Shooting for ~300 whp, MSM diff?
 

I'm finally getting around to building my car, and I'm planning on an Efr6258 and 250-300 whp for a DD/Trackday car. Currently on a 99 5 speed, so I know that will grenade first and am looking for a 6 before I drop in induction, but after that I'm looking at the diff.

Is it worth hunting down a MSM diff at ~$1200+ dollars for used parts just for the stronger axle/CV? I don't see many broken axles (except from Miata drag racers :nuts:), although a lot of the racing guys do consider them consumables. Would the MSM axles be any less of a consumable? Especially since they're NLA, rebuild only parts? Or should I just stick an OS Giken in my stock housing and call it a day with my power goal? What about the V8R Getrag kit?

I thought the standard torsen was good for 300+. Subscribed for when someone who actually knows what they were talking about chimes in :party:

MSM diff/axles are stronger than the regular ones, and less likely to break. If you want it, buy it. If you don't launch the crap out of your car, or let it wheel hop, you'll probably never break anything on a regular 1.8 diff/axle. And if you do, they're cheaper to replace and easier to find parts for.

I run a MSM setup, but for what I do to the car (break axles, diffs, crack subframes, almost pull front wheels off the ground on launches), the stock diff/axles wouldn't last very long. I've already broken a MSM axle, though not a MSM diff.

Yeah for what you're describing I don't see any need for MSM diff and axles. Assuming you have a Torsen, it and the axles should be completely fine for the uses you are listing. Wheel hop will destroy miata Torsens in very short order, but otherwise they're extremely tough; the transmission and / or axles are much more likely to fail before the Torsen, and not at the power levels you are listing.

For track use on a six speed I'd keep it to a max of 250wtq.

My 6 speed limit is 290 for hard use.

I expect it to be a consumable but without any major failures, so far none.

A few cars and some with slicks, all ok.

I'm on a full poly bushing set, and will be getting some Xidas to replace the old blown Konis soon, and don't plan on launching the car. Will have to find a better final gear ratio for the six speed and induction, though.

How gingerly would one have to treat a five speed to keep it alive at ~250 wtq? I can haz mechanical empathy. I ask because I've driven the six speeds and the feel is meh. Will go there if I have to.

My favorite summary is this:

https://www.miataturbo.net/attachmen...t-untitled-png

At the power point where swapping in a T5 and the Getrag comes in, that 6L out of a wrecked Escalade starts looking mighty tempting...

IIRC when Lazarus swapped in the msm drivetrain the 5 speed only lasted into the 2nd session with 235 wtq. Mechanical empathy won't save it, running that much torque on track will disintegrate the 5 speed.

Has anyone seen a TII transmission install that doesn't just weld angle iron to the ~20 gauge sheet metal in the tranny tunnel for a mount? I've found like four or five install guides that all do the exact same thing and it doesn't seem like something that'd stand the test of time.

Ratios look usable with my 4.30 T2 (looks like if I'm not launching or hophophopping I'm fine), and they won't grenade. The lack of a transmission solution was why I was limiting myself to 300 and a 6258 versus 300+ and 6758, since literally the only different parts in my build list would be the turbo.

Looks like the other option would be a T5 with the front half of a miata transmission adapted to it, as seen on the wine and cheese forum. There's a place in Cali that sold a kit with a shifter adapter and PPF mount, but no price listed, website gone. Was still sponsoring cars a year ago, though.

There is a kit on eBay. And TSE is also working on a kit.

Well, I'd call that perfect timing. I'm going to get the chassis and engine management sorted before boost, so by the time I'm ready to break the five speed TSE will probably have their kit out.

Come back in 2025

Surely you jest, it's not Begi I'm waiting on. Although the most recent stuff I'm reading on this is back in January with you, TurboTim, and Sav brainstorming shifter extensions.

I honestly would not expect anything to be on the market within the next year. Probably 2-3 years before we actually see something that is order-able. Low amount of demand coupled with high costs means it will not get rushed.

