Dale FZ1

He's running E85. Carbon buildup won't happen.

^^ agreed.

Appreciate that you're sharing the important bits. Couple of constructive observations: Your ECU interpolates between cells quite effectively. The MAP row 95kpa on AFR target is largely redundant. Looks nice, does very little IMO except divert attention. I get the gist of the 115kpa row, but unless your logging shows that the engine often hovers around that point, and the fuel and ignition mapping is done to reflect/capitalise that, maybe not a lot to gain. Similarly with the ignition map showing a row at 90kpa. I take a pragmatic approach, and if logging shows you rush through that zone very quickly or don't actually spend "that much" time at that load point, don't add complexity to the map. Get rid of it. You're on ethanol. Add 3 degrees of timing across all cells from 140-200kpa (and play carefully). If you're running decent advance sub 100kpa then quickly take it away as boost rises, it's going to feel flat. You know it's going to need a dyno session with someone who is at least moderately competent at some point to get ignition right, across the full load range. Run an AFR log or two, with steady accel, and then with decent throttle above 50 percent. The data streams will show rate of change of throttle, boost, and accel enrichment + how closely actual AFR follows the target. To say the accel enrich values "look big" could be mistakenly ignoring that it potentially needs more. Finally - Have an experienced driver who doesn't know your tune pedal the car in those situations, and get their honest impression about "feel" once it's tuned more satisfactorily. It may be better than you're thinking, and over analysing the performance of an old car.

When I ran the more common 56T 3076, it was very obviously providing urge at 3000. By 3500 it was really strong, and by 4000 it was all happening. And all very progressive with no light switch delivery at any point. General impression is this thing does similar but doesn't really offer the airflow (ie power potential). Failing gaskets and old components don't help if you're trying to get the thing running right. Flex fuel sensor is a no-brainer, fairly cheap and makes the whole exercise of using ethanol simple when supplies aren't where you travel. There is nothing at all deficient about the Link/Vipec ECU for what you're trying to achieve - change of ECU to Emtron won't help if the approach to tuning isn't right. Saying it feels like there is a "fuel lag" , along with other comments along the way about pursuing fuel economy makes me think there's a fundamental issue with tuning this thing. I'd like to see the target AFR table (assuming the actual AFR is pretty close to what is targeted, and the target is rich enough), and think the accel enrich area is the other place to look. Seems like it's probably too lean as you come into boost, and insufficient enrichment as you come onto throttle. Too little fuel will do that. The other issue I would investigate is the WB kit. Are the readings it delivers accurate? As in comparable to a known good unit? (if you get it onto a dyno, check it against what the operators shows). It's not that uncommon, and may be due to ground plane differential. Tuning with a mistaken belief that your AFR are correct because that's the numbers you're logging can lead you up a blind alley, unless you're reading the signs.

Still waiting Seeing this talk of doing an EFR upgrade, are we to presume that the turbo doesn't hit the desired mark? Or are you looking at resolving the air ducting systems before committing to a final opinion? Considering the volume of discussion over some extended time on this oddball 52T 3076, it'd be good form to give us your drive impressions of this unit on an RB25. Clearly it's an outdated/superceded spec, but some direct commentary helps paint a picture for us all.

Amazing what a hammer can fix.

I hope this thing is going to go down the path of some of those Euro diesel drift boy setups (Benz, BMW). Give it a big turbo, 50psi boost and plenty of fuel. Still won't rev but ought to make enough torque to screw clutches and gearboxes with ease. Watching with interest.

So how's it go, and what issues needed sorting in the fitment and tuning of a system like this? Importantly, would you do it again?

With less than 300rwkW you're not going to strike any restriction problems with an ethanol sensor. You've identified the air delivery system as being a restriction point, suggest sticking with the cooler ducting and cooler itself. Maybe the cat also, from memory. Meanwhile in the absence of a dyno sheet, give us an idea what you actually think of this 52T 3076, the whole point of this thread (I think?). How does it stack up as a streetable responsive setup?

In this area of modifications, my best friends are tin snips, 1mm cutting disc, and MIG. Can't go wrong!!

Throw up the dyno sheet for this setup on 98. And one for ethanol when you get it on the rollers again. We understand this thing is not all about the numbers, but it'd be good to see.

All good progress. Cut a bigger hole in the trans tunnel, make access to that stuff easier!! While the cutting gear is out, why not hack off the lower section of the rear bumper - relieve any air trying to tumble out the rear but caught up behind the bar? The work you're doing looks good though.

If you want to replicate what Gibson's cars ran, you'll need to go dry sump. The breather system on that setup will be different from a conventional wet sump.

Have plans (as in interested, talked a bit, done nothing towards acquiring the bits yet) for an R chassis and an S chassis, with the Astra pump setup and a steering quickener. Main identifiable issue is lag on the assistance - unknown just how much flow capacity is available from the electric pump vs even a standard engine driven pump. Neither is really spec'd for motorsport application.

