Jump to content
SAU Community

Wpc - Cryo - Shot Peen Treat For More Strength ?

cobrAA
 Share

Recommended Posts

cobrAA Mentor

cobrAA

Posted
Posted

I want to strengthen some of my tranny component and I'm looking for feedback or opinion on this.

1) Anyone tried one of these process ? should I only do one process or can I do 2 or 3 of them ?

2) which part should I think about treating ? gear + synchro ? Anything else ? Should I try to treat other component of my engine rebuild ( valve- valve spring - camshaft - piston etc.)

Thanks guy :)

  • 1 month later...
sucram Rising Star

sucram

Posted
Posted

Shot peening and cryo seemed to help on a diff. Never tried WPC

Some gearsets come peened and cryo from factory, i.e albins

Also heat can make shit expand, a pinion heated up to 80 deg c gained 2mm in length which changes

the contact patch, if your running on the brink of failure for 20+ mins in competition you want to

look into additional capacity, additional fins or even pumps and coolers

Wouldn't bother doing it to an aftermarket gearset, most are peened already if helical.

valve springs are already peened, would not bother cryo

Would not bother with cam either, snapping cams you have other issues

I have cryo'd a crank before, but that was when it was new and still cheap.

warps Mentor

warps

Posted
Posted

Closer to .02mm

Given that steel has a thermal coefficient of expansion of about 12x10-6 m/m K, a 50mm diameter pinion will grow approximately 0.033mm when heated from 25 deg C to 80 deg C.

On the heavy mining equipment we run the gearboxes with .5mm to 1.5mm backlash, and those pinions are about 300mm diameter, with gears about 1.5m diameter. The change in backlash is negligible when they are at full operating temperature. Scaling that down to an automotive gearbox running 0.1 - 0.2mm (?) backlash, I would think that any expansion beyond 0.1mm (combined between the pinion and gear) would be catastrophic.

sucram Rising Star

sucram

Posted
Posted

Nope, it was 2mm, pinion in particular was from a Subaru front. It is very long

and part of the layshaft so box temp is the same as front diff. An R200 is about

half the length.

Peened, cryo, backlash set for higher temps, gearbox oil cooler and pump

solved the problem

  • 2 months later...
tricstar Mentor

tricstar

Posted
Posted

Yep. True story.

Altho that clutch also saw off a couple OS gear sets too. I think someone needs to try it with a friendlier clutch, for a better test.

But my gearbox guy cryo's high hp 4WD autos with really good results also. ?!?!

GTRPSI Mentor

GTRPSI

Posted
Posted

Autos force shock impact will always be less than that of a manuals shock impact.

Many are Cryo treating Auto parts with great sucess, manuals are more a mixed bag of results with more manual components failing.

Those breaking manual boxes and drivelines on launch (only) have learnt that loading up the driveline with some clutch grab to take up the driveline slack before launching violently have had reduced breakages just by changing to that technique.

Most breakages are from sudden shock impact loading.

MrStabby Grand Master

MrStabby

Posted
Posted

tric - any oiling mods in your gearboxes? I hear that Award Diff and Gearbox here in Sydney do *something*. Might also be worth trying something like Liqui Moly Mos2 gear oil additive as a hack as it should help if there's any starvation causing the gears to fall out of sliding hydrodynamic into boundary lubrication.

Edit: are your failures as you just start to gun it in the gear, or after you've been gunning it in the gear for a while?

tricstar Mentor

tricstar

Posted
Posted

Thanks Stabby. I have since sold the GTR with a new OS box and coppermix clutch. I did put a lot of the breakages down to brutal R3C OS clutch. Most breakages were on the shift or just after. And quite a few were towards the end of track work or sprints so I definately think a cooler would help. But this is all getting a bit off topic, so I still couldn't definitively rule out Cryo being an option with a nice sprung centre clutch.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • LegendGTR
      EFR7670 exhaust selection RB26

      By LegendGTR · Posted

      I'm looking for some real world experiences/feed back from anyone who has personally ran a EFR7670 with a 1.05 exhaust housing or a .83 I'm leaning towards the .83 because its a street car used mostly for spirited driving in the canyons roads. I"m not looking for big numbers on paper. I want a responsive powerband that will be very linear to 8000 rpm. I dont mind if power remains somewhat flat but dont want power to drop off on top. The turbo I've purchased is a 1.05, although the mounting flange T3 vs T4 and internal vs external waste gates are different on both housings, I not concern about swapping parts or making fabrication mods to get what I want. Based on some of the research I've done with chat gpt, the 1.05 housing seems to be the way to go with slightly more lag and future proofing for more mods but recommends .83 for best response/street car setup. AI doesn't have the same emotions as real people driving a GTR so I think you guys will be able to give me better feed back 😀   
    • PranK
      Stock Airbox and Snorkle for RWC - VIC west

      By PranK · Posted

      Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • PranK
      Duncan's V37.......race car?

      By PranK · Posted

      This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • Duncan
      7 Speed Auto transmission fluid change (Skyline, Q50, Q60, Fuga, Q70, A62 Titan and probably heaps of others including Navara...)

      By Duncan · Posted

      OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
×
×
  • Create New...