Roman

Needs a speeduino, using some fuel cut decel and lean burn strategies and it'll pay for itself pretty quick

I live in matamata so I do lots of motorway type driving normally. So I can just leave this running when I'm going somewhere. Anyway, it looks like it will be worthwhile... Tests were run at 97kph So middle of the road results at following points either side of optimal timing: -5 deg: 87cc / min (5.38l per 100km) 27% more fuel 0 deg: 68cc / min (4.21l per 100km) +5 deg: 72cc / min (4.45l per 100km) 5% more fuel Cant wait to get the BMW ITB on there if it works out good, because I cant easily do this kind of test with cable throttle.

Alright so I got cruise control working, hooray. Firstly without the brake pedal wired up, which was not fun so quickly added that too. So it turns off if you tap the brake. So the plan from here is that I can turn on the cruise control and have the car try to hold a constant speed (say 100kph) Then I am using a timer that slowly sweeps an ignition trim from subtracting 15 degrees of timing, to zero, to adding 5 (didnt want to make it knock, so start out on conservative side) So if the motor is losing power because of the change in ignition timing, the cruise control has to open the throttle further. And vice versa. So driving along the motorway with this looping over and over and over, it starts to build up a trend of what ignition timing needs the least amount of throttle to hold speed (which of course means makes most power) So the dip in the graph is the ignition timing with best fuel economy. Surprisingly, it looks like it wants to pull about 4.5 degrees timing out from existing number (about 22 deg). I guess high compression means everything burns fast, even when the load is low. Because now my low load numbers are going to be a few degrees different from full throttle. I figured my existing numbers would be conservative, if anything! So now I can just repeat this process about a billion times and start building up a nice ignition map for 91 octane at cruise conditions. Otherwise I can try get my canbus thingy working that automates this process that I made for the carina ages ago. But need to get my head around all the code again, gets complex pretty quickly. So that's a maybe.

They've got an amazingly knock resistant head, I think because the combustion chamber has such a small cc volume. So 13.4:1 is a nearly entirely flat piston top. I think part of the reason why some high comp setups are more prone to knocking is because they need a gigantic peak on the piston to take up the combustion chamber shape. Then the flame expansion does weird shit as it travels out around it. Some of the Thailand guys are running 15:1 compression on E85.

Yeah E85 isnt very viable anymore here. However it wont necessarily make any more power on E85. It's not knock limited on 98 anyway, so more timing with E85 wont necessarily help. Also it's just been pointed out to me that the 13" dot rated M&H tyres that I've bought are no longer being produced. So I was lucky to get this set, wouldnt be able to buy them new anymore unless I found some old stock. But this pair should last for an entire career of Echo drag racing haha.

Buy an OBD2 reader then connect a phone or tablet up to it, and set it up so you can watch the fuel economy in real time on the dash. As well as the numbers from your trip so far. Then it becomes a game where you need to try get a better score, rather than demoralizing and dreary haha.

Have you ever thought about having golfball texture in the intake?!

Well one of the S1000RR manifolds was on Australia Ebay for stupidly cheap, so bought it. We shall see if 48mm is a bad thing... I'll just have to try make the manifold as long as possible from head to throttles to absorb the shape change a bit. EDIT: I've just realized that at the outlet, silvertop throttles are 45mm anyway. So 48mm wont be as much of a drastic change as expected. Apart from less of an hourglass sort of shape inside the throttle itself down to 43mm at the plate. Fingers crossed that the actual spacing between throttles is reasonable.

Hmmm okay. You know what, I was thinking that a less aggressive taper in the manifold from port to the throttles would help fill in the low end a bit. As it's quite aggressive currently: But actually looking at the full throttle fuel values from my ITB vs Aqua manifold, the Aqua manifold isnt any better, anywhere: Apart from that tiny smidge at 4k-ish. Despite having a consistent runner profile all the way. Admittedly I havent adjusted cam timing or done much else to the Aqua setup yet. Maybe ITB is richer everywhere just because its uneven or leaks perhaps. But it's not what I was expecting. I found a page of common bike throttles and their dimensions. Having 80mm throttle spacing sounds close/good, and 42mm throttle size. But then when I model it up, the narrower spacing is a worse situation than the slightly-too-wide of the silvertop throttles. Some of the Yamaha options are cool, in that there are two sets of butterflies. One is completely cable operated, then the other completely e-throttle. So in theory you could probably have best of both worlds somehow. At trackdays, leave the e-throttle ones completely open and have the response of cable. Then on the way home, lock the cable ones open and rely on e-throttle so you can have cruise control etc. However I might just look for one of the S1000RR setups. They arent tooo expensive, (likely 3-400 landed) especially if factoring in that I could sell the silvertop and blacktop throttles that I've got here already for nearly that much. And it's an incredibly neat and tidy setup!

