Roman

So I've had a bit of a nerd-on regarding fuel economy etc recently, Was reading about that guy that whale tailed his civic (which looks utterly rediculous) However he now gets 2.8l per 100km What the fuck!! I didnt even think that it would be possible to improve by that much. I want to keep this car looking standard, but there's some low hanging fruit in the aero department because the front of a the car, from underneath, is a frigging mess. Gonna have some side sections sealing off radiator entry so it uses the fan less. Then try get a flat tray underneath the front of the radiator area and a short distance behind it too. Might be worth a few KPH at the far end of the straight at Hampton. Found this cool excel sheet, will give this a go before and after and see if there's any difference. Not expecting miracles but I do think there will be at least some quantifiable change for the better by attempting reducing drag a little. If not, as usual, will chuck it in the bin. www.iwilltry.org/b/wp-content/uploads/2010/05/Drag_Coefficient.xls Made a start on some side panels for radiator, just corflute for starters. Will check with pressure sensor for before/after and see if it makes any difference. "When you've got carbon fibre taste, but a real estate sign budget"

So little air that it's truly negligible compared to what else is going on around the wheel. (in the example of this particular disc etc at least)

Absolutely! A very crude approximation of the wheel well etc is in the model, I've just hidden it for sake of pics.

Looking in plan view over a wheel Isosurfaces are my new favourite gimmick. really need to see the 3D model and rotate it to get an idea of shape though. Basically it draws a 3D mesh of where the flow is at a certain speed or pressure or whatever. So this is wheel going 120kph but showing where the flow drops to 90kph or below. Which is pretty much as per the picture above.

Julian Edgar is the man. Read one of his books back in the day, first time I'd seen anyone try to quantify changes for anything to do with modifying cars.

(Disclaimer: Below rambling is for sake of interest, not necessarily that I need extra airflow to brakes at this stage) Last night I drew a fairly accurate model of one of my front wheels, the hub, and the disc, and a big slab of "ground" No caliper or suspension yet but just for interests sake looking at the basics of how air flows around the disc / spokes / etc when its rotating. It seems that when the wheel is travelling forwards at 120kph, (and rotating...) There's virtually zero air flow through the centre of the wheel or near the disc. The tire builds a big wake that seperates at the leading edge of the tire and thats the last airspeed that the wheel or disc pretty much ever sees. Even with a crude representation of the front of the car covering upper half of the front of the wheel. The flow around the wheel only changes things ever so slightly because it's the high pressure zone down low under the front of tire which intiates the wake that then spills upwards. I was sort of expecting the spokes of the wheel to be stirring up some air in a semi meaningful sort of way, but doesnt look like it acheives anything useful. What's interesting to see is that without supporting aero mods ahead of the wheel. Aerodynamic wheel covers, despite looking sleek likely acheive next to nothing as there's no air speed going past them. Which is probably why they were last seen in the 80s. Even if they stuck out by say 40-50mm it wouldnt make any difference currently. I can now see the rationale behind "speed flaps" ahead of the tire mounted to the lower gaurd. Which are there to disrupt airflow before it gets to the tire, so it flows more uniformly around it. I'm not taking the above results as gospel but it was certainly a lot different to how I imagined flow in and around a wheel would work. Will post some pictures later so this rambling makes more sense.

I'm pretty keen to wire up sensors either way, for interests sake. Ferodos have been good in terms of braking feel / no fade / etc but yeah, its the wear rate thats the killer currently. Ahhh well at least my discs arent wearing by any significant amount so far. I'll try a different type of pad next time.

Thanks, not sure on brake temps but figuring out a way to measure is pretty high on my list. I've got an IR gun but it's hard to know peak temps if you're only measuring when you get back in the pits after a cooldown lap. I've been doing some joogles and I see there's a fairly popular sensor that goes to 1000cc and outputs pwm relating to temperature, so could wire some of those in. Or even better have some tire temp sensors as well and wire it all up as can/bus so I've still got inputs and outputs left. I definitely agree that getting some data about the actual problem is the first step before "fixing" it. I dont get brake fade at all, just high wear rates. My rear brakes havent gone through a set of pads at all yet, but front brakes do most of the work and a set of pads lasts about 4 trackdays. Keeping in mind that this isnt a dedicated race car with race pads, as per usual I'm trying to tip toe through that middle ground and keep a drivable car on the street. (Using Ferodo DS2200)

Your girlfriend is pregnant.

Then wait until after... You're dealing with 30+ year old parts so something unexpected will happen. If you just swap the guts over, your contact patch on the gears might not be correct anymore. In which case it's a bit more tricky to setup from there. So long as you leave the pinion gear completely untouched, and use the same bearings you might be right. Just dont back off the nut on the pinion flange EVER unless you're replacing the crush tube etc inside.

