how much hp is to much in a westfield

how much hp is to much in a westfield

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Sam_68

9,939 posts

244 months

Tuesday 3rd January 2012
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Crippo said:
Lets be honest......

its about willy waving!
Course it is! Just that few people are brave enough to admit it. And if you try bragging down the pub about having 3-way adjustable dampers with digressive valving, people just back away from you, slowly...

Kevp said:
Am I correct in saying a road going superbike has about 700bhp per tonne (excluding rider). If so then a car with similar performance is no problem.
Depends on which bike... a quick google reveals that the Hyabusa has 639bhp/tonne based on its wet, unladen weight. But that's only really useful if you ride your bike psychically, from a distance.

One of the other anomalies of light vehicles is that driver (rider) weight is a bigger percentage of overall weight than on a heavier vehicle, therefore it has a bigger influence on power:weight ratio. If you sit me on a Hayabusa, the power:weight ratio instantly drops to about 452bhp/tonne, but yes, that's still gonna kill you if you try to exploit all of it on the road.

I had a mate (even fatter than me, as it happens) with a Hayabusa, who reckoned he pretty much never took it above 8,000rpm, even in a straight line. Mind you, it was his Sunbeam S7 (all 24bhp of it) that came closest to killing him, and left him with one leg 2" shorter than the other...

For clarity though, I personally always talk about power:weight ratios in terms of kerb weight+driver. Anything else is pointless.

Crippo

1,180 posts

219 months

Tuesday 3rd January 2012
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Dont forget that person x on a motor bike weighs considerably more than he or she would in a car. Leathers, helmet boots, gloves all weigh around 8kgs more than a tshirt and shorts

Kevp

582 posts

250 months

Tuesday 3rd January 2012
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Crippo said:
Dont forget that person x on a motor bike weighs considerably more than he or she would in a car. Leathers, helmet boots, gloves all weigh around 8kgs more than a tshirt and shorts
Maybe. But the car driver normally carries more fuel & baggage. Also if its a super fast-light weight Westfield (no screen). Then I would perhaps wear a helmet & suitable jacket.

Of course kerb weight & power at wheels are the correct performance measurent. But when it comes down to figures, its always the most against the least.

jason61c

5,978 posts

173 months

Tuesday 3rd January 2012
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Kevp said:
Am I correct in saying a road going superbike has about 700bhp per tonne (excluding rider). If so then a car with similar performance is no problem.

But if the question is "how much power can I have, and still boot the throttle every where?" Then I would say 300 bhp/tonne is a serious amount, but only in the summer.
Most have over 1bhp per kg.

slomax

6,646 posts

191 months

Wednesday 4th January 2012
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jason61c said:
Kevp said:
Am I correct in saying a road going superbike has about 700bhp per tonne (excluding rider). If so then a car with similar performance is no problem.

But if the question is "how much power can I have, and still boot the throttle every where?" Then I would say 300 bhp/tonne is a serious amount, but only in the summer.
Most have over 1bhp per kg.
you are of course forgetting that a car can corner and brake much better than a bike, even if acceleration and top speed are in the bikes favour. Of course this depends a lot on the car/bike and driver/rider. A well set up 200bhp seven will give any bike a run for its money in the twisties.

one eyed mick

1,189 posts

160 months

Wednesday 4th January 2012
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Crippo said:
Lets be honest......


or pi--ing over a wall










its about willy waving!

Sam_68

9,939 posts

244 months

Wednesday 4th January 2012
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jason61c said:
Most have over 1bhp per kg.
  • cough* bks *cough*
A handful get close to 1bhp/kg based on the weight of the bike without rider.

Most have over? Not even slightly...

But I'm not sure what relevance this has, anyway, beyond proving that it's just as easy to build a bike with unusable amounts of power as it is a lightweight car?

Kevp

582 posts

250 months

Wednesday 4th January 2012
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My point of bringing the power to weight ratio of a superbike into this was.
When ridding a bike there is a continuous thought process going on over the speed/throttle/road, against how much & how quickly to put power down. With due consideration to road users (possible & actual) against the road itself.

Now we know of stories where an "experienced" guy was chucked off by his 2 wheeled machine due to to much power. But as I have mentioned with care, riding a bike with 500bhp per tonne is no problem. Therefore with the added ability of a car (braking & grip) I dont see why figures of 500 - 700 bhp a tonne (1bhp per kg??) should be a problem for someone taking the same care.

However if you where to drive a very high powered car the same way as I drive my 250bhp/tonne car, then I would expect to crash.