My bad re: the cams. Scanned the post and missed it. Re: punching boost into it. There's 3 runs on that first overlay. Green run shows (IMO) lazy boost control that was resolved with the red run, basically pretty consistent across 4000-6000rpm. That looks pretty satisfactory to me, but the pink run simply added more in that same range. That's what I meant by punching extra boost, simple turn of phrase. End result is 240 rwkW which compares VERY well with any GT-RS equipped RB25 running pump 98 without water injection. (Bear in mind the variability across different dynos etc.) The grid lines on those graphs always make it hard to determine exactly what boost number it's producing, but yeah I can see the consistent trend in the top end. Can't fault your drive for trying to improve what's there, and a muffler change (or delete altogether for testing?) plus wastegate actuator change to a big diameter canister/diaphragm are both legitimately likely to help if you're pursuing a flat boost curve. When it's all done though, you're not likely to make much more than another 10rwkW unless you go E85. Discopotato03 reported about 270 running a GTRS, head fitted with poncams, oversized exhaust valves, and E85 blended down to about E50. From memory he was pretty skinny on providing dyno sheets for that setup, or the subsequent GT3076 setup, but I'll be surprised if it wasn't starting to roll off (meaning torque plummeting) at 6000rpm. That all adds up to a lot of effort and expense, which is something you'd have to weigh up for the likely outcome(s). PM him for advice/experience, or perhaps he might chime in on this thread for all to see. Worth noting that total system efficiency is also impacted by the inlet piping and filter, intercooler piping, and intercooler spec. Every little bit counts when it's an efficiency hunt. Be interesting to compare what you have got vs what your brother has. There's been some decent input in a couple of threads by Stao from Hypergear. Torque characteristics are largely impacted by mass airflow, and boost is a measure of resistance to that airflow. If there's a future upgrades plan, I'd run what you've got until there's money to fit a different spec turbocharger with bigger mass airflow capabilities. You'd probably find those poncams also able to make more impact in that situation. This sort of thing has been discussed/dissected/commented on over many years in this forum, so worth looking around if that helps your understanding and decision making. Don't know anything about the other modification path you're on, but at ~320rwhp it would be very desirable to make sure money is being/has been spent on suspension/brakes/tyres to make use of whatever it's making. Good luck with your project, keep us updated with progress.

Bigger turbo with generally softer response sub 3000rpm and less restrictive turbine can all contribute to fairly respectable fuel consumption in those conditions, for sure. I agree with Jared, pretty good result when you think what it does when the taps are opened.

The original overlays showed the tuner punching extra boost in mid range, and it made extra hp earlier. Makes for a more lively response. All good things. Boost tended to fall away after 6000rpm to broadly similar levels. So broadly similar power number - quite predictable. No mention (that I could see) regarding cam spec being non standard. This Apexi turbo seems broadly similar in impeller dimensions to a Garrett GT2871 - something with which I have experience on a RB25. It fell away after 6000rpm too. Bloody good little turbo provided you want a good street performer and don't expect big hp numbers. This one seems the same. Second dyno sheet really only shows boost bumping up in 1-2psi increments. If you want to establish its limits and are happy to pay, have the tuner bump it up to 18-19psi and see what happens. Predicting more mid range and falling away after 5500. Earlier comment stands - if you want a bigger hp number, get onto a more modern bigger turbo. The total effect might surprise you. Others (pm Discopotato03) have previously thrown around lots of discussion in this area. Bigger turbo won't necessarily mean poor response, and it will make much bigger numbers if that's what you need/want.

Quick search on turbocharger spec found this old thread: If that's correct, OP is probably experiencing the flow limitations of a relatively small turbocharger. 320rwhp from a unit apparently capable of supporting 380ps @ crank would be quite acceptable. It's probably not making any more hp with more boost simply because it can't inhale/exhale more air and maintain efficiency. 2psi pressure in the exhaust at full noise is nothing to sneeze at. More telling would be comparing that figure with the turbine inlet pressure, and boost pressure with TIP. Pressure differential across the head, and across the turbine is where it's at. More hp probably requires upsizing what's now old spec.

Mine's an economy car by comparison. Seems to consistently run about 60l/100km. Not running ethanol though. I'd expect that to increase by about 30 percent on E85.

Isn't this thing a race car or something? Why number plates and driving on the road etc? Put it on the track. No police. Solved. Cut and raise the floor, lift the exhaust. Solved. in truth, looking ok. Just give a few more updates, presume it's actually hit a dyno and you're moving onto the next problem areas to solve.

Less interested in the cool bang bang. What happens when you nail the throttle after that?

My daily (not a Skyline) has a Detroit locker. Much more aggressive than any plated centre. Takes a bit of fancy footwork sometimes to keep it smooth, but it's all down to technique. Left foot braking and better throttle control can overcome a lot of issues. Overall driving characteristics are way better than the original gear, and on gravel or wet tarmac it's unbeatably good. Same can apply to these plated jobs. On-thread, Jordy's made a smart purchase, interested to hear what the driving impressions are.

You won't regret this upgrade! First modification step beyond tyres and pads should be a cradle bush + diff centre + HICAS eliminate + bump steer eliminate. A bit of time spent in that area pays off big time for any half serious driving in a boat.

It's been mentioned earlier: The rate at which the fuel is being circulated directly impacts fuel temp. A bigger capacity pump will circulate the fuel even more quickly and you may actually gain temps. Are fuel temps critical to your tuning strategy/methods - eg is it using a VE mapping setup? Do you actually need to control fuel temps? Is the fuel boiling in the tank? They're the things I'd consider before actually doing anything. Sometimes we can pursue a line of thought that seems logical but actually is flawed. Especially if this is 99% road car, I'd investigate Sneakey Pete's suggestion and PWM control the fuel pump speed. Far less effort/complexity and you may yield a good result. Good luck either way, and please update the thread with pics and results.

VW use a completely different cooler design. If you're focused on running a cooler, look at the spec/type they have used. Otherwise, really consider what Sneakey Pete has recommended. Better approach all-round IMO.