1.8L build, aiming for ~275whp
 

OK ladies and gentlemen, here is what my car is reduced to

https://www.miataturbo.net/attachmen...ine=1350667646

What started as this: Low-End tapping & Engine Swap questions

Turned out to be this :(

https://www.miataturbo.net/attachmen...ine=1350667646

Seemingly on only one cylinder

https://www.miataturbo.net/attachmen...ine=1350667646

Now, my mechanic is still taking apart the rest of the block but as it looks now, and as he and I both said, if I'm this deep, go a little deeper. I'm considering building a semi-custom rig when the block and crank get remachined (if needed on crank) but I've never thought something like this out before and need some help. I'm not planning on increasing stroke (obviously ill need slightly larger bore after the block is honed), and not sure what to do about compression ratio (keep stock 9.5 or go lower). There are a few obvious things to replace, and a few things I've found so far that aren't over the top priced (no offence FM, I wish I could afford a build with your parts :'( I'll be running Megasquirt MS2

Rods (Eagle H-Beam Forged
Bearings (rod and main) (ACL Race)
Pistons (Supertech) (what ratio though?)
Headgasket (not sure on what versions available)
Oil pump (not sure if upgraded ones available or needed)
Oil Squirters (he said they are in the bottom of the block and recomended doing a new set, where do I find them?)
Headstuds (ARP)
Main Studs (lower block also by ARP)
Injectors (have 440CC but won't be enough)
Clutch (stock, need recomendations)

There are some things I am not sure if I should touch. One of them is the head, I don't know if it really needs any upgrading. I was considering going with the intake cam for the exhaust, but not sure where I can find em and how much one would cost. Also, the clutch is a question, the one in there is a stocker with 75k, looks OK but not enough for what I want to do. Valve kits aren't too expensive, but I don't know if there's a benefit.

My goal? 250+whp, somewhere closer to 300. I'm also not sure what turbo to run that will get me there. I like some of the starter kits BEGi offers that give you a manifold, turbo, and downpipe, but dont know whether to go log or tubular, and what turbo that will work best with the build above. I was considering a Disco Potato GT28. My goal is a RELIABLE, streetable, and FAST MSM. Emissions don't matter, it's a secondary car and gets exempt.

Please, I NEED help. The guy doing my build is a great tech when it comes to assembly and doing everything properly and checking it 5 times, but he usually deals with stock engines, so he can't really recomend anything specific, all he is going to do is give me a list of what he would recomend because he knows what the car means to me and wants to build it good. Have at it! I'll be taking the block and crank to the machine shop in a week or two to get checked and I'll at least know what size bearings and rings to get with my new stuff.

Also if you can post part recomendations and where to get them at fair prices, I'd apreciate it. Here is a list of the other mods on the car, some of this will be able to remain. I've got about 3 months to do this, I don't want to cut corners but using all expensive parts is not an option either.

2004 MAZDASPEED MX-5 : JoeMazda Intake, FlyinMiata Downpipe, Corksport 80mm Exhaust, CXRacing FMIC, RC SL9-440cc Injectors, BEGi/ChipTorque Reflash 12psi (to be replaced with MS2), AEM UEGO Analog WBo2, Tein FLEX 7/6, Hawk HPS, SS Lines, 15x9 949Racing 6UL, 225 45 15 Ventus RS3 Tires, TurboSmart BOV & MBC, HDHCDD Rollbar, MRSS Kit, 50lb weight reduction

Oil Pump: Probably not needed unless you want to rev a bunch, but everyone here seems to go with Boundary Engineering.

Clutch: The Flyin Miata clutches seem to be the recommendation for a street car. inb4 arguing about 6-puck clutches on the street.

Also I believe a lot of people who are not tracking/running ALLOFIT just use OEM bearings. Again probably depends on what you want to set your rev limit at.

Pistons: 9 or 8.5 on pump gas, 9.5 or 10 on E85. Usually 1mm overbore.

Headgasket: Again, I think most people just install a new OEM one, but I don't remember what years they use, as some are made of different material.

Note: I have no first hand experience with any of this, just what I have picked up from reading build threads.

My 2 cents...

Bearings : ACL works just fine
Pistons (Supertech) : I liked 9:1
Headgasket : OEM
Oil pump : Boundary engineering, critical protection for your expensive motor
Oil Squirters : Not sure why you would need new ones, clean and put back in?
Injectors : Run whatever you are running now so you can break in the motor without a new tune as well, swap later
Clutch : I love my FM clutch, pucked discs suck to drive on the street


As for the head, if it were my car I'd mostly leave it alone. Since you are on a budget, I'd just leave it stock and do the block right. Clean it up, maybe do some mild porting and polishing to get some more flow, but that's about it. Leave the cams alone, you already have the better intake cam from the factory.

The only thing I might do to the head would be to put new valve springs so I could increase the rev limit.

Oh yeah forgot about the head.

Soviet just put up 400hp on a stock '99 head, so you definitely don't need any headwork done unless you need to rev past 7500 (which you won't if you don't have any headwork done, since Miata heads flow like shit).

