Coming from someone who has had a 1.6/1.8T/built 1.9T/and Fe3 in his miata..

Either swap in a lsx or use a 4 honda motor (k24>f20/22) and turbocharge it.

Everything else is a waste of time and money.

The realist in me says stick with a FI BP motor.

The dreamer in me says stuff this in there.

http://www.h1v8.com/page/page/1562069.htm

Hey k24madness do you have more info on your car by any chance?

k24madness, that h1 is pure crack. almost makes you want to sell everything you own and buy a locust and go bombing down the nurburgring. it also almost makes the billet sr20 blocks (http://www.bulletcylinderheads.com.au/billetblocks.php) at $7k seem reasonable :hahano:

Some more pictures and info here.

https://www.miataturbo.net/race-prep-75/track-prepped-rotrex-supercharged-miata-47756/#post577783

Still not quite done yet.

While we are on the topic of dream motors how about Billet Aluminum BP block with Iron sleeves.

Its never done, I would love to do the 600hp H1 V8 Twin Turbo since that is the closest you can get to a F1 engine without owning one. An F1 engine is a pain in the ass to daily drive, since you have to pre warm the engine up before starting it and you can't ever stall it.

Honestly I had a friend that did a S2000 swap, that is a great forever revving swap.

k24madness, i just realized you have tony's old car. i have got to see that. i stopped by the shop once when he was getting that thing dyno'd. if i was a little faster on the draw i woulda traded him my strada+$ for the pista, oh well.

enjoy sir

I like this above as it provides hope for a lightweight swap.

Just to put it into perspective. In my past life at job "X" we swapped a 7.0 LSX with a Harrop into a Solstice. Yes it was brutal about 700 horsepower on the engine dyno but it weighed a TON. To make the car better we had to swap in a stock 7 liter and T56 but it was still Corvette heavy. CanBus mania , billet bellhousings, hand made headers and exhaust all made for fun and expensive engineering with snowflake parts. Calibration, ignition switches and dashboards required friends who worked at car companies. ;)

If you can get a Miata in true street trim with your desired creature comforts to weigh in at 2,500 pounds I think you would be very happy and have a field day hunting down Cobra kits cars for snacks. I can't help but think that a budget build based on a 1.8 and a turbo would make for a nice driver just as much as an LS swap would make for a brutal power broker. What most of like to hide from is the dreadful scope creep that seems to be somewhere in every engine swap. Frankly, I wouldn't bother swapping any other 4 cylinder
into a Miata when the guys here have enough recipes to suit your needs.

I might do a V8, (LS), but I think I will drive a few turbo cars before I tear my car apart. I have tons of LS experience and parts from my past but I bought a Miata to capture the sports car part of it not so much as a cheap Cobra wannabe swap project.

out of curiosity, can u fit a k series up to a rwd tranny?


here is something for all the haters. still working on the adapter (tranny <-> ppf), but getting close, i guess. seems there is some trial and error involved here lol.


https://www.miataturbo.net/attachmen...ine=1340461600

I know of a S13 with a turbo b18 conversion. He used a s2000 gearbox with an adaptor plate. This makes me think it should be possible with a k series. Haveu been able to measure any weight reduction from the sr20 being alloy block?

Yep:
http://www.hondatuningmagazine.com/t...p/viewall.html

My 2 pence:

If you're doing an engine swap purely to make your car faster around a track, go with an LSx. A turbocharged F22c would produce big numbers… but a turbocharged LSx would produce even bigger numbers, so packaging trickiness aside, the LSx is the most logical choice.

On the other hand, I can understand rotary and naturally aspirated F20c swaps from a subjective standpoint. Both are characterful and 'fun' engines - far more so than the BP - and that alone is worth the cost and hassle of doing a swap to many people, including myself.

The SR20 falls into neither category above - it's not characterful enough to enhance the driving experience over the BP, and neither does it have massive horsepower potential compared to an LSx, or even compared to a BP. So it's a swap that I really, really don't understand.

