Richard L

iTrader: (5)

Very good question.

Most EMS ADC input are high impedance type so it does not load the sensor. Because of this, it is subseptable to noise ingression. Normally it fine if the pin is left unused.

If a longish cable is attached without terminating to another device, in this case - the DDS3. This little length of wire will become a ariel, noise and spike can be picked up quiet easily.

For this reason, I have discussed this with Jamie by adding a pull down resistor within the harness he supplied so that the ECU always sees a ground reference if the link is severed accidentally.

dudical26

iTrader: (17)

Thank you for posting that info richard. So even if I were to replace the 5.1v zener with a 4.7 and connect a 1 wire link, I still run the risk of having it disconnect and picking up noise and interferance which the ECU may pickup and think it is supposed to switch maps.

I guess all this discussion is a moot point anyway since I am runnig v8 and not v9, lol. But it will be helpfull for those who may want to make their own harness in the future.

Boricua_Evo

iTrader: (7)

I recently received the V9 DDS3. Yesterday I had gone to radio shack to buy the parts to make my Harness for the Tephra V5 patch.
Stupid question, but seeing that V9 has a 5.1V, would that mean I could purchase a 5.1V Zener Diode without being detrimental to the ECU compared to the 4.7V Zener Diode. I remember this was talked about but I wanted to make sure it was for certain that it could be dangerous if anything would occur.

dudical26

iTrader: (17)

Supposedly the ECU can handle 5.1v without any damage but 4.7 is on the safer side.

Boricua_Evo

iTrader: (7)

That's where I'm trying to lean towards, thanks Dudical.

Jack_of_Trades

iTrader: (17)

Don't forget, these zener diodes have a tolerance too. So if you buy a 5.1v zener diode with a 5% tolerance the voltage can be anywhere from 4.85volts to 5.36 volts. Just food for thought. The reason I use a 4.7v zener diode is because the average zener has a tolerance of 5% (which the ones I use do) so even at its highest voltage I will only be at 4.93 volts. You can get zener diodes with a 1% tolerance if you search well.

Boricua_Evo

iTrader: (7)

The one that I had in my hands (5.1v Zener Diode) had a 5% tolerance. I will continue to search... Thanks Jamie!

Richard L

iTrader: (5)

Looked like the future v9 will have a 4v7 zener...

dudical26

iTrader: (17)

Yea I think that will be a good thing to do in the future.

Boricua_Evo

iTrader: (7)

I bet that future Aquamist setup is going to be out of this world!

Jack_of_Trades

iTrader: (17)

I must say, no other alky kit company listens to their customers as well as Aquamist does. Its astonishing how much they take the Evo community into consideration. Richard, if you can find a 4.9v zener with a 1% tolerance, thats as close as I think you'd get without crossing that 5.0v mark. The price probably doubles or triples though for the 1% tolerance.

Richard L

iTrader: (5)

Jamie,

There are many ways to produce a precision 5V source but zener is most cost effective one.

A voltage reference diode is the next step up. To produce a 1% 5V source with 1% temperature drift is very very expensive.

You can trim a fixed zener clamp voltage by applying different load current. Heavily loaded zener can get very warm but stable.

I think we are focusing too much towards a accurate voltage source where the ADC input can tolerate anything signal between 0-50V even it is specified for a full scale range of 5V.

All ECU input has very tough clamps on spikes and over-voltages.

Without feedback, it is difficult to improve future products. The EVO community is great and not shy to speak out if something is not well explained in a direct and honest manner.

As an engineer, I welcome and enjpy how things works on this community. Most impressived with Jamie and Tephra patch.

Richard L

iTrader: (5)

Jamie,

When are you getting your own car back together again? I haven;t herad much progress from you lately.

Jack_of_Trades

iTrader: (17)

I have it back together now, getting it ready for the big DSM Shootout in August at Buschur Racings event in Ohio. Unfortunately, I had some serious bills rear their ugly head so my budget is..well...destroyed, so I won't have any 'toy' money until after the trip. I cant wait to finish my alky kit, I want the extra power so badly!!!!!! The harness' are helping me get back on my feet (so thanks guys,really).

I am going to be offering harness' for users without failsafes in their system but use the Zeitronix wideband with the alarm trigger output. Also a hybrid kit which uses the DDS3 and the zeitronix together for an AMAZING amount of safety!!!!!

Boricua_Evo

iTrader: (7)

Hey guys,

I installed my MAC Valve 36A-AAA-JDBA-1GD yesterday, this Valve is similar to the 36A-AAA-JDBA-1BA; instead it has a red and a black wire. It also has a transparent top with a built in L.E.D. to let you know it is on or off, which I'm sure the other ones have as well. Long story short for anyone out their, this MAC VALVE works as well and these were in stock when I bought it!
Anyway, I ran 2 wires from the glove box where my Junction box to the engine compartment. In this case my MAC Valve is taking place of the "OE BCS." The red is connected to the +12 BCV, then the black wire is connected to the MAP-SW1; MAP-SW2 is ground to Pin # 24 (0V-IN).
I turned on my Kit to check and Viola, Mac Valve led is on!




One thing I did realize is when my DDS3 Gauge is off Mac valve will only let me go up to 10 PSI at WOT... Now my car is not tuned, I'm not trying to be stupid I just was testing to make sure connections were good and nozzles were spraying. When I turned on my DDS3 "HSF-1" gauge, I gave it some gas and wow, it just passed 10PSI like nothing it reached about 19 and I just let go of the throttle... So now I need a tune for sure.

Question is it supposed to limit my boost with the MAC Valve off, I can't remember? I am working on installing the Jack of Trades cable as well... Any insight will help, thanks!