This sounds dirty.

[VR6 Turbo]

Ive never really been taken by the Lexus LFA

but it Sounds amazing.

http://www.youtube.com/watch?feature=endscreen&amp...

what else have I been missing out on?

VR

[Funk]

The revs rise and fall so fast, an analogue needle couldn't keep up - so they made a digital representation of it. IIRC, it revs out to about 9,000rpm..!

Here we go:

http://www.youtube.com/watch?v=cmP42s56PKc&fea...

http://www.youtube.com/watch?v=xQjntdiAHag

Edited by Funk on Saturday 17th December 20:13

[Dave Hedgehog]

Funk said:

The revs rise and fall so fast, an analogue needle couldn't keep up - so they made a digital representation of it. IIRC, it revs out to about 9,000rpm..!

Here we go:

http://www.youtube.com/watch?v=cmP42s56PKc&fea...

http://www.youtube.com/watch?v=xQjntdiAHag

Edited by Funk on Saturday 17th December 20:13

I smell marketing BS on that one, when i start my car both needles flick over to max and back to zero in about 1 second

[Twincharged]

Dave Hedgehog said:

I smell marketing BS on that one, when i start my car both needles flick over to max and back to zero in about 1 second

That little snippet suggests that they can engineer an entire engine (with all its reciprocating mass) to alter the speed at which it's running quicker than they can move a small plastic needle.

And the engine is already performing 100+ turns per second, whereas the needle has to move part of a single turn.

Hmm...

[Tycho]

Dave Hedgehog said:

Funk said:

The revs rise and fall so fast, an analogue needle couldn't keep up - so they made a digital representation of it. IIRC, it revs out to about 9,000rpm..!

Here we go:

http://www.youtube.com/watch?v=cmP42s56PKc&fea...

http://www.youtube.com/watch?v=xQjntdiAHag

Edited by Funk on Saturday 17th December 20:13

I smell marketing BS on that one, when i start my car both needles flick over to max and back to zero in about 1 second

Agreed, motorbike needles do this all the time.

[Or888t]

Sooo worth the money <3 XD

[VR6 Turbo]

agreed very pricey.

Im not convinced by the looks either, but the noise

[Or888t]

VR6 Turbo said:

agreed very pricey.

Im not convinced by the looks either, but the noise

I think it looks awesome.
There is more 'special' looking metal, but i think what you need to see it as , at that price point,is you could have any super car, the LFA would simply be part of your 'collection'.

[mrmr96]

Tycho said:

Dave Hedgehog said:

Funk said:

The revs rise and fall so fast, an analogue needle couldn't keep up - so they made a digital representation of it. IIRC, it revs out to about 9,000rpm..!

Here we go:

http://www.youtube.com/watch?v=cmP42s56PKc&fea...

http://www.youtube.com/watch?v=xQjntdiAHag

Edited by Funk on Saturday 17th December 20:13

I smell marketing BS on that one, when i start my car both needles flick over to max and back to zero in about 1 second

Agreed, motorbike needles do this all the time.

Yeah, but they said about the needle thing on Top Gear, so therefore it is True.
Evo's are also "1 wheel drive" in extreme corners, doncha know.

[HertsBiker]

9000rpm? Big deal! F1 cars double that, most 125 bikes do this, race bikes easily 14k. Sure a needle can move that fast, look at a 'timing' clock. Goes round the dial 10 times a second!
Nice car though. :-)

[jon-]

Might not be to every ones taste, but up there with the CGT as the best sounding cars ever made.

V10s rule.

[andy43]

Spoke to a sales guy who had two of these (think there's only 3 in the country) in the showroom - engine is Yamaha (I think) and it is literally like a switch - zero to full revs instantaneously. Seemed very well put together and looked incredible. Bit of an NSX choice though - 99% will go for a dancing donkey instead.

[Dave Hedgehog]

mrmr96 said:

Yeah, but they said about the needle thing on Top Gear, so therefore it is True.
Evo's are also "1 wheel drive" in extreme corners, doncha know.

i stand corrected

[AmitG]

Dave Hedgehog said:

mrmr96 said:

Yeah, but they said about the needle thing on Top Gear, so therefore it is True.
Evo's are also "1 wheel drive" in extreme corners, doncha know.

i stand corrected

Assuming it's true, I reckon the issue is damping.

The LFA engine has an incredibly quick response time. As another poster said, it goes from zero to 9,000 RPM almost instantly. No other engine of comparable size can do this.

Customers obviously expect the rev needle to reflect this.

All mechanical rev needles have a degree of damping built into their response. More damping means that the needle moves more smoothly, and doesn't bounce around so much with small variations in engine speed. But it also slows down the response. This is not what customers want. They've paid for an engine that goes from zero to 9,000 RPM instantly, and they expect to see that on the rev counter.

The only way to get a mechanical needle to respond sufficiently fast in the LFA would be to have very low damping. In that case, the needle would bounce around too much. Not what customers expect in this kind of car.

Hence the need to go digital.

Or maybe they just did it because it was really cool

[Watchman]

There's nothing particularly physics-defying about that engine. The V8 Cerbera had a very low mass flywheel which allowed it to rev quickly. Motorbikes more-so.

Just about any aftermarket rev counter could keep up with that rate of change.

[Dracoro]

Watchman said:

Just about any aftermarket rev counter could keep up with that rate of change.

Accurately?

0-10,000 in 0.6 seconds....

Damping, as above.

Also, it's not just how fast a rev counter can spin round, it's how quickly it can respond to the signal. I'm sure many rev counters can do the former but maybe not the latter.

[Scuffers]

Dracoro said:

Watchman said:

Just about any aftermarket rev counter could keep up with that rate of change.

Accurately?

0-10,000 in 0.6 seconds....

Damping, as above.

Also, it's not just how fast a rev counter can spin round, it's how quickly it can respond to the signal. I'm sure many rev counters can do the former but maybe not the latter.

rubbish, race cars tacho's seem to manage just fine, as do bike ones.

with respect, it may have very low inertia and rev really fast, but that's still sluggish compared to an all out race engine.

and just think about this for a minute, the throttles on this engine are DBW, and I am dam sure they can respond much faster to tracking the pedal, they also weigh slightly more than a needle.

[Mr2Mike]

Scuffers said:

rubbish, race cars tacho's seem to manage just fine, as do bike ones.

Exactly this, it's a pretty lethargic engine compared to most sports bike and plenty of them manage with an analog tachometer.

[AmitG]

Scuffers said:

rubbish, race cars tacho's seem to manage just fine, as do bike ones.

with respect, it may have very low inertia and rev really fast, but that's still sluggish compared to an all out race engine.

and just think about this for a minute, the throttles on this engine are DBW, and I am dam sure they can respond much faster to tracking the pedal, they also weigh slightly more than a needle.

Agreed - but a race car tacho doesn't have to be silky smooth. If it jumps around a bit it's OK. LFA customers will expect their tacho needle to move smoothly. It's the combination of quick response and smooth movement that is hard to get mechanically.

It's like suspension. You can have suspension that responds instantly, but it will be rock hard and shake you about. To get it smoother, you have to add damping, but in doing so you blunt the response.

[Scuffers]

AmitG said:

Agreed - but a race car tacho doesn't have to be silky smooth. If it jumps around a bit it's OK. LFA customers will expect their tacho needle to move smoothly. It's the combination of quick response and smooth movement that is hard to get mechanically.

rubbish.

current race car tacho's are perfectly stable, they don't 'jump about' any more than the engine does.

you think it's less important for a race cars tacho to be 100% at all times than some road car?

tacho's are all servo-driven these days, they can be made to move as fast or slow as you like.