Roman

A few developments (not really) Have mentioned a few times that 4x100 wheels in 13" are incredibly hard to find. Apart from options from America drag honda scene if I wanted to buy brand new. So although I've known already what tyres I want to buy, need to make sure I could get wheels first. So guess what @Snoozin found for me on Marketplace? Lenso 7.5" wide 13" wheels with the 205/70/13 M&H dot rated tyres already on the bloody things... for less than a set of these tyres brand new. Stoked! Stoked to see that they clear the brakes, and have miles of clearance to the strut. These are a +25 offset so +35 or so would have been perfect to fit in the guards better... But I'm not complaining what so ever. Can. not. wait. to get back to the drags. The sidewall squish is just delightful. It's like these tyres are made out of dish washing gloves. Big thanks to @Stu for lending me the Stusiers and convincing me that drag tyres are 100% the way to go. Will be interesting to see how they compare. This combo is incredibly light, havent weight one yet though as I was keen to see if the brakes cleared or not. EDIT: Under 11kg for these, vs 14kg for 14" wheels with R888R. Sweet! There's a guy in Australia who races a stripped out Echo with a fairly standard engine, on standard ECU - runs 14.7s but with an absolutely incredibly 1.9 second 60ft. I'm currently closer to 2.2 60ft for a 13.8 at the drags so there's potentially still a bit left in the tank! Also in aid of finally ever making an exhaust (after just blowing this months exhaust budget on wheels) I've started printing some dude noodles to try figure out headers shape. Need to print some straight bits so I can lego something together on the car and see clearances etc. But it's exciting to see some tangible progress anyway. There's a reasonable amount of room for these, just have to try wiggle things around to find the best shape that gives good clearance to shifter cables and the steering column. So hopefully I can come up with a scheme so someone can help me weld a final version together without wasting too much of their time. Exciting!

shit yes! Full rally spec looks awesome

I can believe that with a clutch type. Like its incredible how much a tight LSD in a RWD car can make the car push the front and understeer. It must be a fair bit of force to be able to do that. like having the inside brake part way on. Basically you need to drive it like a gokart, tip it in so hard that the inside rear tyre is off the ground Good for economy too to keep the speed up

I doubt LSD makes much difference for a few reasons: -Viscous LSDs are basically the slushiest option and when the difference in wheel speed is low, the goo has the least friction in it (Gets more thicker as it gets hotter doesnt it?) -At any decent speed your cornering angle is very shallow, so the inside/outside wheel speed difference isnt that much. If you're driving slow and turning tight corners then you're losing your economy from having to slow and get back up to speed. Basically - time for ECU for economy improvements Or at the very least, drawing some graphs about it

Keen as! Thanks will pm you

Another slight off topic, but it's been incredibly hard to try drive this car sensibly. So I've not had any good fuel economy results to see if it's hideously worse than before. I put the windscreen wipers back in and went for a drive over to Te Awamutu to pick something up. Results were good! While out driving I also had some thoughts about part throttle tuning. Mainly, what the hell are you actually trying to achieve at part throttle? Full throttle is easy. Get the maximum amount of air in there, then give it the right amount of fuel for max power, right amount of ign for max power. But part thottle there's so many considerations. If you maximize airflow at every cell you can end up with a weird wonky fuel table. If you try maximize power you run really rich and fuel economy isnt great. If you try optimize BSFC, then its gonna be running lean and boggy - so how do you transition that nicely into full throttle power mode. Also it seems with a nice smooth cam angle map you can still get a lumpy looking fuel table. So had a new idea. I'm going to try change the shape of the fuel map to look nicer, by committing atrocities on the VVT timing table to reduce airflow at strategic points. Fuel map currently looks like this, notice how at 40% throttle (blue line) There's shit all over the place up and down Looking at a slice of VVTI and VE settings overlapped, at 20% throttle: If I push the blue line up, (advance the cam) the red line should come down. (Fuck you, airflow) At least that's the theory. Will have a play over the next few days, will be interesting to see what the vvt and fuel maps will end up looking like taking this approach.

Oh yeah, I'll give it a go with that lip trim stuff! Will send you a PM, thank you. Yeah I'm not yet completely convinced that the drip tray area is as awful as I'd first suspect though, because of shape of the car. In saying all of this, since half of the point of this car is that parts are cheap and readily available. It would be interesting to get a spare bonnet and cut lots of holes in it, then fit one way flaps that cover over them. So it'll show where's good for vents or not. However I'm not all that keen on having bonnet vents on the car, for visual reasons. Something else that's interesting, is just how little pressure it needs to make a big difference in lift. If my bonnet was 1m squared, and there was 1psi pressure difference from one side to the other. Then there's 1550 square inches in a square meter. so 1550 pounds of pressure? 700 odd kg? Or is that not how it works... Seems like heaps! Or is the actual pressure difference for aero stuff only very small? I cant imagine there being anywhere close to that amount of pressure causing lift. I've got this in the shed, which is about size of a dinner plate: plus or minus two inches of water is only a tiny amount, total usable range about 0.14 psi Will be interesting to see if it shows anything on that sort of scale or if it's too sensitive. A normal 0-5v MAP sensor is definitely not going to have enough sensitivity though.

