deezums

iTrader: (3)

I believe Curly is in the wrong here, partially.

It's perfectly possible to broach external splines. It's not something done very often, but small volume parts for sure.

In fact, you can use a normal CNC milling machine to broach, assuming it's got a real spindle with encoder. It's not easy on stuff, but it can be done.



And external rotary broaching, something that would be run in volume.

DNA54

I like where this thread is going
Beautiful crack bro, I like your style

18psi

iTrader: (76)

patsmx5

iTrader: (16)

New axle is in, car drives and will spin both cold tires in 1st. All gears seem ok. Looks like it was just an axle failure.

I have two more axles on the way from a 28k mile mazdaspeed, so now it's fixed, and I'll have two spares. Already have a spare MSM diff and MSM trans too. So now I have a complete MSM drivetrain in the car, and spare MSM drivetrain.

ID 1300's show up tomorrow.

18psi

iTrader: (76)

MUWAHHAHAHAHAHHAHA

yes yesssssssssssssssssssssssssss let the boost flow through you

patsmx5

iTrader: (16)

So let's talk about something that will make my car faster and help to not break my axles. Flat shift.

Here is exactly what I want it to do, and I need you guys help on how to make this happen.

I launch on launch control, I got that part working ok, it's flat shift that's not right.


So I launch, and I hit 8,500 RPMs in 1st and my shift light comes on.

I push the clutch pedal in. As soon as it moves about 1/2" or so, the "clutch switch" kicks in and "flat shift" is enabled.

I change gears

I let clutch out.

At last 1/2" of clutch pedal coming up, switch is tripped and flat shift is over.

Now here's what I want it to do:

As soon as I push the clutch in, I want the engine power off/stop accelerating right now. Spark cut is fine, but I want the timing to go very retarded, like -20 or -30, so that HP drops to almost nothing so the revs can fall.

I change gears. I change gears faster than the revs can fall, so when the clutch come out, it "Drags" the engine RPMs down as it's grabbing.

I want the engine to not produce much power during this part, but I want it on enough to keep the turbos spooled up. But it does need to produce a little power to take up drivetrain slack, so say, 50hp coming out the crank or something, enough to load the drivetrain up but not enough to ever break anything.

As soon as the clutch switch is tripped with the pedal all the way up, bam, instant power. But if all the above happened, the rev's are matched and drivetrain slack is taken care of, so the shock loading should be minimal at this part.

Now, how do I make it do that the best way possible?

This is what I ran when I broke an axle.



Next I'm going to update my settings and post what I think will do what I want, and I welcome any advice on how to make it better.

18psi

iTrader: (76)

adjust clutch switch position for starters

why are you retarding so much? (well, I mean I know cause you just said, but it makes no sense). you don't want to retard 30 degrees. you don't want to kill power completely, you want it to transition into the next gear smoothly.

I'll look at your settings more later when I'm not so busy, but I was pulling only 5* and my flat shifts were FLAWLESS. car was basically like an auto in a roll race, smooth non-stop power

DNA54

this.
About the spark retard: I can reach about 10 psi with the clutch disengaged, and with just -10 retard and a looong tube manifold. 30 degrees is asking to burn the gas after the first turbo

patsmx5

iTrader: (16)

Here's the datalog of the failure. It failed the axle shifting to 2nd. Notes in pic to explain what was happening leading up to the failure.



EDIT: Also hit 8,990 RPMs when it failed.... LOL

patsmx5

iTrader: (16)

How should I adjust it? I don't think it's adjustable by design, but if I can, how should it be adjusted?

On the timing, my goal is to keep the fuel on, and not cut spark, and pull enough timing that the motor makes say 50hp. That should be the nicest for the turbos I would think. Or spark cut if I need to, or both, just want to do whatever works and is best for reliability.

This car, the faster it's gotten, the harder getting flat shift right has been. It feels smooth in the car, but the shock loading can be seen in the logs and I have to fix that for reliability.

