knock sensor location..Ideas??

[turbobrat930]

My cylinders are not drilled for the stock 3.2L knock sensor bracket (JB Racing cylinders)... small oversight on my part... Where would be a good place to mount said sensor? I was thinking about lengthening one of the intake stubs on cyl#4 (it can only be cyl#4, as the shape of the runners of the 3.2L intake prevent any other stud on the intake from being used) Keep in mind that the engine is mounted into the car, and taking it out, or disassembling said engine, is NOT an option.... Any ideas/ comments??

[Tippy]

3.2's don't have knock sensors, I believe only the 993 had. This has been talked about at length, but for some reason, it slips my memory where most prefer.

[turbobrat930]

Yea.... I remembered after posting that said it was only a 3.6 liter that had them.

there is also a longer stud that is one of the three studs and bolts the engine throttle bell crank or quadrant to the engine block and I was thinking about using that one. that stud is located at the base of cylinder number 3 on the crankcase itself

[alwaysflat6s]

Try using SEARCH on this forum. Like Tippy said, lots of discussion.

One spot I know of is underneath the left side of the throttle bellcrank plate. Obviously, that will require some work to get at, but you are not going to find any suitable spot that won't require a little work to get at it.
GL

JR

[sjf911]

I had a single sensor on the breather cover before converting to twin 993 bridges, seemed to work well.

[turbobrat930]

I was able to attach the sensor to the side of Cyl #2. Drilled and tapped a hole on the side of the intake. There is enough meat on there to get a good 10 to 12 threads tapped... Tightened up perfectly, and now the knock sensor is right at the head.

[IMG][/IMG]

[jpnovak]

Great location. I really like the knock sensor on the head. Would be great to have one on both sides of the engine. How much did you have to clearance the cooling shroud to clear the sensor?

I have installed them at the base of the throttle plate next to cyl#3. Just shorten the aluminum spacer the same amount as the thickness of the knock sensor.

[turbobrat930]

Originally Posted by jpnovak

Great location. I really like the knock sensor on the head. Would be great to have one on both sides of the engine. How much did you have to clearance the cooling shroud to clear the sensor?

Thanks! I did not have to do any clearancing of the air shroud. It fit with no problems....

[spuggy]

Originally Posted by jpnovak

I really like the knock sensor on the head.

Exactly where Bosch say not to mount it.

[turbobrat930]

Originally Posted by spuggy

Exactly where Bosch say not to mount it.

I have never hear that... However, I will be able to tell via the laptop if it is working or not...

If it is not working, I will regroup, and pick a different location....

[proffighter]

Mine is under the throttle linkage bracket:

[spuggy]

Originally Posted by turbobrat930

I have never hear that... However, I will be able to tell via the laptop if it is working or not...

If it is not working, I will regroup, and pick a different location....

It'll work. But you'll also pick up top-end noise from the valve gear - and if there were any cylnder base and/or head gaskets, that'd tend to insulate a sensor from the other bank. So then you'd need two sensors. And on a water cooled motor, you don't want to be on the outside of the water jacket.

You want to be bolted directly to the block. Apparently.

Yes I know the factory used cylinder bridges on the later motors. Who the heck knows why?

I used the M8 studs directly under the shroud - although at least a couple of folks have had sucess with using the throttle linkage mountings - which are certainly easier to get to.

Jake Raby uses a bell-housing bracket on a Type IV, distance is not that critical. The denser the medium the further sound travels.

[Tippy]

Was reading that the frequency is so different than any other sound, that having false triggers were really not a problem.

Was thinking about this a little, and I agree since the valvetrain on our engines make "clacking" sounds while detonation makes more of a "tinking" sound, which is a higher pitched frequency.

I'm going breather cover and see what happens with fingers crossed.

[Tippy]

Sorry to hijack.......

turbobrat930, just saw your sig. My gawd, what kind of power are you making with that combo? Jealous.....

[turbobrat930]

Originally Posted by Tippy

Was reading that the frequency is so different than any other sound, that having false triggers were really not a problem.

Was thinking about this a little, and I agree since the valvetrain on our engines make "clacking" sounds while detonation makes more of a "tinking" sound, which is a higher pitched frequency.

I'm going breather cover and see what happens with fingers crossed.

I agree... I mean you have the cam chains at one end.. scavange pump at the other... valvetrain on each side... But, i think you are right, it is listening for a different frequency. also, I think it is searching (the ecu is, in my case) for an anomaly... IE: you have say a 140 value at 2,000 RPM, then at 4,000 RPM, you have 220. Then all of the sudden at 4K, you have 298.... the ECU will say hey, something is not right. I am sure that it is also tuned to pick up a certain range of frequency...

If it is not working where I put it, it will not take too long to change it...

[turbobrat930]

Originally Posted by Tippy

Sorry to hijack.......

turbobrat930, just saw your sig. My gawd, what kind of power are you making with that combo? Jealous.....

LOL... thanks!

I am shooting for 750 at the flywheel on E-85. But I think I may need to step up to a bigger turbo in order to hit that... we shall see... I just installed dual 044 fuel pumps, and changed all the fuel stuff over to teflon SS braided line.. and we are running ID1000 injectors.. so could get close to 120lbs on the injectors with just a slight bump in fuel pressure...

I am planning on a write up about finishing the project in a couple weeks when she runs for the first time.....

[Tippy]

Wowzer, I think you you might be there. E85 is some serious gas that allows a lot more power than a turbo is rated at.

Anxiously awaiting the write up.

[turbobrat930]

Originally Posted by Tippy

Wowzer, I think you you might be there. E85 is some serious gas that allows a lot more power than a turbo is rated at.

Anxiously awaiting the write up.

Yea, I have a local friend here who drag races... He won the Dynomax challenge a few years back in Vegas with his twin turbo AMC rambler... That engine at its final config was north of 2,700HP.... on E-85

That fuel is awesome for our cars... even more so because we are air cooled.

I would like to see what it will do, but the final number is not really whats important to me. I will scale it back a bit, for longevitys sake... The car is mostly carbon fiber and only weighs 2100lbs... so very light... and very fast!!!

[Tippy]

That's litrebike acceleration hp/weight ratios! GL on the endeavor.

[patkeefe]

I didn't have the 993 bridge, and wasn't going to take everything apart. I haven't used them or set them up yet (no calibration). [img]