emira acceleration

[LotusB]

M2 is slow compared to what, the Tesla? If so, then I can understand. Otherwise, it should be quite a bit quicker compared to the Emira.

Look at the post I was responding to for context

Do you mean you have to get a 4.3s or better yourself, or a reviewer or Lotus? The published figure for the V6 Emira is 4.3s. How good are you at zero mechanical sympathy and power shifting?

Tom, it's important to note that 4.3 is the target. Recall that the Evora GT was advertised by Lotus as having a 0-60 of 3.8 seconds, yet I haven't seen anyone replicate it. One magazine was able to get 4.0 seconds. Food for thought... don't take everything at face value. It will need to be tested by a 3rd party for sure.

 

[TomE]

I agree, hence my question. Manufacturer’s figures need a dose of skepticism and the tests we’ve seen so far haven’t pushed the car as hard as they could.

 

[MCS]

I agree, hence my question. Manufacturer’s figures need a dose of skepticism and the tests we’ve seen so far haven’t pushed the car as hard as they could.

I wonder how many of us in all the excitement were hoping that lotus were being modest and were understating the target performance?

 

[Leonard]

I wonder how many of us in all the excitement were hoping that lotus were being modest and were understating the target performance?

I think when you hear the MD say ot will have 416bhp you are going to hope

 

[First Lotus]

I wonder how many of us in all the excitement were hoping that lotus were being modest and were understating the target performance?

I was definitely hoping for that 416! I don't really know why... I don't know if I'd notice the difference. But bigger is better rightMy main barometer is my current car... 490hp, 343Nm, 0-60 3.9secs. But 2006!
Would be interested to hear how diffrent people would expect it to feel. .. Nearly 20% less hp but about 20% more torque!
As long as it feels about as quick I'll be happy. I'm mainly in it for the looks and a level of modernity I certainly don't have ATM!

 

[Tonyshepp]

I was definitely hoping for that 416! I don't really know why... I don't know if I'd notice the difference. But bigger is better rightMy main barometer is my current car... 490hp, 343Nm, 0-60 3.9secs. But 2006!
Would be interested to hear how diffrent people would expect it to feel. .. Nearly 20% less hp but about 20% more torque!
As long as it feels about as quick I'll be happy. I'm mainly in it for the looks and a level of modernity I certainly don't have ATM!

My wife's Mini Cooper S has more low down torque available than my V8 M3, her car feels definitely nippier around town once rolling.
I think that's the crux of it when rolling the Emira will feel nippier. Accelerating from rest it won't feel as quick for you.

 

[Porter]

I was definitely hoping for that 416! I don't really know why... I don't know if I'd notice the difference. But bigger is better right

The difference in numeric HP is due to the lowered redline. The car doesn't make less torque through the rev range, it just doesn't rev as high numerically so the top figure drops slightly. So it's not a lower state of tune, the drive and response is the same except for where the rev cut hits.

Reminder that HP is a calculated figure, not a measured one. If measuring torque in lb-ft, it's (torque * rpm) / 5252 = power in HP. If measuring torque in metric (Nm) it's (torque * rpm) / 9.5488 = power in kW.

 

[First Lotus]

The difference in numeric HP is due to the lowered redline. The car doesn't make less torque through the rev range, it just doesn't rev as high numerically so the top figure drops slightly. So it's not a lower state of tune, the drive and response is the same except for where the rev cut hits.

Reminder that HP is a calculated figure, not a measured one. If measuring torque in lb-ft, it's (torque * rpm) / 5252 = power in HP. If measuring torque in metric (Nm) it's (torque * rpm) / 9.5488 = power in kW.

Thanks for the reply.
So (and I might not be understanding this right), if I was to only drive my current car (with 20% lower torque) up to 6600 (or whatever the emira is now!) then it would be a bit slower than the emira as the emira has more torque and I'd effectively be limiting the effective hp of my current car because I wasn't pushing it to its redline (8500)?

 

[Porter]

Thanks for the reply.
So (and I might not be understanding this right), if I was to only drive my current car (with 20% lower torque) up to 6600 (or whatever the emira is now!) then it would be a bit slower than the emira as the emira has more torque and I'd effectively be limiting the effective hp of my current car because I wasn't pushing it to its redline (8500)?

Well I'm not sure what your current car is, so it's hard to make a comparison.

But yes, if you lower the redline of your car without making any other changes, you'd make a lower numeric hp number (on a spec sheet) but the car would drive exactly the same as you are used to at all of the normal rev ranges that you use when driving.

