question about evoscan knock sum!
Mar 21, 2007, 10:00 AM
#46
Account Disabled
iTrader: (3)
Join Date: Apr 2006
Location: USA
Posts: 1,029
Likes: 0
Received 0 Likes
on
0 Posts
If some of you guys spent half the time tuning/wrenching on your own cars then we wouldn't have these back and fourth threads of meaningless info about the same subject every other week. Furthermore the people speaking the loudest are the ones that sound like they don't tune or work on their own cars. Sobeit.
Sean you have my respect. Keep it up man.
Sean you have my respect. Keep it up man.
Mar 21, 2007, 10:11 AM
#47
Evolved Member
Hi
My thoughs are, for an experienced tuner, with the ability to cross check the ECU knock count , with other methods, knock link, det cans, in a controlled enviroment, they will have the tools to push the tune safley in a far more aggressive way than those of us road tuning, using the tools we have.
Those of you advocating running higher levels of knock, say over the odd 1-2 counts, ask your selves this, am I prepared to state, that the information I give won't result in someone else blowing there car?
The way some people post on here that, running with constant higher knock levels is ok, you'd have thought they had a degree in automotive engineering. If they are really so sure that it's Ok to run their car like that, why don't they look around and find out how to disable the knock routeine?
MB
My thoughs are, for an experienced tuner, with the ability to cross check the ECU knock count , with other methods, knock link, det cans, in a controlled enviroment, they will have the tools to push the tune safley in a far more aggressive way than those of us road tuning, using the tools we have.
Those of you advocating running higher levels of knock, say over the odd 1-2 counts, ask your selves this, am I prepared to state, that the information I give won't result in someone else blowing there car?
The way some people post on here that, running with constant higher knock levels is ok, you'd have thought they had a degree in automotive engineering. If they are really so sure that it's Ok to run their car like that, why don't they look around and find out how to disable the knock routeine?
MB
Mar 21, 2007, 10:31 AM
#48
Account Disabled
iTrader: (38)
Join Date: Aug 2005
Location: Virginia Beach, Virginia
Posts: 9,319
Likes: 0
Received 1 Like
on
1 Post
I had a friend that's old school and didn't believe in the knock sensor on his 3000GT VR-4.. he said "I had dozens of muscle cars and we didn't have a knock sensor, we just advanced timing until the performance dropped off" a few weeks later he figures out that the maximum timing the ecu can pull is 12* so, he unplugs the knock sensor, the computer pulls that 12* and he adds it right back in with the e-manage to be effectively pulling no timing or 0 btdc. The car is nice and consistent, he keeps adding a couple of degrees of timing pass after pass and the traps go up.. about 3 passes later he comes back through the pits with rod knock. I'm sure if it weren't for the forged pistons and rods the pistons would have gone first.
my theory is that on lower HP cars some knock isn't going to do much damage, but when you get into major HP levels it can flatten a bearing in a single pass. It just isn't worth the risk. Tune for < 3 counts and allow the ecu to do it's job and quell knock unless you're pretty good at rebuilding the engine.
I spoke with Ray Pampena about his 900+ awhp VR-4 a while back and he also confirmed that with high HP it only takes one bad pull to get bearing material in the pan. He does regular oil analysis on his car and sure enough, one nasty knock filled pull later the bearing was toast.
Do what you want on your own car but I still think it's very risky to be sending out flash files setup that way.
my theory is that on lower HP cars some knock isn't going to do much damage, but when you get into major HP levels it can flatten a bearing in a single pass. It just isn't worth the risk. Tune for < 3 counts and allow the ecu to do it's job and quell knock unless you're pretty good at rebuilding the engine.
I spoke with Ray Pampena about his 900+ awhp VR-4 a while back and he also confirmed that with high HP it only takes one bad pull to get bearing material in the pan. He does regular oil analysis on his car and sure enough, one nasty knock filled pull later the bearing was toast.
Do what you want on your own car but I still think it's very risky to be sending out flash files setup that way.
Last edited by Mellon Racing; Mar 21, 2007 at 10:35 AM.
