Dale FZ1

Got a dyno graph with boost curve overlay? Interested to see it.

Particularly if it's a new unit, I would be looking for some sort of build plate on the centre cartridge to identify its specifications. I don't know that I'd have any issues with some casting imperfection on that comp cover though. It's either structurally flawed, or just a cosmetic thing. Pull the cover off and have a look inside. That will tell you whether to be worried about it or not. I do think there needs to be a bit of re-orientation of the centre section so that the oil dump is facing downwards, and not upwards though.

10 seconds worth of searching. input keywords "Greddy+install" for title, any date, and hit enter. It will come to the top of the list. And you have just learned how easy it is to find things for yourself. Happy reading. cheers

edit: double post.

Looking at the difference in breathing efficiency through cam specs/timing, and compression ratio, I'd hazard a guess that there would be a reasonable (but not massive) spool advantage towards the 25. Perhaps 250rpm faster to hit max boost? But then the 26 would make better power, continuing to produce torque as the revs climb. The disadvantage with running stock 26 turbos would have to be (as usual) the ceramic turbines.

I questioned the same sort of thing happening with mine. I thought it was a rich thing, until using a WB sensor proved otherwise. A lean mixture due to decel fuel cut will give the result described.

Is there any idea why it has been picking up on those bearings?

The two blokes to ask this question of would be The Mafia - 3076 BHDave - 3071 edit: not intending to lead this thread off-topic so apologies to R34NRG. In that respect, I would say if comparing same/similar housing running a different/larger rotor eg. GT30 vs GT35 you would have higher mass flow capacity from the GT35 because the exducer size and corresponding hole in the rear end of the housing is larger. It would become a bit of a juggling act if going up from (say) GT30 0.82 to GT35 0.63 and probably counter productive. I think Al is onto a reasonable proposition with considering a TO4Z in split pulse though, especially at the power rating either that or a GT35 is capable of supporting.

Bigger turbine A/R without changing any other turbocharger specification will permit higher maximum mass flow rate for a given turbine inlet pressure. The cross sectional area is increased to give the bigger calculated ratio, so it’s a bit like running a larger diameter exhaust pipe. The exhaust breathing is more efficient. That should lead to higher maximum power capability, as the engine is scavenging its combustion chambers more efficiently. Turbine backpressure will effectively “back up” exhaust flow out of the chambers like a log-jam in a watercourse, so the larger A/R reduces the metaphorical log jam. Supposing your power target is somewhere between 350-400rwhp based on turbo choice, the other consideration is power delivery. The smaller 0.63 A/R while tending to choke things as revs/power rises, will respond a lot “sharper” to throttle. So you could have something that tends to wheelspin easily. Maybe what you want for drifting? Also the 3071 will accelerate its rotating assembly more quickly/easily than a 3076, which could give an aggressive delivery too. I’m now running a HKS 3037/3076 with 0.87 housing. It is proving to have a progressive delivery without wheelspin tendencies. A Garrett 3076 with 0.82 would be very similar in most respects. There are other members around who are running different combinations eg 3076 + 0.63A/R, 3071 + 0.63A/R, 3071 + 0.82A/R. If able to be run on an “equivalent” tune, they would all produce power more aggressively than my particular spec. I know the chap running 3071 / 0.82 is about to change to a 3076 / 0.82 to cut down the amount of smoke he tends to produce… Any of those specs will produce some pretty good results for a moderate $$ spent. The point is, they will make their power in different ways and will suit different applications or driver preferences. Hope that’s a help

Obviously they have sourced reproductions of the RB25 and VG30 housings, mating them up to Garrett cartridges. That gives the advertised 0.63 and 0.71 A/R. GCG and HPinabox are doing similar products. Simon-R32 is running the 3071, which comes with the 56.5mm cropped version of that turbine. It also has a 0.5 A/R comp cover, which is big enough to flow 280 rwkW. I would suspect that the larger 0.70 cover used by tweakit is being used purely for underbonnet bling and it will necessitate the use of a spacer plate for the turbine mounting just to get clearance from the manifold. I ran a 2871 hybrid similar to the tweakit version. Not hard to fit up, and gave plenty of responsive poke. FWIW, those power claims each seem a bit high. But they'd likely do a pretty good job for the money. Just another option out there in the market.

It's all about the effect of pulses travelling down the headers and into the turbine, and minimising reversions that affect scavenging of neighbouring cylinders. There's a fair bit of science in it, and I'd say that twin wastegates would be required to nail it technically. There was a thread that ran last year. Helped resolve a few things in my mind. http://www.skylinesaustralia.com/forums/Sp...;hl=split+pulse She's obviously going to be a multi purpose car. Big difference in power requirements for drag and motorkhana. High or low boost, should go like a cat shot in the ass. Sounds like fun.

