I think its been just under a month since I put it in. Low mile 1.6 5spd.

Same thing, a little roll in 5th to speed up to 110kph, made 180kpa an bang.

Someone sell this guy a 6 spd for cheap:S


-Dean

 

Holy **** only 110 KPH, thats about 70 MPH O_O. Phil (levnubhin) had a 6speed, but you being in canada makes it a little difficult. Good luck

 

I love my 6-speed/3.63. Some of the best money I've spent.

 

PM me your info and I'll get you a quote with shipping.
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Was it a junkyard tranny?

Chris

 

Came off my other miata (low km) now I'm really boned, I'll have to find a 5speed for it now too lol. Pwned.

I really want to dyno my car now lol

 

Ive done 100-200 a few times, cant believe it would break there.
Are you into the drags? Launch hard?

 

sucks...

 

So how many 5-speeds have you broke? I find it hard to believe under the circumstance shown this happened. Have you taken any of the broken ones apart to see what fails? There may be something more to this than horsepower/torque.
What do you guesstimate for HP/T?
Is the flywheel/clutch straight to the rest of the world?
Does the trans input sit straight to the crank centerline?
Is the PPF and diff sitting straight?
Does the engine accelerate smoothly in the range this happened at?
I am in Red Deer, I do know of a 6-speed available, about $900cdn

 

This was transmission #2.

Everything looks like its lined up fine, if the imput shaft was off center or misaligned wouldn't the tranny not sit flush against he block, which I does.

PPF is as straight as it can be, being bolted to the trans and diff.

I have solid mounts on the tranny and motor, the motor accelerates smoothly but quite quickly in any gear.

HP/TQ- best guess is 300whp. I went door to door with a raceported fully built GT35R FD @14psi from 60-200kph while I was running 15psi.

My motor is fully built, top and bottom end, ported intake, 2871 blablabla.

I did pull apart the other trans, found some teeth and gear pieces bu couldn't see the gear. Its somewhere in the fore part of he tranny. I still have forth gear but nothing else.

Also I know the case of the trans flexs when this happens because I had a SS band around the trans holding the exhaust up (didn't hook it up :S )

Alta Racer pm me your name number or something cause 900 sounds good.

Oh and if my grammar or spelling doesn't make sense its because I'm posting from my shitberry.


-Dean

 

The problem is overloading a shitty weak transmission in a high gear, or making to much torque to quickly in a high (and weak) gear.

 

> Everything looks like its lined up fine, if the imput shaft was off center or misaligned wouldn't the tranny not sit flush against he block, which I does.

Nope. If the alignment is not correct the disc will sit off center in the clutch assy, this can cause side loading on the input shaft. The dowel pins may not center correctly, be back of the engine can be off alignment from crank centerline, same as the bell on the trans. Flange of the crank can be not straight, causing a wobble on the flywheel. All these things can crate havoc with trans internals, and the trans will still slip right into place. Remember that this is not precision fit from the factory. BTDT Just had a major go around with my ACT clutch, the pressure plate was not parallel to the cover.


> PPF is as straight as it can be, being bolted to the trans and diff.

There is some adjustment to the PPF, its a minor thing, but I have heard of vibrations from that area. How is the balance on the driveshaft, and is it straight? U-joints don't have any bind?


> I have solid mounts on the tranny and motor, the motor accelerates smoothly but quite quickly in any gear.

HP/TQ- best guess is 300whp. I went door to door with a raceported fully built GT35R FD @14psi from 60-200kph while I was running 15psi.

> My motor is fully built, top and bottom end, ported intake, 2871 blablabla.

Power can break things, but usually gears are broken when things are violent, not smooth.



> I did pull apart the other trans, found some teeth and gear pieces bu couldn't see the gear. Its somewhere in the fore part of he tranny. I still have forth gear but nothing else.

4th gear is straight though, its almost like a straight shaft through the trans. None of the gears on the cluster shaft are used. Would imagine that it is the input to cluster gears that broke.


> Also I know the case of the trans flexes when this happens because I had a SS band around the trans holding the exhaust up (didn't hook it up :S )

Case flex was always understood to be the weakness to the trans, Quaife says it is in reality the gears that are weak. Expensive, but would be my choice over the 6-speed.


> Alta Racer pm me your name number or something cause 900 sounds good.

Will do

With the trans out, get a magnetic base dial indicator, and measure everything you can! I have seen many broken transmissions, standard and automatics, that fail due to the "assumed" factory correctness. I have not had a Miata trans apart, but I will bet that the bellhousing part comes off, and has a round hole you can use to check alignment to the block and crank. Flywheel is easy. Crank flange is ok if the flywheel is straight when you spin the crank with the dial indicator base on the block, and the needle on the flat surface for the disc. There are offset dowels for other engines, not sure about Mazda. Added benefit if this stuff doesn't fix the trans breakage, you can find some free horsepower, by getting it all straight. There are a ton of things that can be done to "blueprint" the driveline.

 

That I can check no problem when I pull the trans. But IIRC she was all lined up, redline on my motor is 8k and its smooth as silk up there.

Acceleration is definately violent


I figured as much there.

Mine aswell, can I borrow a couple grand


Sounds like fun, but I do want to make sure if I put a 6 speed in there I don't break it(atleast not before I dyno the dam thing)


-Dean

 

Alta,

I would be very interested to learn what can be done to balance the Miata's drivetrain, I am sure many here would be too. If you discover anything, please post.

 

I would like to know about this driveline blueprinting as well.

 

So what's the count? 2 or 3 1.6 diffs? 2 transmissions?

What's the constant here? Stop driving like a tool.

 

Track your car much? Is that driving like a tool? Or are you just jealous that my miata is faster? Lol

 

It isn't faster than my Miata right now is it? I was driving mine just today.

And no I don't take my car out to the track. Having two kids and a new house has limited the time I've had to drive my car for fun. Next year I plan to do a couple laps on the go-kart track. Maybe me and my slow (running) car will see you there.

 

I feel your pain. Pics of my transmission:
Link

+1 on details for driveline blueprinting.

 

Correct me if I'm wrong.. but blueprinting a driveline would just be measuring everything and making sure individual tolerances are not too far out of wack, and making sure that the tolerance of multiple parts don't add up to too far out of wack.

If all the tolerances are good, the driveline should be good. The problem with things like transmissions is that there are so many tolerances that even though individual parts may meet the requirements, if you add up all the variations you may get an inferior product that still passes inspection.