I picked up my rear end swap today (open rear, axles, rear brakes, loose torsen, 2 sets of hawk ht9's = $450...lol).

Any sense in getting that **** cryo'd with <300whp?

 

I'd say no, the diff will be good at 300, tranny will not.

 

less than 300.

 

It does not hurt to get it cryo treated.Consider it insurance,cause you never know.

 

It's really not a bad idea. Cryo treating it will help it deal with excessive heat created running it fast on the highway and on the track.

 

where can one get it done?

 

Cliff notes: Can a cryo treated 7" ring a pinion take drag racing abuse?

Yes, I know the thread is old.

Long:

So my 3.636 gearset arrived from mazdaspeed earlier this week.

I have been debating getting the gearset cryo-d. I can't seem to find anyone locally who does it.

How much does it usually run?

Will it actually do anything? I have seen some people drag racing blowing up even 7" R&P's here on mt.net.

So basically, With the megasquirt (launch control) and some 225/50/15 drag radials, If I built some boost of the line and dumped the clutch will the cryo treating save my diff or not?

Because I am not blowing up a discontinued $350+ gearset launching it hard if the cryo won't save it's ***.

My drivetrain setup:

Fidanza 1.8L Flywheel
ACT HD PP, 6 puck race disc unsprung
Stock 2 piece axles
Rebuilt RX7 LSD Clutch Type
3.636 Gears (Cryo treated?)
5spd trans (Eventually upgrade to a 6speed)
Edit: MMR Diff Mounts
Edit: Mazdaspeed Motor Mounts

If the setup can't take the 200-250whp and 250-300whp (with 6spd) I will not launch it with launch control or dump the clutch.

I will just live with half a second to a second slower 1/4mile times, Drag racing isn't why I bought the car anyways.

 

Unless you're willing to sacrifice your gears, why risk it?

 

Your location says Ontario which I assume is Canada, but if you are in Ontario, California there is a shop down here in San Diego that will cryo treat your stuff.

Certified Metal Craft

 

Exactly my question, Will cryo'ing make it so that I don't sacrifice the gears.

Some of you guys are making big power here, But I don't see anyone posting vid's at the strip shooting flames and building boost and dumping the clutch.

With EBC I can build a few PSI, the question is how much does it take to brake a 7" R&P. 150whp launch, 200whp launch, 250.... etc. Or has nobody measured?

I would rather NOT be the testmonkey and end up with a broken R&P, but I would rather not totally baby the setup if it can take it.

 

https://www.miataturbo.net/forum/sho...en+slaughtered

ApexOnYou seems to be the only one that is doing repeated drag racing on here.

Maybe I will send him a PM and discuss.

I am NOT looking to spend my friday nights all summer long at the local dragstrip, but I would like to go a few times and see what my car does.

Even on the street, it would be nice every once in a while to get a sweet launch in and see the WTF? looks.

 

FWIW, you might want to check your backlash to make sure it's in spec if your wanting to make it as strong as possible. I would adjust it to the lower number of spec, which reduce the amount of free play between the ring and pinion. It's the 'shock' that breaks the gears, not the power so to speak. That seem to contridict itself, but what I'm saying is it's not how much power you have, so much as it is the shock you place on it. A stock miata with drag radials and a stought clutch can place a lot of shock on the stock R&P with a clutch dump.

Also set the preloads on the tight side, or even a spec tighter if you dare. This keeps everything tighter, which means when everythings under a load, it will stay closer to spec, which is good. However, to much preload is bad, as it causes excessive heat, noise, and will wear out the bearings quicker. It's a fine line to get it all balanced for strength and reliablility. A shop that builds drag cars can tell you more than I can, but anyway there's more than one way to do it, sort of. When I do mine, I'll be setting everything to the tight end of spec, or tighter, since I drag race and am welding the spider gears so I can launch harder. Run synthetics as they hold up to heat better, and cut down on friction.

Oh yea, Cryogenic treating will increase the amount of shock the parts can take before breaking, so that's not a bad idea either. However, setting the rear end up to counter the shock is gonna do more than cryo.

Edit: you'll need a 6-7 or 7-8 inch micrometer to check the preload, and a magnetic based dial indicator to check backlash. Lucky me I have a dial and a 6-12" set of micrometers too. Talk about exensive.

 

I was always under the impression this was NOT doable by a DIY guy. I have the micrometers, but not the magnetic based dial indicator.

I will read up on this, but like I said, depending on how much a local drivetrain shop would charge me I was thinking of bringing them the pumpkin,lsd and r&p and paying them to assemble it, set preload and backlash.

I have spent a fair chunk of change on this diff, I would rather it not blow up.

I forgot to mention I will have MMR diff mounts and mazdaspeed motor mounts.

 

It's doable if you have the right tools and know how to use a mike and a dial idicator. I've never done it before, but it's justs taking measurements and adjusting things in order until everythings in spec, then torque down the adjusters, and reassemble. There's a link in the garage section on miata.net that explains what to do and has pics too, as well as the specs. Look it over and see if you think you can do it. I would feel better doing it myself, as I KNOW it is right because I actally did it, not some yahoo at a shop.

 

I'm not sure if it can take it forever but cryo treating it would sure help in prolonging its life. I've allready lost a Torsen at the strip, and I was only at 10psi on Azenis with no 2 step. I kept hearing that the Torsens can handle 350HP+ but not if you are drag racing. I would guess I only had 10 or 15 runs on that diff. Maby this video will make you want to get it cryo'd haha.

Or this picture






:edit: That was NOT cryo treated..

 

Hey,

How much Power are you making?
What Clutch?
What did you launch at?
Dump or Slip the clutch?

Any warning before the diff went?

Thanks.

Edit: Wheelhop?

 

I haven't dyno'd yet, I would guess around 250hp-ish. I have a ACT Stage 2 (If I remember correctly, its been over a year since I put it in) clutch with a 8.8lb flywheel. I didn't have a camera in the car on the run that I munched the diff on but i'm almost positive I launched around 5k, if not 5500. I slip on launch at the track. Also may want to mention that I dont let off the gas on my 1-2 and 3-4 shifts which is another shock on the diff. No signs of warning before it failed. I did wheel hop for the first time the run prior. Im thinking that had the most to do with it.

 

Once the diff is off the car it's super easy to set backlash/preload. I did mine and it was my first. The procedure is all clear and in the manual. Pie.

 

eliminator77 is running a cryo treated 7" torsen, beats the **** out of it, and is now at 590 whp.

 

Now that's awesome.