Thanks for the kind words! Yes lots of experimenting and failures on the path to good results but then very satisfying when it all comes together. Worth noting that I couldn't have achieved a lot of this without some incredible generosity and support from a wide variety of people who have also pitched in. Which has been incredible. Come say hi some time next time at the drags! Which hopefully wont be too far off. I'll promise to try not to talk about 32 pages worth of Echo stuff... Maybe.

Okay soooo The wool tufts dont go mostly up or mostly down, just mostly just nearly flat towards the base of the windscreen but with lots of wiggling around. Maybe because the open area is so large, it can just equalize the pressure top and bottom no problem. Doesnt seem particularly conclusive, but maybe it needs some more context with more dangly bits on surrounding areas. Or maybe I should just fit a pressure sensor under the bonnet instead, as that's the real issue (or not)

I think "it depends" If you have a long flat bonnet and a steep upright windscreen. Then its more likely to be a high pressure area there. Which is where cowl induction works good. Echo has a tiny short bonnet, and a very shallow angle from bonnet to windscreen. Similar to the rally car I posted which has its vents right up the back. What I was thinking is that I will retain the lower half of the drip tray, and add some one way flaps like in baffled sumps or radiator shrouds. So they only open if pressure in the engine bay is higher than the outlet area. But for starters I can just have the whole tray out and see what happens with some wool tufts or a manometer.

Mine isnt really a 13 second car in the way that others are though - it's mainly just because of the tyres. Which on one hand goes to show yet again how important the right tyre for the job is. However street cars which do mid 13s on street tyres, that's a really proper fast car. Look forward to seeing how this comes together

Nah nothing like that. Will use the drip tray area so it looks a bit more standard / nicer. Maybe a bit of a front lip to reduce the amount of air going straight under though. Interestingly some of the newer shape Yaris rally cars have their engine bay vents very close to the base of the windscreen.

Another issue I've been thinking about for when I finally get to a trackday. Is to try tame some of the floaty feeling of driving a bean bag shaped car at 180kph+ Currently all of the engine bay air has to go out underneath. The drip tray and windscreen wiper area unbolts, so its easy to remove a big chunk that should flow a bit of air out even if it's not an ideal location. Might do some wool tuft tests and try see where the air wants to go when the whole panel is missing. I am guessing that the engine bay air will mainly want to try escape past the wing mirrors rather than going over the top.

Yeah or just cast threaded rod directly into it. But first test is seeing if I can get a piece out of a mould at all.

Thanks for your input! Do you think adding some filler, like carbon or fibreglass strands will give it some more dimensional stability during curing? Kinda like how it helps the nylon 3d printing? Going to try this stuff. https://www.smooth-on.com/products/epoxacast-670/

Mould is ready to go. Will do another coat of PVA mould release stuff on it first, then blob it up once epoxy arrives. I'm 90% confident that it's not going to come out of the mould, and it's gonna go straight onto the wall of shame. Also it might not like being drilled and tapped, maybe it will just break? Which reminds me, I need to setup a wall of shame in the shed. For some reason its fun when I think something might not actually work. It's exciting to see if it will.

Yeah doing an aluminium casting would be fun. Although, lost PLA for a plaster mould for the epoxy stuff could be a good scheme too. Might try that next if this doesnt work!

Yeah the carbon nylon stuff has a higher melting temp. But its a bit harder to print and its a lot more expensive. My next scheme is to make a PLA mould and pour in a tool making epoxy. Maybe with some chopped carbon strands smooshed in. Then hopefully melt away the pla to leave the part. Ive found a tool making epoxy that is resistant until 170c, and looks to be decently strong. Needs to be cured for 2 hours at 80deg, then after that an hour at 120. So should melt off the majority of the pla in this process hopefully. Might take a few iterations to gst the idea to work (or it might not work at all) But will be fun. Im printing this at the moment.

Lately the car has been a bit... flat. And it's lost its doort noises for some reason. Since I've fixed the wideband, none of the settings it "wants" have made any sense. It's running way richer than it should be... But everything seems fine? I was thinking my wideband is probably chooched. But it's been slow as well. I was suspecting that the cat converter might be blocked, seeing how I've been using an ignition cut for rpm limiter and launching. Thought I'd better check inside the intake just in case though... Ahhh wtf haha It looks as though the areas of my manifold which werent covered in carbon, have gotten a bit melty and jizzed up the ports. This doesnt seem to make sense because it's been going for months and months just fine... and I've had the manifold off and on several times in that period. But thinking back, this probably happened when the electric waterpump failed and the motor boiled all of its coolant out, and I drove it home as-is. haha. As this material can widthstand "about" 100 degrees, the motor probably quite easily got to 120 or 130. Looks like there's no damage. If there was though, would I regret having a printed manifold? Shit no! 3d printing has been a cornerstone of making this project possible at all. No regerts. Not quite sure what I'll do from here yet though. Maybe a 100% carbon version. Or maybe get some alloy flanges laser cut and get someone to weld the bits together with some pipes in between.

