crispeed: 1.3v/10 LED's equals 0.13v per LED.

It sounds like you might be lowering the boost, a la the Saab APC, also known as "automatic gas pedal". Saab's tech paper said this method is safer than spark retard, since it doesn't raise exhaust valve temps.

The Saab paper also hinted at EMI problems (electrical interference from the spark plugs), so I doubt if they got knock retard working reliably. Of course, this was back in the early '80's.

I bought my first knock sensor from a Saab dealer in '83, and started experimenting. At the time, I was buildng boost retard units for AK Miller and Kas Kastner. I had mine on the market before MSD, must have been in '81. Ak put one on his propane turbo Ford, and it made the cover of Hot Rod.

Dr. Jacobs (CompuSpark, etc.) and Bill Hayes (Stinger Ignitions/Centerforce Clutches) both called me the day it hit the stands. We had Bill over for dinner, and showed him my home lab. I guess he wanted to see if I was a threat or not. He told me, NOBODY goes into his lab except his engineer. Dr. Jacobs didn't get an invite, though one of his spys made it in later.

 

Thanks for the info.
I still have one of the early units with the adjustable pot on the bottom that I bought form Carlos way back in the early 90's. Still kicking ***.!

''Automatic gas pedal''
Now that's a great name for it!

''AK Miller and Kas Kastner''.
Have not heard those names in a long time. The early turbo gurus. Ak was the 'suck through'(draw through) king. Corky 'blow through' king is young compared to those two!

 

Interesting...I always thought it was purely a single-channel device that did not know what engine it was installed on.
I don't suppose you remember all the units ordered?
This was an order for three units that went to Hawaii...


I dunno either.
It was out of my control.
I think the FD was running a Pettit "Unlimited" ECU at the time.
It wasn't a stand-alone, and I wasn't responsible for the car at that point in time.


Thanx for offering such detailed information.
I know you got better things to do than argue with a bunch of online idiots.


-Ted

 

While I have two Haltechs on stand by I currently have the J&S with PFC...I assume as a moniter. I must say it's great to have John providing a rare product insight and addressing issues that we need to now as owners and my self as a laymen.
Thanks

 

RETed:

I was always confused, when you would post that I had no idea how an RX7 ignition works. I finally had to go off on you, just to get my post count into double digits.

I do vaguely remember shipping three early RX7 units to Hawaii. Seems like you had to have them on a Saturday for a dyno session? About all I can remember.

The black box versions were fixed at 20° knock retard range, so that engine may have run into a negative split issue.

I don't know if I have a copy of the early software. It was on a hard drive that crashed. If you have a version made before '95, I may not be able to change the knock retard range.

 

I had to go over my previous replies, and the only idiot I was going off on was [B]GUITARJUNKIE28...who seem to have mysteriously went silent after I question his experience with J&S units.

I don't think I ever directed any of those insults directly at you.
If I did, it wasn't intentional and apologies up front for any misunderstanding.

Yep, they were shipped in "expedited", but they were some of the early production purple boxes with dual-displays (knock + AFR)...dunno if that makes a difference.
You mention a 5th DIP switch? I swear the box only had 4...


-Ted

 

RETed: The purple boxes with four switches have the 10/20 select switch (S1). The range can be reprogrammed to 5/10 max knock retard.

 

mysteriously silent? you said you heard it from like 50 feet away, so i was under the impression you weren't the tuner. man, you must have one LOOOOOOOOOOOOOONG serial cable.

you mistook what i said as a personal insult, then tried to retaliate with some bullshit. if you don't like the unit, don't use it. stfu and be done with it.

most other people on earth understand that concept, why is it so hard for you?

 

Woa, cat fight! I say that if anybody is to use the J&S on a rotary they should use the 3 or 4 channel unit, and not a single channel.

 

that's not a fight... it's ted trying to start **** again.

come on, we're all used to it by now.

 

Claudio:

Three or four channel unit for the RX7 is still on the drawing board. I know what to do, I just have to do it.

 

Ah, sorry, didnt know, i honestly thought you had a 3 or 4 channel unit by now. I hope you have time to do it. Or ill have to get Haltech to do knock control on their units...

 

Id be interested to know if the frequency of the noise from rotary knock is different than piston engine knock...
And is the mazda sensor neccesarily the best to use... I have tested the stock retard system on a few TII"s and its not the most sensitive device in the world..
I have some experience withe HKS knock amp, very usefull tool if you know what sound you are listening for, but it unfortunatly is only as good as the people using it, another problem is that its nice to listen to the car on the wind up to listen for other faults. Hard to do wearing a set of headphones, the clutch could be disintegrating and one wouldnt know it..When I first saw it in use, I thouht the guy was listening to music while he was tuning....
I might have to invest in one of these as I test the bounds of pump gas...

 

Max:

I don't know the knock frequency, so I use the Bosch sensor. It's non resonant, meaning it responds to all frequencies.

 

I would ask where is the best place to mount the sensor on the rotary? the factory sensor on the S4 is on the intermediate housing and on the S5/6 is on the housings. Also, John, is the J&S compatible with the mazda sensors?

 

Claudio.
The factory sensors are poorly made. They fall aprt from heat most of the times. The present one on the rx-8 have been re-designed and closely ressembles the bosch one.
The best place I've found to mount the sensor is in the little hole right above the trailing plug. The most sensitive area that give the most knock was actualy in the dowel area on the rotor housing.

 

Wait a minute! crispeed, arent you Cris from South Florida, next to Frank's SFP shop?!?! Man, i had no idea, we met there last year there remember. I was there last week to say hello to the guys, but you werent around, im in california right now.

What a nice surprise.

 

It's written up on an SAE paper by Mazda.


-Ted

 

J&S supplies a "stud" which is the same pitch as the stock Mazda knock sensor.
It can go either on the center iron or Kouki FC3S rotor housings.


-Ted