Jump to content
SAU Community

Recommended Posts

Proof is in the pudding. But still dubious of the 300-400% claim. Can someone point me in the direction of a good article on this?

My understanding from the old Iron Carbon diagram has always been strength-Ductility-toughness vs hardness is greatly dependent on the rates of heating and cooling etc and grain size and type. With cryo freezing you are not changing the grain structure type/composition, rather just refining the grain structure by making it slightly smaller and more uniform. So you are not increasing the UTS etc of the component, but stress relieving it so that it wont fail at its weakest point.

At work ATM, will post up excerpt from textbook tomorrow. But yeah basically what I got from it was that you're not actually make the gears any stronger.

Please don't get confused here... strength and hardness are two different properties. Hardness will most likely increase as a result of cryogenic treatment due to the formation of martensitic grain structure in the steel. With increased hardness the material wll become more brittle.

But this is just piss in the wind, I doubt anyone knows what steel the gears are exactly or if anyone has examined the grain structure before and after to know whether it has actually made a difference.

Please don't get confused here... strength and hardness are two different properties. Hardness will most likely increase as a result of cryogenic treatment due to the formation of martensitic grain structure in the steel. With increased hardness the material wll become more brittle.

But this is just piss in the wind, I doubt anyone knows what steel the gears are exactly or if anyone has examined the grain structure before and after to know whether it has actually made a difference.

Ring Heat Treatment Australia. Their exact words were: 'improves the strength of the metal by 300-400%'. This certainly does not mean you are wrong, just relaying what they said as I am definitely no expert

They do the same thing to ambulance rotors and get more than double the life out of them. Not sure about the formation of martensitic grain structure but I know for a fact the gearboxes we have done are definitely stronger, which is the point.

I wonder with the ambulance rotors if that affects braking power?

I was always under the assumption that softer rotors provide better braking. With ambulances though, it is only designed for street conditions so that would be ideal for longevity.

OK I have finally made it to the 400 kw thread.

Car running rb26 block and -5's

Car made on 19psi 420rwks - I'm wrapped :D

Massive thanks to Trent & Cat from Chequered tuning who tuned the car over the weekend (wouldn't go anywhere else)

Trent tuned a felxi fuel set up on my Autronic

Also a huge thanks to Tas (Power Glide GTR) for getting the car to where it is - car has turned out mint mate :)

This is a hub result, yeah?

yeah, but my car has read 350'ish awkw on 98 at Chasers 4WD dyno and 356rwkw on 98 at Trent's dyno. I'm due for a service and what-not, so i'll try and can get a Racepace one done as well.

For Melbourne, Trent's dyno is inline with all other big shops

i was under the impression it was 20psi

doesn't sound that far fetched... i got 400rwkw on 256 cams at 21psi - this car has bigger cams would seem reasonable i guess

It's E85 as well remember :)

420kw on 19psi is.....questionable.

Your kidding right !!

I dont jump in on these threads much but I've seen plenty of cars in Japan running 1.3 bar and pushing well over 400kw.

I know of a few floating around oz as well.

You dont need big boost to make response and power, just a well built motor top to bottom.

well if its a hub dyno then yea its goin to read higher,

mine made 375rwkw on a chasis dyno, on gate spring pressure which was around 18 psi

cam gear set on 0 and on Pump gas

LIke Marcus said, everything needs to be set up correctly.... EVERYTHING!

and everyone else has missed the fact the Trent's dyno DOESN'T read higher than other dyno's in melb :rolleyes:

It made 370rwkw on 98, which is about what you'd expect for 98 for '5s RB26 - it's around what the RP cars make on 98, Chasers cars make on 98 etc. If an RP car came up in a thread saying they made 370rwkw with -5's on a 98, no one would blink an eye and think it's just par for the course.

