Ah, so it just comes back to the Mazda B series being a crap engine to rev high.

I do? :party:

I can't find it. Thought there was some quote about having to tighten it up regularly, if I was wrong I'm sorry. :ohnoes:

The studs occasionally break and I may have found a nut or two loose once, but it's not something I need to hit regularly with a wrench.

I'll add that to my nut and bolt list, which also includes the plenum bolts. If I notice a loose bolt while in the shop it gets blue loctite, but I don't normally have time for that at a race.

So, it sounds like there is a lot of vibrations/harmonics stemming from the intake manifold?

Is the brace something worthwhile running for those of us that leave it off... all other things unchanged?

No, it stems from the things moving in the block ;)

ITB or Squaretop, it vibrates the same, the brace would most probably alter the harmonic frequency for the manifold.

Next season it's time to change the bushings to 70's, it will make installation of the mounts smoother as well. My whole dash have started to vibrate at idle now. :(

Brace, no brace, doesn't matter. TB's still break if you spend a lot of time at or above 7000. Read the linked Miata.net thread.

Clif notes:

BP's shake a lot
OEM Miata TB is a weak design and fails, a lot

Sorry, i was speaking of vibration in general.

I just didnt know if when you balanced the miata engine if it made it feel like vibratey like some other nice 4 cylinders on the market.
No harm, no foul

Engine prep continuing. I decided to stick with the BP4W head for the 200whp project. Mostly because the biggest cams I have here are for the BP4W. I have found that when you get the seat duration much past about 260°, the low end torque the stock BP6D can generate disappears. Folks probably don't want to hear this but if it is maximum low end torque you are after in a BP6D, stick with the stock cams. A built high compression 2.0L, fully coated chamber and exhaust ports with the right intake will make 160lbs/ft below 5000rpm.

Our 95R street/HPDE project car will get the 200whp monster for a little while just so we can tune and dyno it. That motor will the go into the Speedster project. The 95R will then get a CNC'd BP6D head with the short duration Tomei cams. That should yield a more street friendly power band and good low end torque but will probably top out at 160whp on pump gas.

Dropped off the maxim... let the testing begin.

So just so you guys are aware... the JDM exhausts have their flanges angled slightly off from US spec. Pictures here will show that.


So we figured we won't be able to run these tests with a proper cat and they're going to use a straight pipe since I have a leftover pipe from the HKS Super Drager I picked up in Japanistan.


Here you can see the comparison of an NA8 header and the NA8 Maxim. Emilio took interest in the abrupt welds of the collector and was curious since it wasn't as smooth as many would want them to be.

And here you can see the very clear difference in the angle of the flanges. So it's just a warning for any of you guys buying JDM headers. I am not aware of the angle for EDM designs/exhaust (although I'd be inclined to believe it's JDM as well).
https://www.miataturbo.net/attachmen...ine=1381503047
https://www.miataturbo.net/attachmen...ine=1381503047

I donno the amazing murahahaha header I worked with bolted perfectly to the exhaust that was in the car that was made for a RB header. Though it was a shorty racecar exhaust without a cat.

that header looks like it's been hacked up and that flange doesn't look like anything factory...

They look like they will be the same angle.


The stock exhaust manifold in that picture doesnt have the head flanges sitting flat on the table while the other header does sit flat.

That is my old NA8 header that I took to a shop (still in the car...) to have a bung for my wideband welded in. It still has the oem flange and bolted up to the factory cat fine.

The other welds are from when I rewelded all the seams and ground out the internal welds because I was too cheap to buy a header at the time. Made 240 hp with that header lol.

Racing Beat vs Maxim Works header
 

Back to back within about 40 minutes, same dyno, car, etc. No gains with the Maxim Works. The RB actually made about 4 more hp between 3800-4600.

This matches other testing we have done with expensive, high end headers. Hard to best the Racing Beat. They make power, last forever and are very affordable. The only header I think might have significant gains is the Maruha VP. We're procuring one now. They're made to order so it'll be a while before we can post test results

Andrew, send that Stahl down here.

https://www.miataturbo.net/attachmen...ine=1381541185

Stock nb2 intake manifold? predictions on what the outcome would be with alternate manifolds ie: vics or squaretop?

Emilio, do you have any comparison plots of the RB vs a Jackson Racing header?

C

No plot of my super awesome modified stock header masterpiece? :party: