ahh its driving me crazy, which should i go with. is it really that benificial having the 1.8? spool is a nessesity, but i can just go with the 1.6 and a smaller turbo. somebody just give me some reasons of why to pic one over the other.

all i can say is the 1.8 in my new 99 feels so much better than my old 1.6. although i must say the 99 i just bought has one of the strongest if not the strongest stock 1.8 dyno I have seen.

Although i do love and miss the rev's on the smaller 1.6.

guess that didnt help any lol

I just read a thread on this. People said they liked the 1.6 more because it had more "character." Although this is akin to describing someones (average) looks by saying they have a really good personality.

A few that had both say if you're rev happy, get that 1.6, it's more "comfortable" up to the limiter. Another point is that a 1.6 or a 1.8 are going to be relatively slow until you turbo it anyway, so it's not a must have either way.

I think I'd take the 1.8 given the choice, and deal with "less character."

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'91 Mariner T28, 2.5" DP, Begi FMU, 265cc, Konig Britelites, RS-2s, Gutted. *Sold*

I'd prolly go with a 1.8 had a a chance...I love my car, but its old....and the rear end is weak...its needs a rebuild more than likely...and the 1.8 produces more power w/ boost.

however, the 1.6 turbo'd are just fun...not monsters, but its a little lighter and the power band just feels...better.

hopefully this will be the case for mine.

well i came from the honda community and honestly spending 1k on a motor sway and only getting another 18-30 hp is almost pointless. but i didnt know if having a 1.8 is really that godly for so many people to have bothered with. itll save me alot of time and money not bothering witha 1.8 and with doing a ground up build and swap and ms and turbo all at the same time i think taking the swap out will save some of the new stuff. if its a really really good idea to i will but its its .. meh ok its better at least i probly wont bother with it. does the extra literage really change your spool dramatically or is that somthing that people have also said wasnt that noticeable about it.

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Having driven several of each, and the list keeps getting longer..(and I also own mazda 1.6/1.8/2.0 cars)... I would opt to TC what ever was in the car. The 1.6 is a great love to rev motor, my friends FM II is an absolute blast @ least til he sold it and bought a seven...
Anyway if your only going for a couple of hundred HP I would stay w/ the 1.6. otherwise it sounds like it would be simpler to just start w/ a 94-97 and go from there...
I enjoy them all, but the 1.6 sees redline+ more than any others in the garage...

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96 - T25_EMB/E01_ACT_Tein_Bilstein_Azenis
94 - M45 CS_MS_ACT_GC/Koni_Azenis

I agree- the 1.8 will take you further, but if you're not going all the way, there's really no point. And it's more work.

makes me want to scrap My 1.8 turbo project and start over lol.

But I love my 1.8 so im good , I will b e happy with 200hp at the wheels

I would choose a 94 miata (and specifically that year) over a 90-93 for the following reasons:

1) There is no replacement for displacement. All things being equal the larger engine should produce more power and earlier spool.

2) 94 has a compression ratio of 8.8:1 vs 9:1 of 95-97 making it ever so slighly more boost friendly.

3) 94-97 already has the upgraded chassis bracing, the bigger brakes, better upper shock mounts, and 7" diff compared to the 90-93

4) 94 and I think most 95 cars retained the real oil pressure gauge

5) 94-95 remained OBD-I making it easier to pass emissions in strict states

FWIW, I own a boosted 1.6 and am very happy with it, but basically have upgraded all the other parts such as chassis bracing, brakes, diff, suspension to the 1.8 setup. Another good choice would be a 99-00 for the better flowing stock head. YMMV.

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91 widebody brg - built 1.63L engine, worked head (MS solid lifters/shim under bucket/Supertech valvetrain/Integral cams), Flipside custom GT2871 turbo setup, Flipside custom IM w/65mm TB, 6-speed trans, 3.63 Rx7 diff, FM front sway, Tein Flex 9/7

Sorry, didn't realize that you were just looking for the engine. Here's a link to FM's dyno of 1.6 vs 1.8 both at 12psi with the same kit. The 1.8 reaches the 1.6 peak torque number about 800-900 rpm sooner.

http://www.flyinmiata.com/tech/dyno_...s_1.8_FMII.pdf

Oh wow, I did'nt relize all of that ^, yay lucky me I have a 94 1.8.

2) 94 has a compression ratio of 8.8:1 vs 9:1 of 95-97 making it ever so slighly more boost friendly.

this makes me happY ^

The 1.6 doesnt rev any better than the 1.8L, its just that the cams on the 1.6L are a little more aggressive and hold torque longer into the rpms ( the 1.8L still makes more torque all over though, even at redline ). The 1.8L will make more power, spool a turbo faster, and get to redline faster. Its just the way to go IMHO.

From what i have seen the hp numbers on the 1.8-1.6 motors are pretty similiar but the torque is the difference i wouldnt trade my 1.6 for a 1.8. Besides having a better dif there is realy no advantage to the 1.8 as far as i can see, i wouldn't do it but i am onry like that.

I swapped a '94 1.8 into my 1992. I do not know which is better, although the 1.8 was a bunch of fun naturally-aspirated before I turboed it. Which one is better, I have no idea. Go with whichever makes you sleep easier I guess.

Kinda related: The only surprise doing the swap that I didn't hear or read anywhere is a possible major interference with the A/C PULLEY and sway bar. I reused my V-belt 1.6 crankpulley (and all 1.6 accessories) because I did not have the front of a 1.8 motor lying around to get the nice Ribbed pulleys. I also have a SOLID RB sway bar. There is MAYBE 1/8 inch between the sway bar and the A/C PULLEY. It's one of the first things people say 'woah ****' about when they see the front of my engine. If you have a hollow sway bar that is larger in diameter, it could hit or be too close for comfort. I assume using 1.8 accessory bits would help this but am not sure.

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The mystery behind ABSURDflow | Design Engineer at Jesel Valvetrain | '92 A-package @ 199k miles | 2.5 KL V6 turbo | 3.90 torsen from a '99 | AEM EMS | 3" stainless exhaust | Tein suspension | Kosei K1/BFG gForce Sports

well let me ask this. with the 1.6 being on megasquirt running a t25.... if i wanted 200-220 whp would the stock 1.6 injectors get me there, and how reliable will the engine be? if i keep the 1.6 and turbo it, that will give me a chance to get a hold of a 1.8 and build it while i am driving the turbo 1.6 around. so id probly only need the 1.6 to last me a year maybe less.

I think the biggest advantage to going to a 1.8l are options. How many SC options are there for the 1.6? Can you stroke a 1.6? Can you significantly bore it out? How much additional development is going to go into the 1.6 by BEGI, FM, BRP and ?????

The biggest thing the 1.6 has going for it is the Greddy kit. This is the only thing the 1.8 crowd doesn't have (easily).

As for the character of the 1.6l motor. Bah, once you throw a turbo on it it feels like an entirely different motor anyway.

But if you are only looking to get 200-220whp the 1.6 will take you there for sure. Now if you wanted 200whp with a SC you might seriously consider the 1.8 swap. The other thing to consider if doing a 1.8 swap is that you now have a Franken Car, and that's something you would need to keep in mind if you were plan to do things like a Standalone.

Just my opinion.

I'm looking at this too. My father owns a couple salvage yards, so I have access to both motors. From what I understand you can run all the 1.6 accessories on the 1.8 with a few lengthened wires and the FM swap kit right?

I plan on running MS for whichever engine I pick.
Is it easier to score a good manifold that won't crack for the 1.6 or 1.8?
I was planning on doing forged weisco pistons with eagle rods for either engine, and knife edgine the crank, just so I can do it once and be done with it.
If I'm going to buy a 1.8 wrecked car to swap engine and trans, is it really worth swapping the 1.8 in and messing with the conversion? If I run the 1.6 at .060 over at 8.6:1, is that a waste?

I only want like 225whp max, and I want it to be reliable and painless. Whats the best option for a car that will see track time and be driven gently in 108* texas heat?

you could do 225 whp without a built motor but for track time in texas i would get a bigger rad and torsen dif. the stock motor will hold up on that just fine heck i dont live in the texas heat but i still push abit more than 225 whp and havent had any issues yet knock on wood. at 300+whp i think building a motor might be a good idea but not all together necesarry.

I want to get 100k out of the thing, and not be afraid to track the car.