Digsy

No idea, but I know that there are two types of (genuine) gas springs for the Supra: One for cars fitted with a rear wing and those without.

Personally I think that having a backup in a seperate box (which could still be a simple 2-bay RAID NAS or DAS) is a far simpler and cheaper solution than investing in a dedicated tape backup and hoping that is and when you actually need to use it in many years time, the media and the hardware to read it are still OK and supported by whatever OS you are using at the time. I'm just talking personal and SOHO use here, I have no idea about commercial solutions. The way I see it: Backup on 2-bay NAS may use "flaky" SATA drives but when one fails you will get a warning so you don't lose any data, and they are relatively cheap to replace. Also the whole NAS can be upgraded for a couple of hundred rather than forking out £750 for a second hand tape solution. Some of the files on my PC are as old as my first PC (1991) and I've only had a proper backup solution for the last 5 years or so. Mind you I've never actually had a hard drive go pop on me at home. Two at work though, so I realise it is a pain in the backside when it does happen.

This is something to bear in mind if considering the NAS option. The NAS boxes run their own OS (NetGear use a Linux based OS). This means that although they use standard SATA drives, the data format on the drives is not the same as the NTFS format used in your desktop PC. Therefore once you start using a NAS you are kind of stuck with it (unless you copy all your data back to a normal PC). The nightmare scenario is that you run a NAS for years and then rather than the disks failing, the PSU or something else internal gives up. You may then be stuck with a legacy NAS which is impossible to repair or replace, and two discs full of perfectly good data which you can't access. Theer are ways around this, but they can be fiddly.

If you want extra robustness you can plug a USB drive into the 102 and run automated backups to that.

I don't store ANY data on my local machine anymore. I have everything on a 2-bay Netgear NAS with 2x 2TB drives. This NAS is configured to backup files that I may want to "rewind" if I accidentally mess up, to a backup share on the same drive, so I have two "live" copies of the (very few) files that are really important. I also have this NAS set up to back up everything to a second NAS once a week, but that's only because I upgraded and had an old one laying around not doing anything.

It's what we call a "cycle beater" technology. A significant proportion of the NEDC test cycle, which is used to measure emissions, has the vehicle stationary at idle. By simply switching off the engine at idle you can knock a good percentage (IIRC its about 5%) off the CO2 figure. I say "simply", its actually quite a big deal but the OEMs get a huge benefit in their fleet average CO2 emissions. It is also a real world thing to a certain extent, especially if you sit in traffic a lot, but you can't use it constantly. My 2012 Freelander2 seems to go into idle stop mode less and less these days so I think maybe it thinks the battery needs to be topped up after the winter (I use my heated seats a lot), or maybe the DPF regeneration is knackered. Idle stop is a CO2 / fuel consumption thing. Those plumes of smoke you can see are particulate emissions which is a totally different thing, and not an issue when the car is new. This is the problem with cycle beater technology: It is becoming purely a road tax / company car tax band thing and less of a real world benefit.

Definitely alternator symptoms, except you say you've changed it out already. The lights I had when mine went were oil level (yellow light) first, (went out wen revs increased). Then catalyst temperature, then ABS warning and last of all the actual alternator / battery light.

Sounds like a mis-interpretation of how a honeycomb laminate works in bending. You can retain most of the bending stiffness of a solid bar by just having the material in the outer edges as this is the material that takes the compressive / tensile loads. The material in the middle does comparatively little, so you can make a composite bar with proper metal on the outside and a filler material in the middle to maintain the gap. For something like a chassis, the hollow sections don’t need a filler as they are already self-supporting when hollow. Unless the foam itself is seriously rigid in itself and very well adhered to the surrounding metal, then its not going to add a lot of stiffness, IMHO. Also, its going to knacker any drainage, which will promote corrosion. And filling crumple zones isn’t a good idea as they are designed to, um, crumple. Anything in there that partially fills the volume is going to reduce the crumple distance which will increase the deceleration forces on impact.

What's the issue in getting them from Toyota? I got a set from my local main dealer without any bother. but that was a while back.

