fc3s690

I picked up a old hks evc1 for my car a few weeks back and have finally go around to putting it in. Problem is Im not sure how the hoses supposed to be hooked up.

Can some one please help me out here





i numbered the lines i need help identifying, from what I have found, I should have a line coming from the manifold, one coming from the turbo and one from the wastegate. my only problem is in what order.

arghx

iTrader: (3)

Perhaps this will help. I have the EVC IV instructions and it appears to have the same stepper (or at least similar) motor:



Now, turn your stepper motor around and it will match the diagram:



The small hose is a pressure signal to the controller (like a MAP sensor line). The big hose with the filter is the inlet to the stepper motor. It is a source of pressurized air that will be delivered out the middle port and to the top of the wastegate. Applying pressure to the top of the wastegate helps push the gate shut in order to increase boost beyond spring pressure.

So your small hose can be Tee'd off a manifold pressure source or have its own dedicated pressure source after the throttle plates. The big hose with the filter can be Tee'd off the pressure source to the side port of the gate like in the diagram. The middle hose goes to your top port of the gate.

fc3s690

That all makes perfect sense now, thanks.

Will having a turbo with a internal wastegate change anything? In my mind I wouldn't think so.

Also If my wastegate actuator is set at 8psi, will it hold the door shut on pressure around the 20psi area? the whole reason i've decided to switch to a electric is because my manual turbosmart boost controller wont hold boost over 15psi in 1st, 2nd, or 3rd. 4th and 5th gear it will hold to 18psi no problem.

So I'm praying an electric will solve this problem, make sense right? I want 20psi in all gears.

arghx

iTrader: (3)

Plumbing is different on an internal gate. Don't use that plumbing. I'll have to get the diagram for the internal gate.

But it sounds like you have insufficient preload in your wastegate arm OR just insufficient spring pressure. Does it have a nut to adjust the length of the arm? That sets the preload. Increasing preload can help it hold more boost put it excessive preload can restrict the movement of the arm. I don't remember if the HX35 has an adjustable arm but I want to say it doesn't.

Try disconnecting the pressure source from the wastegate completely and see how it drives in 1st through 3rd. If you can't hit 20psi then your gate is most likely blowing open from backpressure. In that case you need a stiffer actuator or more preload (if that's possible).

In 4th gear you may actually have your gate wide open but you are getting boost creep and the wastegate is getting overwhelmed. One of the problems with the HX35 is that the wastegate passageway only draws from one of the scrolls (assuming you have the typical twin scroll 12cm^2 hotside Dodge Ram HX35) so the exhaust can't easily bleed off. This is yet another reason why people don't tangle with internal gates on Rx-7 engines unless they are stock or modified stock turbos. Most people with HX35's weld the gate shut and go external.

fc3s690

I have an adjustable rod to set preload, how do i know what is correct preload tho? when i installed the turbo I set the rod to where the door was shut completely and then gave it a few more turns to keep pressure on it.

What will happen if the preload is to high?

arghx

iTrader: (3)

If the preload is set too high you can have spiking. You will just have to play with it.

fc3s690

any luck on finding the internal gate diagram?

arghx

iTrader: (3)

yeah you just put the middle port right to the actuator and set the switch on the back of the control unit to internal wastegate.



Here's something weird though. These diagrams are from the instructions for the EVC IV. It says in those instructions:



yet when I look at the pictures of your EVC I stepper motor it seems to be the same as the EVC IV diagrams...

fc3s690

So turns out this is not a evc1 but a evc ez. I hope theres no difference.

Not so sound stupid, but what does the SW and PO switch stand for? I dunno which one I need to have it set to.

arghx

iTrader: (3)

If I had to guess, SW = Swing valve (internal gate) and PO = Poppet valve (external gate)

If you have an HKS EZ then according to the instructions all these diagrams I've posted should work

fc3s690

Just thought I would bring everyone up to date on this install, turns out the wastegate actuator was a little loose. I tightened it up alittle more and now can pull 15psi in 1st, about 16psi in 2nd, then 3rd 4th and 5th an easy 20psi. I'll prolly try to tighten up the wg alittle more and see if I can squeeze 20psi out of 1st and 2nd. Wg spring is only a 5-8psi spring so that may be a limiting factor.

Thanks for the help again. Will post videos after it's all right. Car really comes to life at 18-20psi!

KD-93R1

HKS EVC-EZ is different than all other HKS controllers. As far as the vacum plumbing the biggest difference is in the stepper motor connections. They are configured different then the others. Also, if still running twins, which is where the EVC-EZ is most benificial, there are special vacum line plumbing instructions that were never printed in English. Not to worry, the pictures are not in Japanese of course, and thats all you need. More on this in a minute.

The switch on the back of the controller (SW<>PO)... If you have a single port, swing valve or internal type wastegate, select "SW". If you have a dual port, poppet or external type wastegate, select "PO".

The HKS supplemental instructions for Mazda RX7 FD used to be available here.
I'm not sure if this is still good or not. I can fax you a copy if you want. Heres where I got mine I think (its been a long time).

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/hks-evc-5-installation-836617/

I am changing to the AEM TRUBOOST boost controller (RX7 Store) because my HKS EVC-EZ doesnt seem to like my new setup which pulls 20psi in the low to mid 4000rpms w/no lag. Not to mention we have been unable to hold it down on the dyno with the EVC-EZ. I think its just that so much low end torque and such high boost levels make you nervous w/the dyno. I know it gets my nerves flared up.

Hope this helps. You need the supplemental instructions w/this controller if running twins, that I know for sure.