JimX

If they were internally gated I'd take one

You're probably right. What else are we left with then? The lower compression of the turbo'd versions?

Sorry, I worded it badly. I didn't mean on open constant throttle on flat road meant you were in positive manifold pressure, I meant at normal cruising, you will go up and down hills unless it's the nullabor or something. Up a hill the turbo can start to come on boost which will make the fuel economy suffer more than it otherwise would. I didn't mean to say that it's always on positive boost constantly at 100kph+. Also I'm sure it doesn't need to be in positive pressure to be using more fuel, just slightly less vacuum than NA would have a similar effect. Even the extra bit of back pressure keeping the turbine spinning will have a slight cost on the engine efficiency. Nothing is free.

Wow, that's the exact same highway mileage my VS 5.0L Commodore got too The problem with our (current) cars is (1) they rev higher for the same road speed, and (2) running on boost requires more fuel at the same amount of RPM than it would off boost. So with our early-spooling turbos, it's sucking down more juice than it would be if there was no turbo. The most I got out of the Skyline was 600km, and filled up to 60L so almost spot on 10L/100km. So that was a tiny bit better than I got on the Commodore. However, that was a standard ECU and boost came on very late, so I think that was the main reason I had it so good. Now I get around just under 11L/100km and I think that's pretty good all things considered. I remember seeing some of the NA boys getting 8 or 9L/100km. Maybe the RB20DET can do that too but I don't expect miracles. I remember the Commodore being a lot better than I expected when I first took it on holidays. Smaller cars don't get double or triple the old 5.0L's economy on the freeway like they do in the city. The low-down torque helps it a lot.

Mostly because by the time you are at 110kph, you are slightly on boost. You'd probably be able to achieve 9L/100k or less if you did the entire trip at 80kph or remove the turbo or even just hold the wastegate open somehow. But if you're hunting for better mileage, it's probably time to trade up to a Toyota Prius

(edited) Never mind.

I've done a search on +injector* +delay and it didn't turn anything relevant up so hopefully this is a new question. Can anyone explain how to set the injector settings on the PowerFC? I had been told previously that it's supposed to be a percentage based on your stock rating. For example, R33 GTS-t stock is 370cc, so when fitting 550's it would be 67% to give the same injector pulse as stock. But I've read elsewhere that 550's should be set to around 85% or so. In my current tune, they've all been set to 75%, but this is in conjunction with an adjustable fuel pressure regulator so that probably has something to do with it (no I don't know what the pressure's set to, waiting on delivery of gauge). Or have I got the idea behind this setting all completely wrong? The other thing is the delay setting. Again, I've been told a couple of different things. I *think* read somewhere that it should be current injector size divided by stock, expressed as a negative millisecond delay. So that would be 1.48 for 550's, rounding off to -0.01 or -0.02? Or if I got that calculation around the wrong way then maybe it should be -0.67ms. My tuner had left this setting on zero and it seems to drive ok. What's the purpose of this setting and if I should change it and why? Thanks again in advance (it feels like I'm doing a thesis on powerFC's with all these questins I'm asking!)

Well, it'll hurt my wallet Flooring it up hills is what I've been doing these past 2 days on a 700km round trip up north and back to visit relos. I think it's acceptable for what I've done for now even if around-town economy continues to suck. It was good that the weather was so hot, I backed off my timings a bit to get it at a "safe" knock level and I still got great economy. I got surprisingly better mileage than I was expecting on the freeway, so I might just live with crap city mileage for now and maybe do a proper road tune once I get my new turbo next year. I'm still working on the low-end timing so perhaps I can still get a bit better economy around town without forking out more tuner $$$ for exact O2 levels.

No, it's only had the AFR's checked on the dyno.

Thanks for the info everyone. The reason I thought closed loop wasn't engaging is because lately I've been getting up to 17-18L/100km around town, with fairly normal driving. Because of that I was worried that I was going to get crap mileage on my road trip yesterday but it seems I was mistaken. I ended up getting 10.4L/100km which is slightly better than what it was before I got the PowerFC. I'm completely happy with that mileage even though I know others are getting better. I did some light load tuning on the freeway, but that was mostly to eliminate knock due to the heat. When I get a Datalogit I'll give it another go as Sydneykid suggested.

I don't know if the ECU is going out of closed loop. I was seeing the ignition timing drop and move around as described above, rather than stay constantly at what I'd set for that particular load point. Similar to what it does at idle (moves around between 15 and 17 or so, instead of constantly at 20). Whatever the case, my economy sucks. I guess I'll just live with it until I can get it fixed by someone that has the right equipment to measure the AFR levels and knows what they're doing.

I noticed something today when checking out some PowerFC map traces and monitor screens, and that is it seems my car isn't staying in closed loop mode when it should. I found that the ignition timings would drop down to 15-25 degrees or so even I'd set it for around 35-45 in that load area, but as soon as I squeezed on more than the tiniest amount of throttle it would jump straight up to what I had programmed into the map. That means I can coast down hills in closed loop mode, and can't even maintain a steady speed on level ground if I want to keep it in closed loop. This is all well under 3000rpm obviously (usually 1500-2000). The load point areas don't seem to matter either. It can be on zero and <3000rpm and still not going to closed loop, just because I have my foot on the accelerator slightly. Does anyone know why it would be doing this and what I could modify/edit to fix it? I thought maybe it might have been because the throttle position sensor was set incorrectly but it's showing up as 0.51V when off which seems to be ok from what I've read. I'm 99% sure that not being able to get into closed loop mode is why I have such crap arse fuel economy. Closed loop seems to be working fine, it's just that I'm never able to stay in it long enough to save me any fuel. Any advice appreciated!

