Popular Post cletus Posted March 10, 2022 Popular Post Share Posted March 10, 2022 that runs 13s and also has very good ecom on pertol 10 4 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted March 10, 2022 Share Posted March 10, 2022 Yeah WTF! 13's are meant to come from a big Holley and a stroker kit. What happened to the days of calling ahead to the small town gas stations to make sure someone could meet you there after hours cos the 24hr stations were too far apart? 4 1 Quote Link to comment Share on other sites More sharing options...
Muncie Posted March 10, 2022 Share Posted March 10, 2022 Oldschool.co.nz economy drags? Where you run 30 passes top your tanks off calculate your consumption against a excel spreadsheet with a pie graph to award the winner. 4 Quote Link to comment Share on other sites More sharing options...
Sungai Sungai Posted March 10, 2022 Share Posted March 10, 2022 this car is redefining goez hard 4 wat it iz 8 1 Quote Link to comment Share on other sites More sharing options...
shrike Posted March 10, 2022 Share Posted March 10, 2022 20 hours ago, cletus said: that runs 13s and also has very good ecom on pertol @Romanhave I missed it or have you already done an e85 tune and maxed out timing? Quote Link to comment Share on other sites More sharing options...
tortron Posted March 10, 2022 Share Posted March 10, 2022 Can only buy e85 by the drum here now, NLA at pump 2 Quote Link to comment Share on other sites More sharing options...
Roman Posted March 10, 2022 Author Share Posted March 10, 2022 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. 4 1 Quote Link to comment Share on other sites More sharing options...
shrike Posted March 10, 2022 Share Posted March 10, 2022 1 minute ago, Roman said: 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. Ahhh ok didn't realize you didn't have knock limit on 98 (considering the compression :p) might be a slight bump from lower intake temps but I doubt it would do much and yeah if no E85 available no point Anyone on here got a still that can sling you some Azotrope :p make your own hahaha Quote Link to comment Share on other sites More sharing options...
Roman Posted March 10, 2022 Author Share Posted March 10, 2022 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. 5 Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 11, 2022 Author Popular Post Share Posted March 11, 2022 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. 17 Quote Link to comment Share on other sites More sharing options...
anglia4 Posted March 11, 2022 Share Posted March 11, 2022 So you’re going to drive the length of the motorway a bunch of times…. In the name of saving gas? 2 3 Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 11, 2022 Author Popular Post Share Posted March 11, 2022 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. 15 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted March 12, 2022 Share Posted March 12, 2022 I wasn't aware that cruise economy was quite so insanely sensitive to ignition timing. Perhaps I will have to fine tune my cruise timing a bit more one day when I can afford getting up to cruise speed Quote Link to comment Share on other sites More sharing options...
shrike Posted March 18, 2022 Share Posted March 18, 2022 Whats the lead time on the bike throttles being in your hands? Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 18, 2022 Author Popular Post Share Posted March 18, 2022 Hopefully here in a week or two, but not 100% sure these days! In the meantime I filled up a tank of 91 again, and then started on a more comprehensive economy tune. So this thing actually drives super nice at a 16.2:1 air fuel ratio under cruising conditions. then at full throttle I've leaned it out to around 13.4:1. Also set rev limiter to 7000rpm. On 91 at full throttle it was knocking quite bigly in some areas, mainly very low rpm very high load. So I pulled enough timing out to stop it from doing that, which was heaps - but then I've also adjusted e-throttle setttings so it cant get to that part of the map anyway. (Talking like, sub 2000rpm full throttle) So despite having spent the first portion of this tank of gas refining the entire map for the leaner conditions, which is obviously a fair bit of time at high throttle openings. I ended up with a near identical end result to my other tank. 729km from 36.99 litres. So again only just just just over 5L per 100km. So that bodes well for this following tank I think I could get close to 800 if I drive it nicely the entire time. By the time that's done, I think it'll be just about time to put some 98 octane back in and get these bmw throttles on there. Cant wait! EDIT: Also did some tests on same stretch of road to see which speed is most economical. Turns out that about 75kph is best economy with this gearbox, probably because at 100kph its doing over 3000rpm. Where as standard gearbox is like 2400 or something. 20 1 Quote Link to comment Share on other sites More sharing options...
Sunbeam Posted March 22, 2022 Share Posted March 22, 2022 On 09/03/2022 at 23:01, Roman said: 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. The Aqua definitely isn’t optimised for high rpm. Mine doesn’t go over 4800rpm no matter how hard you mash the throttle. Which is probably why the petrol engine only makes 54kw. 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 22, 2022 Author Popular Post Share Posted March 22, 2022 Yeah the way the cams work in the standard motor, it's more like a 750cc motor with an extra long stroke on the expansion side. I test drove an Aqua that my partner was considering getting, it's so absolutely hilariously different to this. This weekend on Sunday is an event at TECT park in Tauranga-ish area. This looks like heeeaapppsss of fun, its basically a super bumpy gravel track that's pretty wild But my car might be a bit low and come home sans bumpers. If I go to this, I'll keep the aqua manifold on as I've got more confidence in its dust filtration abilities. Alternatively if the red light situation changes, it might be Night Speed Drag Wars by this Friday. In which case the ITB stuff can go back on, no sign of the BMW bits yet. Otherwise I'm gonna hang these up on the wall until the other bits arrive. Pretty stoked with how this stuff turned out, and some of the milestones achieved with it. I've been trying to get a head start on the situation with throttle spacing on the BMW setup. I managed to find a scanned image of the engine's head gasket, then scale some measurements to try find bore spacing. Then I'm assuming the intake ports are central to the bores on each. 1NZ is 83mm bore spacing, and it looks like the S1000RR motor is going to be in the vicinity of 83-85mm centers based on scaling. So fingers crossed that this is the case, as it'll make it super easy to machine a manifold. Assuming an 85mm spacing it ends up like this, so slightly narrower would be just fine. Also if I end up CNC machining a manifold, I can keep the design a lot simpler because the material is so much stronger. I will probably add some degree of bridging between cylinders and add a few fillets once I know the tool sizes we'll have. But I can just focus on trying to make the whole thing machinable from one fixture position on the bed. (hopefully) Version 1.0 probably through to version 6.0 of this will likely be 3d printed anyway I guess. The tool path simulation stuff in Fusion 360 is pretty cool 26 1 Quote Link to comment Share on other sites More sharing options...
Popular Post Roman Posted March 26, 2022 Author Popular Post Share Posted March 26, 2022 After trying proper drag tyres at the drags, and semi slicks at the track. Its really cemented my opinion that the wrong car on the right tyres, is better than the right car on the wrong tyres. Today I attended a gravel autocross at Tect park which was absolutely incredibly awesome. However doing so on 1.5mm tread direzza star spec track oriented tyres was hilariously unsuitable. Average rpm was ~4000 and average throttle angle was 18%. Was just impossibile to get any power down. I was 10 sec slower than a near standard vitz rs, and about 5 sec slower than a four door K11. Ooohhh the shame of it all! Incredibly fun track layout though, with some decent speed not just pottering around cones at 30kph. A++ will attend again on suitable tyres 24 1 2 Quote Link to comment Share on other sites More sharing options...
deankdx Posted March 26, 2022 Share Posted March 26, 2022 video of dorts in the dust not loading? sounds like a blast, needs a 4wd conversion next? Quote Link to comment Share on other sites More sharing options...
Roman Posted March 27, 2022 Author Share Posted March 27, 2022 Nah was a zero admin day. Didnt even bring any tools. Doesnt meed 4wd, just needs tyres that have tread blocks. 1 1 Quote Link to comment Share on other sites More sharing options...
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