Dale FZ1

And I've run a faultless 15000km with my settings. As per previous, it may be that the lag time is not a critical value. Starts, idles and runs cold or hot without any noticeable difference from stock. I've been waiting for a comment from those who know more than I do, and waiting, and waiting... The lag/latency values do not seem to have made a difference to the running of either of our vehicles, and sadly there is no (none that I could find) values available from Nissan for the OE injectors. That is why I took notice of that spreadsheet. The correction figure seems to have been the most important, and my wideband logging showed it was on the money. Any further ideas to add Paul?

I did hear them - in their heyday when they ran at Lakeside in the Group A era. I was also a Nissan fan then, regardless of whether they copped a pounding from the Sierras (and they did - clearly outpaced as a rule). Sorry, those turboed Group A touring cars just didn't have "it" for exhaust note. BUT - the in car with engine noise sounded magnificent. I'm just happy to see them brought out for a run now as a historic class.

Had to use a bit of real estate to get by on the inside. Looked like he was sizing things up for the previous lap or 2, probs with getting power down out of the corner but plenty of legs up the straights before braking wiped out the ground gained and do it all over again The old Falcon Group C grunter certainly had punch out of the corners. Two things impressed me from the in-car. The engine sound was really good, and the closeness of the gearing. Notice the engine rpm did not drop much at all on the up-shifts? To be honest though, the R31 or any of the turbo cars from that era didn't sound great from the outside. Leave that to the M3 BMW; no muffling effect from a turbo, and running up to 9000rpm they were brilliant sounding.

Compressor spec differences between those two particular units is not huge. 56 trim vs 52 trim impeller gives the Pro S a little more pumping capacity and perhaps another 30 crank hp if you want it at maximum flow. At that stage the higher flowing turbine (and wastegate design) in the Pro S probably allows another 15-20 hp to be developed as well. Figure on a maximum difference of around 25rwkW between the two designs, but I'll stick my neck out and run with the GT-RS as being noticeably quicker responding to a transient throttle, regardless of which A/R turbine housing is mated to the Pro S. Slightly off-track from the original question, but as for whether a GT-RS will be less boost-responsive than any of the more commonly used high flows, I would doubt it. The Garrett based cores use essentially the same rotating assembly and may flow slightly less than the HKS housing combos, but they will (should) accelerate into and through the boost range at a similar rate. Exact specs of GCG style and Slide high flows are not known, but there is little complaint about their overall performance. Bottom line: GT-RS for street use and around 250kW is probably the best unit, but at a price. High flows are probably just a short distance behind performance wise, but a long way in front price wise. If you wanted more than 250, then the Pro-S is a viable alternative - but given the small increase in power capabilities you would have to consider the GT30 based units (eg. 3076R) which are capable of supporting even higher power for the $$ being spent. Very standard advice is to carefully consider the application and your own maximum power ceiling + transient response requirements + budget and then make a choice.

I can't say for sure, but it seems that people use the terms "latency" and "lag time" interchangably. I believe they mean the same thing. I don't know what it actually means/measures, but all I need to know is that it's a characteristic of the injector, and the ECU needs to be told what it is. Look at Paul's link to a side feed injector spreadsheet, which I suspect he accessed same as me through the (members only) Datalogit community. I didn't have a look for, nor see any acknowledgement of his source. The figures on that spreadsheet are at odds with what is on his main page. I went with the spreadsheet figures in the absence of other data, and it ran/runs faultlessly. Maybe it's not a critical value if you've noticed no difference Birnie?

After a fair bit of searching, I was given these specs: Basically I went with conservative figures, and at stock rail pressure according to these specs, the lag time adjustment should be +0.13. Similar to Birnie, when I input the numbers into the PFC my car started, idled and ran just fine. I've never felt the need to revise the settings.

R32 spec = RB20DET = smaller A/R compressor housing = lower flow capacity. Go with a 25DET spec unit.

Compressor maps are something derived from testing by the development engineers. Nissan don't publish them. My GT2871R 48T high flow runs a very mild size upgrade from stock, using R33 spec housings. I suspect maximum useful boost sustainable through the range will be around 15-16 psi. Any higher and compressor flow limitations would probably see boost dropping towards the 6000rpm mark. There are some good combinations out there able to meet your requirements. If it were possible to simply replace the composite impellers with metal items (probably not available in exactly the same specs), then it would be an expensive exercise. You can get a performance increase with little discernable lag penalty if you do some homework. Try looking at the stickies section, and use the search function. Plenty of experiences to draw from. cheers

It's all about cubic capacity. Being down on swept volume by 1.5 litres compared to the Ford means it will require extra rpm, but it will also take a lot more rpm before it runs out of puff. Changed final drive (diff) ratio may provide a fix. The other would be to use a 3 litre bottom end. Then there is the option of laughing gas :laughing-smiley-014: Overall, it's like trying to wear size 12 boots when you've got size 10 feet. Not as good as it could be, and it won't feel nice until it's changed for something with a better fit. Oversized turbine housing for an application will result in lazy response. The boost question is relative to how much power you want to make. What is your target?