Paul, do you remember where the knock goes over 80'ish? Just so I can keep an eye on that area too and not increase it too much. When I was road tuning the other day there was one area where I slowly increased my timing up to nearly what you had and the knock was virtually zero all the while. Around N5-N6 and L1-10. There were other areas which had more knock that were tuned by the workshop, so I think there's still plenty of room for me to increase it there.

Thanks mate! I'm not loading the exact map, but I'm seeing where you are putting in your biggest timing advances over stock and my tune, and focusing on those areas. Saves me a heap of time not touching the ones which are around the same.

I tried it in Firefox and IE and it still seems to have hard coded line feeds. Also can I please have a copy of your latest map? Gonna do some more road tuning this weekend

Hey Paul, any chance of fixing up the word wrap on your FAQ? At the moment most of the text is a bit too wide to fit on my screen so I have to constantly scroll across and back again for each line while I read it.

Heya man, don't try convincing yourself that you are 2nd rate anything. I am half aussie half chinese-malay, and all through my school life I copped a lot of racism from aussie "yobs". But also my friends were white aussie in school (though I've lost contact with all of them now). It's not about race. It's about yobbism and stupidity, and you can get that from any race/culture. I hate any sort of gang member that propogates this sort of violence. I've had my run ins with "leb" gang members before, but I don't hate arabs as a race. One of my best friends is Syrian, and he is one of the nicest, most decent human beings I've ever met. All this shit that's been happening doesn't even make me think any lesser of him, because it's nothing to do with race. His family left the middle east to get away from all that bullshit and now it seems like it's followed them through no fault of their own. I gotta feel for him and his family

Best thing to do is back up the tune manually, especially if you spent so much money/time on it. It only takes about an hour to write down all the settings from fuel and ignition maps from the hand controller. You can use a lot of shorthand in the areas where all the numbers are the same. I did that then typed it all up into a spreadsheet which was even quicker.

I'm about to go do some experimenting on my PowerFC with the help of PaulR33's map cross-referenced with mine. Since I seemed to have little trouble when testing with the +5 setting on light throttle, what I intend to do is compare the 2 maps in the N/L 1 to 10 range. Then wherever I find my timing is less than his, increase it by +5 or up to whatever he has set, whichever is less. In the areas where my timing is the same or more than his I'm leaving it that way. Does this sound like a good idea? Anything I should be wary of that isn't already covered in the thread?

That's how I thought it worked too. Seeing as though there's just a hole there now instead of another vacuum hose to assist with opening the valve, I suppose it will just suck air straight in instead of releasing the pressure on the valve and make it more difficult to open.

Had another look yesterday, and I found that it's missing the barb fitting from the second vacuum hole. Anyone know where I can get a replacement? I'm going to see if the other one is the same size, if so it should be easier to find one the same. Where does the second vacuum line go?

Ah goodo, I'll make sure I have a co-pilot to see where the spikes occur if at all. But today I am starting on the brakes. Need to be able to stop properly before I can test the go-fast

Ok, I've done a leetle beet of testing tonight. Tested just mainly low-mid range throttle, especially around the "stumble" zone of around 2000rpm. I dialed up an extra 2 to 5 degrees and at 3 or above it seems to get rid of the 2000rpm stumble/misfire altogether and give a noticable extra bit of power too (obviously - not firing means no power!). I need to record exactly which part of the map it's using there, but from memory it was around the L6/N6 area. It seemed to be fairly good all round on about +5. I never took it above 4250rpm (used the hold setting to check) and the knock never got above 21-24. Usually the maximum knock on the map it has now is around 19 or 20, but at maximum noise it sometimes gets up to mid-high 20's. Does this mean that I can somewhat safely kick up most of the timings below 4200rpm (N10, 4000rpm) by 5 degrees? I'll only adjust up to the highest load point I'm seeing on the map trace. unless someone thinks I shouldn't? I'll also use Paulr33's map as a guide to see roughly what maximum timing I can have at each point, like if there is a big difference between his and mine, I could experiment there with slightly higher values. (this is what I was always going to do, not load his map straight in) Thanks Paul

Thanks for the advice guys, I'll give it a go when I have some time hopefully this weekend.

Ok, questions questions! Firstly, do you want me to post a map trace with just WOT from idle to redline? Or just in the range I'm getting the stumble? I think I'm going to have to find a spot where I'm not going to run over people/pets or get done for hooning/street racing/speeding Secondly, I know I've got "boost" written down but I had that from another map that someone sent me. I had copied it over and didn't check it on the hand controller because I don't know where it's set. So I don't know if load point 20 is indeed 1.6 bar of boost, or anything else for that matter. Where is it on the hand controller menus? And how do you "fiddle" with them? I have no idea if they've been modified or not, or why I should modify them. Thirdly (maybe relevant), the AFM is set to "Super 90 VH41" or something, which I'm not 100% sure matches the Q45 AFM because it says VH41 which I've never seen elsewhere. Am I supposed to be using "Custom" instead? I don't know, I just picked up the car and went. But to me it looks like it has more timing down low than either the previous tune or the factory one. Which bit are you talking about specifically? Last comment to keep it all in one post: Paulr33, I've got a copy of your map you put into another thread, I'm going to use it to modify my own tune. I notice you've got a lot more timing down low, is there anything I should be wary of when doing the same to mine? I'm thinking of slowly increasing the large differing values up by a few degrees each time rather than just doing a blind copy and paste of everything. Goodbye to another tank of fuel experimenting with all this I think!