I get the question though. If the car makes less torque at a given RPM than the Emira does at the same rpm, then which is faster? Well, you still have to do some calculations on gear ratio and tire diameter to figure out the effective ratio between the engine and the wheels. This ratio acts as a torque multiplier. And you also need to compare the vehicle weight and calculate that as well, to figure out accelerative potential of the vehicle at any given rpm (assuming max throttle).

But with a car that revs as high as the one you have currently, it doesn't make sense to compare output directly by RPM. Maybe instead it's appropriate to plot the difference by percentage of total available rev band, from idle to redline? Or overlay the torque curves from equivalent dyno plots. The shape of the area under the torque curve is what generates most of the sensation of speed and response for the driver. Difficult to come by that data without both vehicles in hand, though, and cars with dramatically different torque curve shapes result in different strategies for driving quickly.

To throw even more complication in, the maximum throttle figures used for dyno plots don't tell you much about how the car feels at partial throttle, which is where most of us do our driving on the road. The way a car feels is often as much about the part-throttle response as it is full throttle output. So that's a consideration as well.

 

[First Lotus]

Well I'm not sure what your current car is, so it's hard to make a comparison.

But yes, if you lower the redline of your car without making any other changes, you'd make a lower numeric hp number (on a spec sheet) but the car would drive exactly the same as you are used to at all of the normal rev ranges that you use when driving.

I get the question though. If the car makes less torque at a given RPM than the Emira does at the same rpm, then which is faster? Well, you still have to do some calculations on gear ratio and tire diameter to figure out the effective ratio between the engine and the wheels. This ratio acts as a torque multiplier. And you also need to compare the vehicle weight and calculate that as well, to figure out accelerative potential of the vehicle at any given rpm (assuming max throttle).

But with a car that revs as high as the one you have currently, it doesn't make sense to compare output directly by RPM. Maybe instead it's appropriate to plot the difference by percentage of total available rev band, from idle to redline? Or overlay the torque curves from equivalent dyno plots. The shape of the area under the torque curve is what generates most of the sensation of speed and response for the driver. Difficult to come by that data without both vehicles in hand, though, and cars with dramatically different torque curve shapes result in different strategies for driving quickly.

To throw even more complication in, the maximum throttle figures used for dyno plots don't tell you much about how the car feels at partial throttle, which is where most of us do our driving on the road. The way a car feels is often as much about the part-throttle response as it is full throttle output. So that's a consideration as well.

Oh, that's cleared that up then .
It's a f430 F1. I do drive it spiritedly but don't find myself killing it up to the red line very often through fear of expensive bills!!! And tbh, mostly in groups driving so no point disappearing off into the distance!
So similar weight cars.
There clearly is no easy answer. And certainly not one I would get my head around!
So guess I'll just have to leave my questions unanswered until Aug 3rd (LDA day!)
Thanks again though

 

[roundincircles]

Thanks for the reply.
So (and I might not be understanding this right), if I was to only drive my current car (with 20% lower torque) up to 6600 (or whatever the emira is now!) then it would be a bit slower than the emira as the emira has more torque and I'd effectively be limiting the effective hp of my current car because I wasn't pushing it to its redline (8500)?

One way of judging bhp versus torque is that bhp determines how fast you hit a wall and torque determines how far you shift said wall.

 

[First Lotus]

One way of judging bhp versus torque is that bhp determines how fast you hit a wall and torque determines how far you shift said wall.

I try my best to avoid walls!

 

[MCS]

One way of judging bhp versus torque is that bhp determines how fast you hit a wall and torque determines how far you shift said wall.

I don’t think that’s how they do the dyno

 

[TheMotizzle]

Oh, that's cleared that up then .
It's a f430 F1. I do drive it spiritedly but don't find myself killing it up to the red line very often through fear of expensive bills!!! And tbh, mostly in groups driving so no point disappearing off into the distance!
So similar weight cars.
There clearly is no easy answer. And certainly not one I would get my head around!
So guess I'll just have to leave my questions unanswered until Aug 3rd (LDA day!)
Thanks again thougKeep

Oh, that's cleared that up then .
It's a f430 F1. I do drive it spiritedly but don't find myself killing it up to the red line very often through fear of expensive bills!!! And tbh, mostly in groups driving so no point disappearing off into the distance!
So similar weight cars.
There clearly is no easy answer. And certainly not one I would get my head around!
So guess I'll just have to leave my questions unanswered until Aug 3rd (LDA day!)
Thanks again though

Keep us posted. Would love to know how the Emira compares to the F430. If it's reasonably close, I'll be very excited.