How much power does it take to make a really quick 7?

[scubadude]

The question was- "How much power does it take to make a really quick 7?"

Its pretty clear that north of 180hp makes any 7 the fastest car in its respective county when you have your foot down :-)
Just got mine and the alleged 200bhp seems to warp the fabric of space-time... I can only presume that to make a "REALLY quick 7" means entering the 300+ territory where fewer 7's exist? There are cars with 400, 500 and 600hp, I cannot actually comprehend what they might be like.

[K800 RUM]

Not caterham but on the subject of very quick cars.
I have recently been for a fast passenger ride in my neighbours 911 Turbo & that felt very fast. It was too easy to be honest & the car is a bit of a license loser.
The same chap owns a BMW 1000 RR sports bike & he said that is fast on a whole different level compared with his Porsche.
The bike has a power to weight ratio of just over 1000hp per ton!

[mike150]

K800 RUM said:

Not caterham but on the subject of very quick cars.
I have recently been for a fast passenger ride in my neighbours 911 Turbo & that felt very fast. It was too easy to be honest & the car is a bit of a license loser.
The same chap owns a BMW 1000 RR sports bike & he said that is fast on a whole different level compared with his Porsche.
The bike has a power to weight ratio of just over 1000hp per ton!

As I said of my GSXR1000.

At a drag day my Caterham R400 did 13.5 seconds and my bike did 10.4, the bike could have gone faster, maybe 10.0 but the track was bumpy so wheelies where a problem.

[bcr5784]

Mario149 said:

The R is an improvement, in the same way that an Street Triple R is better than a Daytona (which was not as fun to ride when I tried one, although it did have many good qualities), but if you're wheelying with TC keeping it in check, you're still not using all the available grunt. Would it truly be any less fun if it had 130bhp? Does 1st still go to 100mph? Like I said, I'm really glad these bonkers bikes exist, and no doubt I'll try one one day to see what they're all about, but one can't help but think the numbers are a bit silly

I have to agree - and bound to think less is more. In days gone by there were VFR400s and fast 250 two strokes capable of 0-100 in 12 seconds or so, now there are no really small really sporty bikes of that ilk. I too tried a Daytona 675 and thought it unnecessarily fast (one up) I'm only 60kg wet so I can imagine bigger guys wanting a bit more, but for me 100bhp (400bhp/ton or more with me on board) is more than enough, and I'd probably be just as happy with 80bhp.

[Upnor]

My Supersprint has 147hp, for me it is the whole experience the carbs roaring and the exhaust spitting, it all gives the impression your going faster than you are,can't see you needing much more on country roads, on a track yes, maybe more but be realistic about your own capabilities.
I've had a few bikes, ridden my mates 300hp/225ftlb monster no TC, you wouldn't want to be on that on greasy/cold roads for sure, my favourite bike only had 52hp so easy to ride so much fun, you could use every bit of power it had, taught me a lot that bike, more is not always better.

[scubadude]

Upnor said:

for me it is the whole experience the carbs roaring and the exhaust spitting, it all gives the impression your going faster than you are

Totally agree with this, downshift's entering villages bang and crackle like your tackling the Mulsanne chinaces in 80's era LMP1, full bore in 2nd sounds and feels like an Apollo launch long before you've reached 50mph and tight bends taken foot to the floor feel like an F1 car around Eau Rouge for 1st time passengers but are within the national speed limit.

I've often looked at bikers on big Harleys trundling along spitting gobs of unburnt fuel, popping and banging and looking totally badass... at 30mph.

Fast is great but Smiles/Mile is the real measure of a good vehicle IMO.

[coppice]

You are so right - and without sounding too smug until a non Sevenista has driven a car as light as a Seven he cannot even begin to imagine how agile and responsive they feel compared to a conventional fast car , and never more so than when braking and turning . To me it's as much about how different as how quick .

[Eugene7]

Eugene is 210 BHP Zetec.
With all the road-work we do within Le BOG Club it has proved to be just about ideal.

