RE: 250 orders for new TVR

[HarryW]

joncon said:

McLaren bought 4 cerberas from tvr to use as test mules

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:45

Only ever seen the two silver ones before, what were the others?
You don't happen to know the registrations to see if any of them are still on the road 😉

[joncon]

think it was 4, no idea of reg no's ...
never seen one...very few pictures of them either

[Blown2CV]

HarryW said:

joncon said:

McLaren bought 4 cerberas from tvr to use as test mules

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:45

Only ever seen the two silver ones before, what were the others?
You don't happen to know the registrations to see if any of them are still on the road ??

i'd imagine they were crushed. I'd also be surprised if they were full Cerberas originally as they would only need the bodyshell. Panels only surely.

[HarryW]

Blown2CV said:

HarryW said:

joncon said:

McLaren bought 4 cerberas from tvr to use as test mules

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:45

Only ever seen the two silver ones before, what were the others?
You don't happen to know the registrations to see if any of them are still on the road ??

i'd imagine they were crushed. I'd also be surprised if they were full Cerberas originally as they would only need the bodyshell. Panels only surely.

Any one got a higher res version of this video, sure there's a number plate on the front of this SLR Cerbera undergoing test http://youtu.be/QuSTt_sQmjs

[Dakkon]

RoverP6B said:

I have nothing against GM and I have never attempted to gain work in the automotive sector. Although I did know some ex-BAe guys went to McLaren, when I left I wanted a change and went into performing arts management instead... I'm just pointing out, GM has only ever had to design and engineer an entire road car (minus engine and some minor componentry) from scratch once, and that was 20-odd years ago. The cigar-tube Rocket doesn't count because it has no doors, no roof, no interior to speak of. The McMerc doesn't count because all the switchgear, electrics, doorhinges and so on were M-B's work. So, it remains to be seen what capability Murray and his present team have of delivering a ground-up road car from scratch, never mind in the timescales given. If it leads to more jobs being created at Shalford, great - although then there might be a sufficient increase in traffic to make widening the very narrow Broadford Road bridge over the Wey Navigation...

You do know it is his company GMD that are making the first two TVR's not GM on his own? He employs a number of very switched on people who know their way around making a car. This project is in safe hands.

[RoverP6B]

Of course I know it's not just him, but I've been unable to find out who else is working at Broadford Road, and it's GM's name that's being most associated with the TVR.

[HarryW]

RoverP6B said:

Of course I know it's not just him, but I've been unable to find out who else is working at Broadford Road, and it's GM's name that's being most associated with the TVR.

If you read the press release, its quite clear the collaboration is with GMD......

[k-ink]

RoverP6B said:

That really is nuts, and not all that attractive.

Meanwhile, just up the road from Gordon Murray is this, the oldest surviving vehicle factory in the UK (if not the world), repurposed as a Wetherspoon's pub...

Only part of it. The main section on the upper floors is for ACM (a family friend goes there to drum).

[joncon]

HarryW said:

joncon said:

McLaren bought 4 cerberas from tvr to use as test mules

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:43

Edited by joncon on Friday 2nd October 14:45

Only ever seen the two silver ones before, what were the others?
You don't happen to know the registrations to see if any of them are still on the road ??

seems only 2 survive , the other 2 were chopped up.....

[RoverP6B]

k-ink said:

Only part of it. The main section on the upper floors is for ACM (a family friend goes there to drum).

Yeah, I was aware of that, thought I'd mentioned it but apparently not.

[Morningside]

Dunno if this has been posted, but here is a test run of the Cosworth engine doing Le Mans.

https://www.youtube.com/watch?v=Q5qZOQL-g0s

[AW111]

Morningside said:

Dunno if this has been posted, but here is a test run of the Cosworth engine doing Le Mans.

https://www.youtube.com/watch?v=Q5qZOQL-g0s

Not much actual information in that clip, but if you look at the exhaust system, it's all clamped together so they can easily adjust the lengths : obviously still fine-tuning to be done.

[anonymous-user]

Amazing what you can tell from that video:

1) TVR are running on the (significantly) cheaper "old" dynos down the end of the Factory corridor, not the swanky new expensive F1 spec ones at the end of the road! (hence the old Cadet10 / industrial automation controllers on the dyno bench)

2) They are running with an MBE engine management system, almost certainly a 9A9 ecu.

3) There's a bit of tip-in Det going on in the video, clearly chasing high BMEP quite hard

[RoverP6B]

Sounds like a bog standard Coyote motor to me too. What could the implications of all this be?