Any feedback on Manley H-beam rods and Weisco pistons? Apreciate all the help thus far.

I'm not sure you can make enough power in a Miata for you to care about specifically which aftermarket rods. I think any forged rod would do. You probably don't even need H-beam ones, but why not? Supposedly even Egay china rods are good for 300hp.

Should I go FM, BEGi, or somewhere else for a turbo kit? I was hoping for a GT2860RS, manifold, and downpipe that would all be premade. I already have a corksport 3.1in exhaust to mate it to.

Basically, what do I need to do to ensure the engine will hold 300whp for years and years to come? Not a daily driver for me. I also don't want to get race parts in some areas if they are higher performance but will need to be replaced often (someone said this about acl race bearing needing to be replaced every so often).

Also, what pre-kitted turbo system and which turbo within it should I use to get to 300whp. Id rather go with FM2 for this, but the BEGi S3 kit looks nice too. I can order my MS2 and get a tune in the spring cause the car is going to get garaged right after the rebuild anyway. The engine build and turbo system I need to do now since the engine is already out, feel as though it's easier and my guy won't charge me extra cause he has to reassemble everything anyway.

You should call me so I can set you straight on what you're really looking for. :party:

I would go for an ARTech Manifold and downpipe with an EFR6258 or 6758. Build the bottom end and you are set for anywhere between 300-400rwhp.

After the kind of results Soviet and others with EFRs are putting out, it would be silly to get any other turbo. You want 300whp? The 6258 should be perfect for that. Soviet made 318hp with that one IIRC. 5x the performance for 1.5x the price. And it will spool like a turbo that runs out of steam at 220whp.

Read the build threads of the guys tracking their turbo Miatas. Genesplicer, Hustler (lol his old ones of course, none of this NA bullshit), Charlie_91, Savington (never did finish his, I need to read through it again), others who I am forgetting. Tracking > streeting as far as wear and tear. If you set up yours for the street they way they do for the track, it will last a million years.

But where do I get a manifold and downpipe, and oil lines, etc. for that piece? The shop where my car is is only doing assembly, he can't make me a downpipe.

I could have him reassemble with stock components and take it somewhere else afterwards, but that means paying labor over again.

rods & pistons almost don't matter as long as they are forged and you balance them.
you probably don't have to do anything to your crank. like, at all. mine was perfectly round and worn just enough for loose bearing clearances.
you don't need new squirters. just clean the old ones in kerosene or something. maybe new copper washers.

you need billet pump
you need main studs
you need head studs
you want block and head surfaces machined flat because it's an MLS gasket and doesn't tolerate shitty surfaces
you really, really, really want an aftermarket crank pulley (ATI damper or Supermiata damper)
you really want MS3
you want ID 1000cc injectors

you also want to talk to your mechanic about oil clearances, piston-to-wall clearance and ring gap - these depend on your application.

For example, mine are:
Mains 0.0020" (loose, past the OEM spec)
Rods 0.0018" (loose, past the OEM spec)
Piston-to-wall 0.0040" (my machinist commented that this is huge clearance)
Rings filed for "Street-Moderate Turbo / Nitrous" application as per Wiseco instructions

As I said before... ARTech makes the manifolds and downpipes for our cars and his are the best. He is a vendor on this forum.

I looked up the site but didn't find much. I'll try to find him around.

My guess is I want the machine shop to assemble the block or recomend clearances based on what I want? I was just going to have the bore and deck work done and then take it back to my dude for reassembly. What clearances do you suggest for my intended purpose? Also why 1000cc injectors for a max of 300whp?

What's the importance of the pulley, as it's pretty damn expensive.

Injectors because they are Injector Dynamics, not because they are 1000cc. They have 725cc ones as well but everything about them is same (other than capacity) so why not get bigger ones? They idle same.

Clearances I'm not going to recommend anything. I only built 1 engine in my life.
So read miataturbo. Talk to the piston manufacturer. Talk to your machinist. Google. Learn.

Some threads:
Supertech p/wall clearance - Miata Turbo Forum - It's the Cat's Meow
piston to bore clerance - Miata Turbo Forum - It's the Cat's Meow
Main and Rod Journal Clearances - Miata Turbo Forum - It's the Cat's Meow

You really, really, really want to learn and figure out what clearances to run. Unless you're building your engine at Trackspeed, don't blindly trust your machinist.

It's not rocket surgery, really. I have large clearances because I'm not really concerned about how long the engine will last - and so far it outlasted a lot of other things on my car

Also BREAK IN YOUR ENGINE CORRECTLY
Proper engine break-in technique - Miata Turbo Forum - It's the Cat's Meow

Thanks for the links. I've got lots of reading to do starting tomorrow, I should really be studying for my psych test right now.

It keeps your engine together at high torque and high rpm. When you triple the power, the stock crank pulley has a tendency to shear off. It's not as critical for a purely street engine. But it's much more critical than, say, polishing your crank or getting headwork.