None of the 3 local LSx conversions have been able to beat the lap times on my car. One of the owners commented if he had to do it all again he would focus on lowering weight more than HP.

While I love the LS conversions I think the S2000 motor is a much better choice.

Or is Thomas that much better of a driver? ;)

Weight difference between the F20C/LS1 appears to be 166 pounds complete: http://www.v8s2000.com/forums/showth...GHT-DIFFERENCE

I assume a lot of that weight is in the T56 transmission though.

As weight obsessive as I am, wouldn't an extra couple of hundred horsepower make up for that 166lbs? (On a large enough track, traction permitting)

You would think. There's certainly a few LS track cars around that are impressive.

Also, a generic weight is kind of unfair because placement matters so much. If all of that weight is in the transmission, it's low and in the center of the car so it's not that big of deal.

hmmm. ok sr is not characterful enough. i'm reading this as: you like the honda motor and not the nissan motor so the swap is dumb. ok, so maybe i am dumb, but i am making an honest effort trying to build a reliable turbo miata. i was sort of thinking we could encourage each other as each of us pursues this mythical creature. unless...... everybody is so mechanically frustrated that mt.n has become a dating site where people sometimes talk about miatas. :D


i dont' want to say too much about the sr because, really, the only way for me to show i'm not dumb is to have a 350whp, reliable, fast miata using a completely stock motor (modulo fuel system and turbo upgrade). then again, even then i might still be considered to be dumb. but thats ok. it kind of is dumb, i should be saving for retirement.

lol, this thread is so damn stupid

thanks njn63, thats pretty neat, the rear drive k series is intellectually interesting because you get to pull motors and aftermarket parts from front drive market which makes it a heck of a lot cheaper.

I don't have a bp block to weigh, but a bare sr block with maincaps is 62lbs.
I hope thats light enough to offset the weight of the turbo hardware.


ok guys, i'm very close on the mount. I want to make sure i'm running the ppf at a safe distance to the gas tank. Can I get somebody to help me out and measure their gas tank to ppf gap? I am running something like 3/8" which doesn't look like an aweful lot to me.

here is current version of mount. i think with one more change its ready to run for this year.

https://www.miataturbo.net/attachmen...ine=1340948102

Unless that dyno is totally unrelated to the SR you're swapping in, those numbers don't make any sense. Blah blah, different dynos, yadda yadda, I stick by my statement.

Also, coming from my brother's experience with years tracking an SR-powered 240SX, they are FAR from "reliable". Even when made reliable, its all the same ---- you'd do to a Miata motor. Might get a little more power "reliably" from one, but not a whole lot. He was making ~280whp with an S15 turbo. Really fun, but ---- broke all the time, and he was safety-wiring nuts and bolts and such. When that all finally held, he started melting pistons.

It's not JDM; therefore,

100% agree w/ you. but this makes me quite happy, as this gives me something to shoot for.

your right, the chart is an NA chart. if anybody has interest i'd be happy to discuss in my build thread.

Jason I don't know anything about that motor but would love to hear more about the weight savings etc.

im dubious there is much weight savings at all:


https://www.miataturbo.net/attachmen...ine=1341552322


With aftermarket clutch, top mount exhaust manifold, external wastegate, cast pan, oil, and alternator.

No water, starter, air filter, MAF, intercooler & piping...

349.8 LBS

ref: Engine/Trans weights, DEFINITIVE... - HybridZ

Huh. I am interested, looking at fail baboon now.

post started 31/3/2012, with all that time and the money you gonna spend you could have a 350hp b4 or bp mx5 by now. i did a 1.8l conversion to mx5 and it took me 3 days at home everything is bolt in and plug and play!
its obviously youre ignoring all advise and trying to be different.
with regards to being reliable it all comes down to the tune, i was reading a thread on here of a guy running 350hp on stock motor!
after your engine swap you still have to upgrade suspension and bracing if you wanna track it = more money.
i understand youre trying to be different and good luck with that but one day you'll race a bp powered mx5 and realise how much time and money you wasted then LOL!