joshuaho96

Pretty sure it’s an actual GTX3582. Dyno is a Mustang 4 wheel dyno as far as I can tell so it’s not laughably high reading. Spectrum Motorsports sells both single and twin turbo kits.

I've been wondering how they've been doing it too, they tend to get results that others don't.

It’s different turbos, supposedly same engine spec within reason. Both running VCAM Step 2 with an HKS 272 exhaust cam.

Curious to know what others think of this data point, this is supposed to be a more modern twin turbo setup for the RB26 vs a GTX3582: "More info Twins vs Single. 4WD mustang dyno, 92 octane, similar weather condtions, Step 2 V-Cam, 272 exhaust cam on both, both running metal cats.Blue run are the DR500 twinsOrange run is GTX 35/82 Again this is just more info for everyone. Each of you will have your own opinions on what setup is better. Its coming to my attention that when we post up data, that we have collected, and speak highly of our results its because we are in love with what we do! Its unfortunate that it has come across as being competetive and that is not our intent. The information is there for you to use, only if it applies to what you want to accomplish with your GTR. And yes we have watched the Motive video." Link: Looks like the turbos are made by Spectrum Motorsports in 42R configuration: https://www.spectrummotorsportssolutions.com/products/r32-r33-r34-rb26-smr600

Higher numeric final drive (shorter gears) would affect the RPM you spool by because the engine will reach higher RPMs sooner. But if you were to do a time to torque/boost measurement you would find it to be faster because the engine is getting up to an RPM where it can spool the turbo sooner. You can play games with dyno load to do this, it's effectively brake boosting.

Doesn't this imply that you would want less CR anyways? I can't imagine running rich all the time is healthy for an engine.

Yeah, probably going to just disconnect the FPCM and use the PWM controller then.

Doesn't that imply that you would have to run rich for too much of the load/RPM map? Modern gasoline is up to 14:1 CR for NA, or even as high as 16:1 for the Skyactiv-X, as high as 12:1 for turbo. I can't think of why emissions would factor into it. NOx obviously goes up with high CR, but 10:1 PFI-T is nowhere near what diesels have done for a long time now.

That is a properly buff pump but probably too much fuel pump for something making 300 kw. Something like the Fuelab 48402 seems to be what I'm looking for, around 10A draw and capable of 300 lph at 70 psi outlet pressure to be able to turn up the FPR to 3.5 bar differential pressure. I might run some experiments to see if the OEM FPCU/FPCM has the right resistances to be able to actually function as the pump speed controller, have to see what the impedances look like. Probably have to just accept that it's a horrendous idea though and just use a standalone ECU to run the PWM controller. Anyways, I don't doubt that high CRs improve driveability, I'm just skeptical that you can run high CR with low duration cams and no tricks like advanced VVT/cooled EGR/E85. I'm sure that Mitsubishi and Nissan would've raised the static CR on the 4B11T and VR38DETT to 10:1 if they could've done so while meeting power targets on pump gas. The VR30DDTT has a 10.3 CR but uses GDI and dual VVT to get there.

I like to spend my hours reading about interesting things, not necessarily productive though. Feels like this has been the answer a number of times I've looked into this. I'm probably going down that road in the end, just want to figure out a good 340 lph brushless in-tank pump solution.

I'm actually just hoping to be able to get an RB to be more modern, running something like high 13 AFR deep into boost and revs instead of 11.5 and maybe push back the knock limit enough to get power equivalent to 98-100 RON fuel with 95 RON. RBs also seem to be thermally challenged so water injection might help in that regard as well if it ever makes it to a track. But if the trade-off is I never actually get to drive the car or I have to pull the engine because water contaminated the oil and trashed the engine it isn't really worth it.

I dunno, random PhDs? Working fine is a relative statement. Even in the M4 GTS there are some reliability issues. If the design goal is OEM reliability and refinement I don't think the aftermarket systems are there. Even the OEM systems may be a bit touch and go. A fuel system just works for the better part of 200k miles or 15 years. A water injection system should be similarly expected to work just fine with just added distilled water for 200k miles or 15 years. The military is ok with 50 hours of maintenance for every 25 hours of flight or a total engine rebuild after 5 minutes of WEP, modern performance cars are basically expected to survive on not much more than fluid and brake changes for 15 years.

I'm not as sure, pretty much every tuner I talk to is not a fan of WMI due to reliability issues, every paper I read mentions water contamination of the oil and cylinder wall scuffing. WMI is really interesting to me as a concept but feels like the details aren't quite there yet. Not worth wrecking an engine over it.

Not a fan of any of the easily available water injection systems. If you're going to do it, you should do it right. PWMing the motor to get the desired flow rate is really, really slow and imprecise. Aquamist is the only company doing a "fast acting valve" so you can control the injector more precisely but the flow isn't to individual injectors, it's to all cylinders all at once. I've seen a lot of literature about injecting water during the low lift phase of the intake cams leading to crankcase water contamination and scuffing of the cylinder bores so it seems unwise to have such poor control over when you're injecting water. Bosch's water injection system is one injector per two cylinders, so it's semi-sequential which is probably ok, but I'm unwilling to spend 2000 USD per injector to find out. The only other option is Nostrum Energy, and they don't actually have a real product to buy, just the director of R&D's testbed R35. We'll see if they manage to ship something as promised.