Coefficient of drag can be a bit misleading. Because its a value of drag in relation to the frontal area. But total drag can be completely different. Echo has a CD of 0.30, and your bike has a CD of 0.55 to 0.6 But because the frontal area of your bike is comparatively tiny, the actual horsepower needed to overcome drag might be something like 10hp for your bike, and 35hp for the car (or whatever)

Got back home on a below empty gas tank. 732km and 37.25 litres. So 5.08l per 100km I guess the cold starts and slow parts of trips ate away my highway results a bit. Maybe if I overtook one less truck it would be in the 4s haha. But still pretty sweet. And yeah those throttles are cool. I was thinking since the s1000rr motor is only 1 litre it would have the throttle centres closer together. But it turns out that its actually got a 5mm larger bore diameter than a 1nz! And a super short stroke so it can rev to a zillion rpm. So i might need to look for a motor in the 700ish cc range to try find a nice center spacing and a little smaller diameter. 1nz ports have the area equivilent to a 37mm circle. So 40ish mm throttle should be good.

Internet says 45 litre tank. But I usually get around 35 litres in from a bit below empty. If theres still another 10 left after thst point then 800 will be doable. Also looking at itb options. Bmw s1000rr has 48mm throttles, built in e-throttle motor and super compact. Also extra injector bosses if needed/wanted. Looks like a sweet setup! Will keep looking for options but will keep these in mind for other projects.

That would be excellent! Not sure when next event will be but i will let you know. In other news I dont think I will manage 800km on this tank. Got about 360-370 by the half way mark. But still a few tricks left to try. This is still on semi slicks and only thing ive changed is the fuel map. Will get cruise control working, optimize the ignition, and some skinny tyres again (not these monstrous 185s)

Cletus I want you to know that this thread is a safe space for fuel economy chat without bullying from Spencer. Got 4.02l per 100km on way to Auckland today. Might set an all new gas tank distance PB. Mean. End of the month will have some $$ for exhaust bits. In the meantime I will setup knock sensing properly.

With e-throttle you can do even better than that, as you can scale your e-throttle table based on rpm and pedal position. So for example at 1500rpm you might flow as much air as the engine is ever going to want to inhale, by only 50% throttle. So you can make 100% push down on the pedal only opens the throttle 50%, meaning you get much better pedal control. But then when you get to the fun rpm zone you can scale it to 0-100% instead. Or you can make it non linear so the first 50% of pedal travel only operates the first 20% of throttle opening, so its not so jumpy when you first press the pedal. Also, I'm surprised at how awful this manifold isnt, it might actually be a good upgrade option for people with the regular 1NZ manifolds. The runner lengths are considerably shorter. Probably because the hybrid engine can use the electric motor to fill in the low rpm area better.

Ahh yeah, I see what you mean. I think the economy benefits from a single throttle plenum come from a few things. Firstly a comparatively big plenum volume generates much more vacuum. So better fuel vaporization as it basically just boils instantly in vac. But then also it's more likely that all of the cylinders are getting an equal amount of air at low throttle angles. (This could be improved with some fiddling on the ITBs) Then if you have any overlap it will draw more exhaust gas into the intake for internal EGR effect. But since I've also had to set my cam timing 1 tooth back to avoid clanging pistons into valves. I think I've also got an atkinson-ish engine currently if I set the cam timing to zero degrees. As its essentially -12 over standard. Having cruise control (havent wired it up yet) means I can do some ignition timing tests and some aero tests repeatably and see what helps or hinders. So some of this will help with the ITB setup when I put it back on, but some wont. I've driven to Tirau and back today, then over to Tauranga and back. The combination of these trips is so far around the 4.4l/100 mark. Will be happy if I can keep that up.

Got this all running with the E-throttle manifold. Pulling fuel out of most places on the table. Full throttle run, not actually too bad: Have definitely lost some top and mid-top end power but the bottom has filled in nicely (thats what she said) Also on some straight line cruising, some promising results! I've got a long drive up to Auckland and back tomorrow, so I'll fill the tank right up and see how it goes. It'll be worse than these numbers when you include cold starts and some start/stopping but looks like sub 5l/100 is looking achievable

