Since the question was asked, ITBs or Forced Induction?

I'll start:

Mine! TWM Induction DCOE throttle bodies, Chrysler T1 injectors, eBay regulator, Earl's plumbing stuff and a ton more polishing to go before I'm satisfied.

MegaSquirt & EDIS to control it :)

I've got both, on variants of the same engine. 1990 Miata 1.6 with a Voodoo II turbo, a Locost with a 1.6 Miata engine with high compression and TWM throttle bodies, and a 1994 Miata with a bored and stroked 2.0 high compression engine and OER throttle bodies. I also get to drive turbo 1.8 and 2.0 Miata engines on a regular basis.

Interestingly, the turbo 1.6 and the 2.0 make very similar power (at sea level) but the naturally aspirated engine makes more torque. The big n/a motor is a lot of fun to drive, a great engine that's much faster than everyone expects from the dyno charts. But it also cost somewhere around 4 times as much as the Voodoo II system. By the time you count the header on that car and the cams, maybe 5 times.

No polishing on the outside, only the inside

I also have a Miata 1.6 with high compression and throttle bodies. Fantastic engine. So much character, it's like a musical instrument instead of a piece of machinery. The feel of that engine as it stampedes to redline is like nothing else. Howls, crackles, pops and the throttle response of a sportbike. And the street behavior of a crotchety race engine. Less power than the turbo and less torque though. Not as expensive as the 2.0, but still definitely more than the turbo option. Probably by a factor of two if you started from scratch, I'd guess. If I want a fast car, I'd go turbo. If I want one to drive for the sheer joy of it, I'll stick with my high compression mills. Now I'm starting to regret my future plans for that 2.0 car...

DMJYwyg wrote: it is so specialize in this line,I can learn from it,I hope you give me more.

CANOE?

Zombie Canoe? He forgot to push his wares. Just like a zombie; always forgetting.

Turbo. LOTS OF TURBO.

Forced induction if you want big power gains on a reasonable budget. ITBs can be useful in certain race classes or when you have goals other than maximum horsepower - there's nothing like the look of eight Hilborn stacks on a classic V8, for example, and the throttle response can be useful in an autocrosser.

I asked myself the very same question when I wanted to upgrade my supercharged Miata. The Answer is LS1

Why not both?

Yeah, I was thinking about this in the shower, and it's not an either/or question. That 2.0 Miata motor of mine was just as much fun with a factory intake manifold, but it was much quieter. That's good and bad, as it makes an amazing hammering noise at cruise now. You can boost an ITB if you want. In fact, we've been planning on doing just that at FM.

I'm not one of the people that attributes magical qualities to multiple throttles, although it does seem there's a bit of a cult around them. That's even with three of them in my garage (forgot about the M5). They can sound cool, they can make more power (or less power) than a single-throttle setup. But they're not the holy Power Adder that some people think.

Keith wrote: Yeah, I was thinking about this in the shower, and it's not an either/or question. That 2.0 Miata motor of mine was just as much fun with a factory intake manifold, but it was much quieter. That's good and bad, as it makes an amazing hammering noise at cruise now. You can boost an ITB if you want. In fact, we've been planning on doing just that at FM. I'm not one of the people that attributes magical qualities to multiple throttles, although it does seem there's a bit of a cult around them. That's even with three of them in my garage (forgot about the M5). They can sound cool, they can make more power (or less power) than a single-throttle setup. But they're not the holy Power Adder that some people think.

I am glad you said that. They look pretty, but they don't necessarily add power over a well design intake manifold.

ITB always! What's not to love about the Infantry Training Bridage?

Maybe I'm thinking of the wrong thing....

tuna55 wrote:

Keith wrote: Yeah, I was thinking about this in the shower, and it's not an either/or question. That 2.0 Miata motor of mine was just as much fun with a factory intake manifold, but it was much quieter. That's good and bad, as it makes an amazing hammering noise at cruise now. You can boost an ITB if you want. In fact, we've been planning on doing just that at FM. I'm not one of the people that attributes magical qualities to multiple throttles, although it does seem there's a bit of a cult around them. That's even with three of them in my garage (forgot about the M5). They can sound cool, they can make more power (or less power) than a single-throttle setup. But they're not the holy Power Adder that some people think.

I am glad you said that. They look pretty, but they don't necessarily add power over a well design intake manifold.

Of course, both of my ITB-shod Miata engines gained power with the multiple throttles But that's relative to the stock manifold, and I know there are better ones out there.

Heh, I've got a nice piece of aluminum square stock to build a plenum out of, plus a BAE exhaust manifold and access to lots of Turbo-Dodge parts. So yeah, I'll be doing both fairly soon, which is why the engine is still relatively low compression.

Figured I'd start with the ITBs, get them tuned before adding the huffer.

Oh and there's plenty of polishing on the inside too as the stock 924 head is a POS. Have another head I'll be working on with bigger valves, stiffer springs and more port work to add down the road as well.

Keith, that's an excellent post about the differences between the various engine setups.

ITBs are moar kewler.

For open-hood wow factor, and the unholy sound they make, ITBs all the way. For actual power output, and cost effectiveness, bang for the buck, a turbo system.

I want a high compession miata now.

Keith wrote: I've got both, on variants of the same engine. 1990 Miata 1.6 with a Voodoo II turbo, a Locost with a 1.6 Miata engine with high compression and TWM throttle bodies, and a 1994 Miata with a bored and stroked 2.0 high compression engine and OER throttle bodies. I also get to drive turbo 1.8 and 2.0 Miata engines on a regular basis. Interestingly, the turbo 1.6 and the 2.0 make very similar power (at sea level) but the naturally aspirated engine makes more torque. The big n/a motor is a lot of fun to drive, a great engine that's much faster than everyone expects from the dyno charts. But it also cost somewhere around 4 times as much as the Voodoo II system. By the time you count the header on that car and the cams, maybe 5 times. No polishing on the outside, only the inside I also have a Miata 1.6 with high compression and throttle bodies. Fantastic engine. So much character, it's like a musical instrument instead of a piece of machinery. The feel of that engine as it stampedes to redline is like nothing else. Howls, crackles, pops and the throttle response of a sportbike. And the street behavior of a crotchety race engine. Less power than the turbo and less torque though. Not as expensive as the 2.0, but still definitely more than the turbo option. Probably by a factor of two if you started from scratch, I'd guess. If I want a fast car, I'd go turbo. If I want one to drive for the sheer joy of it, I'll stick with my high compression mills. Now I'm starting to regret my future plans for that 2.0 car...

such an awesome post.

I have nothing to add besides my all trac's turbo kicks in pretty nicely and itb's on miata and s2000's sound heavenly.