knock question

M

Maverick87

Member
I am wondring of the guys that have very low kr are they using race fuel to acheve this? I have put the stock chip back in my sy to see if I can get rid of my knock problems. I have tried rasing and lowering the fp but I still get about 2-3 deg of kr. I have new cap, rotor, ngk ur6 plugs gaped to .032,plug wires,fuel filter,walbro. what can cause it to still knock? :-?
 
jwaller

jwaller

Evil Genius/SyTy Guru
oil....PCV system is putting oil down inside the motor.. remove the TB and look down inside your intake. you should prob clean it all out then give it a shot. also mat temps can cause big problems. what are your temps...what are your eng temps???? the lower the better.
 
InvisiBill

InvisiBill

Active member
Have you tried higher octane (race gas or xylene) to make sure it's not false knock? Do you always get 2-3 degrees, or just at specific points?
 
B

bigjohn

New member
i have always had knock problems. i tried 2 gallons of xylene to 1/2 tank of 92 oct. and knock was gone. so was $16.00 in xylene. :drinking:
 
M

Maverick87

Member
my ia temps are about 68-75 to start with and go up to 95 at the end of 1/8 mile. Motor temps are about 140 to 160. Just cleaned the tb & upper intake, also just replaced the pcv's . I have tried octane booster seems to help a little. It knocks when I first get on the gas at the line then it knocks at the shifts.
 
jwaller

jwaller

Evil Genius/SyTy Guru
it sounds like you have something loose. maybe an exhaust part thats clanking under high load conditons.
 
InvisiBill

InvisiBill

Active member
Maverick87 said:
I have tried octane booster seems to help a little.
Click to expand...

Did you use the "Super Mega Hyper Octane Booster" bottled stuff from the store? When that says it raises your octane 7 points, that's 92 +.7 = 92.7, not 92 + 7 = 99. 1/3 xylene to 2/3 93 will give you 101 overall.

If octane booster helped, I would think that it's not false knock (at least not all of it). Higher octane shouldn't affect how your exhaust clanks around...
 
manitoufs

manitoufs

Member
I would not waste my money on any of the off the shelf octane boosters. A while back I tried a couple of them and did controlled tests using Datamaster. They did not yield any reduction in knock or spark retard. They just lighten your wallet.

Some of other owners have had success using xylene.
 
M

Maverick87

Member
I am thinking about alky. :drinking: when you guys get low or no knock is it with or without higher than 93 octane gas? Is there a way to get low knock without all the added stuff like alky, race gas,xylene.
 
M

Maverick87

Member
I just dont understand your iatemps are out the roof but still low knock!!! It is just not fair :( . your o2 volts are about 100 points above mine. I have replaced the o2 sen. I guess I can try and put the old one back in and see if it makes any difrence. This sucks!!! Can I send you a Dm run to look at to see what you think?
 
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