Audible Knock Detector

[salvageV6]

What if any is the correlation between the scanmaster and the Caspers' Audible knock detector?
I got 4.2 degrees stored on the scanmaster and no beeps out of Caspers unit.

It did beep this morning when I started the car so I know something works on the thing.

I also have another light bar gray case meter that had a couple lights on it after the WOT run.

Not sure if it's a problem with too much load on the KR line but I doubt it since they should be very high impedance circuits.

Anyone know a relationship? TIA

 

[TheDoughboy]

I would also like to know about this. I have a Scanmaster and Caspers audible knock detector I will be installing this weekend. The Caspers not emmiting a tone at 4.2 makes me wonder too.

Any ideas anybody??

tia,

Ron

 

[salvageV6]

Ron I am leaning on trusting the Scanmaster over the Caspers unit.

 

[peterkin]

i don't know what the threshhold is for it to beep, but when it does in my car i back the he11 out of it......then i hit recall and get over 6 degrees of knock....when you hear it go off don't be surprised, just back out....i hardly ever hear mine, and normally only hear it at startup also.....

 

[salvageV6]

Well I'll be borrowing the laptop from work and going to dyno day.

Guess I'll trust the Scammaster and the Direct Scan since they most likely will be more sensitive.

 

[tminer]

I had 2 new Casper's and niether worked right. First one would trigger and then not shut off until I removed power. I could never make the second one trigger even using a prescribed test procedure. Maybe I was just unlucky, and I could have gotten the second one replaced too, but I gave up and wised up to the fact that if I was needing an audible knock detector, I was too close to the edge for my liking (conservative).

Tom

 

[TheDoughboy]

I wonder if I should even install the Caspers unit. Maybe I should just sent it back and get my money for other toys?

Ron

 

[Steve Wood]

Salvage, why don't you address the question to John Spina? He always seems willing to discuss such issues with his products.

Then share the answer with us.

 

[OKTurbo]

salvagev6....You're talking about sensitivity and such, but the Casper's gauge and both the ScanMaster and DirectScan/TurboLink all are using the same knock sensor on your motor.

The Scanmaster will be no more accurate than DirectScan since they are just reading what the car's computer is seeing...as reported through the ALDL port. So basically....the number you see on the ScanMaster is accurate, but it only gets updated every 1.5 seconds through the ALDL.

John Spina w/ Casper's makes some 1st class stuff for our cars. He is very knowledgeable and will help you work out what is going on. I suspect that the audible gauge won't squeal at you until the KR gets up to around 6 degrees.

The big advantage to the audible gauge is (other than it beeps at you) that it plugs directly into the knock sensor wiring and isn't hampered by the 1.5 second scan rate of the ALDL.

HTH,
John

 

[salvageV6]

Actually I thought it was a very easy question since a lot of people use them. I guess many don't really know why.

I even thought the information should have been in the literature.

Obviously Direct Scan, due to it's update rate, will be the most accurate yet hardest to see and read while driving of course.

I guess Direct Scan will be the best tool to correlate the thing with due to the fast update.

I'll do the testing as soon as I can get a laptop. I just wanted to know about how much KR a short beep and a long beep are.

I realize it could vary due to certain conditions.

If it doesn't beep, short or long, under 6 degrees it's kinda useless for me for tuning at high boost. Then again I bought it for the other car anyway, it's mostly stock. I'll find a home for it.

I already know about the beep on startup.

 

[tim87tr]

SalvageV6, I too have always wondered at what kr the knock guage responds. Today I started using the extender chip and the fast update on it really helps out. Plus, the chip eliminated all of my kr also. Thanks for the info on making the scanmaster portable in the other post.

 

[GNVenom]

Ahh, the chimin' in needs to wake me up! I can shed some light on the Knock Gage and Audible Knock Module.
Actually they only can show the "severity" of knock, not actual knock retard...that's a calculated value based upon a number of variables; RPM, LV8, INJ PW, 3rd or 4th gear, etc. You can test either product by turning the key on, then "rapping" at the base of the knock sensor, under the coil pack, using a long screwdriver or 1/2 in. drive extension (my favorite). The audible module will either submit a short chirp, long chirp, or long tone, or anything in-between. The corresponding Knock Gage will show a green LED, yellow LED or red LED. The idea is, if you hear a chirp, knock is low to moderate, a longer chirp - moderate, and a long tone indicated severe detonation. The gage works the same way; green in minimal KR (2 to 4 deg. of knock typically), yellow means moderate knock (typically 5 to 7 degrees of KR) and red means excessive KR, usually more than 8 degrees. These are only representative values and they can vary from pass to pass. So, it's strictly an indication of knock, not a definitive indication of knock retard. If you need to know exact knock retard, look at the scanmaster, turbolink, direct scan or other scantool...but it will be after the fact. The gage and module does it in "real-time" which gives you better control of your right foot. And, the audible module allows you keep your eyes on the road, or boost gage, tach, or other pertinent indicator in your line of sight.
Hope this helps,
John Spina
http://www.casperselectronics.com

 

[salvageV6]

Thanks for the information John.

I guess mine is defective or miswired.

Had 3 runs of 7-8 KR stored in the scanmaster and no beeps.

Did beep when I started the car.

I will recheck my wiring and do some tests.