Low Rpm Part-Throttle Knock
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Low Rpm Part-Throttle Knock Ever since I installed my new heads and smaller blower pulley, I get 7-15* of knock at part-throttle. If I give it a bit more throttle it goes away.
EFI
EFI
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
I'll tune it out if that is what I need to do. I just can't see getting all this knock just because of a head swap and a pulley change. I don't even get into boost.
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
At WOT under boost I can understand. Which is why I am going to tune it again.
But going 21 mph, TP @ 30% Engine turning 2600 rpms. No boost. No load. The extra air is going to affect it? Then why by giving it more throttle the knock goes away?
Sure I can bring in PE sooner or pull timing. I just want to make sure that is the correct way to solve this. Thanks.
But going 21 mph, TP @ 30% Engine turning 2600 rpms. No boost. No load. The extra air is going to affect it? Then why by giving it more throttle the knock goes away?
Sure I can bring in PE sooner or pull timing. I just want to make sure that is the correct way to solve this. Thanks.
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Joined: Nov 2001
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From: Bellevue, Wa
But going 21 mph, TP @ 30% Engine turning 2600 rpms. No boost. No load. The extra air is going to affect it?
Then why by giving it more throttle the knock goes away?
also your VE is going to be very different now and when that is way off it will produce seemingly random KR in all sorts of conditions.
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12 Second Truck Club
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From: Sacramento, CA
Exactly...
This is the fun stuff I am learning from Rick@Synergy and Heath. The tuning being done on a lot of the car leaving Rick's shop are reporting MUCH improved throttle response and overall driveability because of the tuning done in places most tuners would not touch. I never really though much about part throttle either but after seeing the differences I am convinced. I had similar problems with my turbocharged 4x4 and through street tuning we corrected it. All those often overlooked cells do mean something.
This is the fun stuff I am learning from Rick@Synergy and Heath. The tuning being done on a lot of the car leaving Rick's shop are reporting MUCH improved throttle response and overall driveability because of the tuning done in places most tuners would not touch. I never really though much about part throttle either but after seeing the differences I am convinced. I had similar problems with my turbocharged 4x4 and through street tuning we corrected it. All those often overlooked cells do mean something.
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you mean most "pro" tuners are not tuning for part throttle??? 
Every car I tune gets a complete tune, driveability and power.
I'm surprised your seeing that much knock at that point since it's not very high load. What i've found is that once I can tune ALL the knock out of a motor I can then increase the timing A LOT more everywhere else.
Once knock starts, it's almost impossible to stop.
Every car I tune gets a complete tune, driveability and power.
I'm surprised your seeing that much knock at that point since it's not very high load. What i've found is that once I can tune ALL the knock out of a motor I can then increase the timing A LOT more everywhere else.
Once knock starts, it's almost impossible to stop.
12 Second Truck Club
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From: Sacramento, CA
What I'm saying is a lot of tuners use a dyno that CAN'T get you to see what the car is doing in each cell and as such you can't tune for every load. Worse yet street logging doesn't usually get you into each cell either. Ask Heath about his 4 days of logging and he still only got a lil over half to 3/4 of the cells he was able to see on the dyno.
Being able to hold a car at 200rpm increments on the dyno is awesome.
I'm sure you'll get it sorted out with some data logging on the street Ed and she'll be back to normal but with some extra kick.
Being able to hold a car at 200rpm increments on the dyno is awesome.
I'm sure you'll get it sorted out with some data logging on the street Ed and she'll be back to normal but with some extra kick.
Thread Starter
Joined: Nov 2001
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From: Sunny San Diego
Thanks alot guys. I am sure I will.
Can a mod move this to the PCM tuning section?
Would it be better to pull timing? Or bring in PE sooner? Since I am not in boost, I would think timing.
Can a mod move this to the PCM tuning section?
Would it be better to pull timing? Or bring in PE sooner? Since I am not in boost, I would think timing.
Last edited by Ed Blown Vert; May 9, 2005 at 08:22 PM.
12 Second Truck Club
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From: Sacramento, CA
Originally Posted by Ed Blown Vert
I brought in PE @ 30% TP and that seemed to have solve the issue.
Sweet.. I asked Rick to chime in here about it and when I mentioned your problem he said the PE sooner thing. LOL Good to hear it's fixed
