Knock sensing- Final Answer
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Knock sensing- Final Answer
The knock sensor is a diagnostic aid.
It's not intended to be a tuning aid.
It's not meant to replace plug reading.
Plug reading will tell you if you have real detonation or not.
Based on what the plugs tell you will dictate your path to cure the problem.
If it's false knock there are a million reasons for it, from broken engine mounts to too stiff of suspension, fractured serpentine belts, etc.
On the MEFI in marine applications, the cure is a 45d pipe fitting with 1/4 or is it 3/8 male and female threads on it.
You want to have it working right, if for street use.
A fast decay rate is usually always helpful.
Have alot of possible retard in case there is an unseen problem.
Getting Mickey Mouse with a K/S can really bite you unless you know what your doing.
Again, weither tuning Carbs, EFI, an aftermarket ecm, you need to be able to read plugs. just no way around it!!!.
On my car I have 24d timing limits, and a 200% recovery rate. YMWV. But, you have to get the mechanicals right....
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hmmmmmmmm, intersting in light of the conversation we had the other day, re tuning timing curves & the measurement of gain or loss.
BW
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Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><
BW
------------------
Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><
#3
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<font face="Verdana, Arial" size="2">Originally posted by Bobalos:
hmmmmmmmm, intersting in light of the conversation we had the other day, re tuning timing curves & the measurement of gain or loss.
BW
</font>
hmmmmmmmm, intersting in light of the conversation we had the other day, re tuning timing curves & the measurement of gain or loss.
BW
</font>
The world is a constantly changing place, and my data base is expanding so, to some degree my statments do vary, thou, generally not too much or often.
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Nothin', for the most part I think that we are all on the same page, just some of us like using Bookman old style & some like using Arial, & some like Times New roman.
BW
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Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><
BW
------------------
Bobalos
aka Bob W.
www.r71camaro.homestead.com
r71chevy@earthlink.net
<><
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Car: 89 formula
Engine: 383
Transmission: 700R4
Hey grumpy, would you know if the 90 and up knock sensor for a TPI350 is less sensitive than the 89 sensor they are different part numbers?
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89 350 TPI,comp cam,edelbrock intake base,SLP headers,highflo cats,flomaster cat back,accel 300+ ign,ported plenum and runners,ported maf,auto w/shiftkit,cold air induction,AFPR,Ed wright chip,3.23 posie best ET 14.011@98.72mph without cam/New best 13.926@98.27mph
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89 350 TPI,comp cam,edelbrock intake base,SLP headers,highflo cats,flomaster cat back,accel 300+ ign,ported plenum and runners,ported maf,auto w/shiftkit,cold air induction,AFPR,Ed wright chip,3.23 posie best ET 14.011@98.72mph without cam/New best 13.926@98.27mph
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<font face="Verdana, Arial" size="2">Originally posted by e-man:
Hey grumpy, would you know if the 90 and up knock sensor for a TPI350 is less sensitive than the 89 sensor they are different part numbers?
</font>
Hey grumpy, would you know if the 90 and up knock sensor for a TPI350 is less sensitive than the 89 sensor they are different part numbers?
</font>
On the GM Marine applications, the use a 45d male to female fitting as a standoff for the K/S to make it less sensitive. Several guys have been doing that with excellent results.
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Grumpy,
I don't get it. If you're supposed to read plugs instead of use a knock sensor to tune your car, how do you tell where on your spark map the knock is occuring? I guess you could use the oxygen sensor to tune the fuel, but how do you tune the spark?
thanks
I don't get it. If you're supposed to read plugs instead of use a knock sensor to tune your car, how do you tell where on your spark map the knock is occuring? I guess you could use the oxygen sensor to tune the fuel, but how do you tune the spark?
thanks
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Car: An Ol Buick
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Originally posted by Homer
Grumpy,
I don't get it. If you're supposed to read plugs instead of use a knock sensor to tune your car, how do you tell where on your spark map the knock is occuring? I guess you could use the oxygen sensor to tune the fuel, but how do you tune the spark?
thanks
Grumpy,
I don't get it. If you're supposed to read plugs instead of use a knock sensor to tune your car, how do you tell where on your spark map the knock is occuring? I guess you could use the oxygen sensor to tune the fuel, but how do you tune the spark?
thanks
Doing the timing table, for optimine best takes a whole bunch of time.
Folks like datalogging, and then back tracking from there, but that ain't the BEST way.
The K/S in oem form are designed to listen for major tip-in detonation / ping, and then up to about 3K RPM. The stock calibration is in part designed to be over rich above that to avoid detonation, and to keep the converter happy, at over 3K RPM. When you start tuning in that range, and making serious HP and solely rely on the K/S you can get into real problems, ie knocking the edges off the pistons.
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Originally posted by 87_TA
How well can you really trust plug raeding when todays fuels have so much garbage in them?
How well can you really trust plug raeding when todays fuels have so much garbage in them?
Lean Cruise, running at Stoic, and with alot more advance then they need all help to defeat plug readings. And the cals are really taylored for catalytic converters.
Once you get to running Open Loop, and have things tuned correctly you'll see them read much better. MUCH!
Of course this is Off Road Only.
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Car: 91 Red Sled
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Grumpy, you need to make your sig read "Of course this is Off Road Only." That way you don't have to keep typing it .
I must say I have found little solice in looking at the knock counts, especially with the slower baud computers. I've been better off just starting with a hunch, going with it, runs better or doesn't, keep going if it's better or go backup. I haven't tried it yet but I'm thinking about raising the required knock counts for retard to like 10 from 2, this way if it is knocking I know it's knock and it isn't my tight suspension or other false issues. I noticed that when the car hits a hard bump it'll run funny for a split second. Maybe with lockers I can verify this is the case.
I must say I have found little solice in looking at the knock counts, especially with the slower baud computers. I've been better off just starting with a hunch, going with it, runs better or doesn't, keep going if it's better or go backup. I haven't tried it yet but I'm thinking about raising the required knock counts for retard to like 10 from 2, this way if it is knocking I know it's knock and it isn't my tight suspension or other false issues. I noticed that when the car hits a hard bump it'll run funny for a split second. Maybe with lockers I can verify this is the case.
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