Miata Engine Swap
 

I have been looking at getting rid of my factory 1.6L for something else, but I love turbo's. I am looking for about 300-400 hp, but I still would like to keep the car light. Factory weight is 2100 lbs, but i don't want to go over 2200 lbs and I will still go with Carbon doors, hood, fenders etc... So I was debating it but what if I went LS1, would that motor/torq be the best for Time Attack. I have seen many Miata's with LS1 swaps but I have never seen one under 2400 Lbs, but there wasn't much in light weight components. So what do you guys think? would it be worth the trouble. I know its in the middle of the season in the northern hemisphere, but I will wait for winter.

Carbon fiber Miata hood is heavier than the stock one.

This thread...

http://www.axispowerracing.com/miata...Miata_Exterior

Stock weight 14
APR weight 7

I know its not a lot but with my hood all ready F--ed up, I'm going to get a new CF one

For time attack you'll need 500wtq or you won't be competitive.

You want 300-400hp and you want to do a swap? I don't understand why. Buy a used VVT head, buy a TSE short block and buy one of the used baller turbo systems that show up on the classifieds. Fit with turbo of your choice and BAM..instant win.

Anything less is just a waste of time. And that 7lbs savings on the hood alone will make the front MUCH lighter and the car should be much faster.

i think this lsx weight thing is a never-mentioned-dirty-little-secret. it looks light but still 2424:

http://www.axwaresystems.com/MX5/buildup.htm

I think a ~2 liter 4cyl with a good flowing head (ala vtec) will get you there.

That's an NC, an NA would lighter I think

built 1.8, vvt head, turbo kitty

I don't want a 1.8, if I'm going to do all that work to throw a 1.8 in there. I might as well go with a S15 SR20 with a dry sump system. I was also thinking of an LS1 for the awesome gas mileage 2002 Camaro 24 mpg, Corvette 28 mpg.

Yeah just "throw" that dry sumped SR in there. Should be easy.

sounds like a crap ton of work for no benefits.

I've thought about the swap when I first got the car and when I saw the swap kit my jaw dropped. A oil pan and mounts cost $3200 AUD...LOL no way, but I could always build the mounts from scratch. The dry oil sump would make it a lot easier to put the engine in and would be better for the oil cooler. A S15 SR20DET makes 250ps and is capable of making 300hp at the wheels. Previous to owning the Miata I had a 240sx(s13), 280z, 240sx(s14) and a 300zx Twin Turbo, so yes I am a big Nissan fan.

You might be a Nissan fan, but there's a reason you're driving a miata. It's a better car.

A built BP can easily handle 300 whp and do it reliably if built correctly (vband, safety wire,coolant reroute, etc.), and it would be much easier and more efficient to do than a SR20.

Im either building the 1.6 or not a 1.8 swap. $8k for the Engine/turbo install or $8k for a LS1 or whatever swap. And how much boost am I looking at to make 300 to 400 hp with 9:1 comp, Kelford 272 with built head.

in my humble opinion the miata is a nice chassis. an aluminum block motor with a variable lift head (sr20 vvl/f20c/etc) is a nice motor. put them together is win.

given a few swap parts (tranny <-> ppf adapter, motor mounts, oil pan) i think a sr20/f20c swap makes sense. without a kit its an awful lot of work.

full disclosure: i'm a fan of both chassis and sr20 motor. in fact, i'm hoarding parts for a sr20ve+t for my miata.

I probably gained 75-100 pounds going from the turbo to the LS swap.

The rest of the weight was gained in creature comforts.

:giggle:

I make 300hp, on a 1.6L with a Rotrex and would likely make more if I actually ran a turbo. As do many others here.

Seriously, if you can't realize we've all been trolling you you are not going to last long here

Just build your 1.6L, slap a turbo on and call it a day.

i may have to back-pedal. if you have that much power you don't need to remove windows and wipers and all the rest. has anybody documented how much a ls swap weighs when car is stripped? (maybe orion or zx?)

No, I just want to see what peoples thoughts on the subject. I don't care if its negative as long as it it is helpful.

I think of the Forums as a car meet at any parking lot and your just asking people stuff and with my question is just with in some parameters.

SR20 FTW im in the process of landing one! Will post pics when i do!

