Actually, my take is that an aftermarket manifold with a decent price point was basically matching (within noise) the best manifold Mazda ever put out for a BP. That makes it a viable option for replacing a VICS or VTCS. And the real testing has only just begun.

Question, SAE correction was the same on the printout even though the S2 was tested in about 5F hotter conditions. Was that just round-off on the printout?

 

Pressure and humidity also used to determine correction factor. Dyno software does all that.

 

Sub'd.

 

Thanks for doing the research and posting! Pretty strong motor even with the square top for CA91, but any chance you have a stock square top upper plenum and throttle body? I'm being needy, I know.

 

Exactly my thought. It's lighter, simpler, and around the same price with the ability to tune plenum volume. To me that sounds like a win.

 

thanks emilio for sharing the data!

i wonder what the difference between the good old stock BP05 mani and the skunk2 is? especially with a boosted engine.
we know the square top is a good pick, but it doesnt fit the old motor, where the skunk2 fits all heads. someone may estimate if its worth it?

cool thing is, you can upgrade your head and still use the skunk2 with its dual hole pattern, never have to worry about fitment again...

 

The BP05 manifold works well with boost and can be adapted to fit NB heads with an adaptor, in Australia they cost around 250USD for a nice billet adaptor kit.

I have used a BP05 manifold on an NA8 with BP4W head and it works well.

Dann

 

thank you, i didnt know that!

 

I'm sorry for going off topic but was humidity actually 8% at the time of testing? Might the weather station be malfunctioning and could this skew future results? Since this is being done for science and all.

Eager to see the what the additional plenum space will do but also was wondering if you plan to correct the runner casting you mentioned you didn't like in the first post? I mention this because this manifold seems like a legitimate option to a square top at the price point especially if one already has the TB. But if fixing some casting imperfections makes it better, it would make it a no-brainer for folks who like to grind aluminum.

And echoing Curly's comment: the numbers are great for a ca91 nb2 with just valve springs.

 

Curious to see results on boosted engine but this is the exact comparison I wanted since I have a squartetop that needs to be ported to match my S2 TB. I redline at 7500 but usually shift by 7, but also making 2x+ this power so gonna wait for more results. Perhaps not worth spending more money for what right now looks to be more noise

 

The weather station is accurate. Conditions change throughout the day. Don't over think it.

 

This is great thanks Emilio! Because I am needy as well would be fascinated,like others on here, to see the Skunk2 on a boosted application with a stock bottom end. I think with your N/A plots and with boosted stock bottom end would put the questions of power gains mostly to rest as that is most of the miata community. That is obviously to me a very controversial statement as there are so many other variables dependent on whether the s2 is better than a vics or eudm squaretop, but like you said not a lot of people shift or drive their car past 7k rpm. I know I dont.

Any takers to perform the test? I'll donate $10 to dyno costs.

 

Bottom end configuration is irrelevant. Search earlier in this thread for a list of the configurations we plan on testing. Additionally, we are not seeking donations but thanks for your consideration

 

So what your telling me is if you already have a NA car with a square top and S2 throttle body, its not worth buying the S2 manifold. If you don't have a square top, then the S2 is a good alternative.

 

Not sure if that question was directed to me or not but we are not telling anyone what to think. Just publishing our test results so that you may draw your own conclusions.

 

Tell him what to think. Because you can. Abuse your power. MUWAHAHAHAH

 

Haha!

 

I think it is pretty clear that the S2 intakes will really only excel on developed engines that flow lots of air. The same will apply with boost... with the stock valves, intake and exhaust ports being the limiting point rather than the intake. Once you have ported the head, installed bigger valves and higher lift cams so that the restriction is removed, only then will you see big gains further down the rpm range. Plus the rpm can be lifted to access the higher power range. Add the movement of the harmonics due to runner length and plenum sizing there can be massive gains on a highly developed engine. I know my Honda S2 isn't the same but I picked up around 40whp at one point on my dyno over a stock NA8 manifold. For a N/A engine that is epic...

I really don't see these helping unless the bottlenecks through the head and exhaust are removed. A stock engine simply can't move enough air until past 7000 rpm that the intake manifold becomes a restriction. Sure you get a shuffling of harmonics but these will only be minor impacts on the dyno. I can't wait to see this on a fully developed Whammy...

 

All that before we have tested the spacers.

Clearly one entirely inconclusive data point proves every theory.

It is fun to guess, but don't post it as fact guys. I'm trying to keep this thread clean

 

Spoken like a true Floridian, Hector!

OTOH, you'll retain your baby-smooth skin long after Emilio changes his name to "Leatherface."