Sam_68

9,939 posts

244 months

Wednesday 4th January 2012
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Kevp said:
But as I have mentioned with care, riding a bike with 500bhp per tonne is no problem. Therefore with the added ability of a car (braking & grip) I dont see why figures of 500 - 700 bhp a tonne (1bhp per kg??) should be a problem for someone taking the same care.
Yes, no dispute about that - it's perfectly possible to drive a 1000bhp/tonne car or bike safely, provided the engine is tractable enough, and you drive with enough restraint: You just make sure that you never use anything like full throttle at peak power revs, particularly in the lower gears. The debate then focuses on whether there's any point in having that power, if you can never (or very, very rarely) use it?

If there was no downside, then the answer would would, of course, be 'hell, yes!'.

But there are serious downsides: cost, controllability, and most importantly weight (and hence braking, acceleration and cornering performance), so the only real advantage to the extra power is in terms of bragging rights.

The ultimate example is the Caterham Levante, which had over twice the horsepower of a Caterham R500, cost much more than twice as much, yet posted a circuit lap time only a few dismal fractions of a second better than the R-series cars even on nice, smooth tarmac of a racing circuit. It also, incidentally, posted much slower 0-60, 0-100 and standing 1/4 times in the hands of 'Evo' magazine than has been achived with some much more mundane machinery, including my own Westfield (presumably this was a clear demonstration of how difficult it was to judge how much of its 857bhp/tonne could actually be used before it disappeared in smoke as wheelspin).

On the road, the Levante would almost certainly be slower than a 'normal' Caterham R-series, unless you have Schumacher-like skill levels, as you'd have to drive with a larger margin for error... and on a circuit, it would have its pants pulled down by £10K's worth of second-hand wings-and-slicks Formula Renault, so apart from being able to say 'look at me - aren't I rich and stupid', what is the point?

andygtt

8,344 posts

263 months

Thursday 5th January 2012
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I think the point being made by both sides has been missed.

Sam says a 7 becomes a knife edge car at huge BMHP/ton mainly down to the unsprung weight ratio.... a light 7 needs even lighter wheels/tyres and brakes... however these MUSt go up if you increase the power a huge amount!

Others are justifying how other machines on the road manage 500bhp/ton without being uncontrollable monsters and this may be true but they are not 7's.... I've got a >500bhp/ton car (including driver) that I can use 100% of the power on the road and is great fun... but its not a 7.

As for willy waving... thats a term thought up by those who have tried bragging about their 3 way adjustable shocks and emptied the pub as as knowone else cared lol.... and yes I only have 2 way adjustable on my car lmao!
FEW people build a car to brag about it, most do it for the challenge and to keep moving forward or have something unique.....

People on this forum get more respect from me as they actually dream it and then build it themselves, most others dream it then pay someone else to do it for them.

chuntington101

5,733 posts

235 months

Thursday 5th January 2012
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andygtt said:
I think the point being made by both sides has been missed.

Sam says a 7 becomes a knife edge car at huge BMHP/ton mainly down to the unsprung weight ratio.... a light 7 needs even lighter wheels/tyres and brakes... however these MUSt go up if you increase the power a huge amount!

Others are justifying how other machines on the road manage 500bhp/ton without being uncontrollable monsters and this may be true but they are not 7's.... I've got a >500bhp/ton car (including driver) that I can use 100% of the power on the road and is great fun... but its not a 7.

As for willy waving... thats a term thought up by those who have tried bragging about their 3 way adjustable shocks and emptied the pub as as knowone else cared lol.... and yes I only have 2 way adjustable on my car lmao!
FEW people build a car to brag about it, most do it for the challenge and to keep moving forward or have something unique.....

People on this forum get more respect from me as they actually dream it and then build it themselves, most others dream it then pay someone else to do it for them.
I agree andy!

As for Caterham building a stupid fast car that costs alot, come on guys this is pistonheads not the Daily Mail! its should be celibrated even if you can go faster for less.