I have a sr sitting in my back shed doing nothing and I still dont think its worth it.

Custom mounts, tail shaft, wiring, a dry sump (are you made of money?), actually buying all the parts for the sr (cams, rocker arm stoppers, cam gears, if you want 400hp you will have to build it) at 400 you will pop a gearbox pretty fast so you may as well put a vg box conversion before you get a custom tail shaft.

If you're serious about a vl conversion you will need custom intake manifold, all the install...

Its a lot of money for the sake of being different... If you did 13b conversion at least you might be able to drop some weight.

Vilko you have a point in spite of your ridiculous straw man. Yes, mounts tranny adapter oil pan are all significant items, no doubt. The sr is a factory turbo motor and would work great a miata in basically stock form up to around 350hp (with an injector+turbo upgrade). This means you could blow up your ---- and buy another det motor and swap it in.

For 400whp you're right, you will need cams and a head gasket. I think with a 3071ish sized turbo, 400 is pretty doable. There are a lot of people running in this power area with stock gearboxes. as power goes up from here, longevity goes down.

That said, the mt.n community is not particularly sympathetic to motor swaps such as the sr. Recent history shows people show up with grand ideas, talk big, and then disappear. To-date nobody has demonstrated any kind of return on investment for the swap. So the community is skeptical.

This is as it should be.

speaking personally, i'm part of the problem. this summer i'll have been sitting on my sr swapped miata for 5 years without demonstrating either power or reliability. I hope to fix that soon, but who knows.

IMO the SR20 doesn't offer enough benefit to offset the cost and pain in the ass installation, etc. If you are going to do it go with an F20C...

A built BP can run over 400 with the correct tune, supporting mods, etc. It may be easier with an SR20 if you have a lot more time and money.

The B6 can also make those numbers, but it is easier with the extra displacement the BP offers. I picked up a BP from the junkyard with 36,000 miles for $200. It was from a 1993 Ford Escort GT. There are several other cars running the BP as well so they are dirt cheap.

Between me and my brother we own about 4 sr20s, and have owned a few more. And a lot of my friends are heavily involved in the drift scene. I'm not claiming to be an expert, but I know a bit about these motors.

Im not too familiar with hp, and if OP was referring to atw or at the fly. Im going to assume atw.

In my brothers car he has about 210-220rwkw, his 5 speed is giving up. 350hp and I think you will start having troubles after the first few spirited outings. Obviously SR 6 speeds are a joke, so you are going to want an RB25 or VG30 box for reliable power. Sure gear boxes are pretty cheap to replace, but if you are going to all the trouble of a conversion you would be aiming for reliable power, no?

I don't know what SR putting out 350hp atw on stock cams. There are drag motors with stock bottom ends that push that power, but they have the cams, etc done. And they don't usually last long.
The 220kw in my brothers car is on a responsive hks turbo, cams, tune and all the usual intake/exhaust/front mount, stock bottom end, 98octane (Australian rating system). Ethanol will help, but not to the power levels the OP was talking about.

Head gasket? Ive never heard of anyone with a sr upgrading just the head gasket unless its to decomp a non-turbo sr or its a fully build motor.

You make a good point with the ability to blow up an engine/gear box and replacing it for cheap. Im living in Australia so that is especially true.

IMO if you want that power from a SR, you are going to have to build it. This forum has led me to believe that for a lot cheaper you could build a 1.8 and put out the same power.

If you are going for 350whp, it would be pointless to do the SR20 swap. You can get that for sure on the BP and it won't take tons of work.

Or you could swap a v8.

Vilko, for sure at 350whp, the BP is the better choice with time and money as consideration.

thats interesting, i get 300whp ~= 220kw. how many 5 speeds has he broken? most of my datapoints are folks running rwd tranny at around 350whp (2871 @ 15psi) and they hold up ok on road course usage. folks doing autox with ka+t (400whp) and sticky tires go through them though.

anyway, sorry to jump on you. my personal opinion is that it is remarkably hard to make a turbo motor reliably produce power levels above 350whp using gas we can afford (91 octane in cali). i think any demonstrations of doing so should be considered an interesting datapoint.

admittedly its the upper end of stock cams but you can with a non-restrictive turbine (ie: not a t28).

u mean BUILD it? props to u aussies :bowrofl:

At 220kw you wont need to replace them too often, this one has stood up for years. But for the sake of reliability at 350-400hp you may as well do the swap before you get a tailshaft made up IMO. Do it once, do it right.

