Rolls

This has never been seen as far as I know, if you are going to suggest it is possible then you need to do the calculations to prove it, someone in the other thread worked out how much that air effectively weighed and its speed, even if the blades were made of plastic or glass they wouldn't bend or snap, they are attached to a bloody bearing, they can slow down speed up do whatever very easily, if the rush of air going back through them destroyed them then they would shit them selves from normal operation very fast. Even if they were effectively jammed shut (seized bearing) they wouldn't break. Someone on here had a seized turbo and drove it for a week, the rear blades partially melted and it shit itself, but they didn't break off.

It doesn't have zero benefit, it has very real benefits and I have explained them in the past. The benefits are it doesn't mess with the AFM signal causing it to reverberate up and down when you use partial throttle or completely back off causing flutter, this in turn makes it easier to tune and avoids the car running very rich when it flutters, it also stops the ridiculous tutututt noise which makes customer go wtf is up with my car, turbo life is not proven to be one of these reasons and has never been specified by them to be one of these reasons. Also a recirc bov allows the turbo to be bypassed at idle and low rpm causing better response and fuel economy. You don't bend bloody blades via the air though, if this was the case you'd bend the throttle plate every time you shut it! Search for my prior posts, I've said the same thing for the last 3 years, the flutter thread has about 20 pages of arguments showing that bovs aren't to stop turbos grenading, I will find it for you. Read this, everyone came to the same conclusion as me http://www.skylinesaustralia.com/forums/FL...BOV-t60655.html I never said you shouldn't use a bov or a bov is pointless, just that not using it won't kill your turbo, hell I run one myself (modified).

so just buy a spare stock motor, it will cost almost 5x less and will meet your demands.

im sure the oil is fine but oil going black is a good thing it means the detergents are picking up the carbon deposits correctly.

why do you even need a rebuild? building a forged motor when you dont need it is silly, you get piston slap with forged pistons which wears the bores faster, just leave it stock and put a highflow on it, when it finally shits it self consider the rebuild then. the motor will be reliable complete standard, they are reliable from the factory, why do you need to pull it all apart?

Fair enough, experience always wins hands down.

Surely they are balanced, if not it would grenade after a few minutes of running, they just use oldschool crappy bearings that is the only issue. Sure they are often poor wheel combinations making them laggy etc but I don't really know why they wouldn't last, just might get poor quality housings making them flow less than optimally.

yeah lol you just set everything to zero or nothing and it will not do anything, eg be the same as running just your factory ecu? lol

no it doesn't. no it doesn't, the VL turbos and HR31/C31 skylines and cefiros came from the factory without a blow off valve, it is a complete non issue, the F1 turbo cars ran something like 50psi with no BOV without issue, there are hundreds of cars running far more than standard levels of boost without causing any issues not to mention all the rally cars that run no BOV as well. sounds like a popped off intercooler pipe, makes a ting noise and you can make about 2psi before it stalls from getting too rich

Is that one big turbo and one small one ?

It will make less power but noise level won't change, mufflers are a restriction but they decrease noise, small pipes will change the noise ever so slightly but they are no muffler. Try putting a straight through 1" exhaust on your car, it will still be very loud.

remove the middle muffler and replace with straight pipe

more lag for not much more power, highflow it or nothing.

Nice post but I never understood why people went the 20 over the 25, it is basically a downgrade from the sr20.

I never really understood the purpose of surge slots if you werent having surge, surely it would just acuse the turbo to spin harder than required for the same given airflow and hence choke sooner (lower power). Not to mention if you were having surge that it meant you could change your blade profile to avoid it and with the larger size (required to stop surge) you could make use of the extra flow up top as well.

Shouldn't be changing ANYTHING to do with a fuel reg if you are running a stock ecu, any change will completely f**k up the tune. Put it al back 100% to stock or get a full tune, there are no other options.

How long have they been off? But yes one having oil and the other not could definitely cause that.

If its not burning oil and puffing smoke and the bearings don't make any noise don't touch it, just lean on it until it explodes, then build a motor, no point taking apart a working motor for small power goals like you are aiming for. Just get a highflow turbo (loads of power down low if you get the right one) and you'll make oodles of power under 5k, stock motor will take it fine as anything above 300kw will mean the power is being made from 5-7 not 3-5 like you want.

exhaust and tune, tune assumes boost increase to 10-12psi or whatever is safe for gtr turbos.

If it is actually detonating it sounds like a fuelling issue, stock ECU should pull back timing loads if you've increased the boost (exhaust + fmic will do this). Can you confirm fuel rail pressure, pump making any funny noises? Really need to get it on the dyno as detonation can kill a motor pretty quick.

wow that really is, at least they could admit their mistake and attempt to save face

yuck, those jap remaps are pretty terrible, 10:1 fuel ratios and shitloads of timing, not good with our fuel or climate, had a car with a mines ECU that wouldn't rev over 5.5k due to rich misfire as it was running below 9:1 fuel. Definitely get it to a tuner and on the dyno, i recommend a nistune for how cheap and easy to tune they are, also they look stock.

has it ever been remapped or properly tuned? If not then you cant expect too much just winging it on the stock ecu get it on the dyno and a remap/nistune

rb20s will run up to 13psi just off the spring depending on intake/exhaust mods, 13psi dropping to 9 in the top end is fine if its been tuned and it looks like it has a decent one, fairly smooth. Just make sure AFRs and knock is in check, power looks about right, usually see between 150-170kw with that boost and a tune, looks fine to me, 30 minutes on the dyno should confirm everything is fine.

think you really need a tuner to look at it, could be a thousand things stuffing up and causing it to run rich, stuff up the timing etc.