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Just now, Birds said:

Power is directly related to torque, son. These engines aren't different enough that if producing the same power there will be a large difference in peak torque. You'd be talking ~50nm at best. The 25 will bring on the torque and power earlier and that's about it. Hardly cog-stripping material. Unless he's button clutching it with a locker and slicks he'll be right.



Tell that to a 7L V8 in an old ute that only makes 200kw but can tow a GTR on a trailer behind it without breaking a sweat. 

RB20s are junk, and their gearboxes are even bigger junk. There is a large difference in low down torque, stop looking at dyno sheets for proof and go test drive the engines back to back. How many people have you seen say that they need to ring a 20's neck above 5k to get it moving. Considering you have a high flow and brag about its response.. I don't think you could live with a 20 even though its "only ~50nm at best" 

If you're gonna convert it to 25, which you won't because you've already made up your mind, buy the box... otherwise whatever.

Completely different engine. Let's keep the comparisons sensible shall we...given we're talking about two engines that, all things equal, are 500cc different. That is why I'm happy to generalise that, with similar power levels, one won't be smashing cogs over the other.

FYI...I have driven RB20s and RB25s, back to back. I agree the former is a piece of shit that takes forever to make power, but this fact is largely irrelevant, because when it does make that power it is nearly the same peak torque being transferred through the gearbox. Load and peak torque are what smashes gears, not where in the rev range that peak is...which is ultimately the difference between a 20 and a 25.

And if we're going down the path of experience...well...I've fitted countless 20DET gearboxes to modified vehicles, from VLs and 31s to S15s and 25DE+Ts. Done a lot of 25DET gearboxes too. It is the far superior gearbox, but as long as you're not smashing synchros and dumping button clutches with slicks, you're unlikely to break the 20DET box with less than 250rwkw in a 25.

Anyway, I can't see Pat putting in a 25, as he doesn't want to overcapitalise on a 5k(?) car. Hence the garden variety detailing jobs.

  • Like 1

Quick question for the IT dudes in here. Revolution IT did the load testing on the Census website and ran it at 150% of the expected users to login at the same time. They charged the government $500,000 to run these tests. Does that seem exorbitant? I can imagine they'd have a powerhouse of a computer and server system but god damn that's a lot of money for something that still failed anyway...

well they failed so yes exorbitant.

 

to load test something that they expect 10 million hits in a couple hours...well you have to replicate millions of users, honestly to do it properly I would expect it to be more.

 

 

 

Completely different engine. Let's keep the comparisons sensible shall we...given we're talking about two engines that, all things equal, are 500cc different. That is why I'm happy to generalise that, with similar power levels, one won't be smashing cogs over the other.

FYI...I have driven RB20s and RB25s, back to back. I agree the former is a piece of shit that takes forever to make power, but this fact is largely irrelevant, because when it does make that power it is nearly the same peak torque being transferred through the gearbox. Load and peak torque are what smashes gears, not where in the rev range that peak is...which is ultimately the difference between a 20 and a 25.

And if we're going down the path of experience...well...I've fitted countless 20DET gearboxes to modified vehicles, from VLs and 31s to S15s and 25DE+Ts. Done a lot of 25DET gearboxes too. It is the far superior gearbox, but as long as you're not smashing synchros and dumping button clutches with slicks, you're unlikely to break the 20DET box with less than 250rwkw in a 25.

Anyway, I can't see Pat putting in a 25, as he doesn't want to overcapitalise on a 5k(?) car. Hence the garden variety detailing jobs.



I agree with everything in this post

I was tempted to see what would happen if deliberately inducing lag by ramping boost late (like a centrifugal charger) would be a way to get 400+kw from a R33GTST box.

Would be interesting to see what the torque curve would be like if you run say 14psi at 4k then ramp it slowly to 25psi at 7k. May be a way of keeping a box going. Should result in a big flat line for torque as opposed to a massive spike then it falling off.

12 hours ago, emts said:

well they failed so yes exorbitant.

 

to load test something that they expect 10 million hits in a couple hours...well you have to replicate millions of users, honestly to do it properly I would expect it to be more.

 

 

 

Pretty much this.. I'm not in the webhosting business so can't explain HOW they'd actually test millions of users at the same time accessing their server(s) I'd guess they'd have a bunch then just use math to multiply the load up to however many users.. 

Lets not forget the failure could be due to hackers etc attacking 'for the lulz'

And also that there's a lot more underlying than just server load.. you've got to have enough network infrastructure and bandwidth to flow all that traffic which I reckon is where it would have failed. Like the Monash. 