Hub dynos read higher if the operator wants them to read higher

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



  • Similar Content

  • Latest Posts

    • Hey Dave, welcome aboard! Good to see another soon-to-be Stagea owner here. The wagons are awesome — plenty of space, still got that Skyline DNA, and loads of potential if you’re into mods. Definitely post up pics when you get it, everyone here loves seeing new builds. What model/year are you looking at?
    • See if you can thermal epoxy a heatsink or two onto it?
    • The other problem was one of those "oh shit we are going to die moments". Basically the high spec Q50s have a full electric steering rack, and the povo ones had a regular hydraulic rack with an electric pump.  So couple of laps into session 5 as I came into turn 2 (big run off now, happily), the dash turned into a christmas tree and the steering became super heavy and I went well off. I assumed it was a tyre failure so limped to the pits, but everything was OK. But....the master warning light was still on so I checked the DTCs and saw – C13E6 “Heat Protection”. Yes, that bloody steering rack computer sitting where the oil cooler should be has its own sensors and error logic, and decided I was using the steering wheel too much. I really appreciated the helpful information in the manual (my bold) POSSIBLE CAUSE • Continuing the overloading steering (Sports driving in the circuit etc,) “DATA MONITOR” >> “C/M TEMPERATURE”. The rise of steering force motor internal temperature caused the protection function to operate. This is not a system malfunction. INSPECTION END So, basically the electric motor in the steering rack got to 150c, and it decided to shut down without warning for my safety. Didn't feel safe. Short term I'll see if I can duct some air to that motor (the engine bay is sealed pretty tight). Long term, depending on how often this happens, I'll look into swapping the povo spec electric/hydraulic rack in. While the rack should be fine the power supply to the pump will be a pain and might be best to deal with it when I add a PDM.
    • And finally, 2 problems I really need to sort.  Firstly as Matt said the auto trans is not happy as it gets hot - I couldn't log the temps but the gauge showed 90o. On the first day I took it out back in Feb, because the coolant was getting hot I never got to any auto trans issues; but on this day by late session 3 and then really clearly in 4 and 5 as it got hotter it just would not shift up. You can hear the issue really clearly at 12:55 and 16:20 on the vid. So the good news is, literally this week Ecutek finally released tuning for the jatco 7 speed. I'll have a chat to Racebox and see what they can do electrically to keep it cooler and to get the gears, if anything. That will likely take some R&D and can only really happen on track as it never gets even warm with road use. I've also picked up some eye wateringly expensive Redline D6 ATF to try, it had the highest viscosity I could find at 100o so we will see if that helps (just waiting for some oil pan gaskets so I can change it properly). If neither of those work I need to remove the coolant/trans interwarmer and the radiator cooler and go to an external cooler....somewhere.....(goodbye washer reservoir?), and if that fails give up on this mad idea and wait for Nissan to release the manual 400R
    • So, what else.... Power. I don't know what it is making because I haven't done a post tune dyno run yet; I will when I get a chance. It was 240rwkw dead stock. Conclusion from the day....it does not need a single kw more until I sort some other stuff. It comes on so hard that I could hear the twin N1 turbos on the R32 crying, and I just can't use what it has around a tight track with the current setup. Brakes. They are perfect. Hit them hard all day and they never felt like having an issue; you can see in the video we were making ground on much lighter cars on better tyres under brakes. They are standard (red sport) calipers, standard size discs in DBA5000 2 piece, Winmax pads and Motul RBF600 fluid, all from Matty at Racebrakes Sydney. Keeping in mind the car is more powerful than my R32 and weighs 1780, he clearly knows his shit. Suspension. This is one of the first areas I need to change. It has electronically controlled dampers from factory, but everything is just way too soft for track work even on the hardest setting (it is nice when hustling on country roads though). In particular it rolls into oversteer mid corner and pitches too much under hard braking so it becomes unstable eg in the turn 1 kink I need to brake early, turn through the kink then brake again so I don't pirouette like an AE86. I need to get some decent shocks with matched springs and sway bars ASAP, even if it is just a v1 setup until I work out a proper race/rally setup later. Tyres. I am running Yoko A052 in 235/45/18 all round, because that was what I could get in approximately the right height on wheels I had in the shed (Rays/Nismo 18x8 off the old Leaf actually!). As track tyres they are pretty poor; I note GTSBoy recently posted a porker comparo video including them where they were about the same as AD09.....that is nothing like a top line track tyre. I'll start getting that sorted but realistically I should get proper sized wheels first (likely 9.5 +38 front and 11 +55 at the rear, so a custom order, and I can't rotate them like the R32), then work out what the best tyre option is. BTW on that, Targa Tas had gone to road tyres instead of semi slicks now so that is a whole other world of choices to sort. Diff. This is the other thing that urgently needs to be addressed. It left massive 1s out of the fish hook all day, even when I was trying not too (you can also hear it reving on the video, and see the RPM rising too fast compared to speed in the data). It has an open diff that Infiniti optimistically called a B-LSD for "Brake Limited Slip Diff". It does good straight line standing start 11s but it is woeful on the track. Nismo seem to make a 2 way for it.
×
×
  • Create New...