DanJ

Its mostly more "cycle beating" by the OEMs, by moving the start/stop system to the "P2" location (between engine and gearbox) from the "P1" location (FEAD connected) then they can drive portions of the emissions cycles that aren't stationary with the engine off. If you have a mild or full hybrid then switching the engine off does make a reasonable difference to the amount of energy that can be captured on deceleration and hence use less fuel. Sent from my Nexus 5 using Tapatalk

Last week I had the opportunity to see inside an HKS supercharger, thought some of you would be interested in seeing the pictures. Happy to answer any questions about what each picture shows, there's some clever engineering in there but they're very simple, I'm sure HKS make plenty of profit on each of these that they sell! Dan.

Phew, I've just been sent some pics of my calipers next to ones from a 2004 Scoob they also have in for refurb......they're identical. Sent from my Nexus 5 using Tapatalk

The fitment on the brackets is different so they won't bolt onto the hub I might be wrong, but I'm 95% sure it's up to 07 before they changed it I'll let you know when I find out for definite. Sent from my Nexus 5 using Tapatalk

If you have metallic paint then the under bonnet is a darker flat shade. My WRB BRZ is like that and I'm sure its the same on the "ginger" GT86. Sent from my Nexus 5 using Tapatalk

Agreed, my most recent experience was a 1-Series manual with start stop, it was awful so I switched it off, that courtesy car was swapped for an E class auto, which was well calibrated and refined. Either way I was still glad to get the Scooby back! The next thing for start/stop is "stop in drive", which is switching the engine off whilst your coasting, going down a long hill etc. That will be much better in the real world in terms of fuel saved, but having driven some early development hybrid cars with it fitted I can tell you its very odd at first! You need a mild-hybrid of sorts for torque infill during engine restart though, although this may be better on the 48V systems. Sent from my Nexus 5 using Tapatalk

Rest assured full electric is along way from being mainstream. It definitely is all about cost/benefit at the end of the day. Things like start/stop will be standard fit on most new cars soon (certainly in time for 2020 when the next step in emissions legislation comes in). I'll stop now anyway and try to keep away from geeking out on the detailed engineering [emoji1] Sent from my Nexus 5 using Tapatalk

Yes I'll be at Bedford on the 29th, I'd be very interested in a passenger ride in yours to confirm my thoughts before parting with the hard earned cash! There's plenty of kits out there that make more top end power for less money, but its all about area under the curve for me, as well as that it's a properly engineered product. Eventually I'll end up sourcing a second hand engine and upgrading rods etc to go to a smaller pulley (can't afford the downtime on a daily driver), but that's a good year away at least! Sent from my Nexus 5 using Tapatalk

It is very similar with a few key differences. The VAG setup uses an Eaton TVS (very similar to the Cosworth kit for our cars) with a conventional turbo. The amount of sound deadening kit they've had to put on it to have acceptable NVH is unbelievable, but they've achieved it AND patented how to do it so the other OEMs are blocked from that route (if they want it to be quiet, nothing stopping them from using an Eaton without the NVH kit). The Eaton setup is run at a fixed gear ratio to the crank and to get acceptable boost at low engine speed this gear ratio is so high that you have to declutch it above a threshold engine speed. Another impact of the fixed ratio is that it spends a lot of time bypassing air, which is all wasted energy. So having a variable ratio drive (or completely decoupled in the case of e-boost) has significant advantages. Having a centrifugal compressor attached to this rather than a positive displacement pump then makes all the NVH issues go away, so no need for sound deadening. Variable ratio is also highly desirable for managing NOx emissions, particularly in Diesels which have very poor control of the incoming air. Sent from my Nexus 5 using Tapatalk

Hey Dan, Sorry mate, but I'm almost certain the fronts are up to 07... Feel free to prove me wrong and I hope you do! But it's what I researched when I got my AP Racing's on the front and then the Brembo from the 08+ on the rear What do you think is different? I'm sure the refurb place will have plenty of other Brembos in so I can ask them to take some measurements and either make me happy or pissed off with myself for not trial fitting! Sent from my Nexus 5 using Tapatalk

I'd be concerned about gonig 50% firmer in the rear without increasing the damping. That will be massively underdampted. I found them a bit bouncy as they were.... I'd check with HKS what sort of range they recommend. I know Ohlins dont recomment going more than +-25% either side fo the standard 60N/mm rates on the valving they are supplied with. Good point, that was an epic maths fail on my part (it was early this morning!), I've already checked and the HKS recommendation is +/-20% Sent from my Nexus 5 using Tapatalk