It is a torque at the wheels graph, essentially

Yeah so there's evidence of the coils binding up. So will definitely put some stiffer springs in there. Thanks for the tip @cletus In other news, I've been wondering if it's actually worth revving to 9k at the drags, or for next time if it's more worthwhile shifting at a lower rpm. So using dyno results, gearbox ratios and final drive ratio. Put together tractive effort graph. (followed this as a guide https://www.hpacademy.com/technical-articles/understanding-torque-and-horsepower-with-tractive-force/ ) So if the lines cross over from one gear to the next, it means the motor is revving higher than what is useful. (excuse my lack of meaningful axes labels and values, CBF) I'm only using 3 gears at the drags, so it looks like it's possibly worth short shifting from 2nd to 3rd, but, there's not much in it. Not like it's wanting to change gear a whole 1000rpm earlier or anything. The blue line of first gear being nowhere near 2nd means that it would still be worth revving it even higher. In order for the blue line to cross the red one, I need to keep revving until the power drops to around 105-110hp

The Bilstein springs have heaaappss of non active coils to soak up the fact that it was lower (not by much) But I think what was happening is that the car didnt quite compress the non active coils at ride height. So when you turn it would just tip slightly, then instantly get a real big spring rate increase. So it stayed nice and flat. But in this case it's a linear rate spring. I found someone else who runs these, and they said the spring rates are something like 3.5kg front and 3kg rear. So not hugely stiff. He recommended trying preloading them more first, which makes sense / easiest first option.

In my 8+ years of ownership this car has had one wheel alignment ever Nah it's not bump steering, well, any more than it used to anyway (semi slicks seem to accentuate it) But yeah, I guess if it's changed the castor angle via the top hats it'll probably be a good idea to get another alignment. The only other time was when I swapped in the manual rack. I dont think there's anything that can be adjusted apart from front toe.

This last tank was 35 litres and about 450km So under 8 litres per 100km with some hooning thrown in. I still havent retuned it properly since the wideband situation has improved. I'm going to try head back to the dyno and see if I can spend some time on part throttle stuff, to get economy areas tuned nicely. I want to see if I can connect my ECU to the dyno with canbus, so I can import power/torque into the logs. Then I can generate BSFC numbers in real time. Which is what you really need to see in order to optimize economy areas. Also, yeah I had all of my suspension wound to the softest settings haha. With everything cranked the other way, it feels too stiff and every single bump on the road comes into the car. So it's nice to know that I've got a good usable range to work with. However even on stiffest, now the car rolls funny in the front when the car turns. It's always previously been quite flat in cornering. Not sure if it's because it's a little lower and I've crossed some threshold where now the front roll center has moved significantly. Or just because these springs are softer than my other ones. (more likely) So I'll start with the easiest option first, and preload the springs a bit and raise the front height some more. Otherwise I've got a few other coilover springs to try here.

Vitz etc is for the common peasants, K11 is for the more refined gentleman I put the coilovers in, I was thinking the fronts would end up heavier than previous. Surprisingly overall, now the suspension is lighter. I put the spring rubbers in top and bottom on the rear springs, but the top ones dont fit right as the spring finishes differently. So it's raising the rear height by probably 15mm or so more than it should. Will pull them back out tomorrow and figure out something else. Net result is a 5kg loss, happy with that! Surely must be creeping towards the sub 800kg mark. The rear shocks were the only thing heavier than they started, but since they're adjustable I'll forgive them. The front and rear shocks both have adjusters on them for stiffness, however I'm not yet sure which way to turn them to make stiffer or softer. The rears adjust from the top, and the fronts from the bottom. So do I adjust the front ones clockwise from underneath, then rears clockwise from on top? Or all clockwise looking down from the top? etc? Will figure it out, haha. First impressions driving it is that the front spring rate feels a fair bit softer than the bilstein springs I had in there previously. However now I've got the option to easily swap! Also interesting to note that the new struts tops have some extra castor built in, by pushing the top of the strut further back. (in a fixed position) The steering feels lighter than it did before, not quite sure why yet. Maybe from the extra castor? Although I'm sure I remember hearing that this makes steering heavier not lighter. I'll need to check if the coilover platform/spring/thread protrudes into the area the hoosiers want to occupy. If so I'll need to swap these struts back out for drags. But its a half hour job, not a big deal. Having stiffer rear springs and being able to set the rear shocks stiff will still be a good help. These will pay dividends when it's time to head to a trackday, hopefully some time sooner than later.