A new artical in a magazine I just read says that if you disconect the knock sensor on the (Z) it is good for about 10 hp anybody here of this yet ?Any drawbacks?

 

It says that it advances the timing without the sensor.

 

It will work for a while until your motor blows up from detonation.

 

whats the magazine? why would you have detonation problems if you use proper fuel and you aren't FI and you have a properly tuned A/F ratio through TS ECU or piggyback system like SAFC?

please tell me more!

 

not recommended unless you have FULL user tunable engine management, as well as vast experience in tuning such systems.

 

It was in a sport compact mag ( I think it was hci )It gave a bunch of tips for different cars on how to add hp.

 

It is in the Jan. 04 edition of HCI and talks about it specifically for 350Z cars. It also talks about adding 10% toulene to your fuel too. I'm not sure.......about that.

 

Wont the ECU detect an open circuit and throw a SES in your face?

Maybe a resistor or something could be added to fool the ECU.

 

Most ECU's check for activity on the knock sensor wire. You could unplug the sensor, and inject a signal.

That's what we recommended to Dinan Engineering. They were tuning chips, and wanted to disable the factory closed loop timing control. At the time, they were using one of our sytems as a detector.

We advised they inject an 8kHz sine wave, at 0.5vpp, which kept the ECU happy.

 

toulene increases octane, thereby making it 'safer' to run w/o the knock sensor

 

well what if i am running 93 octane shouldn't that be enough. the manual (that tells you what to use like oil and stuff) says 87 or higher. I am sticking with 93 and if i end up in a pinch ever i will go one or 2 tanks at 89!

oh well, sounds like too much of a hassle!

 

printing that in a magazine is horribly irresponsible journalism, IMO.

pulling the knock sensor? christ. It's not like it's an emmissions control. It's there to save your neck from detonation. The ECU constantly tries to run the timing as aggressively as it can, while retaining a safety factor. You can go ahead and pull that sensor, but if you ever get one bad tank of gas, or get stuck in traffic in an Arizona summer, etc, then you're going to be sorry, no matter how much toulene (essentially a homemade octane booster) you pour in the tank.

 

There is a reason the knock sensor is there. Azrael described it pretty good. A high compression motor without a knock sensor is a ticking time bomb.

 

The knock sensor detects knock (obviously). When knock is detected the computer retards the timing to protect the engine from knock induced damage.

It is true, removing the knock sensor would trick the computer in to using more spark advance. You would have more power, more knocking, and eventually run the risk of serious engine damage.

I wouldn't do it. (and for only 10 _claimed_ hp?)

 

Good points I would'nt do it anyways because I'm running nitrous but I just thought it was interesting that they suggested it.

 

I think whoever wrote that in the magazine should be fired, because there will probably be some kid out there that tries it. Only to find out a couple months later that their engine has lost all compression.

 

Everyone above described this situation well...DON'T do this.

All I have to say is that I agree with Jesse (as usual), that journalist should be fired.

 

Uuuummmmmm..removing the kncok sensor will not in and of itself advance timing..it will just keep timing from being retarded if the knock sensor picks up a signal it perceives as being knock.

A knock sensor is nothing more than a microphone that is meant to pick up singlas in a specific frequency range. It has no way of knowing itself if the sounds it hears is actual knock, or something else moving around in that frequency range (ie loose heatshield, etc.).

To disable the knock sensor, you can simply ground it out...that will totally deafen it's ability to detect anything, but this is 9 times out of 10 a recipe for self destrution except in the hands of an expert tuner with full datalogging, fuel and igntion control.

In other words, leave it alone

93 octane may or may not be enough...depends on your level of mods. I would say all but the most modded cars 9especially thoe rvery modded cars in hot humid climates) are fine running standard pump gas (hi octane)..if its not, then its really lost its status as a daily driver in my book, and mvoed intot he realm of race car (not that there is anything wrong with that mind you).
Adding toulene is a great inexpensive way (compared to race gas to bump octane, and because it retains the unleaed status of the gas, will not harm the 02 sensors or cats.