Even Mad Hatter in 'The Yob', with its' stupid power levels could not better Eugene on the road.
(And as per other thread Eugene is Live Axle).

But, on-track a different story!

Steve

[unclefester]

Murph7355 said:

If you really want to upgrade, I'd stick to 200bhp. Cheap-ish to tune to this level and they don't take markedly more to keep fresh. You'll need things like a dry sump oil system, but that's a decent thing to have anyway. Balance on the road is still pretty good, though it will frustrate slightly more as you can't deploy everything in the same way you can with an SL.

If you dry-sump, think about where to put the oiltank.

I had a Titan sump with the 220bhp K1800 engine I bought to stick in my K1600 SV, but swapped it for a Pace double scavange with huge Brise kidney tank....which sits right in front of the engine.

This is fine until you want to change the cam-belt which is a frequent chore on a tuned K engine with high-lift cams.

The proximity of the tank to the cambelt cover means you have to drop the oil and remove the tank, which in my case also means dropping the coolant!

I can change a belt quick enough under normal circs but this makes it all a fat PITA.

The Brise does hold a lot more oil than the Titan/Apollo tank though.

You could use Caterham's own bell-housing dry sump tank of course but it holds less oil...

Edited by unclefester on Monday 7th March 16:47

Edited by unclefester on Monday 7th March 17:25

[fergus]

Murph7355 said:

Esceptico said:

Whenever to issue of power is raised in Biker Banter it is mentioned that the throttle goes both ways. ....

I have some sympathy with that view, but....

Part of the joy is the feeling that you're extending the car fully. Holding back on throttle doesn't allow that.

Also, total throttle travel is broadly the same. So harder to modulate within sane realms on the road.

Traction control is also a necessary evil on high powered cars these days. As soon as those yellow lights flicker, you're wasting the power of the car.

Andy - if the TC light is flickering, it could well be down to poor traction in terms of chassis setup though, e.g. PASM in a 997 GT3 versus a decent set of passive dampers.

[rubystone]

fergus said:

Andy - if the TC light is flickering, it could well be down to poor traction in terms of chassis setup though, e.g. PASM in a 997 GT3 versus a decent set of passive dampers.

Is he talking about the TC light on his 7? (a) it doesn't have TC and (b) there's a fair chance I was the last person to drive that car on the road....at least 5 years ago perhaps we should all meet up for a beer?

[bcr5784]

Another bit of grist to the mill FWIW. Drove a 420R over the weekend. The Caterham guy's view was that for the road the 270 was the sweet spot, for the track the 420 (better than the 360) - but on the road the 420 was likely to put you in license losing country.

I partly agree. realistically the 270 IS fast enough on the road, but on the track it can feel lacking on decent straights - as can the 360 to a degree. But on the road (and it was damp in places) I found the 420 perfectly well mannered. Sure, I probably didn't use the last 1500 revs available but the power was progressive and the engine surprisingly tractable, so it was no problem. And any Caterham gives the impression of going like stink at modest speeds (unlike some more refined fast cars) so you are never in doubt when you are in license losing country.

I had dismissed the 420 as a bit OTT for me - now I'm not so sure.

Just my two penn'orth.

[James.S]

cwin said:

I think Torque makes a difference how fast the car feels, 175 bhp with a bike engine doesn't feel as fast as 175 bhp with a Duratec, I drove our green Duractec N/A car today with 300 +bhp and 220 flbs torque and it's just too much for the road, just couldn't open the throttle up in any gear, unless your on a circuit and can get some heat in the tyres anything over 200 bhp is too much on cold tyres on the road,, Imo.

Agreed, 180-220 is great for the road, anymore is tiresome for wick point to point stuff.

Still a great choice to be making though

[mic]

Its still good to build big power cars, even if there're a bit much for the road.... :-)

[Mario149]

bcr5784 said:

I found the 420 perfectly well mannered. Sure, I probably didn't use the last 1500 revs available but the power was progressive and the engine surprisingly tractable, so it was no problem.