Its not about cost, but about emissions. You get some cost reduction on the downsizing if you're losing cylinders, changing the spec of something at the design stage has very little impact on the ultimate piece cost, the vast majority of the "sale price" is amortisation of tooling investment and the engineering program to design and then validate a new design. That's why things like the HKS kit cost what they do, in relative terms sales volume is low to recoup the investment over. Jarno is right that it's ultimately about emissions, all the OEMs are looking at the most cost effective way to meet the emissions legislation and all have a metric something like £/g of CO2 saved over the test cycle they're willing to pay. There are future fines coming in for every gram of CO2 an OEM's fleet average is over the target, and that target decreases in regular intervals. They've all gone after and had most of the "low hanging fruit" (start stop is a con just to get good numbers on the test cycle for example, the real world benefit for most is tiny) so they're now having to look at more innovative solutions. Its impossible to aggressively downsize (or down speed) with a single turbo and get transient response that customers would accept, hence the trend towards multi-stage boosting. Sent from my Nexus 5 using Tapatalk

I think were close to having a heated agreement on most points! Electric supercharger on its own is not viable, it will always have some other addition to the power train to capture the energy to drive it (belt ISG is probably the cheapest option). I strongly doubt electric only compressors will come to road cars, combined electro-mechanical units are more likely but these still have significant challenges with the high speeds required for the electric machine elements. I do agree that multi-stage turbos are a nightmare, that's why the industry is looking at single turbo with supercharger, be it electric or mechanically driven. Sent from my Nexus 5 using Tapatalk

I think turbos in their current form will remain the norm. You can't beat the efficiency of a mechanical shaft linking the turbine to the compressor when you compare it to all the efficiencies involved in getting the energy from an electric turbine to the battery (via power electronics with AC to DC conversion, DC voltage conditioning, then electrical to chemical energy in the battery) and then back again through the same efficiency chain to the electric compressor. The best place to get energy to run an electric compressor from is regenerative braking, which has access to whole vehicle kinetic energy rather than just exhaust gas energy, and is available when the engine is in overrun fuel cutoff i.e. wasting very little extractable energy down the exhaust. Sent from my Nexus 5 using Tapatalk

E-Boost (either 12V or 48V) is coming too but its unlikely to ever be adopted as a stand alone alternative to a turbo. It cannot deliver sustained boost without draining the battery and OEMs are not going to give up on recovering wasted energy going down the exhaust pipe, its just not feasible with the direction of current and future emissions regulations. It is definitely a competitor to our system for multi-stage boosting applications though, on that I don't disagree! Sent from my Nexus 5 using Tapatalk

Just need to pull my finger out and sort it! That spring rate increase is thankfully inside the +/-20% range recommended for the adjustable damping without revalving. It'll be fine on the road I'm sure but maybe a little underdamped on track, but given my current ratio of road:track miles is about 99.5:0.5 I think I'll live with that! Sent from my Nexus 5 using Tapatalk

You've got me worried now! From the web ferreting I did beforehand I was sure Fronts up to 2012 and Rears 2008 on fit without brackets. Will find out if I'm cursing myself for not trial fitting before sending them out for refurb, I'll just mill up some brackets at work if I'm wrong though. I am also having the bleed nipples swapped as part of the refurb, that one I've definitely got right! Sent from my Nexus 5 using Tapatalk

Not likely at the moment, there's not much point in having the variable ratio drive on performance applications, the real benefit is for multi-stage boosting which is where the car industry is heading for the next gen of engines (there's a few out there like this already but not many yet). The principle is to have a large turbo to enable an aggressively downsized engine and use the variable supercharger for transient response until the turbo spools up, we're expecting to hit a nice to drive on the road 140kW/litre specific output eventually [emoji3] Although that sounds like it would be great for the FA20 its a lot of boost so you would need a built engine for it to live. That's why it's targeted for the next gen of engines so they can bake in larger bearings, stronger rods etc from the get go! Sent from my Nexus 5 using Tapatalk

It was for a competitor teardown for a project at work that I'm Chief Engineer on, we make a variable ratio drive supercharger with our own traction epicyclic. http://www.torotrak.com/products-partners/products/v-charge/ Sent from my Nexus 5 using Tapatalk

Neil, did you buy it new yourself? If so where from as these are out of stock on the ca-fi site, I was just looking at one of these at the weekend so tempted :-)

This definitely happens at some places, at Nissan the rule was all parts for press cars were 1/3 of the usual production tolerance band. Sent from my Nexus 5 using Tapatalk

Just signed up for the day so that's one more for the list :-)

Those wheels look superb, I much prefer them to the old ones :-) Staying silver on the intercooler gets my vote. Sent from my Nexus 5 using Tapatalk

That deserves an email to Toyota customer services surely, absolutely terrible service! Sent from my Nexus 5 using Tapatalk

+1 for the Toms, this has reminded me how much I despise the standard ones, its still go-faster bits for me first though! Sent from my Nexus 5 using Tapatalk