Implementing Series 8 rats nest into USDM FD's
 

Ive heard alot of people say the conversion is easy but have yet to see anyone post a how-to about this. If someone who has done this please chime in and give some feedback it would be greatly appreciated to people who would like to do this. Im sure all of us would like to simplify our rats nest by switching over to the newer simplified version.

The connectors are the same, and color coded the same as well. You should just have to extend the wiring a bit to make it fit. The mounting for the "black box" is a bit different then the stock rats nest.

Here's a pic of the vacuum block on my series 8 engine.

http://i723.photobucket.com/albums/w...e/IMG_0966.jpg

Thanks, exactly the information I was looking for.

huh?the connectors are different!!you have to remove the connectors from a jdm harness to make it work!

Shit really? My mistake then. I will be at the garage later today and will compare the two harnesses. I'll take pictures if I can. :scratch:

are they the same style connectors that are on the precontrol/wastegate?

Yes I would like to know this as well.

Here's the deal.

When I first found out about the JDM "black box" (which, BTW, Mazda went to in the '96 model year in Japan) I was stoked. But, there's some MAJOR drawbacks to the black box.

First, the check valves are BUILT INTO the black box. They're the exact same crappy, failure-prone check valves that our cars have. With the early rat's nest, you can easily replace them with Viton check valves. With the black box, you need a WHOLE NEW BLACK BOX.

Second, the solenoids are all built into it. On the early cars, if you have a solenoid that goes bad (as they do) or you break a nipple off the solenoid, you replace that solenoid. With the black box, you need a WHOLE NEW BLACK BOX.

See a theme developing?

Also, most people like to simplify the rat's nest, removing all the emissions stuff. The black box is it, that's what you get.

There's just no good reason to try and make it work on a '93-95 car. When it does fail, good luck tracking another down.

If you really want to clean things up, remove the unneeded solenoids and vacuum lines and make it much tidier.

Dale

The solenoids are available individually and separate from the box - sometimes - just as unreliable though.

The plastic box itself is tidier, experience locally has shown it to suffer from heat effects, and develop leaks.....so with the steel spaghetti, at least you've only got to worry about a few dollars in hose rather than 400 or 500 in plastic when it dies.

You've still got the front harness loom plugs to worry about as well as the engine harness.....so not sure how this is going to be a painless swap.

Those colored connectors don't look the same at all.

Not that it's rocket science to get a cut JDM harness and replace the connectors, but I'm just sayin'...

Dave

It would also be tricky to figure out how the vacuum lines are supposed to hook up. The later engines also have different metal hard lines as well, and the coil pack is changed to fit with the revised hardlines.

I had a '96-98 JDM longblock at one point in my garage (stripped it for parts) so this is first hand knowledge.

Billyboy, I really don't see how any part of the black box could be swapped out. I had one, it's plastic welded together, there's no screws or anything to take it apart. It's one solid hunk.

Dale

Dale, the box can be separated. its easy to do. I'll look up for some pics.

The box top bottom are glued together, you can separate it but good luck on future vacuum leaks.

I have one of these on my bench; I was interested in studying it but came to the same conclusion as Dale. Nice, but not great and in the wrong direction for improving reliability.

The good thing with the black box solenoid valves is that the can hold 16+ psi forever.What i did with my car is the following:I replaced the engine harnesss solenoids connectors with the connectors from a 97' jdm harness,and installed the upgraded solenoids to the existing rat nest location(with some minor modifications).Regarding the black box,surely it can be dismantiled and reassembled with ease.

So I was working on a friends protage today and noticed the emissions solenoids or whatever they're used for have the same exact connectors as the vacuum block uses. I bet you could get all the connectors you'd need from a junk yard fairly easily.

Here's the Mazda parts breakdown of the box, one-way valves and solenoids are designed to swap out.....believe there's a few here using the aftermarket vitons even. Still a lot to be desired on longevity.

http://img229.imageshack.us/img229/7603/034oc9.th.gif

hose path

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/s7-s8-wireing-diagam-792369/

Those asking, the pre-control and wastegate solenoids are the same, so shouldn't be an issue there with connectors.
Edit: see the Q is whether the black box connectors are the same.....can't answer that one!

Even with the minor increase in factory boost and possible improvement in solenoid design, anecdotal evidence seems to have failure rate of solenoids as bad if not worse - might be skewed with the number of import S7/8s running around down here though.

Personally, I have a pet hate of solder hack jobs for minimal, if any gain.

Dale, apologies for the delay. I remember having seeing it somewhere online but no luck. Anyways, i picked this up a couple of months ago for parts.

http://i45.photobucket.com/albums/f7...00404-1806.jpg

There is no glue whatsoever holding them together. Simply remove the two metal "rings" marked on the next picture and gently pry them apart. I have done this about 5 times. You can break a nipple if you are not gentle.
http://i45.photobucket.com/albums/f7...00404-1814.jpg

Here are the complete innards of the box.
http://i45.photobucket.com/albums/f7...00404-1819.jpg

Good luck

Dev

As the previous post states it is not glued. rubber gassets hold the four "sides" , solenoids and check valves togerth, can be completely disassembled. I took mine aprta today and was going to post this correction before seeing it had been done.

You guys are brave...............

Every time i look at a FD vacuum system It makes me want to grab a hand full of hoses and rip them right out and yell nonsequential while I am doing it.

:lol:, +1, very brave! Every time I look under my manifold and see no rats nest, no solenoids, just a lot of empty space, I get the same joyous feeling I did when I first realized I didn't have to put any of it back in when I went single :tonque:.


Seems like it would be nice to tidy up the rats nest a bit, but I'm not sure how I would feel about replacing it with a hunk of plastic. Seems like it could cause just as many headaches as it fixes, but I don't really know anything about it either.

I am trying really hard to keep the twins going on the newly acquired 2001 RB because when they work its awesome. My other fd is "headache" free running single but power delivery wise, i'm liking the twins!! :P

Thanks for posting the take-apart pics! That's really good to know.

Now I wish I still had one in the garage to play around with :). I sold the one I got off a JDM motor a while back.

Dale

Definitely! :lol:

im also tryn to buy this s7 black box, can anyone gimme for info on this please. i have a 93 rx7 USA california. my rats nest is missing 2 Solenoids so im thinking bout upgrading it

Sounds like what I did on the weekend, except I was yelling simplify!!