And if you think you can go out there and build something better for less money then PLEASE go and do it but make sure to post pictures and info on here for everyone to enjoy! smile

Sam_68

9,939 posts

244 months

Thursday 5th January 2012
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chuntington101 said:
As for Caterham building a stupid fast car that costs a lot...
The whole point is that because it's over-powered (and from the only published, independent test results I've seen) the Levante isn't stupidly fast, just stupidly expensive:

0-60 in 4.8 seconds, ffs. You can go quicker in a straight line in £12K's worth of TVR!
0-100 in 8.2 seconds (ok... you'd need £15K's worth of TVR to match that, but it would be a damn sight more comfy)
Standing 1/4: 12.7

To put those figures in perspective, my Westfield (with a mere 190bhp) has been timed 1.2 seconds faster to 60mph, and a virtually identical standing 1/4 (12.626 seconds). What's happening to the other 360bhp from the Caterham's engine, I wonder? scratchchin

Evo magazine said:
Getting the car off the line hasn’t got any easier, though. Imagine trying to tread on an ant attached to the clutch pedal without squashing it and you get the idea of how delicate you need to be with your left foot. In order not to stall, you need to do a granny start then feed in 550bhp without lighting up the rear Avons. ...the result is a yawning 0-30mph time of 2.9sec... The fiddle to deploy the Caterham’s power means another three tenths have been eked out by the Caparo by 60mph...
As to the 'technical challenge', the Levante isn't too difficult to replicate, if you're so inclined. It's still just a steel spaceframe (based on the 'SV' wide-arse variant of the Caterham chassis), so all you have to do is bolt an RST V8 engine into any common-or-garden 'Seven' style spaceframe and you, too, can have something hopelessly overpowered and ludicrously expensive. biggrin


Edited by Sam_68 on Thursday 5th January 19:12

andygtt

8,344 posts

263 months

Thursday 5th January 2012
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those times are terrible.... the caterham R500 would absolutely destroy all of those times so surprised they built something 10years later thats so much slower.

Not a good example IMO

Have to say for me the R500 takes some beating as a 7 type

ayton 1

69 posts

168 months

Friday 6th January 2012
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Have diven one of the caterham levante's which has had a fair bit more development
work done to it's set up & now on slick's. I can say is it's totally different from when
EVO tested it & is now scary quick on track instead of just Scary!!!
In answer to original question I personally think 300bhp is the max most people
can use fully in a 7 type car

Edited by ayton 1 on Friday 6th January 20:08

rhinochopig

17,932 posts

197 months

Friday 6th January 2012
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And to be fair though, only teenage boys care about 0-60 times. I would imagine the Levante would torture an R500 for in-gear acceleration.

Russ Bost

456 posts

208 months

Friday 6th January 2012
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It would help if the OP had specified whether we are talking about on the road or on the track.

If you're talking about a light car on the road then anything over about 350Bhp/tonne is largely a waste of time & money, unless you either have a death wish or don't enjoy possesing a driving licence. On the track you could probably nearly double that with a perfect setup, perfect weather & the right slicks - but try taking the same car out in anything other than perfect conditions & unless you are a very special driver you are an accident looking for a location.


Sam_68

9,939 posts

244 months

Saturday 7th January 2012
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ayton 1 said:
...now on slick's.
Slicks own their own will make a massive difference, of course. But the thing about slicks is that they are not road legal.

...And if you're looking for the quickest way around a circuit, you're wasting your time with any sort of 'Seven' because it's quite simply obsolete technology.

The engine is in the wrong place, the aerodynamics were a joke even when it was new (the Seven only exists because there was a market for a 'poverty spec' clubman's car for those people who couldn't afford the streamlined bodywork of the Eleven, and that's before downforce was invented...), and if you stick to a traditional steel spaceframe, the chassis isn't stiff enough to act as an aerodynamic platform even if you could make the aero work.

If you're looking for a non-road legal car that's quick around a circuit, high-powered 'Sevens' remain equally pointless - you'd be better off with a Radical or almost any wings-and-slicks single seater.

rhinochopig said:
And to be fair though, only teenage boys care about 0-60 times.
scratchchin Do you not see any irony in being dismissive of 0-60 times, whilst using the equally misleading power:weight ratio as a measure?

I agree that 0-60 is now less meaningful than 0-100 as a test of overall acceleration, and you need a full set of incremental acceleration data to make any worthwhile analysis.

But it's still a valid indicator of how much power the car can put down to the road, off the line, and the thing is that the Levante isn't blindingly quick even in the upper speed range - Evo took figures to 140mph and the Caterham took 6.3 seconds to go from 100-140, compared to 8.8 for a TVR Cerbera; quick, but not pant-wettingly so. The R500 will doubtless be much slower, but that's merely a demonstration of how inadequate 'Seven' aerodynamics are.

The trouble is, stupidly high powered 'Sevens' fail to make sense whichever way you look at them: at the bottom end of the speed range they can't put the power down and at the upper end of the speed range it's all absorbed in aerodynamic drag.

Every way you look at them, they lose... frown

rhinochopig said:
I would imagine the Levante would torture an R500 for in-gear acceleration.
In the higher speed range, I'm sure it would.

