My 89 HKS Supra build

Backlash2032

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Sep 20, 2010
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With megs compound it really doesn't take a lot of paint off. I got the buffer off Amazon, 89.99 with everything you see. And 2 microfibers you don't see. All you need is a drill and you have a DA buffer!
 

Silver MK3

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Jan 24, 2011
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Backlash2032;2043865 said:
With megs compound it really doesn't take a lot of paint off. I got the buffer off Amazon, 89.99 with everything you see. And 2 microfibers you don't see. All you need is a drill and you have a DA buffer!

Nice, let me know how it works for you!
 

Backlash2032

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Ill probably make a quick little video explaining how to buff and such. And showing the benefits of buffing 26 year old paint lol
 

Backlash2032

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Bought some red line MT90 for the transmission. Speedway Motors FTW. Same price as Amazon, no shipping :)

And I'm getting ready for the first drive of the year.. it's supposed to get really nasty tomorrow night (hail, thunderstorms blah blah blah) and my dad needs his garage back for his new truck and his girlfriend's new jeep.. so it's gonna be a night of Tetris.. too many nice cars, not enough garage space. 2004 dodge ram Cummins, 2010 Jeep Liberty, 1989 Toyota supra, 1995 Mazda miata (my girlfriends), and 3 parking spots lol
 

Backlash2032

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All the cars are nice and tucked away for the storms. School tomorrow... But.. Issues! Well, issue. I think I've figured it out in my head, but only time will tell. Basically, my EVC isn't controlling boost. At all. On the plus side, my hand rebuilt turbo hit 15 psi without blowing up...

But, I think the cause of this is the fact that I hooked the MAP sensor for the EVC up to the power steering idle up vac source.. which sounded like a good idea (hell, it was right there!) But I have a feeling that only has manifold pressure with the throttle plate closed.. or it has a check valve in the throttle body or something! Causing it to not reference the MAP sensor with positive boost pressures... So what I'm thinking is if I T into the BOV signal line, I should be in okay shape. Should...
 

Backlash2032

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I forgot to update this thread. No check valve or any reason for the EVC to act like it does. More details in my thread in the mk3 general discussion sub forum.
 

Backlash2032

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( copied and pasted from my other thread)

Well, I think I've muddled through the issue in my head. I haven't been able to check anything out, as I'm not at my car right now, but! first gen EVCs do not have external switches for internal or external wastegates. They are sold as either or from HKS back in the day. However, they do have the switches inside the control unit to change it from internal to external or vice versa.

So, on a external gated setup, the diaphragm side of the wastegate is fed with constant pressure from the charge pipes. Then, your boost controller feeds the spring side of the wastegate with pressure. So the boost from the boost controller actually helps "increase" spring pressure. So spring pressure with a boost controller would be the boost controller sealed shut.

On an internally gated setup, boost from the charge pipes is feeding the diaphragm side of the wastegate. Very simple... Spring pressure with a boost controller would be the boost controller wide open.

So in my (hopefully) case, with the EVC set to an external gate setup, when I first noticed that the boost was over 10 psi, I switched it over to manual, and turned the volume knob all the way down, which would basically result in stock boost... Since the EVC is setup for external gates, then it would seal the valve shut. Which would be correct in an externally gated setup. This resulted in my completely uncontrolled boost. Then, I switched the control units power off, which also results in stock boost. Again, since it is set up for external gates, it sealed the valve shut, resulting in complete loss of boost control.

Also, the reason it didn't control boost on the low setting, is because the way it controls boost for internal or external gates is completely different. For one psi over spring pressure in a external gate, the boost controller has to feed the spring side with 1 psi of boost (it's probably a hair bit over that since the spring would take up some surface area on the diaphragm.). In order to raise the boost pressure one psi the boost controller needs to feed the diaphragm side with spring pressure once the manifold reaches spring pressure, plus one psi.

So yes, EVENTUALLY the pressures would equal out.. Maybe if I switched it over to the high side, then it would hold 15 psi or something like that... But I think I'll just move the dipswitches around... :)
 

Backlash2032

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Take this HKS guy! Worthless customer support!

09fc691c3c2a933af59dd79d39a65498.jpg


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Yep, setup for external

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All good for internals! Can't wait to put it back on!
 

Backlash2032

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Starting to get really discouraged. My EVC still isn't working the way I would imagine it should. Hooked it up, turned the power off (defaults to stock boost, which means the EVC valve should be OPEN), still can't blow through the middle port. Which means the valve is still closed. Ugh.

Also, while I thought I fixed my power steering leak by replacing the feed line from the reservoir.. But apparently I just made it worse. Dumps all the PS fluid in less than 10 miles. Ugh.

Does anybody have any ideas on what could be causing my EVC issues? Getting really tired of this.. Just want to drive my car!
 

Rollus

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Jun 2, 2011
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I get that the valve is normally closed, which would be fine for a internal WG, as there is no leak and this allow stock spring pressure.

I guess this is a normal behavior of the valve?

I don't really know dual ports external wategate. How should it be hooked without BC?
 

7MGTEsup

Formerly 'Down but not out'
Jun 14, 2005
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Sounds like the ports are back to front so all your boost pressure is going to the spring side of the wastegate. Or least thats what happened to me with my controller when I had my car in bits and made that slip up on putting it back together. I use a gizzmo boost controller so yours may operate in a completely different way as my solanoid has 3 ports.
 

Backlash2032

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http://www.hks-power.co.jp/usa/faq/dd/pdf1740.pdf

http://www.hks-power.co.jp/usa/faq/dd/pdf1739.pdf

Those are the manuals for the internal vs. external gates.

Untitled.jpg

And heres the layout of the ports for the internal gates

Untitled2.jpg

And here's the layout of the ports for external gates.

#1 is a MAP sensor port, the EVC controller uses it to monitor manifold pressure...
#2 is the pressure input line. Underneath this port is the stepper motor and the pintle valve. The more the pintle valve opens, the more boost gets through to port #3
#3 is the output of the valve, going to the wastegate.

So if the pintle valve stays closed, no boost gets through to the wastegate, and therefore, no boost control happens...