Moderator!

Yes, I get you I just ran this through my bolt calculator. Assuming the flywheel bolt is M10x1.5 grade 10.9 and the crank is forged steel with a UTS around 900MPa then the bolt can be tightened to full torque (which is 50Nm, slightly more than 36lb-ft) with only 7.1mm of thread, so with 15mm everything should be fine. The crank is steel, isn't it??

I have to disagree with you there, Chris. I've never come across a crank nose, cam nose, flywheel or any other torque transmitting joint that relied on shear loading of the bolt. If it is a face to face joint then its always torque transmitted through the friction between the two faces which is a function of the clamp load. I've done several cranks from scratch and the flywheel palm has always been designed to transmit the instantaneous torque from the crank torsionals that are present between the more or less constantly rotating flywheel and the torsionally vibrating crankshaft. Drive on a face, a taper or a spline. Never a bolt or a key That's how it is in OEM-world, anyways. God knows what you racing types get away with

Are the stock flywheel bolts not yield tightened then?

Don't assume that it will be OK with 7 bolts. Chances are if 7 bolts were OK Toyota would have designed it with only 7. OEMs tend not to add components for the sake of it.

IIRC swinging the intake cam pivots the torque curve around roughly the mid point, so what you gain in top end you lose in bottom end. It could be that the top end performance is more dominated by the turbo so if you are only interested in top end power then a couple of degrees here or there makes very little difference. There ought to be a trade off with the bottom end though. Personally I would say that cam timing is equally important on NAs and turbo engines if you are interested in total performance. They're only indicators anyway. You can set TDC as accurately as you want but if you build with cam pulley dowels (which is what "preset timing" means) the engine will settle into own timing as soon as you put the belt on and turn it over. I'd expect cam timing using the stock dowels to be accurate to within a couple of crank degrees. Nowhere near as good as you can get it by timing it manually but also nowhere near as bad so as to risk jumping an entire tooth on the timing belt.

If the cams and pulleys have dowels or keys fitted then the closest you will get is within one tooth on the timing belt. Timing an engine manually is only relevant if you are using vernier pulleys or cams without dowels. During development its normal to leave the cam dowels out so engines can be built with precisely the same cam timing without production tolerances getting in the way. TBH a pre-timed cam with dowels should be pretty bloody close unless the manufacturer has messed up. However if you then want to swing the cam VERY close to the limits of valve-piston clash then knowing precisely what your timing is becomes more important.

This. Not saying its the cause of your issues but its not going to help. The 2JZ has a twin plate thermostat which not only opens up flow to the radiator when warm but also closes of the radiator bypass. By removing the thermostat you have opened the radiator flow AND the bypass flow, so you will have less flow going to the radiator than if the thermostat was fitted. If you really did want to do this mod then you should fit a jacked open thermostat (i.e a thermostat that has been modified to always be open).

I think the physics model is too over-simplified to be useful. I don't believe that cars have anything near a third power relationship between size and mass. I would guess that cars vary quite widely in height and length but in % terms not very much in width. I would also guess that a car's moment of inertia is almost totally not coupled to its size nor its mass as (is discussed later on) the mass distribution has a much more significant effect. So as they say themselves, I more or less agree that the results are qualitatively correct, but more by coincidence than anything else.

Sure its not just the washer on the bolt making it look like that?

The SAE spec is roughly size for size but there are a few anomalies in there. Depends on the size of the retaining bead, too.

