Helping a friend to ask ..　what is this ? JDM solenoid box
 

https://www.rx7club.com/attachment.p...1&d=1365381531

Hey guys ! ok, my friend said his FD is a 4th GEN, so instead of having 72 vacuum hose, it has this black box thing.

long story short, the box's boost contolling nipple, as you can seen from the pic, broke (he got it used), he overboosted and BOOM.

so now he is trying to find this box's part number, he couldn't find any. and it's hard to speak to Japanese people with English

so I wanna kindly ask if anybody know this black box's part number?

Thanks !

There is no 4th gen RX7 yet.

looks like a f**K bomb went off in there.

In Japan, the "3rd" gen we call it, breaks into 6 different generation.

1-3 is considered as "early" version, while 4-6 is considered as "later" model.

I've never seen the part number for it posted in this section. However, a few years ago, one of the Australian members posted a photo which was part of the 99+ parts fische which would have it. You should try making a most in the Australian section and see if someone can help you out.

finally someone who knows what he is talking about comes in

thanks, i will look into that

in the mean time, i am getting the japanese parts system, but it takes a while to download.

It's a solenoid box from version IV, V and VI JDM FD's, part number N3F1-20-4B0.

6 different version, not generation...

There are 3 generations and 8 series
1st and 2nd are 1-5
the 3rd gens are series 6,7 and 8
6=93-95
7=96-98
8=99-02

Wow, whole lotta confusion in this thread.

That "black box" as we typically call it was on the JDM RX-7's from '96-02. That replaced the old metal vacuum spider. While it seems neater, it's IMHO more of a pain - if one solenoid messes up or one nipple breaks, you replace the WHOLE THING instead of just the one solenoid. No thanks.

They shouldn't be too hard to find, you just have to get one from a '96+ JDM car.

The whole "series" and "version" thing is really getting confusing and doesn't need to be in this post, but here's some clarification on the topic.

The FD was sold in Japan from model year '92 to '02. There are 3 real "revisions" - '92-95, '96-98, and '99-02.

'96 changed to the black box, added the all aluminum Y-pipe, and the round taillights. '99 went to the whole "99 spec" with the new front end, new spoiler, etc. The ECU and wiring changed in '96 and again in '99.

In Japan-land, they use a weird "version" system to keep track of the changes. The '92-95 cars were I-III, then I THINK the '96-98 was IV and '99 was V. There were many small changes in '92-95 and I think that's why the broke it into 3 version numbers - the improved interior plastics, etc.

The Aussies came up with the Series nomenclature - Series 6 is the '92-95 FD, Series 7 is '96-98, and Series 8 '99-02. That just goes with the facelifts/refreshes Mazda did over the production run.

Dale

thx for clearing it up !

well, gen/ver/rev/series/etc its just a name, it's all fd, right ? :)

ok, gonna start looking for the box. thx ! :)

I'll pose one more idea nycgps. I'm guessing that a solenoid from a 93-95 FD would work just fine. This means that you'll have to identify the other vacuum lines that are associated with the broken one, move them to the stand alone solenoid and find a way to connect the electrical connection to the solenoid.

I'm making lots of assumptions in that statement, so search around. If the black boxes are expensive I'm sure that someone else has looked into what I'm suggesting and can provide some advice.

It's possible, but it would be a pain in the ass.

No English version I've ever seen of how that black box is plumbed in. You'd have to work out how all the vacuum lines are run, figure out what that particular nipple does, wire it in, plumb it in....yeah no.

The black box was designed to simplify things. You have fewer inputs, instead of having to branch all the inputs in and making a lot of vacuum lines, you have 1 vacuum, 1 pressure, etc. that goes into a manifold of sorts and into the right solenoid.

The black box really simplifies the rat's nest, but at the expense of flexibility. You can't easily do a simplified sequential, for example - it's all or nothing, you can't pick and choose what solenoids you want.

Going back to the rat's nest from the black box would be a bitch too as the wiring harness is quite different. The connectors are different, and the harness layout is different. That would be a huge pain.

I've had a '96-98 engine in my garage that I've broken down for parts, I've seen all that stuff in person. Mazda did a better job on it and probably eliminated a lot of failures, but not all.

Speaking of, I can't see how any vacuum line that came off could cause a blown engine. I don't know if that would be related.

Dale

Thx for all the input guys

most people overseas (I moved out of NYC a while ago) including people from Japan likes to do a swap to Kouki (later model), simply because it's later and it makes more power and it's less complicated.

but like DaleClark has pointed out, it turned everything into a "all or nothing "stage, so for me I prefer flexibility more so if I have to, I will keep most of the stuff from zenki (early models) and start from there. if I want more power or want the later model turbo I can always grab it off Yahoo Auction from Japan.

As for "Why the engine blew up", honestly I'm not 100% sure BUT what I do know is, the guy who build the engine (and install) has already told the owner that, he must change his fuel pump cuz it's on it's last leg. obviously he never did, instead he spent the fund on Ohlins, Wheels, etc. and although he had all kinds of gauges installed (BOOST, water temp, oil temp, etc) He NEVER look at them ... ok, to his credit he does look at the Water Temp gauge and one time he said it went UP TO 120 CELSIUS ! if what he said is true, I think his housing/iron already has warp/weaken

As for the rest of the gauges, he said he don't understand other ones, and he install them because they look COOL...