Mar 21, 2007, 01:26 PM
#49
If some of you guys spent half the time tuning/wrenching on your own cars then we wouldn't have these back and fourth threads of meaningless info about the same subject every other week. Furthermore the people speaking the loudest are the ones that sound like they don't tune or work on their own cars. Sobeit.
Sean you have my respect. Keep it up man.
Sean you have my respect. Keep it up man.
Mar 21, 2007, 01:45 PM
#50
Evolved Member
iTrader: (5)
Join Date: Nov 2003
Location: Birmingham, Al
Posts: 849
Likes: 0
Received 0 Likes
on
0 Posts
Hi
My thoughs are, for an experienced tuner, with the ability to cross check the ECU knock count , with other methods, knock link, det cans, in a controlled enviroment, they will have the tools to push the tune safley in a far more aggressive way than those of us road tuning, using the tools we have.
Those of you advocating running higher levels of knock, say over the odd 1-2 counts, ask your selves this, am I prepared to state, that the information I give won't result in someone else blowing there car?
The way some people post on here that, running with constant higher knock levels is ok, you'd have thought they had a degree in automotive engineering. If they are really so sure that it's Ok to run their car like that, why don't they look around and find out how to disable the knock routeine?
MB
My thoughs are, for an experienced tuner, with the ability to cross check the ECU knock count , with other methods, knock link, det cans, in a controlled enviroment, they will have the tools to push the tune safley in a far more aggressive way than those of us road tuning, using the tools we have.
Those of you advocating running higher levels of knock, say over the odd 1-2 counts, ask your selves this, am I prepared to state, that the information I give won't result in someone else blowing there car?
The way some people post on here that, running with constant higher knock levels is ok, you'd have thought they had a degree in automotive engineering. If they are really so sure that it's Ok to run their car like that, why don't they look around and find out how to disable the knock routeine?
MB
I'm getting tired of running in circles with you. The Evo knock control scheme WAS partially figured out by looking at and comparing it to the DSM knock control setup. I don't care that its not the same ECU, blah, blah...the engineers used basically the same system for the Evo that they did for the DSM. You can write me back with a paragraph of pure fluff and say absolutely nothing like you've been doing, but so far you've just "beaten your chest" and shown no real knowledge on the subject. Big words don't impress me, I use them every day.
Judging by your posts about how my car might blow up with knock counts over, say, 3 or 4 then I'd say my car must be a freak of nature since I have 62k on it, over 300 whp since 5k, over 400 whp since 35k miles and all the while not a issue with my car with it tuned in a way you would not agree with. Compression is 180 across the board, no blow by...OH and did I mention I'm faster than any other similar setup big turbo, stock ecu tuned car I've come across? Go talk theory to someone who cares, I'm more interested in what actually performs.
Mar 21, 2007, 01:57 PM
#51
Mar 21, 2007, 02:13 PM
#52
Evolved Member
I'm getting tired of running in circles with you. The Evo knock control scheme WAS partially figured out by looking at and comparing it to the DSM knock control setup. I don't care that its not the same ECU, blah, blah...the engineers used basically the same system for the Evo that they did for the DSM. You can write me back with a paragraph of pure fluff and say absolutely nothing like you've been doing, but so far you've just "beaten your chest" and shown no real knowledge on the subject. Big words don't impress me, I use them every day.
Judging by your posts about how my car might blow up with knock counts over, say, 3 or 4 then I'd say my car must be a freak of nature since I have 62k on it, over 300 whp since 5k, over 400 whp since 35k miles and all the while not a issue with my car with it tuned in a way you would not agree with. Compression is 180 across the board, no blow by...OH and did I mention I'm faster than any other similar setup big turbo, stock ecu tuned car I've come across? Go talk theory to someone who cares, I'm more interested in what actually performs.
MB
Mar 21, 2007, 02:32 PM
#54
A big part of the problem here is most people have no clue what the knock #s mean, is 15 high or low? Is it dangerous? What impact does it have on the engine long and short term.
Without this type of information, it is hard for some people who are only starting and are only tuning one simple combination to determine what it is they are shooting for, also some tuners have a different approach where they let the car run on the knock control.
Experience is a huge part of the tuning equation.
Ask yourself, "how much knock would it take to push a stock rod through the block?"
