How do you wire the Hydra to control VVT?
 

I found a built motor - 94 block with an 03 VVT head. I have read that you only need to solder two wires to control VVT with the Hydra, but that's all I've heard.

Does anyone know specifically what to do to allow the Hydra to control VVT?

Basically you have to connect your hydra VTCS pin to one of the VVT solenoid wires. I have no clue what the solenoid wires are but I am guessing it's 3 wire:

power
ground
signal

Or signal/ground??


Jeremy has the Hydra pinout. If yours is the same as mine, the VVT signal output pin is A11 on the small blue connector. Your harness may already be set up and if it's not, then you'll need to order some pins from Jeremy.

Anyways connect them bitches then

Go to Output Configuration
click PWM 2
Make sure PWM MAP 9 radio button is selected
input x rpm spread %
input y load spread %

Then hit ok or whatever

Then go to Select/3D PWM/PWM Map 9

That should be your VVT map.

Also here is the 2.5 manual and it talks about it more:

http://flyinmiata.com/support/instru...ECU_Tuning.pdf

In short, your map is probably already set up, your harness is probably already set up so just wire that shit up. I don't have the factory wiring diagrams with me but they're on here mt.net somewhere.

^Thanks, I really appreciate the info.

power and PWM = 2 wires. the power wire goes straight to the harness +12.

Let me guess. It's the white wire with the red stripe?

Ok, is it this simple or am I missing something (Hydra 2.5)?

1. Wire the power from VVT solenoid --------> Hydra harness A11 on small blue connector

2. In Hydra, go to --> Select --> 3D pwm --> PWM Map9 / VCTi

err...

4D, Yellow, goes to +12V (you can splice into 4AF, yes white with red stripe)

4R, violet with yellow stripe, goes to whatever the VVT output pin is.

I was not familiar with the Mazda pins, sorry. I think I understand now. Thanks.

BTW be careful. Jeremy told me of a few instances where customers did not make their map smoothed and fucked up their shit. I don't really understand that but take heed.

^ Thanks for the heads up. I don't plan on tuning it, but rather letting a "tuner" do it on a dyno. But, I am concerned about the settings during break in.

Right now my settings in my current map under PWM MAP9 are all set to -12.5.

EDIT; I will just make sure the OFF radio button is checked under PWM2 during break in. Then I'll let the tuner turn it on and set the X, Y spread and go with it.

Love the search function on this forum. This is just what I was looking for. This made me a happy camper:)

I actually have the VVT retrofit stuff as a document, email me at work & I can send it to you. Same for TPS if you're coming from a 90-93 chassis, and 94 alternator retrofit if you're tired of your NB voltage control..

So this is a very old thread I realize but I do not have any A11 pins or A anything pins. I'm looking at the Wiring Pinouts for my Hydra 2.7. I have a 99 Miata which will now have an 01 VVT or VCT (hey we should add some more letters that mean the same thing just to further confuse folks, sorry, inside voice). I understand there is a +12v source (easy enough to find somewhere under the hood) and a ground to actuate the valve. I am "guessing" that the A11 pin called out above is on my chart the BB 11 - Trigger -ve pin? Or the ground in question??
https://cimg3.ibsrv.net/gimg/www.mia...2e66ec0b5a.jpg

Any guidance is appreciated.
Thanks,
Ken

You run power to the solenoid and the Hydra takes the other side to ground on BA11 . Go to FMs site ,and download the Hydra manual , its all there .Fredb

First, thanks for answering and chiming in. I'm a bit confused though because on the 99-00 wiring schematic provided by Jeremy, BA11 is for VICS. I did read through the manuals from the FM site and they state something like this...."You can retrofit a VVT head or engine to a non-VVT 1.8. It is a lot of work, but it may be worthwhile for your project. Contact FM for the VVT wiring & Hydra settings info you'll need."

BB10 says VCT1 on the 99-00 Hydra wiring schematic. That "seems" like the right pin but then again it "seems" like this question would be spelled out in the manual (VCT1 is the ground for the VVT solenoid).

That paper is gold! Thank you so MUCH!!!!!!!