My beloved miataturbo,

I am once again at that point in my life where I need more power. ~270rwhp just doesn't do it for me like it used to and all this talk of 400+rwhp has lead me to create a few options that may calm my anxious mind. I've also always wanted to build my own engine before my dad is too old to pass on his knowledge.

Please help me choose what I do next to my '92. Keep in mind I would like to still daily drive the car in the warm months and fuel economy plays a certain factor (i.e. 16mpg isn't an option). I will attempt to add a poll to this thread with the below 3 options. If you could pick one and help me further complete my pro/con list for each, I would be eternally grateful. Really.

Here's the three options I'm considering to get me to my ~450rwhp goal. Added headroom would be nice for bragging but not required. With each, I am leaning towards the CTS rear diff conversion, and probably a T5 transmission with appropriate bracketry as I do not want to redo the factory drivetrain afterthefact when it grenades. I am not very open to any other engine options at this time (no rotarys, honda engines, Nissan V6, 'busa, etc), but that may change of course. These are listed in order of cost and difficulty, from low to high, not in order of what I am leaning towards at the moment.

1. VVT 1.8, forged internals, big (ts efr?) turbo, honda intake mani or the like, basically the build some of you crazy wackjobs are doing at the moment. I'm even considering the McCully Racing Motors 2.0 but I'd rather build my own engine.
Pros: relatively simple & documented. I :heart: turbos, good MPG.
Cons: more "common", high strung?, ??

2. All aluminum high rpm, low cube pushrod V8. If small displacement doesn't hit my target HP, I'd add boost.
Pros: It would sound nuts, able to take advantage of some perks of working for Jesel, HP target easier, parts are cheap, job security, able to retain use of A/C probably, kits available to install, ??
Cons: It would be loud (I like quiet). V8 may be out of the miata 'character' IMHO. Bad fuel economy?

3. Big turbo KLDE (mazda's DOHC 2.5 v6). KLDE cause they are cheaper and lower compression than the KLZE, good for boost theoretically.
Pros: These sound insane too. Unique. Turbo. Good gas mileage compared to V8.
Cons: Not much info on the strength of these. Youtube videos of these on 14psi show disappointing HP numbers. Forged rods/pistons are custom, expensive parts compared to the above 2 options. I'd hate to get it done then have it dyno only 375rwhp and/or shoot a rod out the side.

So what would you do?

Thanks fellas... xoxo

 

the internals are good for about 350-400hp, with pistons and millenia S rods they can do 500hp.

 

Don't forget the LS1 Miata for sale here..

 

big turbo 4-banger. VVT, Reverant MS2...win win win.

 

I'd like to see a 1uz rear mount build.

 

I voted for the v8, but I would do a Honda F20C swap with turbo. Make 900HP.

 

v8

 

Damn, I'm gonna love you guys!

Before I started researching the miata I was doing V8's. The goal you have in mind is pretty easily attainable with the V8. Honestly, it looks as if it's reasonable doable with a solid 1.8 build. Nothing too exotic, just bigger. You guys are the pros on turbos that big, and the potential lag that might well be associated with 'em, so I won't even attempt to comment there.

Some V8 insight: I've seen and marveled at 289's pushing 400hp on an engine dyno. 8000 rpm never sounded so damn sexy. Personally, for your goal, I'd use a 347 stroker, some reasonably well sized heads (200 CC would be good) and spin it up. Main girdle, forged crank and light valve train are a must for big rpm in a 5.0 block, blah, blah, blah.

You will have plenty of torque for that little car all over the place, even down low, out of the powerband of a cam that will get you to your HP goal.

Yes, you will take a MASSIVE hit in the mileage department. My favorite set up N/A only pulled 12 mpg around town. And I do so love to drive. Gas will only get more expensive from here on out. Do you love to drive? A lot? I could build another 400hp mustang, but dammit, I love to drive. You will burn GOBS of fuel (cash). The very thought of it is what brought me here in the first place.

If you love to drive the wheels off it, and have money to burn, I vote for the V8.