Sean
Without this type of information, it is hard for some people who are only starting and are only tuning one simple combination to determine what it is they are shooting for, also some tuners have a different approach where they let the car run on the knock control.
Experience is a huge part of the tuning equation.
Ask yourself, "how much knock would it take to push a stock rod through the block?"
Sean
Mar 21, 2007, 02:50 PM
#55
Evolved Member
Mar 21, 2007, 08:08 PM
#57
There a few things to consider here:
1. How much knock before the engine is damaged? No one really knows that for sure. No one knows how much pounding a rod bearing can take before it fails. But it is preferable to tune to 3 counts of knock or less. When I do my 3rd gear pulls I can feel my car lose power when the knock counts are 10 or more. The power loss is really felt.
2. Regardless of whether the knock is real or phantom we know that three counts of sustained knock will pull 1* of timing. That will happen and it has been documented to happen. So you should tune for 3 counts or less, otherwise your timing is getting pulled and producing less power.
3. I had a custom tune for 91 octane on my xede that I rarely used. It was created by Tuning Tech in CA. When I recently ran the map on 91 octane. It registered 10 counts of knock @ the top end and leass than that everywhere else. It turns out that the timing was set @ 18.6* @ 7000+, 11* @ 6000 rpm, 7* @ 5000. The AFR was set around 11.2:1 and tapered to 11:1 by redline.
The tune that I did had a slightly richer AFR (about 0.25). Most of the change, however, was done to the timing. Timing was pulled back siginificantly. I set the timing @ 13-14 @ 7000+, 5.5* @ 6000, 4* @ 5000 rpm. Virtually all the knock in the mid-range and the top end was gone and the car made MORE power than it did before when it was knocking.
This is the before and after power chart on DLL. The temp/preesure/humidity is almost the same between the two runs and the car was logged @ the same place. The benchmark numbers are the after and the "your hp/torque" numbers are the before.
This is not the first car that I have I had this happen to. This is the second car that was knocking and that I de-tuned (specifically pulled timing) and had the car produce more power than before. I really do not see how a knocking car will produce more power than a non-knocking car. That has not been my experience.
1. How much knock before the engine is damaged? No one really knows that for sure. No one knows how much pounding a rod bearing can take before it fails. But it is preferable to tune to 3 counts of knock or less. When I do my 3rd gear pulls I can feel my car lose power when the knock counts are 10 or more. The power loss is really felt.
2. Regardless of whether the knock is real or phantom we know that three counts of sustained knock will pull 1* of timing. That will happen and it has been documented to happen. So you should tune for 3 counts or less, otherwise your timing is getting pulled and producing less power.
3. I had a custom tune for 91 octane on my xede that I rarely used. It was created by Tuning Tech in CA. When I recently ran the map on 91 octane. It registered 10 counts of knock @ the top end and leass than that everywhere else. It turns out that the timing was set @ 18.6* @ 7000+, 11* @ 6000 rpm, 7* @ 5000. The AFR was set around 11.2:1 and tapered to 11:1 by redline.
The tune that I did had a slightly richer AFR (about 0.25). Most of the change, however, was done to the timing. Timing was pulled back siginificantly. I set the timing @ 13-14 @ 7000+, 5.5* @ 6000, 4* @ 5000 rpm. Virtually all the knock in the mid-range and the top end was gone and the car made MORE power than it did before when it was knocking.
This is the before and after power chart on DLL. The temp/preesure/humidity is almost the same between the two runs and the car was logged @ the same place. The benchmark numbers are the after and the "your hp/torque" numbers are the before.
This is not the first car that I have I had this happen to. This is the second car that was knocking and that I de-tuned (specifically pulled timing) and had the car produce more power than before. I really do not see how a knocking car will produce more power than a non-knocking car. That has not been my experience.
Last edited by jrsimon27; Apr 17, 2007 at 10:13 AM.
Mar 22, 2007, 08:07 AM
#60
Evolved Member
iTrader: (5)
Join Date: Nov 2006
Location: milfburn
Posts: 638
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for the nice informed post, with plenty of supporting data and taking the time to explain how you got such good performance from your car. I'm glad you run 400whp on a stock engine ( you don't mention a forged lump). Again thanks for explaining every thing so clearly, it's been a real education.
MB
MB