Don;t call these guys Hackers, thats giving them way too much credit, it is script kiddies doing a Ddos via a zombie network. (if it was an attack)

 

It's that easy even Birds could do it.

http://www.symantec.com/connect/blogs/renting-zombie-farm-botnets-and-hacker-economy

 

the funny thing is load testing is a very similar process, get a whole bunch of boxes and start loading/posting data to the site. monitor.

 

What is interesting is that this might not actually be a DDos attack just a crappy scoping exercise.

so apparently they estimates the traffic at max 1 million users per hour, so the load testing at 150% would be 1.5 million users.
now lets say there around 10 million users submitting online.
I would guess around 1/2 would have sat down in the evening and gone ok Fk it lets do it.
so 5 million in 2ish hours or much more than they scoped.

they could have Ddosed themselves with legit traffic.

 

that also said doing it in the "cloud" is meant to mitigate this as they can just virtually throw more CPU's at it till traffic is gone. 

 

 

 

3 hours ago, Kinkstaah said:

I was tempted to see what would happen if deliberately inducing lag by ramping boost late (like a centrifugal charger) would be a way to get 400+kw from a R33GTST box.

Would be interesting to see what the torque curve would be like if you run say 14psi at 4k then ramp it slowly to 25psi at 7k. May be a way of keeping a box going. Should result in a big flat line for torque as opposed to a massive spike then it falling off.

Keeping all the bad parts of a turbo and getting rid of the good is a Mohsen spec idea.

Might as well fit a smaller turbo that will deliver the same boost and power much earlier on. The reason you'd be getting 400rwkw from the box is that the engine is seldom going anywhere near that and you've effectively dulled your turbo to perform like a small one, but with more lag. If the box can't handle 400rwkw, the day you take it to that peak is likely the day it will break. Unless the box weakness is its input shaft, 4th gear being a 1:1 is less likely to strip cogs.

Think of it this way - a chair is rated to seat 100kg. Someone 140kg sits down on it, quick or fast, that chair is eventually going to break under their weight. You can break it with 80kg if you jump on it (ala dumping clutch).

A turbo ramping up fast isn't quick enough to snap teeth; only the torque limit of the box or a sudden surge from standstill will do that.

2 hours ago, UNR33L said:

Pretty much this.. I'm not in the webhosting business so can't explain HOW they'd actually test millions of users at the same time accessing their server(s) I'd guess they'd have a bunch then just use math to multiply the load up to however many users.. 

Lets not forget the failure could be due to hackers etc attacking 'for the lulz'

And also that there's a lot more underlying than just server load.. you've got to have enough network infrastructure and bandwidth to flow all that traffic which I reckon is where it would have failed. Like the Monash. 

Oh I forgot to...carry the 1

tumblr_lkhcjft2j91qztjn5o1_500.png

  • Like 1
16 minutes ago, Birds said:

Keeping all the bad parts of a turbo and getting rid of the good is a Mohsen spec idea.

Might as well fit a smaller turbo that will deliver the same boost and power much earlier on. The reason you'd be getting 400rwkw from the box is that the engine is seldom going anywhere near that and you've effectively dulled your turbo to perform like a small one, but with more lag. If the box can't handle 400rwkw, the day you take it to that peak is likely the day it will break. Unless the box weakness is its input shaft, 4th gear being a 1:1 is less likely to strip cogs.

Think of it this way - a chair is rated to seat 100kg. Someone 140kg sits down on it, quick or fast, that chair is eventually going to break under their weight. You can break it with 80kg if you jump on it (ala dumping clutch).

A turbo ramping up fast isn't quick enough to snap teeth; only the torque limit of the box or a sudden surge from standstill will do that.

That's the thing though, most dynos have *peak* torque at ... I dunno, 4k? Usually when the car hits full boost, middle of the range.

If you backed power off in that range, your torque would not look like that. Instead of being 620nm at 4k then bleeding off to 500, you could have it peak at 500 and stay at 500 the whole way through the rev range.

Look at most people's dyno sheets, the max power figure is not where the most torque is.

At least in my car having huge power at 4k only rips tyres anyway. I'd probably result in a car which is faster through being easy to drive, and won't smash gearboxes. I am aware that losing traction means driveline stress wouldn't happen anywhere near as bad, but usually 33 boxes die from stripping gears. Under load. Usually 3rd. Usually when cars are on full boost/torque and not losing traction anymore.

 

So my idea was simply to spread that out over the rev range instead of having it all come in hardcore when the turbo spools up.
Going a smaller turbo isn't an option for me, my car has the tendency to choke the living shit out of anything smaller than a GTX3582R. I had to run a GTX3076r with a limit of 5700rpm to avoid the car melting itself.

 

Ideally you'd just have a gearbox that can handle the torque. But rarely do we get exactly what we want in modding cars :P

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