But how much time do you spend above 100mph in a 'Seven', whether on public roads or on the track? Again, the only published, independent track times for the Levante put it mere fractions of a second quicker than the R500 (1:19.6 compared to 1:20.2 around Bedford West circuit, with a peak speed of 118.6mph vs. 115.7mph).

...So your extra £78,000 and more than double the horsepower has bought you smidge over half a second a lap and 2.9 extra miles per hour on your peak speed.

Proof, surely, that the Levante's power:weight ratio is so far into the realm of diminishing returns for a car of the 'Seven' configuration that it's quite simply ludicrous?

westy turbo

26 posts

156 months

Sunday 8th January 2012
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True that high hp is hard to handle smile having mine at 045 bar and 275hp,and havent raised the boost yet lol

busa turbo

228 posts

200 months

Sunday 8th January 2012
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Sam_68 said:
ayton 1 said:
...now on slick's.
Slicks own their own will make a massive difference, of course. But the thing about slicks is that they are not road legal.

...And if you're looking for the quickest way around a circuit, you're wasting your time with any sort of 'Seven' because it's quite simply obsolete technology.

The engine is in the wrong place, the aerodynamics were a joke even when it was new (the Seven only exists because there was a market for a 'poverty spec' clubman's car for those people who couldn't afford the streamlined bodywork of the Eleven, and that's before downforce was invented...), and if you stick to a traditional steel spaceframe, the chassis isn't stiff enough to act as an aerodynamic platform even if you could make the aero work.

If you're looking for a non-road legal car that's quick around a circuit, high-powered 'Sevens' remain equally pointless - you'd be better off with a Radical or almost any wings-and-slicks single seater.

rhinochopig said:
And to be fair though, only teenage boys care about 0-60 times.
scratchchin Do you not see any irony in being dismissive of 0-60 times, whilst using the equally misleading power:weight ratio as a measure?

I agree that 0-60 is now less meaningful than 0-100 as a test of overall acceleration, and you need a full set of incremental acceleration data to make any worthwhile analysis.

But it's still a valid indicator of how much power the car can put down to the road, off the line, and the thing is that the Levante isn't blindingly quick even in the upper speed range - Evo took figures to 140mph and the Caterham took 6.3 seconds to go from 100-140, compared to 8.8 for a TVR Cerbera; quick, but not pant-wettingly so. The R500 will doubtless be much slower, but that's merely a demonstration of how inadequate 'Seven' aerodynamics are.

The trouble is, stupidly high powered 'Sevens' fail to make sense whichever way you look at them: at the bottom end of the speed range they can't put the power down and at the upper end of the speed range it's all absorbed in aerodynamic drag.

Every way you look at them, they lose... frown

rhinochopig said:
I would imagine the Levante would torture an R500 for in-gear acceleration.
In the higher speed range, I'm sure it would.

But how much time do you spend above 100mph in a 'Seven', whether on public roads or on the track? Again, the only published, independent track times for the Levante put it mere fractions of a second quicker than the R500 (1:19.6 compared to 1:20.2 around Bedford West circuit, with a peak speed of 118.6mph vs. 115.7mph).

...So your extra £78,000 and more than double the horsepower has bought you smidge over half a second a lap and 2.9 extra miles per hour on your peak speed.

Proof, surely, that the Levante's power:weight ratio is so far into the realm of diminishing returns for a car of the 'Seven' configuration that it's quite simply ludicrous?
Hi just another one for the pot I have a Dax Rush with a Hayabusa Turbo in it and absolutley love it, the car has no traction control apart from the right pedal.
Power is between 200-500 bhp depending on boost, I agree that 300bhp in a 7 type car is spot on for a very fast car but its nice to have the option of a little more!! as for times 0-60mph low 3 sec
0-100mph in high 5 sec, I also went to Bedford West circuit for the first time in December not an ideal time to go, as it was very cold and damp and the car was on slick's but wanted to have a go at the MSV How Fast competition held at Bedford. In practice we did a 1.19.4 with a indicated speed of around 128mph on the time run it started to rain and we posted a time of 1.20.7. Here is a link to the How Fast leaderboard http://www.howfast.co.uk/leaderboard.aspx and a link to on board video
http://www.youtube.com/watch?v=qfhymdBb_WY&fea...


mnrvortxf20c

430 posts

147 months

Sunday 8th January 2012
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was the r500 not faster than almost all the supercars on the tg test track. that would indicate to me,that it can get power down,it does handle well,brakes well due to its light weight.
not totally sure on this but think its 0-62 time is about 3 seconds. you just dont need a faster car than that.