Lithium

PowerFC is a good computer when you want minimum effort to get a decent tuneable ECU. I've heard patchy arguements that MAPs are better than AFMs - I've given answers to the AFM vs. MAP debate already SirRacer. I'm not going to join the arguement, but I vote the MAP sensor without hesitation. ST mainly tunes PowerFCs, no wonder he's pro PowerFC.... if he can't tune other things, why would he tell you to go with others? There are quite a few cases around the place of people getting over 500whp on stock internal RB25s, though at least a thicker head gasket is well recommended.

Ahh ok - I understand the turbine and compressor families, though evidently made an incorrect assumption when I was reading a compressor map that had overlays of different GT37s - I assumed that a compressor map which was titled GT37 would be for the different trim variations of the GT37 compressor wheel.

Or if you're lucky, it'll be like mine where the intercooler caught the bits. A GT30R was a nice problem solver. Edit: Oh, only small bits missing - mine chomped off big bits... eek

I needed one for my real GT3076R with T3/T4 style turbine housing, which I assume the GT30-IW turbine housing would probably be based off the general style of. I'd be very interested to hear how these go. I find it interesting that Garrett list their 52-trim GT37 as having an 82mm exducer.

1. So has anyone installed a set of these on their RB25? Yes - bought them from Greenline 2. If so, is there any customizing involved? No 3. Do I need a collar set? No 4. Will it fit straight on the fuel rail? Yes 5. Will they plug straight into the fuel sensors? Sensors?! They plugs are compatible with the stock ones 6. Are these side-feed? Because they say they are for R33's Yes, sidefeed and high impedence - no resistor packs or anything. Its like changing the stock ones for other stock ones. You will NEED a tuneable ECU though, I dropped the base fuelling by a LOT and it still fouled the plugs straight away! They flow heaps more than the stockers.

Hm. Mother load of turbos for SR20 - wouldn't one think that a bit more aggressive trim would be more suited to a 2.5l? So far I love the 56T GT3076R on the 2.5 - so far I'm not sure where the lag people talking about them having is, though mine is only at .6bar at the moment (Reached <3000rpm)... though would be interested to hear how a 52T goes on an RB25 if someone goes this combo.

Damn - some cool things going on with RB25s at the moment. I will watch with great interest at how the GT3071Rs go - I got >< close to going one, but decided a GT3076R in the end. The RB25 dyno thread will be interesting watching soon!

Car is running with a rough tune in it with the 56T .63 GT3076R, so far so good - less "laggy" on the road than I expected.... I can definitely live with what it feels like so far only using it with low throttle openings etc. In 5th gear at 100kph, leaning on it ever so slightly can push it towards positive pressure.

Cheers for all your input and my slight deviation from the topic D. I didn't realise there'd be that much in the actual scroll design, had always focussed on the wheels. Live and learn. Have you guys looked at the link I gave earlier in this thread of the dude with the GT3076R .63 on an RB25 running 16psi? His dyno plot didn't seem bad to me - aside from what looked like some queer tuning issue in the higher revs.

Nice - that must feel fun How does it drive around normally? Just verifying - Disco/whoever, what you are recommending is exactly what I have but with a different turbine housing? If so, I will report how mine goes with a .63a/r - and if it DOES seem like its a problem, I will just change to the .82a/r one and report how that goes. I never knew GT3071Rs had a port shrouded version...

It is the Ford style one - using stock manifold, and the split in the Ford-style housing "looks" at least to be nicer than the concept of cutting the stock manifold, or using one of those nasty 90degree bend spacers. At this stage I'm only aiming for basic upgrade power levels - and getting enough flow to the external is the highest priority as I'm running a standard internal motor and want to keep boost levels in check. A lot of things will be changed when I end up with for forged internals - ie, new manifold and turbine housing... In real world terms - for the stage I am now, how obvious do you think the upset flow will be - or what effect it will have?

Yeah thats what I'd figured - I had independantly done research and decided on the GT37 job, but with a .63a/r turbine hsg at least in the meantime. My initial setup with it is stock internals and only 1bar anyway - so hopefully the .63a/r won't be too much of a huge problem. Tell me if you feel otherwise. When I go stronger internals, I'll probably go .82a/r and ~18psi. Cheers on the manifold pressure rant as well - ties some things together I had been pondering about This is mine test fitted to an RB20 for fab reasons etc (its going on my ECR33): And with wg, dump pipe: Got oil and water lines made up and the turbo in car now, just sorting out intake piping and the dump -> exhaust fabrication and then it should be pretty much ready to run.

