R400 or CSR260

[Rosco]

Listen to Jackal, he knows his track Caterhams!

I have used an R400 a few times on track days and now race a C400 (Duratec). On track days I have come accross a couple of CSR260's and in a straight line drag, there really wasn't hardly anything in them as they are heavier cars.

Also on that note, I would much prefer the duractec engine over the K series as it is much torquier, doesn't have a really noticeable powerband and lasts much longer, apparently

If I wasn't racing and could decide on any Caterham, my choice would be the new R400 duratec everyday.

[The Pits]

Being smaller, lighter, less torquey and higher revving makes the k series a fundamentally better engine for the seven.

If you can afford the rebuilds it's worth having. The only advantage of the duratec is durability. As I only use my seven on the track I don't need high mileage durability but I do want to make the most of the short time I'm in the car and a sweet high revving engine with exotic internals does that for me.

I have been offered a duratec but I'm sticking with the k-series. The R500s, R101s and R500 'evo's are exciting in a way the duratecs aren't.

[dannylt]

Err, the point with a Duratec is you don't NEED exotic internals for a reliable 230ish bhp. And it's hardly noticeably heavier. If "exotic internals" are part of the fun for you then you can do the same to your Duratec for 9000+ rpm and a load more power.

[The Pits]

it is heavier and the car is less fun imo with a duratec. put exotic internals in a duratec and it's more expensive and will then need rebuilds too.

[rubystone]

I swapped back to a K from a VX precisely because the engine's characteristics (for me at least) suit the 7 more. My (admittedly limited) experience of the Duratec was that it was similar to the VX in the way it delivered its power (the car in question was Caterham's CSR260 demonstrator).

I expect to blag a ride in TVRTED's R400 soon though and perhaps that'll feel different?

[casbar]

Being a K owner, now feels like it used too when I had a xflow and everybody raved about the K's.

Now its the Duratec which is flavour of the month It looks like a darn fine engine though, but happy with my R300 for now, I can peddle it quite well around the track !

[jackal]

The Pits said:

Being smaller, lighter, less torquey and higher revving makes the k series a fundamentally better engine for the seven.

my 2.0 litre duratec car was around 520kg with full race cage
it was a light car and lighter than my old SLR
my mates R500 (and yes it did go bang with ALL the factory upgrades) weighed 499 with NO CAGE and NO screen. Thats a real world weight, not a brochure weight so it tells you what a good weight my car was. Falling back on some 'low weight k' theory or trying to compare it to a VX is really clutching at straws.

As for revability and driving style my duratec redlined at 7750 so almost as much as the VHPD... the aggressive cam was such that its natural redline felt as though it would have been ~8250 so at 7500 the car was still screaming blue murder and pulling hard. It was just as zippy and satisfying to pull through as the SLR. The only difference was there was more power and a shed load more torque, it ran sub zero all day long whatever the weather, oil pressure never even twitched and it lasted 3 whole years without chewing itself into a mound of nasty iron filings.
The handling character wasn't changed at all, it was as adjustable and configurable as any caterham but obviously not snappy like a bike engined caterham and not having the dreadful endogenous understeer problem that the R500 suffers as do some VX cars. There really is no debate here. Its been done and proven already, many years ago now in fact. This is old ground.. move along etc.. for anyoen coming fresh to the market with good money in hand, the duratec and the K20a now reign supreme in the lotus & caterham market, end of story. Certainly as far as the 2.0 litre is concered the lightweight/high-revving argument is just pure mythology.

Edited by jackal on Wednesday 3rd October 17:16

Edited by jackal on Wednesday 3rd October 17:27

[The Pits]

no it isn't

redline of 7750 does not compare with 9000 rpm of my car. peak power is 8800, yours around 7k I imagine. You may not like it that way but I do. Each to his own.

[jackal]

The Pits said:

no it isn't

redline of 7750 does not compare with 9000 rpm of my car. peak power is 8800, yours around 7k I imagine. You may not like it that way but I do. Each to his own.

errrrrrr, you said you own an SLR which redlines at 8k
if yours redlines at 9k then you dont own a standard factory SLR

If you've tuned yours to 9k then fine, you have lots of revs which i totally agree is great on a trackcar.. but you are compromising the reliability very seriously. The K just can't sustain those sorts of revs for very long no matter what bearings you use. So to compare like with like, you can of course tune a duratec that way in any case if you so desire and you will have an equally long powerband. So you see, there is no advantage there. Also, my weight/handling statement still stands ... no weight penalty and no handling issues.