If you wanna keep embracing technology, get some good MPG, still brag that you can wreck the corvettes, mustangs, and pretty much everything else, stay on the path. Follow the light.

....as interested as I am in the 1.8T, I've never heard one sound like a V8 gurgling with a big cam and flowmasters. Barney Rubble, knuckle dragger, but so damn sexy.

 

Tim, we all know you work magic. So whatever you choose to do will be done properly with good taste.

If it was me, and uniqueness played a factor, it would have to be the KL.

I mean come on, listen to these damn things. You'd be listening to your own personal F1 car everyday on the way to work.

 

I gotta admit, that 6 sounds fuggin awwwwwesome!

 

Tim i know that we chatted back and forth about the awesomeness of the ford small blocks and how easy and cheap it is to make power, however I recently had the chance to drive a v8 powered datsun 280z, it was a carbed ls1. I previously had been given the opportunity to drive the same year and model car with an sr20 in it with a hta 35r on 14psi. Both cars made between 375-425whp and though i could not say which was actually faster i can say that the high strung smoother sr20 felt ALOT faster. The v8 seemed to move the car around from side to side way too much, the torque did not seem right for the car, and i could only assume the effects would be exaggerated in the smaller lighter miata. I was literally planning a trip to the u-pull it for a 302 before i got in that car. Now i have realized that more power does not really = more enjoyment. The way a turbo 4 sounds and feels makes it a more enjoyable power plant for smaller cars imo. My vote is BP with vvt and a precision 6262 or an hta gt35r. Its a big turbo but there is a silver NB making 500whp on that turbo and the powerband is heavenly. Now that i think about it it might not even be an HTA, hopfully he will chime in. (yes i have referred to this car a thousand times, it works and works good)

 

I picked: "All aluminum high rpm, low cube pushrod V8. If small displacement doesn't hit my target HP, I'd add boost."

You wanted:
~450rwhp: An LSx will not having a problem achieving this goal, with supporting mods your goal I believe should be fairly easy to achieve, especially if forced induction comes into the equation.
Not completely **** fuel mileage: The C5 Corvette is capable of high 20's, even 30mpg, so a similar engine/trans should yield as good or better mileage.
T5 Your gonna want a T56 with an LSx
Cons: Loud: I think you could probably quiet it down, but I'd be something I'd ask about.

Edit: Take a drive in a high power turbo car and a V8 swapped car, see what you like.

 

KL: Keep it Mazda, make it different. Based on your prior build and skills, the v8 seems too predictable/simple and the 4 banger is more of the same.

 

The KL does seem really cool, and it would be different.

 

Although its not a 450rwhp car, my little v8 roadster has been been pulling consistent 17.5-19.X mpg numbers in town with several WOT passes per tank. It's not loud at all. Without cats, Jasons exhaust gives it about the same db as a stock C5Z with the smaller cube asa cammed engine. Pissing off the passenger by making their head smack the back of the seat in 5th every time you blip it is also loads of fun often missed with the 4 cylinder.

 

V8. If done right, less headaches. I'm assuming this'll be a daily driver which makes more sense also.

 

I voted for the V6...just not that V6. Sure it could be cool...but definitely unblazed trails.

Go with a VQ...lots of info (and parts) out there for them...and Yamaha never shorts on R&D.

 

Boosted 4-cylinder. Simple reason: boosted cars are more fun to drive around town every day.

 

I drove my friends '99 vette that just dyno'd at 360whp. I wasn't impressed. It was smooth, and it did move pretty good, but I just didn't like how it felt. It has 3.something gears and it had a lot of top end, but I didn't like it.
My other friend's LS1 camaro with 125hp shot of NO2 was the same way. It has 4.10 gears and it pulls really hard, but it just isn't the same in terms of how I'd expect a miata to feel.
Last week I rode in a 400whp turbo Miata.
There is nothing more to be said from me except...build a 400 whp turbo miata.
Perhaps if I rode in a V8 miata I'd have a slightly different opinion, but it's still not a true miata then.
I'm expecting your fab skills and your education to build a 4 cylinder turbo miata that suits you.

 

Big turbo VVT glory.