If you're not using the last 1500rpm in the 420, you could prob save yourself some money and go for the 360? The 360 loaner I had was brill - I weigh in at nearly 110kg at the mo and the 360 I drove had an SV chassis and the 5 sp box and it was ace fun despite prob being significantly off the performance of a 360 S3 6sp with a normal sized person in it. Still pleeeeeenty quick for the road, and as i mentioned before, more fun there overall than the 620.

5sp really seemed to suit the car as well, if I was buying a 360 primarily for road use, def don't think I'd pay the extra 2500 quid for the 6sp.

[tight fart]

A lot depends on the engine not peak power, when I first installed my Zetec that has 220 ish bhp it was terrible on the road.
It is a Dunnell and an ex race engine and had his ecu and map. It had nothing to 4000 rpm and then everything up to 7500.
I then went to had a Emerald fitted and Dave walker mapped it, the engine still makes the same peak but pulls from tickover.
It's now a superb engine that can poodle through town when required like a Honda Civic or scream away on track.

[bcr5784]

Mario149 said:

If you're not using the last 1500rpm in the 420, you could prob save yourself some money and go for the 360? The 360 loaner I had was brill - I weigh in at nearly 110kg at the mo and the 360 I drove had an SV chassis and the 5 sp box and it was ace fun despite prob being significantly off the performance of a 360 S3 6sp with a normal sized person in it. Still pleeeeeenty quick for the road, and as i mentioned before, more fun there overall than the 620.

5sp really seemed to suit the car as well, if I was buying a 360 primarily for road use, def don't think I'd pay the extra 2500 quid for the 6sp.

Certainly wouldn't go 420 for merely road use, but thought it might be too compromised for road use - but I didn't find it so even though it was damp (only drove it on the road). Re 5 speed vs 6 speed I find the 6 speed ratios just too close. I'm not convinced about them on the track either. That said the 5 speed ones are rather wide (even with the Mazda box).

Is there some reason (other than the fact they can charge £2500 for their 6 speeder) that they don't fit the Mazda 6 speed box?

[Mario149]

bcr5784 said:

Re 5 speed vs 6 speed I find the 6 speed ratios just too close. I'm not convinced about them on the track either. That said the 5 speed ones are rather wide (even with the Mazda box).

Is there some reason (other than the fact they can charge £2500 for their 6 speeder) that they don't fit the Mazda 6 speed box?

Ref 6 speed, if they're broadly stacked like in my 620R, then yeah I think they're probably too close for the road. I don't mind stirring a box regularly, but when 6 ratios are all stacked like this like in a motorbike:

|-------------1---2---3---4---5---6

rather than something like this:

|--------1----2----3----4----5----6

....it's a bit too much for regular driving!

The 5sp I found very good, my only complaint is that 1st is a bit short, and third was a bit long at about 100mph at 7500rpm (max revs) in the 360. Something like this:

|-------1-----2------3------4-----5

Silver lining was that although 2 to 3 dropped you quite far down the rev range, it meant that you were climbing back up to peak torque when giving it the beans in 3rd giving you that nice feeling of increasing acceleration (as well as speed)

Edited by Mario149 on Tuesday 8th March 10:02

[Upnor]

An extra £2500 for 1 more gear, that makes the whole car a bargain if the gearbox alone is worth £15000!!!
I personally have never driven anything with 6 gears that I liked, I've always found there just there to make up for the engines lack of torque, add it to a diesel with such a small rev range and you soon get the hump!

[scubadude]

Mario149 said:

The 5sp I found very good, my only complaint is that 1st is a bit short, and third was a bit long at about 100mph at 7500rpm (max revs) in the 360.

Mine has the old 5spd box with a "long first" (although I don't know what the ratio is) its feels just right for the road, however I can imagine with a less torqey, more rev happy motor the 6 might work. It sounds like it needs an old-school overdrive for any distance on dual carriageways.