Yeah, T28 wouldnt even get close lol. Im suprised you can get out 300hp from stock cams, news to me!

Mmmm... VE... Thats a different story! ---- the budget, just drop in a Mazworx SR24VE!

I know a guy who weighed the major components. He said the LS motor was lighter, but the tranny and rear end where heavier, everything included it added up to about a 100lb gain... at least the weight is in the middle/rear and not the front of the car.

But for comparison sake, the same LS1 in a Fbody weighs in at about 3600#. Power to weight ration the LS1 Miata is much better.

Ya 13b is not light
http://forum.miata.net/vb/showthread.php?t=338950

With all the conversation about having to build a SR and if it would hold up to that 350-400hp range. The LS1 would be easier, but if done it would be the typical American thing "Just put a V8 in it". I don't like to do that. With only a 100 lb gain that would be easy to adjust the weight for that CF Doors -60 lbs, seats -20 lbs. There are a lot of conversion kits out there and a lot of people that already done them that could help.

jasonb--- The aussies are lucky because they get the Euro, Japanese and most of the American cars.

get two hyabusa motors and connect the crankshafts.

Thats about as unamerican v8 as you can get?

Are you talking about this little baby lol, its only a twin turbo 1000 hp 2.8 liter


https://www.miataturbo.net/attachmen...ine=1333648323

https://www.miataturbo.net/attachmen...ine=1333648323

:drool:

Coming from a bike background, if that is an bike inline 4 converted to v8, I LOVE it!!

Revs, glorious sound, torque, top end power.....crazy !!!

Although I would be just as happy without the turbo's....

But I wouldn't say no....either way.

Where you getting these?

They will build you anything you want, if you want a dash made they will do it. It is the same place that Sport Compact Car lost 154 lbs in exterior body parts.

http://www.modified.com/projectcars/...k/viewall.html

http://www.axispowerracing.com/miata.html

Holy $hit at $1800/door but if they're really 9.5 lbs each they're probably worth it considering the stock doors have to be like 50 lbs or more.

not really considering gutted stock doors are much less than 50 and probably no more than 15 lbs? I don't think anyone has weighted them but considering Moti took 80 lbs out of his NB doors, I would say they are in the ballpark of 15 lbs gutted.

I seriously doubt a steel door is only 5 lbs more than a carbon door.....at best 20-25 lbs. Anyone weighed their gutted steel doors?

Yep, here we go:
http://www.targamiata.com/tags.php?tag=weight%20loss

25 lbs with most of the metal still in place for a window crank, 14 lbs with maximum weight savings. The 14 lb door looks similar to moti's door. I think moti has a slight bit more metal on the bottom, but that stuff is light. I think Moti's door is probably no more than 2-3 lbs more.

We can meet in the somewhere in the middle and say 19 lbs for the average since most gutted doors don't have anything in the middle to allow for door bars.

Losing weight can be expensive, if they are saying that the Targa Miata doors are at 32 lbs and the carbon doors are 5 lbs than you have a savings of 54 lbs. But lets say you buy some FIA seats and they are $700 USD. So the factory seats are 34 lbs and the Racing Seats are 22 lbs you are shaving 24 lbs for $1400 USD.

Price to Weight Savings
I am going buy PRICE/SUBTRACTION OF WEIGHT

Seats 63
Doors 66
Hood 100
Trunk 58

Lower the Number is better

You are comparing an overweight gutted door with the carbon doors and an overweight FIA seat with factory seats.

You are being as optimistic as possible for the carbon doors, which are likely to get you the least amount of benefit.

a $700 fiberglass FIA seat will come in at 12-14 lbs, maybe 16 lbs with an aluminum mount.
Even the targa miata doors at 24lbs + 6 lbs for glass, will be under 32lbs (which you also need to add in the weight of the glass for the carbon doors).

Hey bro I heard you can just plaster a shyt lot of CF on top of the body and make a CF shell. Then, retrieve all the body panels and replace with your balled CF shell... you'll shave lots of weight and will be the fastest.