So I think his engine pop because he overheated before, after that it was the overboosting(I heard 1.5 bar when it was tuned for 1.0) + running lean (weak fuel pump) = BOOM ?

but weird part is, he has HKS EVC installed ... it SHOULD limit his boost no matter what ... ahh I don't know.

I've been doing some searching around the forum on old threads and things. Happened upon this thread.

For reference, I've butchered and chopped apart quite a few of these "mysterious" vacuum black boxes, because I wanted to understand whats in them, how they work, etc.

The ones I've seen (and I dont know if this is true for all the black boxes) are in fact completely serviceable- a few machine screws and the lid comes off the black box. Inside, are just the good old 1992-1994 solenoids, and they can be pulled out or replaced at will. The solenoids are just mounted inside the box with either small screws or they just use the molded clip on their body to slide onto a plastic rail inside the box.

It has been a few years but either:

A. the individual solenoid nipples poke out of holes in the black box for connection, or

B. the solenoids nipples connect via a short rubber hose to an internal nipple on the box wall, which then pokes out on the outside of the box.

I am 98% sure that it is the former A.- the actual solenoid nipples themselves just poke out of holes the box (and then get heat brittle and still snap off anyway, thanks Mazda....!)
In fact, if you look very hard at the OP's photo, you can see that his snapped off nipple is not part of the box casing- it is part of a solenoid in there that is poking its nipple through a hole in the box.

The box itself does not hold boost pressure or any sort of pressure or vacuum. It is simply Mazda's attempt at neatening things because they realized they were scaring mechanics and their own dealerships with the horrible looking rats nest, and servicing the cars was a real issue.

If anyone ever wants one for some reason, they are still available here in Australia. At a cost of around $700-$750.00 for the complete black box unit new, or second hand they are selling around 600 each. Pricey. You could easily afford one of the AzeKnightz custom solenoid racks and have plenty of change left over instead of buying the Mazda black box...

Personally, having spent time playing with them, I prefer the rats nest. At least you can get diagrams for the rats nest. The black box has scarce diagrams for it anywhere, and to replace a failed solenoid, you must pull the entire box out, open it, etc. It looks prettier, but just like my ex, it is harder to service and maintain.

(I found out how much they were worth only after I had been hacksawing and cutting up perfectly good black boxes just to see what was in them. I admit that was not the smartest thing to be doing at the time. I probably ruined $2100.00 of perfectly good black boxes I could have sold to Australians who want them, on Ebay. I have regrets...)

To me, it looks like everything is there. Either 'fix' the box, or go old school and set it up as the US FD is equipped.

you can buy them in nz easy enough, $50 on trademe lol.

13B Rx7 Series 7 Solenoid Block | Trade Me

I will sell you a black box.

^-- NO .. Never , absolutely Not . should never cross your mind . stay the hell away . They went to the box for a very good reason .

pic is from the JDM parts catalog, as you can see solenoids are available.

Based on everything I know and have read, there is some considerable debate about that. Regardless, the OP can do what he chooses. I suspect he has some options, however.

The box is not an improvement IMHO. It is a "pretty bandaid" for a system that could have been better designed (TOYOTA SUPRA) in the first place.

Say one solenoid fails.... You have to remove the entire box and everything just to get it open to replace the solenoid inside.

On a normal rats nest, you just remove the dead solenoid and replace it, no problems.

They only went to the box, to stop scaring the Mazda dealership mechanics. In reality, it did not help.

The Mazda mechanics here, do not open the box and replace the dead solenoid. They charged the customers the retail AUD $750.00 for a whole new black box each time something went wrong inside it.

Many Australian FDs use the black boxes. We are right hand drive and we have many Spirit R/Bathurst R/ RZ/ RB etc cars here. The owners are usually very pedantic and they dont like to remove or change or alter anything on those kinds of cars, because of the value of them. The black boxes are a high demand thing, and low supply to the owners who absolutely "must" have their 2001 RZ in perfect factory condition and drive it once a month, etc.

Since your in Australia, you have access to Trademe..you can get good used, tested working solenoids and black box;s for next to nothing on there as long as your not too fussy about them being brand new.

see above link, complete black box $48. Two of the solenoids are not working but still... $48nzd..get another couple of solenoids for $50 or whatever and your away laughing without a $750 price tag :icon_tup:

and mechanics see that mess of brittle vacume hoses and theytell you the motor is blown . hah ,

the Series 6 system .. is a mess yes I guess you can bandaid it with some magic hoses ,

But using a Series 6 rats nest does not work .. You would need a series 6 harness and other good stuff .. first engine I purchased was a series 7 motor , it had hte black box . and I had planned to use it because it just looks somuch simpler and neater , but I was informed that you need to do alot more hten just plug it in for it to work with a series 6 harness .

so using a series 6 rats nest with a series 7/8 motor is like I said a bad idea .

seems like someone should buy these problem boxes, replace the solenoids, and sell as rebuilt?