Lithium

Well, it'd have to spin fast enough to move more air than the engine can - which is usually quite a bit... so until it is moving more than the motor would pull through, its actually a restriction

0-200kph is an odd kind of requirement - but for 700hp, and for under $2k... http://www.atpturbo.com/Merchant2/merchant...tegory_Code=BCS

No need to preach to the converted - there is no replacement for displacement Just convince the RB20 people that the same thing applies to them when in comparison to an RB25, to an even bigger degree I'm happy with a 2.5 in the meantime, because just because a monster can beat it - doesn't mean it ain't quick.

Oh sorry, missed that.... my bad

The TD05 is a bitch to fit, but for what its worth - its a fair bit better than the stock R33 turbo. A mate of mine runs a TD05 16G from an EVO 3 on his RB20DET. It DOESN'T spin the "wrong" way, has a single pulse turbine housing, spools about the same on the RB20 as R33 turbos spool on RB20s - but flows an absolute crapload better up high. It hit ~200rwkw without trying too hard.... They run a much larger turbine wheel than R33 turbos, and a slightly bigger compressor wheel - I'd say they'd have to be easily comparable with an HKS GT2530 in terms of power and spool.

He is right but there is some stuff missing from the story which is worth knowing. Link ECUs only have 4 coil drivers, so the way that it deals with your 6 coils (I had this issue too) is it fires 2 at a time - much like you do with wasted spark. One will be the one which is actually due for an ignition stroke, the other will be going into exhaust stroke. If your coils are getting "tired" then even if it was all working fine before putting the Link in, when they have to go double time due to the Links way of getting around of too few coil drivers they will show their weakness. Only way around it is new coil packs or the more logical way which would be to convert to wasted spark, seeing as thats how the ECU is treating them anyway.

Nice thread dude, enjoying all the WMI info as well - starting to make me think Do you think the initial spool is completely to do with the compressor design, considering how much the restriction of the RB25 turbine housing has been referred to - maybe the "tight" nozzle of the RB25 turbine housing is a lot more of the reason for your much lower power figure, and also better response than the shift from 52trim 7 blade to 56trim 6 blade? Obviously the 6 blade is going to have greater pumping efficiency, but shouldn't it have a bit less inertia as well? Just questions - not debating one way or the other

Nice result man After having both the 7-blade and 6-blade "GT3076R", which do you prefer overall? Do you think the top end power justifies the extra bit of "lag" down low? What I notice about mine is its reasonably spongy below 3000rpm but then it pics up in a big way above there, so in my opinion is very liveable - I associate that kind of power delivery with what stock R32 GTRs are like. Makes me want to get an >1bar tune

That sounds about right, I've been in a car with a .63 GT35R on an RB25 and ~1bar at around 4000rpm in a high gear. Closer to 4400rpm with .82a/r.

Should look up the VK45DE engine 253kw stock from a 4.5l quad cam V8. With a few boltons and some tuning that picks up a lot - imagine that in an R33 GTS!! Solid 12s NA....

193rwkw sounds about right for those mods on a lot of the dynos you get over here - think of different dynos as different measurement standards. Stick to the same one and it SHOULD read the same.

WTF? I suppose you guys are flooded with the crappy TO4S GT3076Rs, my RB25 starts building boost quicker on my GT3076R than my mates GT3582R does on his RB30DET.... his actually starts accelerating harder earlier but thats more to do with it being a 3litre in an R32 than the turbo match to the motor. The GT3582R does take a bit of spinning to get going on the 3l, has more of a "big turbo" feel than my GT30R which feels more like a stock turbo.

Yep this is what I running, @ .8mm

That is very very impressive power for an RB20, has a nice good power band. Looking at that I tend to agree, at least if you aren't using it on the road - bang for buck looks like a matched turbo in an R32 is a good way to go. A GT2871R should be quite nice on one as well. Nicely done

Falls off chair

Argh if you ever are in NZ, let me know and I'll take you for a drive in mine I understand your theories, but thats all they are. What really matters is how the car ACTUALLY performs. You're saying what will provide said driving experience, I'm saying mine does it. I could probably match if not out accelerate a stock R33 GTS25t in 5th from 100kph, and the car makes solid power up to 7000rpm - what more should I be aspiring to? I'd love to drive a car with a GT3071R or 52T GT3076R to see the difference, but as it is my combination is one of the only GT-BB GTSt Skylines I've come across. Cubes - I like your concept Very cool.

Definitely agreed... OK - just curious, have you actually ever driven a RB25DET powered Skyline with a GT3076R or a GT3071R fitted?

I've not driven in the last couple of weeks (under going further mods), but I'm pretty sure positive pressure is from ~2000rpm - if it weren't for the whistley turbo passengers reckon they'd not know they in a car with a bigger turbo... you definitely feel it building boost in the 2000-3000rpm range, maybe not so much in 1st - but it goes past too quick to notice.

Well my turbo is a GT3076R, is laggier but not a crap load laggier than stock - and a GT3071R is advertised by Garrett/ATP as spooling MUCH better than the GT3076R. I reach 8psi by 3300rpm with the GT3076R, I'd say it stands to reason than a GT3071R should be at that point by 3000rpm quite happily.

I'd imagine you'll probably be lucky to get much happening at 4500rpm with a T78, if what you mean by spool is "Making reasonable boost". The biggest turbo I could imagine getting much going on at those kind of revs would probably be something like a GT4088R, and that'd not be full boost...

With a bit of thought, you'll notice that none of the GTRs are tube framed or tubbed - and are 4WD.... they have more weight, more drivetrain loss, and less tire on the track. Heat Treatments (fastest GTR in the world with a 7.57) have a tube frame drag chassis in the build which will weigh heaps less, have way more traction and generally be a better base for going outright fast. The running gear from the GTR will be going in that..

You actually wondered why the dude bothered with a twin scroll on a 4G63 as they spool GT30-based turbos well anyway - after looking back on it, so I guess not necessarily knocking the setup persay...

Nice to see how a GT2871R behaves on an RB25 - sounds pretty cool. Good work and cheers for sharing results I had been looking into it and decided a GT30 based turbo would suit me more... Strange, I mentioned our discussions and decision to go with a twin scroll "real" GT3071R on a particular car and you seemed to consider it a wasted exercise?!

HKS Car = Eye candy, turned yellow and not racing. Heat Treatments = some rumours that it has grown some bigger balls than when it was in Oz for the 7.57 (was probably in the vicinity of 1600hp) We shall see

Hard not to roll ones eyes at some of these comments.... but yeah, the trap speed tells no lies which is why the time and trap was mentioned in the first place. Just a shame you guys seem to treat any result from a dyno which reads different to your precious Dyno Dynamics with contempt. AndrewD - Yeah, thats why I said that SAE is a standardised adjustment. The number which comes out the other end often comes out higher than if DIN adjustment was used on a hub dyno.