They are ratios Paul. No indicator of their physical sizing relative to each other.

Just to add a little further, HKS 2530 equivalent = GT2860RS = 60mm compressor = 320hp rating 2535 = 69mm compressor = 350-370hp rating, no direct spec equivalent from Garrett Garrett 2871 48T = 71mm compressor = 380hp rating, no direct spec equivalent released by HKS Garrett 2871 52T = 71mm compressor with bigger inlet + T25 turbine flange pattern = 400+ hp rating = HKS GT-RS (but this has T3 flange pattern) Running beyond a compressor's flow capacity will yield more midrange torque for sure, but run them into choke and as everyone's saying you won't make any more high rpm torque and possibly strike detonation issues unless the tuner takes strong notice of what the mechanical specs are and what information is being logged during the process. Bottom line: do the numbers really matter, or what it does on the road?

Happy dyno?? Worth a review of published data from Garrett. Considering the GT28RS (aka Discopotato) with flow maps and a compressor spec near-as identical to the 2530 is rated to 320 CRANK hp, the claim seems a bit high. Still, if that's what he got, and it's backed up by times down a strip or round a circuit, then who cares? Great result if that's what he got.

I have 225kW and through data logging found the fuel pump wasn't up to the task. Upgrade from stock fixed it. Make sure you do it too.

I've been checking out the Adaptronic for a while now here: http://www.adaptronic.com.au/index.php and it seems to be a good thing. Has the sort of features found on other units costing $$$ and there is an Adaptronic community for support. Should prove to be a good thing, I believe. PFC is already a known quantity though. I'd second other comments about the turbo too. At that planned power level you're going to need big mass airflow = big revs + big boost. What's the planned usage for the car? Trying to work out your thread title too - what's water got to do with it?

Re: the response and lag issue. Some people have difficulty getting their head around lag. For some it means the boost threshold engine rpm, and for others it means transient response (ie. how long it takes the turbo to build boost from a closed/low throttle situation). The general info you've been given indicates going for a small-frame type upgrade ie. stick away from the GT30 or equivalent medium size frame turbos. For a power target in the mid 200s I'd agree. This will keep the boost threshold down closer to stock, and depending on the impeller specs, with transient response not that far removed from stock. The different airflow capacity / efficiency of the actual impellers will tend to give a much stronger on-road feel when it is running on boost though. Going for the likes of a GT30 would see you hovering somewhere just under 300kW but basically you'd expect the useable engine rpm to have gone up the range by 1000 odd. So it would come on 1000 later, and hold it for that much longer. My view is that you would be looking closely at gearbox/diff ratio changes to capitalise on that, which is starting to equal $$$ There is plenty of good quality information in the stickies section as you know, but I'd have to say before settling on whatever you want, write a list of EXACTLY what use you intend to put the car to, and in what PROPORTIONS. In other words, prioritise. If you drag race it every single day, then transient response is less of a concern than if you use it for daily driving and the odd competitive hillclimb or motorkhana. Work out if you're happy to sacrifice 15-20kW off the max power number in the quest for sharp/immediate response. Some people will, some won't. Any of the commonly cited high flows seem to work very well, and the likes of the GCG and Slide units are known quantities. The GT-RS will be more expensive but if I had the $$ to spend I would probably go that way. Real world budgets applied in my case, so I went high flow and have no complaint. Hope that is of some help. cheers

After the dyno session, I adjusted the exhaust cam timing to 2 deg retarded as a compromise and will run it that way for a time. I have no doubt emissions engineers are responsible for a big chunk of the production design parameters, though at this power level I think cams are a bit of over-capitalising. The exhaust system already has a resonator in it ex-Japan as part of the Blitz cat-back system, so it's basically a case of either cope with the drone, or take the extra power. Personally my ears and tinitus win the argument.

