kcbhiw

iTrader: (1)

These are likely the ones Mike is talking about (gutted/throated '99 manifold):








Not the highest quality pictures, but they should suffice. The cast EGR tube that runs through the throat occupies a significant amount of space.

richyvrlimited

iTrader: (1)

you want me to pull the intake Mani? damnit!

Maybe tomorrow I'm done for the night now

emilio700

iTrader: (3)

I'll save you guys all the trouble: You want one.

In short, the rest-of-the-worldDM 1.8 manifold is better than the USDM in every way you can quantify. At least 9 small changes add up to a better design overall. I've been trying to set up a supply chain for a few months. Getting closer to that but for now, you're on your own trying to find one. You see, they don't break and dismantlers don't always want to sell long blocks without them. So finding orphans is proving quite difficult. Good luck.

Doppelgänger

iTrader: (12)

Which makes me wonder- With how long Mazda produced them, why has this not been discussed on here before?

Doppelgänger

iTrader: (12)

So I've talked with someone who may be able to get them. He got the part numbers and will be in touch with his connection in Japanland. Will keep this thread posted. Cost is a ???? right now, and these will be new from Japan...not used. I did check the price on a new 2001 manifold (2-piece) and it runs from $700-$800.

emilio700

iTrader: (3)

Mazda is out of stock all the way back to Hiroshima. Tried that. Had two on back order for 3-4 months and finally gave up. Best bet is finding used ones but even those are hard to find. I found mine on ebay UK.

Personally, I'm not making too much noise about it. Just raises the price.

Doppelgänger

iTrader: (12)

Thanks for the heads up, guess we'll see how it goes.

y8s

iTrader: (8)

here's a tip:

if it's within 20% of the cost of a custom built manifold, quit looking.

if it's under 200 dollars, keep looking.

JasonC SBB

Does this magic manifold have EGR?

Anyone know at what RPMs it gains and loses vs the VICS mani? Versus the VTCS mani?

y8s

iTrader: (8)

Jason, do you still have a 00 manifold that you want to let me borrow?

JasonC SBB

Er, I did but now it's time for it to go back onto the engine.

richyvrlimited

iTrader: (1)

Yes it does have EGR.

MiataRoadster

FYI, this is what one looks like off the car.
Note that it no longer has the air valve or the coolant passages between runners 1/2 and 3/4.

YAHOO JAPAN AUCTION

Doppelgänger

iTrader: (12)

Auction lists that as a NB6..not NB8

richyvrlimited

iTrader: (1)

That's not the same manifold. it's 1 piece for a start.

As Doppelgänger says it's for the 1.6 cars rather than the 1.8. it's considerably different.

disturbedfan121

iTrader: (5)

7,990.00 JPY

=

88.9218 USD

how much would shipping be is the question.....if it was 120 or less i'd get it to test it out

JasonC SBB

How does the "throat" look in this mystery manifold?

Doppelgänger

iTrader: (12)

Bringing back this thread to add positive information that someone was nice enough to provide...

http://www.mazdaspeedy.com/2010/03/2...-vtcs-msm.html

I took some measurements and pics of my MSM manifold today. It should be the same as 2001-05 VTCS manifolds on USDM cars.

I also measured ID and OD inlet and outlet of the MSM throttel body which is probably the same as all Miatas.



Some data for MSM manifold:


Plenum volume: ~ 1.1 l
TB inlet: 59 mm
Runner diameter: 42mm
Runner length: ~31-32 cm
Weight: 7.3 kg (With EGR valve, no TB )


JDM manifold: ( from my earlier post )


Weight: 6.4 kg
Throttle body opening diameter: 59mm
Runner diameter: 50 mm
Runner length: ~ 30 cm
Plenum volume: ~ 1.5 l
Calculated runner volume: ( 3.14 * sqr(2.5) * 30 ) / 1000 = ~ 0.59 l each


MSM TB:
OD inlet 66mm
ID inlet 62 mm
Throttle plate / ID outlet 55 mm
For dummies: The Miata TB is 55mm. NOT 62mm.




Lets look at some differences between the MSM and JDM manifold. JDM on the left:



I need to tap for vacum for the MAP on the JDM as it has at least 1 port less.





Looks pretty similar from the other side.
Plenum looks shorter on the JDM manifold but if you compare with the runners they are pretty much the same width.




Underside looks the same. Hopefully the manifold brace from the MSM will fit.



No obvious changes from this angle. EGR fitted to the MSM manifold and you can see the holes from the removed VTCS shaft.



TB inlet has a more straight path and less restrictive bulges and holes on the JDM manifold:



On closeups the difference is very noticable:



JDM manifold has 50 mm runner diameter vs. 42 on the MSM.
Also the MSM manifold has a strange second chamber between the runners and Helmholtz chamber. That could mean the Helmholtz chamber on the JDM manifold is bigger.





The runner outlets on the JDM is connected to the Helmholtz chamber via small 1-2 mm ports in runner 1-3. MSM does not have these:



The runners protrude about 1 cm more into the top part of the plenum on the MSM.
EGR outlet is also bigger.





I'm finishing off with some pics of the throttle body:










So... Which is best ?
You really don't know without a dyno or a flow bench as fluid dynamics stuff is a very complex subject ( I have been told...)
However it is hard to not notice the straighter flow path and more open design on the JDM manifold. The plenum and runners are larger wich could be a good thing for overboosting.
I would also think there would be better gains of fitting a larger TB as the air doesn't have to smash into a couple of 45 deg walls before entering the chamber. No restrictive VTCS butterflys or holes to weld if they are removed.


In my head the JDM manifold is better.

JayL

iTrader: (12)

Somebody find a source for these.

cueball1

iTrader: (13)

Just to throw out the "miata manifolds for dummies" question. That jdm intake would only fit NB heads?