I need to make better progress on this whole MZR swap thing. For like a grand more than a full engine build and a 6 speed you end up with a 400hp capable 2.5 liter with a t5 behind it and a dry sump.

For a grand more than a full engine build and a six speed (let's say $9k) you'd be one wrecked GTO away from a 1000hp capable 400hp stock 6L V8. ($7100 V8R kit, $1000 L92, $150 Getrag)

As to the kit, it looks like front-halfing a Miata 5 speed gets you all the good hard to fab bits, even the TOB surface. Shifter relocation isn't anything new in the T5 world, and you guys have found a ton of working examples, it's just dialing in the miata-specific fitment. and the PPF mounting.

We'll see who gets there first. If I need to run a six speed with the boost turned down for a while, so shall it be.

Built engine from TSE: 2600+shipping.
6 speed: 600+shipping.

3200+shipping and other odds and ends. <$4k still

You're a little off with 9k.

I went with the $7000 Supermiata Big Whammy build and figured $1000 for a six speed, since I didn't see one on the bay. Remembered them being like $500-600 a few years ago.

$7000 whammy build is a horrible comparison. You can build a 400hp setup for much much less. Thats a race engine.

2600 for a fully built complete engine? where do I click pay?

I love these stupid discussions about prices. One party always overbudgets, and the other always claims absurdly low and cheap prices, omitting all the nickle-n-dime stuff and counting labor as free and timeline as unlimited.

at least the overbudgetters are not setting themselves up for failure and more prepared

Well would you look at that. TSE built engine is now 3100.

Come on Vlad. You know a LS swap isn't even close to a turbo build in price.

I bet if I added up all these cheapskate builds and how much money and time was wasted that never gets tallied up, they'd be right up there with the rest of them.

It's so frustrating to see "oh bro, allz you gotta do is" or "oh man, it only costs $3.50 to make 500hp"

No shit. Not claiming that. But LS swap is a different level.

And you know that 99.99% of all the builds on here have ended up costing drastically more than planned, and you also know that your comments about how simple and cheap it is are really counter-productive.

I'm just sayin. Armchair experts

correct.

both are expensive. the latter is significantly more so

maybe I'm just getting old and you young bucks have a whole new approach to this stuff that takes a weekend and costs 2 grand :)

so far that hasnt been the case doe

I'm not saying that I'll have one out this year, but I do have plans to make 400whp in the next ~6 weeks, and necessity is the mother of invention. :party:

Six spd well easily handle 300 whp.

And he forgot the $1500 junk yard 150k mile t56. :giggle:

On the mzr swap, I'm thinking once the bugs are sorted out it'll end up being around 5k excluding the cost of anything you would have to do to take a stock car and turbo it normally.

And you dont have to tell me about nickle and dime costing. I'm pretty sure there $500 worth of AN parts in a box under my toolbench that were purchased on figuring out my nearly impossible oil drain. :vash:

Plus how many hours of labor?

Right now its looking like about the same wiring as a 1.6 to vvt swap, a few hours to install the tranny and diff mount and make sure you do it right, slight bit of re-plumbing the fuel lines in the engine bay, the half a day it takes to reroute the brake lines through the cowl, and however long it takes you to mount and route the drysump tank lines.

"oh it's like 3 hours of labor"

..........*3 months later, car still on jack stands*

We were specifically talking about an MZR swap's price relation to a turbo build. TSE's price ($3100) is very reasonable, definitely a great value, but that's a shortblock. Are you going to stick a stock head on your 9:0 forged bottom end? Start adding in SUBs, valves, machine work, accessories, etc. and the price goes up. That's why I picked the SM Whammy for comparison.

From a quick bit of research it looks like the MZR's like to bend conrods at around 300hp, so it's not like I can snag a 2.5 out of a Ranger or a 2.3 out of a MS3, or a 2.0 out of a NC drop it in with a better turbo and boom 400hp. I'd have to build the MZR as well, which would cost as much or more than the BP. There is also less collective R&D on the platform. The stock NC transmissions appear to be the newest versions of what we already have so I'd need to source a T5 and Quad4Rods bellhousing just as if swapping a T5 to a BP, and would still need a shifter relocation/rear diff/ppf solution. I just don't see the price being comparable, especially considering I have a perfectly good 94 longblock as well as bearings, seals, gaskets, arp studs, etc. etc. waiting for machine work (and rods and pistons).

