Knock Knock!

[klmnla]

Yes, I have read a dozen posts and articles on Knock Issues. Most of the checklists seem to be for "false knock " issues. My knock at WOT is real, and sounds like what we called "pinging" and "detonation" when I was younger. I have posted the Scanmaster readings below after I ran the car for a few minutes. The car has a translator plus with an extender chip. I guess its set in open loop mode as the decimal never stops flashing on the scanmaster display. I have the adjustable wastegate actuator set very low, as barely pulled it 1/4 of an inch to connect the rod to the lever. It seems to activate at about 15-18 lbs of boost on the gauge. I am running pump 93 octane with octane booster ( I know, a waste of money ). I bumped up the fuel pressure to about 40 on the gauge at idle. There is a hot wire kit on the fuel pump also, with stock fuel lines and fuel filter. If simply getting an Alky kit will solve my problem, then Im good to go. Otherwise I would like to know some causes of "real" knock.

02 MV- 464 at idle, 800 at wot
Retard at WOT anywhere from 3-11

AF- 03
L8-36
Bat-13
Int-128
bL-127
Clt- 190-209 ( with a 160 degree thermostat)
Ats-89
R-825
TPS-.48-.50
IAC- 50-57
CC- 06-244
PL-4.3
SP-25
MAL-0

 

[Razor]

TPS should be .38-.46 no higher. I typically set it to .42-.44
.48 the ecm thinks your foot is on the gas. Loosen bolts and tap it down a nudge.

IAC can come down a little.. simple way open TB about 1/4-1/2 a turn and reset TPS.. go drive car should be lower. i set mine at 15-20 in idle no accessories running.

The coolant temp is high.. new radiator will cure that. F-body unit from an 89 Trans Am will take care of it pretty cheap. You can search this option.

The above three wont cause knock but they are drivability issues easy to solve.

Take arm of off wastegate and go full throttle.. if the boost obviously goes lower and you dont see any knock.. that eliminates all false knock.

93 octane and anything above 15 PSI is a maybe. Especially with a motor that has a lot of miles/carbon buildup.

Sounds like alcohol is in your near future

 

[1fast6]

15-16# is about all you will get with 93 unless you take out a crapload of timing throught the chip. you can also ad some fuel through the chip.
It comes down to octane. either alky or race gas but if you want big boost you need octane!

 

[3.8L V-8 eater]

I don't see alot of mods in your signature... With upwards of 11* of knock at WOT this will take it's toll on that motor.. The more HP the deadlier that knock will become..Take Razors advice on becoming an alcoholic!!

 

[Fast4Ward]

if your really want to know about the knock your getting, leave your boost and chip settings as is and dump in a 5 gal pail of race gas. go rip it up and see....i think you'll be surprised at the non existent knock....my car can't seem to handle more then 14# on 94 octane with 1-3 KR...by 15# KR climbs fast....race gas is another story.

 

[klmnla]

I will make some minor adjustments and plan on getting the Alky setup. I think I can be happy with less than 20lbs of boost with this high mileage motor. In the mean time I will try and find some race gas to try out. I would be nice if I could hold it to the floor without worrying about knock issues. Thanks for all the useful advice.

 

[NorEaster]

scanmaster

I will make some minor adjustments and plan on getting the Alky setup. I think I can be happy with less than 20lbs of boost with this high mileage motor. In the mean time I will try and find some race gas to try out. I would be nice if I could hold it to the floor without worrying about knock issues. Thanks for all the useful advice.

What are the mph of o2s and knock? Are they happening at the same time? Found my car likes to be on the rich side about 8252 for mv. Good luck.

 

[krazy86t]

Powerplate for 1-3 more psi???

What about using one of those throttle-body/intake plates with the slots to even out the air flow to the cylinders? there is a vendor selling these under the "powerplate" name. allegedly allows for higher boost with everything else the same and reduces knock in rear cylinders. could be a shell game though because the plate will seriously restrict flow through intake so it takes higher pressure to pass same mass flow of air to engine.

my car does not like much more than 15 psi on 91oct pump gas. I thought that the PTE SLIC would allow me to increase boost due to better heat exchange of pressurized air charge into motor, but I have not seen this goal realized with that IC upgrade. probably limited by stock turbo efficiency, so IC upgrade was waste of time until other items are upgraded.

rest of my bolt-on set-up: 42.5 inj, KN cold air intake, LT1 MAF w/ translator pro, 3"DP, Pipes exh with larger flow cat. 2200 stall converter and stock rear brakes that cannot hold 235/60-15 BFG TAs on sticky fly paper. Methanol injection is probably my next upgrade after boxing rear control arms and changing out rear bushings, springs, shocks (front bushings were painful).

 

[klmnla]

The Knock is at any speed as soon as I get on the pedal. The high KR seems to happen at higher speeds. Im going to stay off the floor until I get this resolved or the Alky Kit. May try a little race gas to see how that works. I plan on tweeking the IAC and TPS levels today, just to get that out the way.

 

[1fast6]

I would get an aftermarket boost gauge and turn the boost down as well. 15-20# is a wide spectrum when talking about boost. My car will run all day with 15#, 93 octane, and no adjustments to the fuel and timing. 20# with 93 and no adjustments will knock like crazy. You need to start out low ie. 12# and start turning up th bosst til kr then back down a tad.
AND READ THE INFO POSTED ON THIS FORUM!

 

[gusszgs]

#1- Razors kit
#2- Quality rad
#3- (if ya can swing it) SLIC
#4-RJC Power plate

All of the above move you away from KR Cheers n tu-d-lu

 

[we4Mateo]

I use a powerplate and it was one of my first mods. It did lower kr @ 15lbs no alky that I had before it. I've never taken it out but it doesn't seem to hold my car back. I saw Jason (rjc racing) demo one using a stock intake off the car with a leafblower through a throttle body and you can definitely tell the flow is more even with than without. Does it work miracles? No...but it equalizes air flow and that can't be bad. Some say alky causes problems with them but I have had none.

 

[NorEaster]

try this

The Knock is at any speed as soon as I get on the pedal. The high KR seems to happen at higher speeds. Im going to stay off the floor until I get this resolved or the Alky Kit. May try a little race gas to see how that works. I plan on tweeking the IAC and TPS levels today, just to get that out the way.

Put it in drive and go about 45. Slowly roll onto it and don't allow it to downshift. Let out as soon as you see knock. Press recall on the scanmaster and then press the other button at the same time. Im curious if you are knocking while lean.

 

[klmnla]

I will try the recall test on the scanmaster. I did lower the IAC and set the TPS. I also ran it with the wastegate disconnected and no boost. There was no knock even with the pedal to the floor, and it ran like a V6 :wink: . It blew out white smoke for a few seconds when I floored it. Maybe had some buildup that blew out since I haven't been able to stomp it in a while. The car never smokes, and only did it the one time. Where can I get a decent replacement radiator? Or should I try to add a fan in the front of the condenser maybe? I think the Alky kit is going to be my best hope for the knock issue. I may try some racing gas just ti try it out with some real octane.