At the moment I'm out of budget to get to any events for a while, or finish exhaust stuff. I almost managed to get a full tank of gas driving economically without hooning around (which ruins the economy incredibly quickly) But had some mates come over on the weekend who wanted a hoon around. So who am I to say no. But it looks like even with the throttles on, results in the ~5l per 100km would be achievable. High compression is win-win! So in the meantime seeing how gas is $3+ per litre. I figure I might try make a max economy effort and be able to run it on 91 octane. So I'm going to switch over to the completely garbage Aqua intake manifold, (with E-throttle!) and I've got an e-throttle pedal from an SCP13 vitz that bolts in. So this means I can have cruise control (hooray) and it makes it considerably easier to try optimize fuel economy by doing some repeat tests over the same stretch of road and comparing results. It turns out the Aqua has a small MAF than the other ones I've got here, and it wasnt included with th eengine. However one of the other standard sensors in the manifold that I thought was IAT is actually a MAP sensor. The factory motor would probably use some closed loop control methods by comparing MAF to MAP results to calculate how much EGR gas is present, and load the motor up as much as possible under steady state conditions. I'm not going to add EGR on it though, but I reckon this setup will be capable of some pretty good results. Surprisingly it looks like the quite tall airbox is actually going to fit in the engine bay okay. In other exciting news, possibly even equally as exciting as fuel economy chat. My Dad has ordered a 4 axis CNC machine, and I'm 100% keen to learn about it alongside. So in the longer term I'm going to try come up with a usable pattern for making an alloy quad throttle manifold, maybe onsell a few as well. However given the crazy price of even silvertop throttles these days, I'm wondering if it's more worthwhile looking for a commonish bike throttle setup? As I see some have factory e-throttle which would be awesome. As ideally I would have the throttle spacings closer together, and a smaller diameter throttle would mean I've got less of a gross transition to the port shape. I dont know much about bikes though, any suggestions on throttles to look for?

For my 13.8 run: Launched at 5500rpm, bogged to 4500ish when the wheel speed caught up to actual speed shifted at 9045rpm - on gear shift drops to 6040rpm Then shifted at 9040rpm, gear shift drops to 6725rpm Then crossed the line at 8400rpm in 3rd So yeah for a daily driver it would be pretty hectic having 35hp more at 3500rpm. But at the drags I get to stay in the meaty part of the powerband the whole time. EDIT: With my new 13" setup, the diameter of a 205/60/13 is smaller than 225/50/15 (576mm instead of 607mm) So on the 13" tyre I'll end up crossing the line at roughly 8800rpm instead of 8400rpm. So that works out better than expected.

This is actually a good one! Most supercharger setups with a piggyback ECU and no intercooler get around 115hp at the wheels. Which isnt an amazing number. But it just cant be overstated how insanely hot they run with no intercooler haha. In other news, I've previously polyurethane filled my engine mounts. But, I've left the standard rubber in place. But the urethane hasnt bonded particularly well to the rubber, and I suspect the rubber is still actually softer than the urethane. So I think the mounts are slowly getting squishier, especially the rear one which takes the most punishment. So I've decided to hack up my spare one, and recast the pin in a full urethane no rubber. So I cut out as much of the rubber as I could, put it in a little tin of petrol and set it alight. I never undertsood that story in the bible about Moses and the burning bush, but now I get it

Think it's just a coincidence - most of these supercharger kits end up around 85kw mark.

One of the chaps in Australia posted up dyno of his supercharged 1NZ results. So I mspainted a comparison (Happy now, @Stu?! ) (His red, mine blue) Pretty meaty through the midrange! Supercharger has about 35hp more at 3500rpm. But then runs out of puff before 7k and he's got to change gear a lot earlier. He's planning on taking it to the drags. Will be interesting to see how it compares!

I've been fondling some plastic shafts in the garage some more, reminds me of my childhood (playing with lego) Looks like I've got a good scheme coming together. Might need to push the whole lot over away from the shifter cable a bit more. Will need to take the middle part of the exhaust out to see what sort of angles I'll need from there. As all of these pipes will be much longer (but all straight hopefully) God bless rear facing FWD exhausts, eh? So the idea from here is that I will hopefully have a shape for each runner that can be made out of only two of these, so only 3 welds needed on each runner prior to the collector: So I'll put these lengths back into my 3d model with the exact cut lengths, then I'll print the a 2d profile of each part onto some paper and cut the parts to exactly the right lengths needed. I also need to buy or fabricate a flange, you can buy them for about $80usd but maybe it'll be cheaper to get one cut locally? As I've got the cad file for the shape. For the collector situation, no idea yet but I'm just going one step at a time

Holy crap, that's tiny! haha. I think the 155 wide tyres with the 13" steelies should do - this way I can get a matching set of hubcaps on front and back

13" 4x100 fwd wheels are absolutely impossible to find. (Apart from narrow steel wheels)