The first part of your post I fully agree with and understand, just wasn't going to say it all for the sake of being concise I'd love the money and the facility to try some of the combinations you have described, they sound really good in concept. I have it in my head you can get a 52-trim T04S covered GT3076R from some places? If I remember rightly the only GT3076Rs we can get here in NZ are 52-trim. Now you mention the pressure in the exhaust manifold vs. the inlet side - how do you determine whats actually going on there?? I had otherwise assumed that the pressure on the turbine side (before wastegate opened) was a good thing, and would help spin the rotating mass up faster - and once the wastegate opens there is additional release. Anything not required to maintain targetted pressure ratio, completely bypasses the turbine housing/wheel and just goes "somewhere else". Cheers

Interesting, I've seen people on here talking about that kind of spool with .63a/r GT3582Rs - and ~4400-4500rpm with .82, high 4000rpm with 1.06. I'd imagine that all things being equal, a GT3076R should have a few hundred rpm on a GT3582R.

Haha. I think thats acceptable, most people were suggesting for me to get a GT3582R.... I think the GT30R HAS to be better even before it hits full boost. SOME positive pressure <3500rpm no doubt. This is the post with dyno plot (and boost plot): GT3076R Dyno (56T comp, .63a/r turbine hsg) Can't wait for the weekend

Discopotato - Have you come across anyone using the GT3076R 56T w/ .63a/r turbine housing on an RB25 and encountering surge? I've read up on people around the world using .63 to reasonable effect without any issues, they just get choked up high (ie, when trying to push well over 400whp Dynojet style). In the RB25 Dyno upgrade thread there is a dude running a 56T GT30R who got >274wkw running the .63a/r turbine housing on a stock manifold and motor and it looked like it was all good. Mine (again .63a/r) should be running this week, so I'll be able to give driving impression this weekend - tuning is on the 30th.

The Zs are VQ series - the drag ones do not have RB motors dropped into them, though there are a couple in the build that I am aware of over there. Aren't Rigoli's building a RWD drag one as well?? There is a RWD tube frame drag car based on an RB30/26 hybrid in NZ at the moment as well. The fastest would have to be the old HKS S13 with the RB26, did a low 7 if I remember rightly... years ago.

I'm guessing you guys know that in testing at Willowbank Heat Treatments have got down to 7.73 @ 183mph? They have a reputation of systematically getting quicker and quicker - so fingers crossed the weather is good for Jamboree! That'd be the quickest run ever by a Skyline GTR in Oz - quite cool when you consider the HKS drag R33 has raced there!

For what its worth guys - in NZ the EVOs also had the reputation of being quite hit and miss for a while, I guess ultimately the EVOs dont have quite as fancy transmissions available to them as the GTRs - and they don't run autos (the ability to load up converters etc) so it was possibly a bit premature to go over to Oz when they hadn't even mastered the NZ tracks. The Rayglass datto and the Croydens GTR have gone over previously, and iirc neither disappointed. Heat Treatments GTR has been under development for much longer, and has always been a consistant runner. It has already cut an 7.81 with the current engine combination in NZ - and has always been "efficient" with its trap speeds. I am pretty sure I remember comments elsewhere on this forum about how slow its trap speed for its 7.9.... I'm not going to make a call on what the car will go like, but I think they're not just over for the one meet - and they've already done a 7. No matter what happens its going to be a show worth going to, but I suspect they won't leave until they've beaten HKS's time.

doh

Sorry - It IS still running a 4WD setup, and also ran into the low 8s before it turned to Methanol. The Methanol setup was the major change which got it into the 7s, and since then its got a new motor and turbo combination - who knows what THAT evolution is capable of. He's taken it to Oz to find out

This is all quite old news, it happened months ago. It was (7.81 @ 17xmph) the first meet with a new engine and turbo setup - the package definately had more in it, and has not done a meet since. I fully expect this car to go quicker than HKS did in Oz.... I recommend going to watch this - seeing/hearing it go in person is definately a hoot Theres no other GTR in the world currently racing that I am aware of which is going to show you solid 7 second runs.

If you want a real sexy sounding induction noise on a turbo Skyline - my 2c go on a port shrouded/anti-surge compressor housing turbo. Me personally, a real GT3076R (GT3037 style...) with .50a/r antisurge compressor housing - while the stock turbo has an awesome "suck", theres nothing quite like the jet-engine spool up sound Or get a T51R... a lot of people think its just because they are huge - or a signature T51R thing, its just because of the anti-surge ring. Moving lotsa air helps of course...

Whats to say Australia will be where they will have to defend their time? Heat Treatments may only be a meet away from beating them...

Niiiiice good to hear. I expect this will probably be quite unrecognizeable in its next stage - HKS's time WILL go down soon. No shame to them though, they were miles ahead of the game for years.