Still Knocking!

Today I just got one of the aeroforce interceptor scan guages mainly to scan for knock so I can put a smaller pully on.
After adding a 3" custom FWI, 180 degree thermostat, autolite 104's and just some magnaflow mufflers that I bolted on for now
I'm still seeing up too 6.5 KR. I was hoping I wouldnt have too find somebody too weld in a new 3" downpipe cause
god knows i cant doo that, and or installing 1:8 rockers because I dont exactly have $400 laying around. haha
Any other suggestions on how too lower those numbers?

Also can the guage scan boost or do I have too get a new sensor for it too be able too do that??
Thanks

The only thing to do is to remove the pulley or stay out of the boost until you can get more supporting mods. Headers, downpipe, programmer, etc. What size pulley are you running?

Stock 3.8 pulley, Ive seen most guys on here run 93 octane, I live in nebraska where the highest at most gas stations is 91 unless I go somewhere where they sell race fuel. But Ive always put 91 Octane in. Maybe next time I fill up ill pick up some octane booster and see if that lowers KR, but I don't think the fuel im using now would make it knock that much.

What octane fuel are you using?

91 octane

Octane boost fuel additive will not do much. Must be some underlying problem. Is your sc coupler noisy or could something else be giving you false knock?

Im planning on changing the supercharger oil and while im at it might as well replace the coupler. Ive put about 30,000 miles on the car and have absolutely no idea if the previous owners even thought about changing the oil in the SC. No matter what, it hasn't been changed in a while. And at idle i can here a rattle coming from the intake but usually goes away once engine warms up. Possibly bad coupler?

You shouldn't be getting that much knock on a stock pulley. What kind of maintenance have you done since you got the car? The coupler usually make a noise at idle regardless of the engine temp. Mine really made a knocking noise when I shut the car off. Take the supercharger belt off and grab the pulley and check to see if there is any play.

Took the belt off. No play at all on the pulley. Ive changed the oil every 3000 miles but thats it. Lately though ive been losing alot of coolant now that i remember. Im going to have too find the culprit for that.

Try some Torco octane boost, in my supercharged Mustang it allowed me to raise the boost significantly.

I figured id give that a try too. Cant hurt anything!

Yeah, you definately have a problem with that much KR. A bad coupler won't cause that. When does the knock occur? What are your O2 readings at WOT. Other parameters? Do you have any scans for us to look at?

What is the gap on your spark plugs? Wires good? Have you run any injector cleaner? Is your fuel filter not too old? MAF clean? O2 sensor good? Any exhaust leaks (at all?)?

Sounds like you really need to run through all of the basic stuff. Certainly don't drop pulley size until you figure this out. Something's up.

I like the big bottle of Techron injector cleaner - I run it every oil change. I also sent my injectors out for a professional cleaning/flowtesting. It may be worth doing. Read your plugs and make sure they are good. A miscolored plug may pinpoint a bad injector. If you discover something, try swapping injectors around and see if the problem follows the injector.

I may have a set of L67 injectors at home that I could send out to be cleaned/flowed and you could buy from me (for the cleaning/flowtesting price). All I ask is for your old injectors in return... or I (or a couple others) can tell you where to send your injectors.

Still tippin on 44s

The knock is actually mostly while i'm mildly accelerating inbetween 2k-3k. Is there anyway I can download and show you guys what I record of my Aeroforce? I dont have any scanning software nor do I know anyone who does around where I live. What are normal O2 readings at WOT.

I gapped the sparkplugs myself about a year ago when I put them in, I cant exactly remember too what I gapped them but I followed the drivers manual when I did it. Scanning guage shows no misfires on any cylinders. I was actually planning on replacing my fuel filter soon, hasnt been done in a couple years.

I havent even began looking at the the injectors, so ill have too pull all the plugs out and look for anything abnormal. How hard of a job is replacing them?

Also I dont know if the guage is broken but just during normal scanning its showing lots of KR, but when I record it and play it back, It reads 0 KR the whole time, even during WOT

Colten225 wrote:

Today I just got one of the aeroforce interceptor scan guages mainly to scan for knock so I can put a smaller pully on.
After adding a 3" custom FWI, 180 degree thermostat, autolite 104's and just some magnaflow mufflers that I bolted on for now
I'm still seeing up too 6.5 KR. I was hoping I wouldnt have too find somebody too weld in a new 3" downpipe cause
god knows i cant doo that, and or installing 1:8 rockers because I dont exactly have $400 laying around. haha
Any other suggestions on how too lower those numbers?

Also can the guage scan boost or do I have too get a new sensor for it too be able too do that??
Thanks

You are at the point where you need to reprogram the spark tables to get control of that knock.

Mild acceleration between 2-3K RPM - while the torque converter is locked, like going up a mild hill?

I agree with Albert here - it's one of the tight spots with some of the heaviest loads. The only way to get rid of that is using a tuner to adjust the timing tables. And with a '96, you don't have many tuner options.

How much is "lots"? 5-6? If so, and it's only in that one scenario, don't fret over it too much. Damage comes from KR on WOT...

Although I don't like having KR anywhere, a little bit there isn't going to kill you.

Well that's good too hear. Most KR I see at WOT is 1.5-2 which is still dangerous but not as concerning as the high numbers I see while normally driving. And yea its usually going up hill when my car is in 4th gear lugging down. I've started putting it in 3 too maybe see if it helps. But there is still high KR numbers. Just not as bad.

And yah that general area. Most I've seen while just "cruising" is 6.5 for a split second. But it usually lingers around 3.

And with tuning. I didn't even know I had any options. Do u know what they are for the 96

If you can find a used DHP PowerTuner (or PowerTunr) - out of production - it will tune any pre-'02 3800 PCM, I believe. If the default DHP software won't do it, I think the TinyTuner software will.

Not sure if TinyTuner allows you to use an HP Tuners to edit a '96 file.

(P.S. I haven't tried any of this as I don't have a '96 available to play with. Confirm a few things before you go spending any money on a tuner!!!)