With the stock crank pulley (130mm IIRC) you can run a 75mm pulley producing 12psi peak at 7200RPM. At this point you are also redlining the C30-74 but not over spinning.

On my set up, I'm running a 85mm pulley and seeing 9.5psi at 7100RPM and the blower is well under it's redline.

that sounds good. I think I saw somewhere that if I were to run a 94 it would actually have less power in the bottom of the power band than the 74 (I need to try find this graph again so i can confirm what i saw). If I were to get a 94 and then bleed the excessive boost off would it essentially build all the boost then power "taper" off when it reaches full boost till redline?

The 94 should be moving more air at all speeds, period, so you should have more lower end and a faster rise to peak boost compared to a 74. I'm not sure what dyno plot you're thinking of that shows differently.

Essentially, what you describe, yes. There are a couple of ways to bleed the boost - put a wastegate onto the intake manifold, or put a blowoff valve into your piping somewhere.

Hopefully I should be able to keep to the 74 then so the powerband stays linear. I read on TDR's website they estimate their supercharger kit for the NB2 (VVT) should make 200HP on 10psi,(i'm assuming this is on a fairly stock setup) I plan on doing cams (and probably valve springs because I want fairly big cams), full exhaust, Haltech/Adaptronic and E85 before I put the supercharger on so i should be able to make ~230HP which is plenty for an mx5 I plan to drive the hell out of

Why not save the money on the cams and just put the bigger blower on it? Stock cams are reasonably aggressive already, they won't be holding you back. Just add moar boost.

Just to toss this out there on the original subject.....

The real issue is that you have serious shit to handle on these drivelines before 300WHP, which is sort of sad compared to most other platforms.

So most people basically want the most power before hitting diminishing returns on their $$. And like most platforms, that means the most power on stock bottom end and transmission. Which is low 200s ish WHP on these. Or at least that the conventional wisdom. Frankly I think that's pessimistic, but since I'm not exactly pushing the envelope over here I cant talk trash about it.

So if you are going for low 200s WHP, what's the most economical way to get there?

DIY-esque Turbo. This is not really debatable.

And while throttle response is cool no doubt, consider the absolute shit TQ curves of many cars that are hailed as 'drivers cars' of whatthefuckever the hard parker magazine term is now. The Toyobarus are great fun, I have driven one many times. Its just plain entertaining. It also has a TQ band that looks like a drunk with a twitch drew it on the dyno chart. Doesn't seem to ruin the experience for people. I like driving it.

So, as you sit there with your ~4K car and you want more power, how inclined are you to spend 5K on supercharger stuff to hit high 100s WHP with most off the shelf solutions when you could spend the same or possibly/likely much less for low 200s WHP, in a car that will be even more incredibly fun to drive than it is now?

Now if you can get a reliable supercharger setup that has no custom guess work, makes low 200s WHP easily, and does not cost 5K, you have a real competitor. That's not so easy. The JR/949 looks promising. CP's used setup is maddeningly tempting, but that's not a deal you see all that often.. Superchargers are generally a road less traveled with a lot of pot holes in it.

Superchargers can be cool, turbo's can be cool. We always bust each other's chops with smack talk towards the junky supercharer setups, and the guys with cool supercharger setups return the favor in every thread they can by talking smack towards the turbo guys. It goes round and round.
Sometimes it's fun, sometimes it's drama, sometimes it's......

Eh. I think the arguments are fairly solid.

Turbo:
* More torque
* Have to wait for spool (Anyone who says they have a no-spool setup gets punched in the junk)
* Cheaper, due to massive proliferation of used kits

Supercharger:
* Less torque
* Get it right now, linear throttle response, just behaves like a bigger motor instead of a turbo motor
* More expensive setups

Anything past that is opinion and dickwaving. Not that there's not a place for that.

Personally, for a daily driver, and for an autocross car, supercharger is absolutely where I'll go, because the drivability and linear throttle response is paramount. For a track/road race car, I'd likely go turbo because it's just easier to get more power out of it, there's less moving parts to break/deal with, and I can set up my gearing to never be out of the turbo's powerband.

You just can't do that on the street/autocross course. Bundy's car is about as close as you can get, with a small turbo, but when you have a 25mph pin turn, that still puts his motor at 2800 rpms in second, which is way out of the powerband. If you downshift to first then you'll light up your tires madly with the ridiculous torque at the wheels and then shift back into second after getting the car pointed the right way again. If he can get spooled coming out of a corner though, he'll have more torque than I would. So, there's lots of places he'll be faster than I will with an SC as well.

The nuance to these discussions are important. You can't just say "turbos are better" or "scs are better". If you want to wave your dyno penis around and only have 2k$ to do it with, go with a turbo. You'll do fine. If you have more nuanced needs, then there's a discussion to be had. Again, on the street, I'll take an SC any day, because you're always in your powerband, and I don't really like the vario-torque of a turbo as much. But you'll never get the silly kick-in-the-nuts as your big turbo spools either, which some people really like. It's really an opinion game for the vast majority of cases.

Anti-lag?

Miataturbo.net circle of life says N/A is best.

At 2800 rpms, there's just not the mass air flow required to spool the turbo. Antilag can't make your engine push more air than it's capable of, it can just make your turbo spool as if you were floored even when you're not. You'll be floored at that 2800 rpms, but nothing real will happen until the motor gets up to 3500-4000. Antilag is much better for things like rally, where the motor is at 5k RPMs and you just want to keep the turbo spooled even when you're off throttle.

I sold my '15 BRZ after 5 weeks because of how un-entertaining the torque curve is. Unless you happen to have curvy roads nearby or on your daily commute, the torque hole in those cars makes them very not fun on the street.

Another option is to run a C15-60. Several guys on m.net did that and they all got right at 200 whp and 150 wtq. Run E85 and I bet that would pick up another 10-15 whp and be super safe and reliable on a stock engine.

Forget this supercharger vs turbo nonsense, kmiata is the new hotness!

Thats definately not true.

You can build unusable amounts of boost with enough fuel, air and ignition retard at 2800rpm.

FTFY

Dann

While I'm intrigued by your response, I'm skeptical. You only use, at absolute best case, about 1/3 of the heat energy of your motor accelerating your pistons. So, the best you can do is recover 80% of that 1/3, which isn't a lot of delta.

if that third gets me down the 1/4 in 11 seconds I reckon it will have no trouble getting the turbine to spin (yes im being facetious I know).

Dann

You clearly have no idea what you are talking about

Aggressive flat shift actually holds my boost at like 170kpa. Too crazy for me, so I dial it to holding like 130 while shifting. I assume antilag can do similar.

My cheap ass chicom turbo will make too much boost at 3100, full spool on wastegate alone is 3800. There is inertia which would be better with a BB or not china turbo, but there is way more than enough airflow to spool down that low.

2800 RPM = 25mph or so on 4.10s