Been a little while getting back with this one, but I had to play around with the cam gear setting to address what seemed to be a mid range torque dip. There was conflicting information from various sources on the board, from those who said that advancing the exhaust cam would boost low-mid range, while others said that retarding it would give a boost all round. Basically the theory on naturally aspirated engines suggests retarded exhaust cam will boost top end at a cost to the bottom end, while advanced will do the opposite. I accepted that once the aspiration is forced, the rules of what works changes to some extent. Those who advised to advance were doing it from a base of experience in chasing the same outcomes as I was, while I think the proponents of retarding were looking for more top end improvements. Knowing that things are just so damn hot once it's been running, I knew there was only going to be one setting I could try per session on the dyno without wasting time and $$ to prove what would work. In the end I went with 4 degrees retarded, and give it a run. On the road any difference seemed difficult to detect. Well here are the results of a retarded exhaust cam: The curve has become much more civilised and smooth, rounding off the edges being shown. All in all a "nicer" curve showing useable power. I'd say the cam timing change produced a worthwhile improvement even though the peak number is lower. What was causing some intrigue was the tendency of the curve to peak around 5500 and then drop after 6000. Suspecting top end breathing restriction of some type, we decided to remove the bolt-in restrictor in the Blitz cannon muffler, giving 75mm then 80mm from the split dump back. No changes other than the restrictor. Here's what the dyno showed: Not bad, and the note is very fruity. Good to listen to, but man talk about drone when running at low load / off boost. The lift in power was a big lesson in just how stock systems cost power in the name of noise restriction. The slight dip right at the top end is ignition related, as I had pulled a couple of degrees out to sort the odd reported knock event. Otherwise, it had more (and more) from 3000rpm onwards. At this stage I am now waiting on the 14psi actuator cannister after a supply problem from Garrett. I think the oscillating boost control is definitely costing some power because it drops from 14psi peak down to 12psi by 5500. Once that is sorted I will post up the results. Again, this is a mild upgrade but may be of interest to guys with similar aims to what I have.

Here you go.

Check this thread: http://www.skylinesaustralia.com/forums/in...0&hl=GT2871 has some pics with impeller dimensions to give you some idea. compare that with published data at turbobygarrett.com to get more of an idea. A/R of the turbos fitted to the RB20/25 engines was not given by the manufacturer, so it's a case of look and learn to a degree. The turbos were manufactured by Hitachi though I believe there was a financial arrangement between Nissan and Garrett for the technologies involved.

Definitely agree on this one. I had the same experience and found the ignition map needed some of the advance taken out to tame down any knock readings coming up.

Please do put it on a flow bench and see. I would like to see this one either confirmed or debunked as myth. FWIW, I'd think it a waste of time if you didn't use your time and make sure it is port matched and tidied up. Keeping an eye on your progress as well.

No probs. Just looked like a poor choice of words. I have no worries helping where possible. Honestly you won't have any probs as long as you look at what you are doing. Re the preload; I have an adjustable rod to give preload. I removed an actuator from a RB20 unit and it did have preload.

Firstly some etiquette. USE SOME MANNERS. You might get a timely and helpful response. Secondly use your eyes. Remove the E-clip / C-clip / Circlip (choose the name you like best) from the wastegate arm. Then remove the actuator shaft from the pin that it was slipped over. This may/may not have a lot of preload, but should take a little bit of effort to remove. Sounds like yours has little or no preload so it should nearly fall off. Then get a suitable sized spanner and remove the actuator assembly from the spot where it is bolted to the compressor housing. The diaphragm assembly and actuator rod should then come away after you remove the pressure feed hose onto the diaphragm assembly. It's not too hard, or time consuming. Best of luck.

The term is annular - as spelt. It is the name of a bearing design. Take it as read that both radial and axial float in a BB unit is significantly reduced over a plain bearing unit especially in a bench comparison. The plain bearing unit of course relies on the film of oil to carry the rotating assembly while the engine is operating. So clearances tighten up and float reduces by a big margin when operating - much the same as the plain bearings within the engine itself. Getting acceptable wear from thrust bearings in turbos used on early petrol engine applications was a challenge for turbocharger engineers when the throttle was installed between compressor and inlet valves ie. blow through as Adrian indicated. No such problems with diesels which have no throttle. This wear problem was partly attributable to pressure wave reversions on closed throttle, which induced opposite-direction axial thrust in the rotating assembly. The old school draw through carburettor installations did not suffer nearly as much so enjoyed a longer life. On-task, the answer is a small amount. Detectable to feel, but would take finely calibrated instruments to measure fractions of a millimetre.

Well it does side-track somewhat, but does add to the understanding. With the results you now have, it must feel something akin to the Coyote sitting on an Acme rocket It would doubtless be very entertaining whether inside the car, or watching. My main issue was/is the type of transient response/spool that the 3071 offers, and whether it sits in no-man's-land when compared to the smaller 2871 or 3076. Mid range would not be where I perceive it has a weakness. Mated to an auto, with kick-down and the stall-up of the converter, the 3071 would/should be a pretty good thing because that bottom end is masked. Adrian, I'm in agreement that the stock engine has limitations and as always it is $$$ and effort that makes the difference whether a specific setup goes together and works in harmony. The light bulb went on for me when you said 300, because that was my target as set and achieved. I'd have to conclude by saying that virtually all turbo specs have their limitations or compromises. The smart operator will get satisfaction by either identifying or accepting them as part of the package. Variety in options is what makes upgrading mechanical specs a lot of fun or a hair tearing exercise and promotes discussions like this one. cheers