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seeing 7*+ of KR with conservative mods... Any suggestions??

97AutoXVette

97AutoXVette

New member
Alright everyone, here is the mod list (1999 GTP coupe w/ 127k miles):

PLOG
3" Catless DP
160 T-Stat
K&N intake
10.5mm plug wires
Al104 plugs
TB Spacer
3.5" MPS
Self tuned with HP Tuners

Doing some data logging on Saturday morning, I saw up to 7.2* of KR at one point. and right around 4-5* regularly under WOT up to 98mph.... I am at a loss. AFR commanded is a steady 11.0/1 throughout the WOT pulls...


Am I possibly seeing false KR? Should I just swap to E85 and be done with it?!?! I am getting a bit concerned at the moment. Aren't those enough breathing mods to eliminate most of that KR, especially with only a 3.5" pulley?
 


Not knocks at all, passing on learned experience.

The TB spacer is usually only good to leak coolant into the intake. Which can cause you issues/kr
160 stat seems very cold for a 3.5" with a plog.
Who's 10.5 wires do you have? ZZP had a bad run for quiet some time, if you see misfires as well and these were ZZP. It's worth trying your old wires to see if the wires failed.
104 Plugs depending on the gap, might be too cold as well.

You say you are comanding 11.0 afr, what is the actual afr?
 
Thanks for the feedback. I always welcome any. I still need to log actual AFR. Don't have a wideband hooked up yet. the wires are ZZP and I just received them/installed them about 3 weeks ago...

As far as the T-stat and plugs go, think I need to be worried about being too cold though?? That should only help with knock right? Figured I can always eliminate knock and then work my way back towards the "hotter" side of things...
 
You need to get a wideband to log your AFR. Commanded does not always equal actual. Get a 180* T-Stat, I have read many things about the 160* T-Stat not allowing the oil to fully warm up and cause issues. 180* is good. Too cold of plugs or improperly gaped plugs can also cause misfires and then cause knock.
 
I have 180 t stat al605 11.7 afr wb tuned headers with 3.5 pulley on genv and only would like 2 * of knock before I installed 1.9 rockers


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hmmm.. clearly I need to tweak something then. Maybe I should throw in plugs that are 1 heat range warmer? I have a 180 t-stat that I can throw in too. But why does ZZP recommend AL104s with both 3.5 and 3.4 pulleys? Not saying that their recommendations are 100% true. Just curious.
 


Running AL104s can help with knock. I stress can. It can also cause it. I am a firm believer in motors having minds of their own on what they like or dont like.

Above all GET A WIDEBAND AND CHECK YOUR AFR. For all you know your running a 13 AFR and thats why you are knocking.
 
I had about 4 sets of plugs when modded. Kept trying different heat ranges and gaps until I found the best fit. There are a lot of other factors that come into play. Air density, altitude, temp, and the list keeps on going. It's not a bad idea for the cost of a copper plug to try a different range.
 


With the stock tune what it was commanding for afr was deff not what the wb was reading so before anything you need to see where you actually are at


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Get a wideband and make sure you are running between 10 and 12 afr at wide open. My personal favorite is 11. Then set the timing to 18* at wide open and do a few pulls. If you are still knocking its most likely real knock. Ignore bursts of knock on shifts. Let us know what happens. If you want to log wideband use the center pin on the egr connector.
 


So much misinformation.... cold plugs are not going to cause kr. Too hot of plugs can, Too lean of fuel mix can, too much timing can.
 
Gotta remember that your plugs show that your cruise fueling is good. Your wide open throttle fueling will not show on the plugs
 
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