Oversquare engines: Advantages: Low mean piston speed Reduced friction Reduced inertia forces on rod, piston and pin (not withstanding potentially increased piston mass) Shorter engine (packaging height) Better NVH (also L/R dependant, but easier to achieve if stroke is shorter) Able to package larger valves. Able to achieve same piston force with lower cylinder pressure (see also disadvantages) Disadvantages: Worse charge preparation at low speeds (reduced bottom end torque). Increased mechanical loads for a given cylinder pressure (i.e. requires a stronger piston, rod and pin) Heavier piston (will partially offset the mechnical loading benefits of having a shorter stroke, although still overall benefit). Longer engine (packaging length). Higher heat rejection to coolant (larger combustion chamber surface area near TDC) Lower average cycle torque for a given cylinder pressure curve. Increased burn time. Suited to: High revving engines with lower peak cylinder pressures. Engines where low speed charge preparation is not critical (i.e. port fuelled engines). Also 60degree V6 engines tend to be oversquare because the packaging is driven by the length of the crankshaft which in turn drives a large cylinder spacing. Making such an engine square or undersquare would be very inefficient, package space-wise. Undesquare engines: Disadvantages: Higher mean piston speed Higher friction Increased mechanical loading Taller engine (packaging height) Worse NVH (sensible L/R harder to achieve) Smaller combustion chamber (valve packaging) Increased piston specific loading for a given cylinder force (i.e. requires a heavier / stronger piston crown and top land). Advantages: Better charge preparation at low speeds (improved bottom end torque). Less heat rejection to coolant (smaller combustion chamber surface area). Higher average cycle torque for a given cylinder pressure curve. Shorter engine (packaging length) Decreased burn time. Suited to: Boosted DI engines where charge preparation at in the off-boost / low speed area is important. Engines where efficiency in the drive cycle region is important. Despite the apparently long list of disadvantages in undersquare engines, the trend in passanger cars is overwhelmingly towards going undersquare. This is enabled by the fact that modern piston materials and design has alleviated many of the issues related to piston strength and mass. Also, with peak cylinder pressures heading towards 120bar, having a smaller piston crown area makes life a lot easier for the piston, pin and rod. Modern approaches to bore honing and piston coatings are reducing the friction issues, as is the now commonplace offset cylinder bore (which reduces piston side forces). The advent of DI has also meant that as you do not get the fuel mixture preparation by injecting further back in the intake system, the combustion system is reliant on in-cylinder charge motion instead. This is inherently better with longer stroke engines because the mean piston speed is higher.

I'm not really familiar with wheel spacers. Does the way they attach to the hub have any self-centering feature, other than the spigot?

My personal opinion is that plastic should be fine unless you are planning on doing a lot of wheel swaps (which might wear the rings inner diameter), or you don't want to have to replace them if somehow your wheel studs come loose. But if there was little or no difference in price I'd probably get aluminium ones.

Weeellll.... I won't dispute that you had problems, but as a simple joint design, the friction between the hub and the wheel when clamped by 5x M12x1.5 bolts tightened to 103Nm should be capable handling of a shock of just over 44kN without slipping. That's equivalent to accelerating one corner of the Supra (weighing 1500kg) upwards at nearly 12g. For comparison I just had a quick chat, with one of our suspension guys and he says that 4g is an "abuse" level. Granted, the pure vertical load case might not be the overall worst, but those numbers give me a lot of faith in the wheel to hub joint, spigot ring or not Of course, as we both said, they help alignment and if your alignment is off wthout then adding a spigot ring will help or sure it, but make no mistake, they should not be taking any direct load unless the bolts come loose.

Hate to disagree Mr. C, but the loads are all reacted throught the friction joint between the wheel and the hub, not through the spigot ring. I ran with no spigot rings for the entire 9 years-plus that I owned my Supra without a hitch. The time that the rings will see a load is if the the wheel studs somehow become loose. If that happens then the clamp load will relax and the sliding force that the joint can accomodate without slipping will be reduced. With no spigot ring in place to control the amount of eccentricity between the wheel and hub, the wheel will slip until the load is reacted through the wheel studs themselves, which isn't a nice way to do it. I don't think it would cause an instantaneous failure, and you would probably feel a good bit of vibration. Of course they also locate the wheels during fitment, but I had conical wheel studs which do the same job. If you are confident your wheels are always going to be proplerly located and will never come undone, the physics says you will be fine with plastic rings, or indeed no rings at all. If you want a safety net, use a ring. Plastic will be fine but if something does go wrong you will probably have to replace them. Metal would probably be a "fit and forget" solution.