Oh snap. Thanks for that!
Another interesting comparison would be the NB1 intake with the vvt head vs the MSM (since it has the NB1 intake....and the bp5A cam). The latter wouldn't be optimized elsewhere, but there were some pretty solid gains with just the bp5a cam iirc. I gues it would just fall on its face because you couldn't hold the torque up towards the end.
I think you're good people!!!

And for the record, I didn't say that intake mani's didn't matter. I said that if the only difference in a pre/post test was the head, then one should expect gains in similar places as a 'better' manifold, but with the entire curve shifted down. I wasn't implying that all the intake manifolds are the same. That's crazy talk!

And bytevenom is right. I'm not against spending money... I probably just overthink it all a bit too much when it comes to planning things out. I'm planning out my current build plans.There's a decent chance that I'm going to buy an NB2 motor that spun a bearing to rebuild it over the fall-spring as I put the parts, money, and time together. Or pull my motor over the winter since the car will be down for 3-4 months and use that time to put some work into the block and/or head.

And to add to what he said, I bought a 2.5 exhaust when everyone said that I should get a 3 incher. I don't entirely regret it because it was much cheaper at the time. There's a good chance that's going to get a do-over in the future. At that point of time I'll cross my fingers and hope I can make most of my money back on it. And Vlad will tell me that I should have listened and he will be right.

All that said, I started this thread for the actual reason I stated. I wanted to compile data/logs/dynos of folks with boosted cars that had swapped to a VVT head and see where the gains were. Maybe it'll just be a natural extension of the NA cars. Maybe something different will happen.

Or maybe this thread will just die a slow painful death.

I dunno what the end result will be, but I'm just tryna stay out of the penalty box!

 

I think the info already discovered/tested/posted is gonna be as close as you'll get to the actual A/B testing that you're looking for. It's just never going to line up perfectly, because someone upgrading their 4w to a 6d usually keeps the vics im, which completely changes the results, or they change something else, which also changes the results, so you end up with fragmented info as you've called it, but that doesn't mean it's inconclusive, or that you can't make some very logical assumptions from it.

as for the penalty box, we all know what happened, no reason to re-hash, let's just move on. I promise you that if you actually take the time to dig up semi-relevant threads, or info, and show us that you're putting in the time/effort, you won't get in trouble. And you already know this too

There's at least 2 more plots I'll dig up later that are closely related to this topic. I'm sure you can find more if you try

 

MSM has vtcs. Not vics.

 

I'll add more to this when I can!
And you're absolutely right about being able to make logical conclusions from that info.

I had actually reached out to Jason to see if he had some pre/post dyno data, but it's been so long that he had no idea where it would be even if he had it.

And agreed re-rehashing.

 

I think you typed that backwards. MSM doesn't have VTCS.

 

Yes it does, unless you are willing to prove it otherwise. VTCS is "variable tumble control system" which is part of the design of the intake manifold. The MSM uses the same manifold as the rest of the NB2s. What it DOESN'T share with the rest of the NB2s is that it uses the same (or similar) head as a 99-00 NB1. It HAS VCTS, but DOES NOT have VVT.

https://www.miataturbo.net/engine-pe...-family-84216/

 

msm vtcs
99-00 vics
01-04 vtcs

the "good" manifolds only came on the 99-00

 

MSM top end is BP5A head with VTCS manifold. Illuminati confirmed.

 

I often laugh at how badly mazda actually tried to mess up the MSM
I mean they pretty much screwed up 80% of that car........and on purpose too

 

Then the MSM would have the BP4W + VCTS head?
https://en.wikipedia.org/wiki/Mazda_MX-5Mazdaspeed MX-5 (2004–2005)[[url=https://en.wikipedia.org/w/index.php?title=Mazda_MX-5&action=edit&section=11]edit]


"2005 Lava Orange Mazdaspeed Miata next to a 2004 Velocity Red Mazdaspeed MiataThe 2004 model year saw the introduction of the official turbocharged Mazdaspeed MX-5, Roadster Turbo in Japan. It featured an IHI RHF5 VJ35 turbocharger equipped variant of the BP-4W engine that produced 178 bhp (133 kW) at 6500 rpm with a front-mounted air-to-air intercooler"

 

So the MSM would benefit with a VICS intake swap. Good to know!

 

That is correct. It's also the only "BP4W" produced post-2001 when VTCS made it onto all 1.8 Miatas.

What it really is is an USDM NB1 motor with a JDM y0 cam, and an NB2 intake manifold.

 

A jdm who now cam?

 

Yep this is true.
BP4W and BP6D both flow @ 215 cfm in stock form at .500
Both flowed @ 240 cfm at .500 with +1 supertech
Advantage: VVT
I don't have any testing on the way I gut a VICS vs a stock square top.
Chiburbian's set up is BP6D +1 with my gutted VICS. This gives you a little over 2ltr of plenum with 11" runners until VICS opens and boost uses the plenum to its advantage.
I have also started research on mounting a 1G manifold.
cheers - JB

 

What wasnt to love? Baby turbo, baby intercooler, boat anchor wheels, a numerically high rear end mixed with a 6 speed, the non vvt head with the shitty intake manifold. Did i miss anything?

I drove one new and thought it wasnt much faster than my NA. I was right. The suspension is good to put on a na though.

 

you missed the creme-de-la-creme of failure: the worst ecu/tune known to mankind intentionally pulling all the timing and all the boost from where the turbo is most happy, and unleashing ALLOFIT in the exact range where neither the engine, nor the turbo actually like to make power............oh and just as it starts to unleash the power at 5500rpm, it adds the cherry on top: the 6500rpm fuel cut

Oh and the "bog" between shifts

 

That car gains TWO SECONDS in the quarter and a solid 5-8mph trap speed from bolt ons and ecu.

Tuning both my MSM's was like tuning a subaru: 50-70hp from bolt ons and tune. You don't usually see that in a............miata

 

Yeah, that's actually mind boggling re bolt ons and tune gaining 2 seconds. It's like a completely different class of car!

Didn't know that they stuck the shitty intake in the car... That like doesn't even make sense...

 

MSM was a parts bin car. Left over BP4W heads, VTCS manifolds. BP5A cams. They hadn't made a torsen in a while. They used the s2k torsen that they were making for honda.

 

With the reservation that Mazda put different parts in the heads for different markets...
My builder constantly hunt for valves out of the 01-05 heads for spec builds in earlier heads (be it BP05 or BP4W), significant (enough to hunt for heads to rob) difference in the flow profile apparently. And the casting quality was higher in my BP6D than others BP4W he has been messing with.
Unsure what valves you get if you buy replacements from Mazda now (Don't know if I would see the difference without guidance).