU is deciding the IAM based on a part throttle condition that could be encountered during hwy cruising and then applying it to the WOT ignition maps. The problem is that at those part throttle conditions, the ECU will be able to push a lot more timing advance w/o detonation because the engine is not at full load. But at WOT and a lot more boost, the engine will be a lot more knock prone and the ECU's attempted timing will result in detonation which it will then see and try to reduce advance. Doesn't this seem like an issue to anyone else?

Thanks
-- Ed
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Old 11-06-2003, 06:30 PM   #118
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Let's assume for the sake of discussion that the "base" ignition map was developed by the factory to provide more-or-less knock-free performance when 87 octane fuel is used and that the "high-octane" ignition map was developed by the factory to provide more-or-less knock-free performance when the factory-recommended 91 octane fuel is used.

There will be a large swath in the low-load area where both maps specify the same ignition advance. In other words, MBT timing can be used regardless of whether you're running 87 or 91 octane. You don't want to learn a new IAM when operating at these loads.

There will be a second band where loads are high enough to cause knock when running 87 octane but MBT timing can be used when running 91 octane. You don't want to learn a new IAM when operating at these loads, either.

Finally, there are loads (which don't require WOT to achieve) were even 91 octane fuel doesn't allow MBT timing without knock. This is where you want to learn a new IAM. The ECU tuner knows the minimum load/rpm thresholds for this area and sets the IAM load/rpm learning criteria accordingly.

I would also like to observe that the ECU has access to the fuel level sensor and it would seem logical that it would try to learn a new IAM after every refueling.
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Old 11-06-2003, 07:34 PM   #119
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Everything you said makes perfect sense but does the tuner actually have control over the learning characteristics of the IAM? As far as I've seen both Vishnu, Cobb, and stock ecu exhibit this same behaviour of learning the IAM under 2-3psi. I don't think this load value falls under the third gategory you mentioned. I've also often wondered the same thing about the fuel level sensor.

-- Ed
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Old 11-06-2003, 07:55 PM   #120
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SHIV,

I read alittle article written by Simon Lines from Pro-Drive, is this where you have learned your trick? By the way, maybe if yourself and company answered back on alittle more email and voice messages, you would retain a good attitude from me!


Good Luck,

MF
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Old 11-06-2003, 08:50 PM   #121
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I just wrote up some info on the active ignition timing. Here's the link.

http://forums.nasioc.com/forums/show...5&pagenumber=3

Sorry, was going to post it again but don't have the time.... work.

Cheers!
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Old 04-16-2004, 03:30 AM   #122
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Default Does this work with a Unichip ?

Sorry about the bump of an old thread, but I had a question regarding this.

I have a Unichip that's been tuned for my mods. I was wondering what would happen if I reset the ECU by disconnecting the neg terminal and pumping the brake ? Would the reset work like in the stock car (shaky driving for a few days then the car becomes much smoother) or would it do something else entirely ? Would the Unichip still serve its function after an ECU reset ? Would the stored info in the Unichip be erased or garbled. Also, will this Vishnu ECU remapping trick work to get full power straightaway with the Unichip in place ? Or will it really mess things up ?

Thanks very much.
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Old 04-16-2004, 04:39 AM   #123
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Quote:
Originally posted by Turb0flat4
Also, will this Vishnu ECU remapping trick work to get full power straightaway with the Unichip in place ? Or will it really mess things up ?

Thanks very much.
Well, I don't know enough about the unichip. Are the timing numbers offsets or absolute values? If they are offsets, then running the "Vishnu reset" routine will quickly ensure that your timing gets to where it wants to be in short order. If they are absolute values, this will have very little effect.

Also, the "Vishnu Reset" has no effect on the long-term fuel trims that the ECU learns and you will still have to let those learn over time, but most of the power feel comes from the timing learning that occurs during this procedure.

In short, what you're doing with the Vishnu Reset is maxing out the Ignition Advance Multiplier (after a reset, it's at 8, after the vishnu procedure, it should go to 16, the max).

Most ECUTek reflashes for quite some time have had the default IAM as 16 so after a reset, you are right at 16 without having to do the "Vishnu Reset" at all, but if you aren't using a reflash, just a unichip, you will most likely see some gains from the procedure, especially at part throttle.
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Old 04-16-2004, 11:51 AM   #124
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Thanks, nhluhr.
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Old 04-17-2004, 11:56 PM   #125
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I hear rumors that this does not work on the STi's though... Also Delta Dash does not list the advance multiplier in the data list right now so if the multiplier exists on the STi at all I have no idea how to see it.
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