I see some interesting designs for people cooling their brake rotors ie. randomly pointing a pipe into the wheel well from a randomly selected part of the front of the car. A vented disc works as a centrifugal fan so air flows from the centre outwards. Often I see people trying to blow air back in from the inside. Much better is when there's a cover plate that pressurises the inner side of the vents. Which is unfortunate on my case as the "inner" part of the vent (which you'd want to blow the air into) faces my wheel so there's no easy way to run a pipe to it. Time to run a vaccum line around the wheel well area to my datalogger and see what's going on. Hopefully running some ducting will make my pads last a bit longer, currently works out to about $100 on brake pads per trackday. The guys with the big heavy cars with lots of HP must have some horrific expenses on consumables!

Sucks about the piston. What's the plan from here? I'm guessing it would be more economical to buy another 1J than rebuild. But that doesnt sound very Sheepers-like

In other news, that work to remake the rear bumper is frigging amazing! Very talented.

Front wheel drives are ideal for a big wing on the back. Setup the car so that it has oversteer tendencies at low speed, and then the wing makes it more neutral when you're going fast by holding the rear down.

With my current setup, when the deadtimes were hugely wrong at least. when I tried adding fuel to the outer injectors below 5000rpm it just wasnt liking it at all. I also was running ~80psi for a while but my fuel pump creaked and moaned about it. So I've dropped to 60psi, vaccum referenced so under low load it drops to 50psi or whatever to give the fuel pump a bit of a break haha. I'll maybe have another go at adding the fuel earlier in the revs once I get another wideband sorted out. Stupid Innovate junk has just chewed through its 3rd sensor. I'm thinking dropping to a lower CC for the outer injectors, and with a multi nozzle head instead of single pintle might be beneficial. I'm keen to switch over to the "modelled" fuel equation which means it the fuel needs a retune from scratch pretty much. But it gives me some extra information which will be useful for tuning, it allows the ECU to output "fuel economy" both instantaneous and "trip" as a value. Rather than me having to work out the maths for it. Once I've done that I'll experiment some more with different AFRs for best economy, and also VVTI settings for best economy. On a recent trip I got 6.7l per 100km which I thought was pretty awesome. According to documentation if you have the VVTI advancing "about half way" at medium load it works like an internal EGR pump by letting exhaust gas back in, which reduces pumping losses and improves economy. But it'll be a lot easier to figure these things out when I've got a graph directly in the ECU showing economy.

Note sure. I really need to get to the dyno and do some runs with and without the staged injection to see what difference it makes. My guesstimate is that the motor revs a bit more freely past 7000rpm but it's hard to say for sure. If I go to the dyno and it doesnt help I'll just go back to previous.

Interesting about the VVTI, I guess yeah it would be a lot more precise than hydraulic with PWM.

Thanks, Yes it uses "Injector effective pulsewidth" combined with RPM, some known variables about the injectors from my bench testing, and then the vehicle speed. If I use the "modelled fuel" setup instead of "traditional" inside the link, then it gives you a fuel economy figure natively in the ECU. I'll probably give it ago on modelled fuel at some stage.

Haha, crackup! Even understeer on lift off, wow. It's weird that they would dumb down the AW11 towards the end, and replace it with the early model SW20 which had the worst reputation for oversteer out of the lot. I found that tires made a huuuuuuggggeeee difference on my SW20 towards reducing understeer.

Ahhh awesome! Thanks. It's been helpful for figuring out where parts go when putting a car back together haha.

What is it about the handling at the moment, that you are looking to change by adding a different swaybar? I find it helpful to try think about handling in each of the different scenarios, individually. If someone says "Does your car understeer or oversteer" its hard to answer if you're thinking about everything together. My car is something like this: If your car understeers there might be 5 different ways you can adjust suspension to decrease it. But out of the 5 one of those options best helps your problem area while minimally disrupting the others which are currently good. Sometimes its hard to think about in the heat of the moment, but I find looking back at in car videos from trackdays helps quantify things. I wonder if Toyodiy provides any clues about the swaybar thing. Although that's pretty much done and dusted now that pics dont load

Oh true, never heard about the electronic VVTI before. Probably not any more complicated to setup with an ECU though as I'd imagine it still runs via PWM. Interested to hear more about the 2GR rwd gearbox mish mash. Since they bolt up to an MR2 box for 3SGE, I would have assumed they have no issue bolting to an Altezza 6 speed either.

Were the main spring rates changed at any point between versions? If the later model ones had slightly stiffer springs it may have negated the need for a rear swaybar. Or perhaps they just removed it to make the car more understeery because the general public are shit at driving mid engined cars.

Pretty sure they're near same weight as a 3SGE as well, since they're all alloy. Just need to find that cross over point where they're not too expensive, but then not all old and fucked either haha.

Factory Altezza exhausts are heat wrapped. They're bukakk'd with chopped strand sort of stuff and then clamped between two stainless steel shells that surround the 2-1 section. Like top set in this pic