[Digger]

Max_Torque said:

Amazing what you can tell from that video:

3) There's a bit of tip-in Det going on in the video, clearly chasing high BMEP quite hard

Could someone kindly run this through one of those transmogrifyer doohickeys - you know, for the hard-of-understanding, like myself.

[RoverP6B]

I had no idea either, but found these.

https://en.wikipedia.org/wiki/Mean_effective_press...

http://www.superhonda.com/forum/f10/what-tip-deton...

[HarryW]

RoverP6B said:

Sounds like a bog standard Coyote motor to me too. What could the implications of all this be?

They should have gone with a 6 pot.......










Couldn't resist, please don't take this as an invite to witter on about engine choices, it's a Ford Coyote tweaked by Cosworth, end of.....

[Ozzie Osmond]

• Your spark plug fires BEFORE the piston reaches the top of its cylinder so that the relatively slow burning fuel/air mixture gives a rush of pressure to the piston a split-second later, after TDC (the top of the stroke) pushing the piston down the cylinder.
• In a modern engine the fuel/air mixture needs to burn completely for optimum power, economy and emissions.
• An engine's ignition "timing" is not fixed. The timing needs to advance and retard to take account of speed and load. Or "torque demand".
• When you open the throttle widely more air can enter the engine than when it is "throttled". That greater amount of air is capable of burning more fuel which gives a bigger bang, more pressure and more power. In other words the greater pressure in the cylinder (BMEP) gives more torque, just like a cyclist who accelerates by pushing harder on the pedals.
• The increased amount of fuel/air which enters the cylinder has different burning characteristics and the spark plug may need to fire earlier. This is called advancing the ignition and in a modern car is done by a computer known as the ECU.
• If the spark plug is fired too soon (i.e. there is too much ignition advance) the effect is to try to push the piston down before it has reached the top of its stroke. In other words, that piston is trying to move in the opposite direction to the way the engine is rotating. This is for obvious reasons a very bad thing. The noise caused by the early detonation is called pinking or knocking.
• If an engine is hot and not correctly set up it is possible for the fuel/air mixture to detonate spontaneously (like a diesel) before the spark plug fires. This is called pre-ignition. It causes exactly the same early detonation and is a bad thing.

An engine needs its ECU programmed, or "mapped", so that the amount of fuel and timing of spark deliver appropriate power/economy/emissions without the engine being damaged by pre-detonation.

[anonymous-user]

Digger said:

Max_Torque said:

Amazing what you can tell from that video:

3) There's a bit of tip-in Det going on in the video, clearly chasing high BMEP quite hard

Could someone kindly run this through one of those transmogrifyer doohickeys - you know, for the hard-of-understanding, like myself.

As mentioned, detonation is the spontaneous ignition of the air/fuel mixture in the endgas (typically the outer periphery of the combustion chamber, far from the sparkplug) regions of the chamber, BEFORE the flame front (which is initiated by the spark plug) gets there to burn that air/fuel in a controlled way. Its bad because the sudden rapid local heat release results in high temp/high pressure and can damage the piston, headgasket, rings and bores etc.

It often occurs on tip-in (sudden throttle openings from a more closed position) for two major reasons:

1) the mixture goes lean for a short period when the throttle is suddenly opened (because the pressure in the inlet manifold and intake runners RISES when the throttle is opened, the fuel puddle mass that forms downstream of the injectors increases (because the vapour pressure climbs) and "robs" some of the injected fuel from the chamber (the opposite happens on tip-outs, when the pressure falls and the puddle evapourates, leading to a rich mixture. Typically, transient fuelling strategies are used to inject extra fuel for a short period to help negate this effect. However, as fuel economy is important (for both road and race these days, especially endurance racing like LeMans) it's worth trying to minimise this extra fuel injection mass.

2) At part load, the engines poor pressure ratio results in a high internal EGR. (at part throttle the intake pressure is low in the inlet manifold, below atmospheric pressure) This high mass fraction of these hot residuals in the chamber take a few cycles to clear out, and tend to linger in the endgas regions / crevice volumes of that chamber. Exactly the same place when Det tends to be initiated!

Listen to the video and as the load comes onto the engine, listen for the high frequency "tinkle tinkle" or cracking sounds that indicate detonation. Interestingly i don't see any in-cylinder pressure measurement equipment, so they are either doing it "by eye" of have already done the base spark cal.

[Digger]

Max_Torque said:

Excellent stuff

Many thanks for that and to Ozzie too.