With an 850kg body to move, a low comp air cooled engine of 2440cc is not going to feel sluggish in the way that a Skyline running under 7:1 would. Run with what is done/known to assist with reliability. The effective compression ratio if running 2.0bar is quite significant too, and will put you close to detonation. Room probably would be a problem (as always ) so where is an intercooler packaged into the back end of a bug and still get good airflow? Both drag and motorkhana are short-run events, so for effective detonation control and simplification of the inlet tracts why not eliminate the intercooler and concentrate on a really good port water injection setup? With that power level you should be able to access a range of nozzle sizes that will work well. 500rwhp is going to take some pretty big compressor flow - more than the combined 520hp of those GT2554. And there would be no real reason to push them over the edge of their efficiency maps. No sense in doing that if there is a better spec available. You'd want something able to run 600hp worth of flow - so if a single was possible to package then try a GT3582 and go external gated. Physically they should fit? Slightly downsized, a GT3076 running a EW 1.06 housing would definitely be a thought. Very free flowing top end, and make use of that low down torque:weight you have while allowing it to not be choked as the revs rise? I agree that a split pulse layout could be a really good thing with the horizontally opposed engine, and maybe something from a Fuso (MHI) truck would give you the goods. They do split pulse turbos in the size you'll need. Likely available cheaply too, so you might be able to easily try some variations there.

If anything, the question really tests what ideas/knowledge/experiences are out there. VW performance is something a lot of the now generation don't experience, but they can be very fast. Also a bit fragile unless done right, so I understand the lower CR approach. Adequate engine cooling, oil cooling, and different level of combustion efficiencies are all things to factor in. A hot running VW will probably have less knock resistance than a modern 4 valve Nissan for instance. I'd be leaning towards the GT2554 especially if you wanted a torque band that starts early enough to be useable on the street. Can you answer these questions: what is the car being used for (ie. is it intended to be a registerable drag bug? ) why not look at a single GT30 have you considered water injection cheers

WD40 or Lanotec and patience is your friend. Apply a little bit over a couple of days and leave it to penetrate. And use some anti seize when you reassemble. The only problem areas I've encountered is with the studs used for manifold:head, and turbo:manifold. Dump pipe has never been a problem.

Look at the pictures. The water unions are clearly there - banjo bolts in place. There is no confusion over that one. The only negative about a Garrett GT28 is that it is not a direct bolt up. Different flange patterns on both ends of the turbine housing, and Paul should know that - it's been raised many many times. Good (excellent) cartridge, but you would have to get an adapter and fabricate a dump pipe. Or spend the difference up front and buy a complete HKS kit which will bolt up. GT-RS is highly regarded for a reason. Best of luck with the decision, and happy searching.

It wouldn't be the top of my list of choices, however please ignore the VG30 = lag comment. You have more blades than a 71mm GT35 series compressor, so it's going to push more air with fewer shaft rpm than one of those. Therefore to avoid surge issues you want it to spin slower. Probably a good reason they used that larger OP6 housing then perhaps? Also, the use of a bush/plain bearing cartridge does not automatically equate to lag. Yes, there is literature from Garrett about quicker acceleration times, but there are plenty of plain bearing turbos on the market from other manufacturers that are considered responsive. My understanding of the main benefit of BB is longer maintenance intervals due to the elimination of a wear-prone thrust bearing. For $1250 you've got a bolt up brand new turbo. For a few $$ more to Dave you've got the rest of the goodies needed. It's a case of priorities and funds I guess...

If you've got the gear to fit the 0.72 straight up, then give it a run. Don't aim to make the RB20 a low-down torque monster because it will just strangle things up high, where it should be able to shine. Search for threads/posts by Roy regarding the RB20 and turbo specs. Set up, and drive it for what it is - ie. not a RB25, or an SR20. Sounds like you have an oddball pair of housings - Pro and Pro S perhaps? Some of them don't have the T3 flange, depending on the job they were intended to bolt up to. Might be worth checking that aspect, and post some pics if you can. Always interested to see how the HKS castings look.

The HKS unit runs a bell mouth insert within the compressor snout. Does anyone know if these are available for purchase? When looking into the inducer of the housing as supplied by Garrett, you can see the square edged lip that the insert sits into. That in itself would not work well for flow, and has to add to the HKS branded item. Just wondering.

20kW is a LOT. That lip might only be 5mm or so, but it's got to cause problems with achieving smooth efficient flow into the turbine. The stock manifold does a good job, but the system doesn't need restriction like that when it's reasonably easily fixed.

One interesting fact is that if using the OEM exhaust manifold, the HKS housing has to be relieved to match the larger than T3 flange on the manifold. So it bolts up, but still has the same slight mismatch facing the Garrett housing.

What injector duty cycle are you running at that power level?

Very creditable results; that shows as +20kW through a large part of the range. Does it show itself as extra response driving into full load (ie boost), or mainly once you're there? edit: bit slow to post, looks like question answered.

Quick search, it appears to be a plain bearing T3 type cartridge used on a WMW diesel. Not likely to be anything special.

Don't discount Adaptronic as a viable ECU with real capabilities.

As described, a stainless steel split dump pipe in good condition. No cracks or defects. Bolt-in upgrade from a stock dump pipe onto your stock turbo. Comes with 3 inch front pipe in mild steel. Pics available if needed. $150. Edit. Item Stainless steel split dump + 3 inch mild steel front pipe Fits ECR33 running standard turbo, or high flow turbo Age Approx 18 months Condition Stainless is tarnished, mild steel in good order. No cracks or dings, perfectly serviceable. Bolt in. I had to change to suit different turbo. Location Sunshine Coast. Pickup preferred. Price $150 Contact via PM