We all agree, a basic turbo build is the cheapest most reliable option (especially if we can just swap transmissions and keep the stock diff) My point was once you get into swapping engines the LSx is the clear winner in $$$/performance/reliability, plus every kink in the install has been ironed out. Parts are readily available from several major retailers.

I clearly said "wrecked GTO" as part of the requirements. XD And I've seen them wrecked with far fewer miles on them than 150k.

That's encouraging. The front part seems like it could be handled by a qualified machine shop. Maybe if you came out with the shifter and PPF solution first, letting people roll their own bellhousing adapter (with your instructions and a weld-in adapter plate), would decrease R&D time versus a cast/fabricated bellhousing that could be added later.

...yes? I made 351whp through a stock VVT head with stock valve springs. Soviet might have valve springs, but stock lifters, and he's north of 450whp on a stock BP4W port/cam. IIRC he didn't even give that head a valve job before installing it. The motor going into my development car is the lowest-spec shortblock we will sell, and it's mated to a stock VVT head with nothing more than a set of valve springs for overrev protection. Most of the motors I sell have nothing more than valve springs in the head. Realistically, you can get a built BP equipped with all the parts necessary to swallow 400+whp worth of boost shipped to your door for under $5k. If you can do the head swap and timing gear yourself, take $1500 off that number.

Well, I know you can. And that the BP performs quite well in such a configuration. But it's already at the machine shop to have the mating surface cleaned up, so a valve job valves, guides, springs, SUBs, a little porting and deshrouding, all might as well do while you're in there. Every little bit adds up. Stuff I figured that was part of the price of a hypothetical "full engine build," that Leafy referenced for his MZR swap costs. He didn't say "built shortblock."

I'm planning on following Soviets build pretty closely, but wanting to do a little porting on the head and maybe some larger valves. Nothing CNC crazy, I'd only go that route if/when I go VVT.

Where are you seeing 300hp? The NC builders recommend keeping nc2 motors below 300ftlbs for total reliability and 2.5s under 350 ftlbs. Though you can go higher you run into limited life issues like pushing a 6 speed. Of course it's temping to do that when there's 20 2.5s writing 20 miles of you for 450.

Well, since the MZR is a family of engines, I did a quick look at the 2.3 MS3 stuff, since I know there'd be turbos and broken bits. Lots of posts about bent rods on mazdaspeedforums, almost all of the engines I glanced at are just over 300hp, but also over 300tq on second inspection. I don't proclaim to know what the aftermarket builders of these engines recommend. The 2.5's go for around $1000 here with life left in them. You can pick up 200k mile specimens for $500.

Now that I'm reading all of this, the MZR 2.2 Diesel sounds amazing. Did that ever make it over the pond? 300tq and 180hp at 50mpgs.... Wonder what kind of gears it'd take to make that thing usable with an 1800rpm wide power band.

Edit: Fuck you Volkswagen. Cheating on your diesel cars and making the Skyactiv-D be on permanent hiatus.

LS Swap is way more then a turbo build. $1500-2k for a T56, a standalone harness or substantial work to a factory one, the mounts/crossmember/rearend/driveshaft/axles/$800oilpan/front engine drive pulleys/bigradiator/fans/etc add up. It gets more expensive if you use prefabbed parts (V8R/Boss Frog, etc)


The engine itself is by far the cheapest piece of the puzzle. The cost is deceiving.

I have a MSM rear end I might be persuaded to sell...

I have an MSM rear end with axles (no driveshaft) I would swap strait across for a torsen with axles and driveshaft...

If only either of you lived anywhere near this side of the country. Going to be getting a Supermiata serviceable driveshaft, so giving up the stocker from the 99 would be no big deal.