18psi

iTrader: (76)

I think I had my settings posted here:
https://www.miataturbo.net/suspensio...g-strip-83764/

you're gonna shock load the car either way. if you want less shock go auto. the difference is you're ramping power through the shift vs letting off and then spiking back up. IMO keeping power through the shift gives you a much higher torque load onto the drivetrain into the next gear, like a shove or a push, but it's still less stressful (again, IMO) on the components cause you're not going from 500whp to 50whp back to 500whp within a split second

glade

iTrader: (2)

Just as an fyi, I've a 94 automatic that worked great, and would be a prime candidate for a level10 build I'd be willing to send your way for dirt cheap. (Literally pay 90% of shipping cost and it's there, I'd like the room)

patsmx5

iTrader: (16)

I posted a log of me keeping power through the shift, and posted pics of what that did.

That was the fist shift with those flat shift settings, I normally keep the power off during the shift, that one the engine came on full power as the clutch was dragging the RPMs down. That's fast if it doesn't break something, but in my case I can't do that and expect it to not break.

My goal is like I said, engine makes like 50hp during flat shift (some number much lower than normal), enough to preload the drivetrain to take up the slack, and then full power when the clutch switch says so. Since I'm dumping a 6 puck, I can't use too much power during this part or I'll still shock the drivetrain.

Torque reduction during the gear change, plenty of OEMs do that for drivetrain reliability.

DNMakinson

iTrader: (3)

I would think that going from 50 to 500hp with boost, even in a split second, is still more gentle than dumping a clutch with all the impact involved. As Pat is saying, the slop gets taken out just before the torque increase.

patsmx5

iTrader: (16)

Yes. Reduced shock loading is my goal, and going from even 5hp to 500 is less shock loading than dumping the clutch when there's slack in the drivetrain. That shock goes through everything, and then could introduce wheel hop which causes even more shock loading. That's why OEMs do torque reduction on gear changes, to save the drivetrain. I want the same thing, for the same reason. Much prefer driving my car home vs an expensive tow truck ride and broken parts.

18psi

iTrader: (76)

look at aidans and my logs doing flat shift





look at how much smoother our VSS is compared to Pats. isn't that the whole goal here?

the more VSS spikes the more "shock load" is being done

18psi

iTrader: (76)

you have theory and you refuse to accept that it may be wrong

I'm looking at my logs and vss is way smoother from shift to shift
I'm looking at yours and there's a dip then a huge spike

to me that indicates massive shock/stress, more so than what my car is doing


Now, yours is way faster/more powerful, so it's not exactly apples vs apples, but I still think dropping/spiking is just as, if not more harmful as loading up into the next gear.

but we shall see which way works I suppose

18psi

iTrader: (76)

VSS doesn't lie. it shows what your tires are doing

*edit: the whole point is to keep it accelerating smoothly with the smallest possible dips/spikes in VSS

patsmx5

iTrader: (16)

V those logs have shock loading in them too. 1st log shows RPMs bounching on 2nd gear chagne, 2nd log shows it on 1st and 3rd gear change. What's your point?

I didn't post a log with VSS, I don't have that setup. Though it's a great idea, and I'll get that done since it would be nice to have.

I have not posted any theories, just stop with that please.

I already said this, my GOAL is to reduce shock loading to save the drivetrain. That's it, that's the goal. I don't care HOW it happens, or who's right, or whatever. I just want it to shift fast, keep turbo spooled, and not break. Could give two craps who's right or what settings or whatever.

Post the launch/flat shift settings you used, and a log that shows timing/clutch switch so I can see when the clutch was out when shifting like I posted. And approximate whp and clutch used. All of that is hugely important. And you said adjust clutch switch, how do I adjust it?

I didn't have this kind of shock loading with the ACT XT organic disk clutch. It slipped on gear changes and saved the drivetrain, but eventually wore that clutch out and it started slipping under full power from overheating.

18psi

iTrader: (76)

you go underneath the dash, undo the 17mm nut and thread the switch back/forward and adjust it.

fm has some instructions about it too (it's included with their clutch kit)


.......I honestly don't think you're gonna "save" your drivetrain with that much power/torque either way. but ok do what you will.

my settings for lc/ffs are similar to aidans/deezums I think. in that thread. let me see