Wow, that really surprises me. Good to know!

It would be nice to see a comparison of a 1.8 + 6 speed.

:headscratch: The quoted numbers don't seem right. I've solo-lifted a 13BNA rotary keg (Equivalent to a Miata long block, no accessories, tranny or manifolds) before*, and I was nowhere near as strong as the quoted numbers claim.

In fact, I know a lot of rotary guys that have duo or even a few single wrestled the keg into the car. I don't see how it can possibly be that heavy. And yet, I know for a fact I have zero chance whatsoever to wrestle a bare Miata long block into the Miata...or even the larger RX7.

:headscratch: I don't know, but those numbers just don't seem right, unless the non-engine related stuff weighs a lot more than the Miata's.

*: Disclaimer, I was a lot younger then, and too broke to afford the proper tools at the time. I wouldn't do it now.

Nev's rotary build showed a weight loss somewhere between 75-90 lbs (I can't remember exactly, I think it was 86 lbs).

I think thats pretty significant considering its coming out of something that you normally can't get significant weight loss out of. Plus Rotarys center of gravity is lower, which has other difficult to quantify benefits.

What do you guys think of putting a MZR in a NA Miata?

Threads like this make me laugh.

"Hey guys I'm going to build a super awesome monster with full carbon fiber everything and NOS and tons of power and and and..............."

Sounds like the typical pimple faced ricer retard in a wal-mart parking lot trying to look cool in front of a fast car owner.

It's a bad idea.

IMO, putting an SR or a 13B into a Miata is a huge waste of time. Just build the 1.8L and turbocharge that. All of the motor mounts, trans mounts, etc. are all engineered for you. If you're going to go through all the hassle of an engine swap, do an LSx swap. It is the only engine that's worth the hassle.

What Sav said. And my money is where my mouth is.

If you want to do an LSx swap and keep the car near 2200 lbs then strip it to the bone, and use a T-5 instead of a T-56. The T-5 saves 70-80 lbs, but it is not nearly as durable as the T-56.

Thanks guys all I'm looking to do now is to sell my Z71 truck first, the 240sx and my dune buggy can stay where it is for now. I was running up the numbers last night and the 1.8 is going to be around $7k usd, so I will get the engine at the end of the season.

These are just questions, there is a chassis that is vary acceptable just like the S13 and S14 chassis, but I guess the swaps on the s13/s14 is more acceptable to better swaps than the NA/NB chassis. But yes I am asking as if I was in a parking lot asking a bunch of car people so questions. I am not some pimped faced ricer retard, I have had some semi fast cars, 1985 Camaro 500ci turbo, RB26 swapped 260z, 522hp Z32. I am just waiting to get out of this sh!t hole called Clovis NM when my second military contract is up then I'm going back to Tampa. But more to come on the build...

sav, if you don't mind i'll make a small edit: It is the only engine thats been proven to be worth the hassle.

reading MartinezA92's thread it seems there's room for a factory turbo motor option. mazda factory turbo seems the obvious choice. anything non mazda has a long way to go to account for the non-mazdaness deficit.

but if the LSx can do it, it can be done. f20c/sr20/13b has to be proven, until then its just talk.

Don't get me wrong, if you actually go through with it then power to you, and I'll be here cheering you on.

Its just that 99% of these kinds of threads usually end in OP just disappearing because they weren't even half serious or realistic when day dreaming about this uber kewl project of theirs.

Good luck.

Im taking a stab in the dark here. But do you think a lot of the weight is in the gearbox? I imagine a rx gearbox (which would probably vary in weight depending on model) would be stronger and heavier than a mx5/miata 5 speed.
But for this power you would most likely use a 1.8 mx5/miata motor with a 6 speed. I feel like you would need a comparison of these 2 motors/gbox on the same scales to get a good comparison.

Edit: Unmentioned benifit of a rotory: BRAP, BRAP, BRAP, BRAP.

Gearbox, much heavier turbos/manifolds, and a few other things I'd imagine, but I think you are definitely on the right track.

There's no way a rotary keg weighs as much as they say, I've handled rotary kegs, 1.6s, and 1.8s - even the 1.6s are way the ---- heavier than a rotary keg.