knock retard=how much lost HP?
Thread Starter
TECH Fanatic
Joined: Sep 2003
Posts: 1,570
Likes: 1
From: San Diego, CA
knock retard=how much lost HP? after my header install i hooked up a scanner and saw 4-6 deg. of KR........
then when i dynoed the car my AFR never dropped below 13.5..avg, @14
could my lean condition cause my KR? if so how much could i gain from a good tune? im guessing 10-15rwhp! any ideas or thoughts?
what should my target AFR be?
then when i dynoed the car my AFR never dropped below 13.5..avg, @14
could my lean condition cause my KR? if so how much could i gain from a good tune? im guessing 10-15rwhp! any ideas or thoughts?
what should my target AFR be?
KR will rob hp. How much? Maybe 2, maybe more. But it will aslo kill your motor if you don't fix it! Fatten it up & your car will be faster. Every deg of KR = a degree of timing lost....
TECH Senior Member
Joined: Nov 2001
Posts: 7,036
Likes: 1
From: Lake Zurich, IL
not sure on numbers.. but you'll lose alot of power depending on knock...
Last year after I did heads/cam I managed to cut a wire for one of my knock sensors...
so it was reading 4* constant knock... which caused it to pull about 8* of timing advance... plus it was forcing me into the low octane tables which lowered timing eve3n more...
I was getting 12-13* of timing at WOT (normal was 26-28)
ran a 13.3@101 .. using edit I changed the low octane tables to match the high and bumped timing a little to compensate for 8* loss... was running 26* timing peak and ran a 12.3@110
so 9mph and 1 full second due to running really low timing... knock robs timing so you stand to lose alot of horsepower due to knock... (if constant, if intermitent or only sometimes or false knock then won't hurt as much but will still hurt)
Last year after I did heads/cam I managed to cut a wire for one of my knock sensors...
so it was reading 4* constant knock... which caused it to pull about 8* of timing advance... plus it was forcing me into the low octane tables which lowered timing eve3n more...
I was getting 12-13* of timing at WOT (normal was 26-28)
ran a 13.3@101 .. using edit I changed the low octane tables to match the high and bumped timing a little to compensate for 8* loss... was running 26* timing peak and ran a 12.3@110
so 9mph and 1 full second due to running really low timing... knock robs timing so you stand to lose alot of horsepower due to knock... (if constant, if intermitent or only sometimes or false knock then won't hurt as much but will still hurt)