10:1 or 11:1 is normal for GDI-T. With PFI-T you can probably only run 6-7 psi boost when not running E85 with that kind of CR. Most people want to make more power on E85, not less. So you see relatively low CRs. Personally one of the bigger pet peeves I have is how rich these RBs run, either on pump gas or E85. Hopefully someone comes out with a proper water injection kit for these cars at some point.

If you're running E85/race gas full time you can bump CR up, but if you're running pump gas only 9:1 CR is pretty much as high as it gets. If you want to run 10-11:1 CR on pump gas you need direct injection. You would have to dramatically drop boost if you used a flex fuel setup when using pump gas, with PFI engines 10-11:1 CR is pretty common for 98 PULP.

Why use more fuel pump than the turbo could ever possibly use?

For a practical car it's indisputable, a newer car is better. Modern engines are better in so many different ways you could write a textbook on the subject. Same goes for safety, that floppy chassis is going to end poorly when everyone drives crossovers these days. Maybe Aus/NZ emissions are harder to meet than US standards but modern gasoline engines don't have a lot of trouble meeting emissions, it's only the EU where you have power-robbing GPFs. You can free up some power by running a high flow cat in the downpipe of most turbo engines but that's about it, the rest of the exhaust is basically sized for full flow with minimal restriction. Tire technology has advanced so far since the 90s that an F40 is slower from 0-100 km/h on 90s tires than a modern Mustang GT. Modern transmissions are so much better and more reliable generally as well, just keep up the fluid changes. With that said there are definitely issues with modern cars, some of which stem from higher safety standards. Others stem from just stupid design choices. The new Audi RS6 Avant now only comes with a choice of 21 or 22 inch wheels. The 21 inch wheels get 35 profile tires. The 22 inch wheels are 30 profile. These kinds of trends are horrendous for ride comfort and pothole resistance but somehow it keeps going on anyways. Infotainment does age like milk but frankly with Carplay/Android Auto you just plug in your phone and ignore all of those issues. The fake engine noises can usually be coded out but yes, it is obnoxious.

For anyone curious, I ended up going GT3-SS because the turbine a/r is 0.54 which is closer to the OEM turbine a/r of 0.49, multiple tuners that have tuned both GT3-SS and GT-SS in the US have mentioned that the GT3-SS trades power for low/mid torque compared to the GT-SS with a 0.64 turbine a/r. The goal has always been street-oriented so fingers crossed I don't regret paying way too much for a Civic Si turbo with an HKS stamp on it. I'll try and update with dyno results once I get it in.

I don't know the exact details of your GTS25t, for some reason though in the 1993-1996 GTS25t it shows the power steering solenoid at the rack as a single part: https://nissan.epc-data.com/skyline/ecr33/3898-rb25det/trans/492/49361/ On the BCNR33 it's a separate part from the housing that you can remove that is somehow triple the price because GTR tax: https://nissan.epc-data.com/skyline/bcnr33/3935-rb26dett/trans/492/49810/

https://www.gtrusablog.com/2017/05/nissan-skyline-power-steering-system.html Might be power steering solenoid? Also check your HICAS control unit capacitors. I would probably start with the HICAS unit, then check the solenoid. Capacitors in a car this old are almost certainly dying.

The best security system is a locked garage. Add bollards if you're extra worried. Alarms are a huge waste of time and really only good for giving you hearing loss when it goes off for no reason but not much else. Transponder immobilizers might discourage casual theft/hotwiring but certainly nobody determined. GPS trackers, maybe with a tilt sensor/geofencing might help you locate your car if someone tries to tow it away and you're extremely quick to react.

I'm definitely going to try and get all the supporting mods in to make sure the engine can perform well. I was thinking of getting the HKS GTIII-SS because of this chart: I don't mind that at the end of the chart the GTIII-SS isn't much to write home about, what interests me is the pretty ridiculous amount of torque it puts out by 3300 RPM. But maybe this is just what happens when you're loading up the engine on the dyno from like 1500 RPM? But even -9s from the same tuner with VCAM Step 2 doesn't make ~213 whp by 3300 RPM, and it appears to also start from 1500 RPM: Kansai Service put out a little blurb from their testing of the HKS GTIII-SS, personally I don't know how much stock I put into it but it suggests a decent mid-range bump, just not as good as what UP Garage is seeing: But the GTIII-SS is a journal-bearing turbo and more than a few people have mentioned that it's not as responsive because of it. So not sure what to do here.

Here I believe it mostly relates to the belief that Skylines are often used in street racing. These days the people who can afford to run a Skyline GT-R are not going to be racing them on the streets.

Maybe that's the answer in the end, feels like it at least. Probably not wise, the other minor detail I didn't mention is that if you get pulled over by a cop that wants to give you a hard time you get sent back to the smog referee. Then it's a scramble to put everything back to what looks like stock.