5 speed power capabilities with boost
 

Hey just wondering how much power can a 5 Mt hold looking at boost

Some of it.

Hey just wondering why you can't read the stickies instead of posting.

Oh if only this was documented somewhere on this site.

I don't know why these guys are being such dbags when all you did was ask a simple question.

The stock 5 speed is kind of a glass case and will break pretty early, like around 5-8 psi. The rods, on the other hand, are super strong, good for 20+ psi. People put Miata rods in all sorts of other engines as upgrades. Little race secret for ya ;)

Trae - it depends on the year of the transmission.

90-93 5MTs are generally luck of the draw - some go at around 150hp, others have been documented to 475hp for hundreds of track hours.

Starting in 94 and going through the 97MY in North America (98MY everywhere else), they pretty much all became butter. 175hp is generally the limit, some have gone to 200hp. There are no documented '94-'97 transmissions running over 215hp long enough to get a good dyno pull in.

To fix this problem, mazda re-looked the 5 speed, but since they ran out of time for the '98 model year, they adapted the old RX7 trans to the Miata in North America for only the '98 cars. Those RX7 transmissions are beasts - there are only 2 documented cases of the '98 RX7 trans going in the Miata, both well over 650AWHP.

Starting in '99, Mazda had generally fixed the problem, and all of the 5 speeds from 99 through end of production are generally expected to hold 450-500 HP for the life of the car. The '99 and on transmissions use different mounting points, though, and are not compatible with any previous Miatas without also replacing the entire front subframe and using the shorter PPF.

Isn't this dependant on what turbo is being used? I can imagine it grenading at 5-8psi with a huge turbo, but I've had no issues at 12 psi with my little TD04H.

Hey now, no real info allowed. We are trolling a noob here.

Shit, whoops.

I grenaded my 5sp with 900whp, but I was granny shifting not double clutching

Congrats OP

You are the 1,000,000th person to ask that question! As your prize, you will be awarded as much sarcasm as we can fit in this thread. If you want an answer, search.

If you double clutch all of your shifts they've been track proven to be pretty reliable upwards of 350+ hp. Its the horsepower that kills them not the torque.

just install a 1.6 that way you limit your horsepower but have diesel-like torque

I'm actually using diesel in mine right now. It required different spark plugs but the torque output is increased by about 38%. It also lets you belch giant clouds of black smoke when you floor the throttle, which is pretty cool.

I hear diesel in a Miata is a pretty cool thing. :party:

No dude, size of turbo, type of clutch, driving style, etc. Has nothing to do with how long the parts will last. Only how much boost you're pushing. Don't you know that's why that's the only question people ask anymore? "How much boost will the engine take" cuz that's all that matters.

Quit complicating the situation with facts.

I guess I deserve an eggplant as much as OP this morning.

when I go car shopping, the one and only question I ever ask is: how much b00zt will it hold bro'z

Fun Fact: customer at work buying a new Jetta GLI at work the other day, overhear them asking the sales person "how much boost does it put out?"

Go with the 4spd, much stronger and better for boost because of the longer gearing. The 4spds only came on the 89' model year so you have to look a bit, but they are out there (most people "upgrade" them to the 5spd because they are stupid).

Isn't that the same Ford 4-speed that was used in the early Fox-body Mustangs?

Be aware, none of the follow up information is correct following the original post in this thread. you are being trolled.

Yes.

Nobody drives a manual anymore. It's best to swap a 2 speed powerglide.

Whaddaya mean "this morning"?

Touche.

Dude, even noobs have a right to solid info. Just because you don't like people helping this guy out doesn't mean you should discredit all this good info.

Dude...Have Fun With This...

OP, the reason you are getting info all over the map is that is sort of an apples-to-cantaloupe question.

How much boost a 5 can take is going to depend on a few things, some of which are listed below:

Your clutch line. Get braided stainless or its pretty compromised.
Roll bar style. Think about how the bar stiffens the chassis. That stiffer chassis in turn provides more stability for the transmission case through the PPF and the mount. 95's have a bit of an advantage with their stock brace just behind the seats. Style bars help minimally here, but a true roll bar from Hard Dog etc. is the way to go.
Steering rack. A powered rack puts more torsional stress on the chassis, and that can weaken the system. People run a depowered rack for a reason.

More accurately, apples to eggplants.

Some of yall are assholes I'm asking a simple question Im new to miatas damm.....thank you the guys that helped me

Answer me this: A sophomore shows up on the first day of tenth grade and asks with a straight face: "How do you dial 911?"

How do you react?

Don't take it too hard, we've all been in your spot at one time or another. Just remember that respect gets respect, and a quick search might help take away the pain next time lol.

The true irony is that not a single post in this thread actually gives the correct answer to your question...

It must be true, I read it on the Internet.

I will say threads like this are why search dosn't work either.

Are you also new to the internet or the concept of research?

Actually you do have a point here. Searching for stuff using the function on this site basically returns a bunch of cat pictures and threads like this.

Just once I want to see someone build a car using info from threads like this with no double checking or filtering of any kind. It would probably have doors that open downward, use an MP62 as a muffler, run a gear vendors overdrive behind an auto, nitrous directly into the valve cover, plasti-dipped cams, 1.6L, ford 9 rear, and a style bar for a bumper.

However, it took me 30 seconds on Google to find the info required here. It was on Miata.net. :rofl:

I would contribute $50 to this build.

Fae and techsalvager tried their best.

Whoa whoa whoa. I did not know this!

I have a 99' but it was built in April of 98. Any Chance that I got the RX7 Tranny? :D

Needs to get rebuilt anyways. It has locked into reverse 3 times already and it getting pretty hard to shift sometimes...

Note to all Noobs who missed it when a couple other people already said it:

ALL OF THE INFO IN THIS THREAD IS FALSE.

:facepalm:

...except for this post...

Real info

How much whp can the 6 spd tranny take? - MX-5 Miata Forum

Nice! -2 props for providing information. The audacity of some people :D