I dont have a problem with what you do per se but i'm all up for correcting any misleading information especially if it means someone coming new to the market and asking for helpful advice may end up blowing his 30k on the wrong car.

[Tango7]

I have got an R400 K series and have tried a friend's R400C a couple of times. Maybe his is still quite tight but whilst it revs freely and certainly has plenty of torque and power, I prefer my K series car for the moment. I considered having the 400C but decided to give it 12 months for the model to settle down and deliberately bought the K series car instead. Cost wise there wasn't that much difference between the two...

T

[jackal]

what cam does the new factory C400 use ? Maybe its on the soft side for higher torque. My car was actually down on power & torque a little compared to other 2.0 litre duratecs of that era, but it certainly made up for that in the revability stakes.

[dudlow]

Thanks again guys for all the info. It seems to be a very personal choice, with each and every one of you all holding strong convictions in your auguments, most entertaining. I look forward to meeting up with some of you at some point in the future. Lets hope I make the right choice, and buy a goodun !!

[jackal]

have you seen this.. its a bit of a bragin imo and has bags of potential if you want mental power:

http://www.pistonheads.com/sales/254738.htm

[thinfourth2]

Throwing in my oar

I would say neither for a roadcar as both are pretty brutal machines which may scare you silly and end up living in the garage

I would steer you towards a superlight/R300/roadsport which are usable machines for touring/spinting/autotesting/hooning/shopping/trackdays/blatting/posing Then if you get the & bug you know exactly what car you actually want not the car that everyone else wants

[mic]

Thinfourth you can't have driven the R400, it is dream to drive. but has plenty of power if you want it.

Hi Rich, C400 uses a Cosworth engine and the R400 uses a Caterham engine. It is almost identical to your one except the cams are milder and there's no piston pockets.

Mick

[Tango7]

thinfourth2 said:

Throwing in my oar

I would say neither for a roadcar as both are pretty brutal machines which may scare you silly and end up living in the garage

I would steer you towards a superlight/R300/roadsport which are usable machines for touring/spinting/autotesting/hooning/shopping/trackdays/blatting/posing Then if you get the & bug you know exactly what car you actually want not the car that everyone else wants

I have heard this said before but maybe its my weight (and pulling an R400 down to something a little less potent) but I can drive my car quickly on the road and never feel its too much at all. I suppose its all up to how you drive it and what the conditions are like, but I haven't yet got into any problems due to the power of the car.

However, the point about an R300 or Superlight is a very good one to determine what you really want without spending the same levels of money.

T

[jackal]

the fun of a car is using 95% of its ability 95% of the time
thats what makes trackdays so wonderful
if i'm not near or on the limit i find it pretty boring to be honest... pure acceleration is only a weeny part of teh equation
thats why for the road only, let alone an R300, i'd be looking at buying a classic, nothing more than about 120bhp with very skinny tyres
you will still cover ground quicker than 99.99% of cars you ever meet yet you half have a chance of holding onto your licence and not killing anyone
driving an massively overtyred R400/R500 on the road just frustrates, at least around where i live it does

Edited by jackal on Friday 5th October 14:01

[James.S]

[quote=jackal] using 95% of its ability quote]

Something that most Superlights never get close to, even on trackdays.

Roadsport is great on the roads although can run out of legs on long open roads, R300 is balistic.

R4/5 really are increadbly rapid, can't really use them effectivly on the roads.

Have never driven a CSR - sorry. Isn't there quite a price difference between CSR260 & R400??

Edited by James.S on Friday 5th October 14:37

[rubystone]

James.S said:

R4/5 really are increadbly rapid, can't really use them effectivly on the roads.

Why can't you? I ran an SLR for several years and an SLR spec car after that. I certainly was able to use the full performance of both those cars on the road, where conditions allowed.

[jackal]

rubystone said:

James.S said:

R4/5 really are increadbly rapid, can't really use them effectivly on the roads.

Why can't you? I ran an SLR for several years and an SLR spec car after that. I certainly was able to use the full performance of both those cars on the road, where conditions allowed.

this is just impossible, either that or there are wildying differing variations of what people mean by "using full performance"

take my old 8v golf gti.... If i drove it round pretty much any large-ish roundabout in the Thames Valley, surrey or middlesex at its full performance or full potential, seriously, someone would pull into a layby, grab their mobile and call the police to report me. This is a miserable 20 year old hot hatch thats less than 100bhp/ton and has tyres on it that are the width of a water boatman's winkle !