Another thing to consider when choosing a Seven.

[JohnK]

Briefly, my interest in "a Seven" lies in how this type of car behaves when

you drive it. I know from some experience that creating a vehicle that is a

revelation to drive takes a gifted designer and considerable investment in

development of the design. Or said another way, building something out of

contemporary hardware that looks like a Seven is not the same thing as building

a car that is as thrilling to drive as a car that deserves the name "Seven".

A while back I had the pleasure of riding over some very choice roads in an

'ordinary' Caterham, driven by someone who was very comfortable piloting said

vehicle at as good a clip as you would like to drive on public roads. I was

struck by two things. First was that, even as a passenger, the combination of

nimbleness and stability of the vehicle was very evident, very surprising, and

very impressive. I found myself thinking, "I bet you could do ANYTHING in this

car". Secondly, it was really comfortable. And this made me recall all the

posts I've read about people driving hundreds of miles in such a tiny car and

enjoying the whole trip.

Being a terminally curious person, I've wondered "How did such a car come to

be?" One thing I know about is the value of investment in development, and I

can offer a data point for those who feel similarly. This info was on the

Caterham site a while back and is obviously a promo for the vendor who did the

work. I grabbed it for my files. Technically, much of it is quite a bit over

my head, but it's clear that Caterham invested quite a bundle to make their

product behave even more like it's something magical. And this is a relatively

recent investment - the Caterham Seven already had a reputation as worthy of

the name "Seven". If you want to own a Seven, add this info to the collection

of stuff you think about when you're making your purchase decisions.

 

Here is the article: https://www.dropbox.com/s/edccxybb5nq2pgr/oconnell.pdf?dl=0

 

And then there's the implementation Dec, 2010

http://www.caterham.co.uk/assets/html/technical/chassis.html

Edited December 24, 2016 by JohnK
added article link; added Relavant link

[solder_guy]

Interesting presentation .. that and seeing the R500 fly makes for a complelling case for Caterham.

 

Rob

[Hank]

Thanks for posting that article, John.

 

That Caterham weighs 1344 lb (page 19). Seems a bit heavy for what it looks like.

 

As a comparison, I don't like that the rear of my Megabusa has the bottom of the shocks in single shear.

 

http://hanksmegabusa.com/images/113008/05.jpg

[scannon]

Too bad that suspension didn't get put into production until the SCR series came out. My SV has the same deDion rear and outboard spring/shock front setup as the classic Caterhams. The SV was already in production by 2003 when the development of this suspension for the SCR took place.

 

1,344 lb is about right for an SV. This is a wider and longer chassis than the classic Super Seven Caterham. My SV weighed in at 1,350 lb including the additional weight of a cast iron block engine, turbo exhaust manifold, turbo, intercooler & plumbing, a half tank of fuel and a few other things I added.

 

The only other type of Se7en I've driven is the FM Westfield which had a normally aspirated Miata engine at the time. I was very impressed with that car, especially the steering which required less effort and had better feedback than my car. It was also easier to heel/toe but some judicious bending of the pedals on my car fixed that.

[JohnK]

I think that this investment by Caterham is just one of several, and, to me, shows that Caterham knows the value of investment in development. I remember a flyer from years ago (1996) bragging that the latest frame had a 30% increase in stiffness, so they seem to have been at this for a while.

 

Hank,

The hub on your Megabusa looks like a nice piece of hardware. Single-shear notwithstanding, I think that, beyond what we generally accept as 'good practice', some things need a Finite Element Analysis applied to them before they get a thumbs-down. Which is way beyond my skills (or budget).

[mebrahimi]

Attachment added.

[Kitcat]

Misc thots:

 

When I was at the LOG 30 Summit Point track day earlier this month, my instructor (an Elise owner) drove my car the first session. The conversation, as we approached the first turn, went something like this:

 

"You see that cone and those trees, you want to start dialing in a little steering right here, WHOAAA, what just happened? Oh my God, this thing turns in RIGHT NOW, forget what I just said, I have to get the hang of the car first, it is so incredibly responsive, suddenly my Elise feels like a boat!"

 

JohnK, thx for the attachment. It's interesting to see how serious the effort is (and difficult the task is) to improve the car's already excellent handling while retaining its purity.

 

My S3 weighs 1225 lbs, 100 less than the larger SV. When I was at LOG there were many SV's and I have to say I didn't notice any size difference compared to mine-their size is so proportionately larger you really have to look to see the difference. In fact, I didn't know they were SV's until their owners told me.

 

Mike

[pi7ot]

Misc thots:

 

When I was at the LOG 30 Summit Point track day earlier this month, my instructor (an Elise owner) drove my car the first session. The conversation, as we approached the first turn, went something like this:

 

"You see that cone and those trees, you want to start dialing in a little steering right here, WHOAAA, what just happened? Oh my God, this thing turns in RIGHT NOW, forget what I just said, I have to get the hang of the car first, it is so incredibly responsive, suddenly my Elise feels like a boat!"

 

JohnK, thx for the attachment. It's interesting to see how serious the effort is (and difficult the task is) to improve the car's already excellent handling while retaining its purity.

 

My S3 weighs 1225 lbs, 100 less than the larger SV. When I was at LOG there were many SV's and I have to say I didn't notice any size difference compared to mine-their size is so proportionately larger you really have to look to see the difference. In fact, I didn't know they were SV's until their owners told me.

 

Mike

Once you own one and acclimatize to the response of a 7, most else is lard.

I was instructing a Carrera 4 owner at a Porsche event on a kart track.

I had trouble getting him to brake and turn where I thought he should, but from the passenger seat, the chassis was inert and heavy.

I realized that I was using reference points for the 7 after the second corner. Once I had the timing of his car down He kept on saying, "It's a quick car isn't it?" and I would just nod.

He was pretty gobsmacked after 3 laps in the 7.

 

m

[Croc]

My S3 weighs 1225 lbs, 100 less than the larger SV. When I was at LOG there were many SV's and I have to say I didn't notice any size difference compared to mine-their size is so proportionately larger you really have to look to see the difference. In fact, I didn't know they were SV's until their owners told me.

 

 

I think there was only 1 SV at LOG - mine. However I agree with you, Caterham did a good job of disguising the size differential with proportioning. You can always pick an SV by focusing on the nose - its the difference between a wide-mouth bass and a regular mouthed one.

 

 

 

Excellent presentation - thought provoking. The CSR suspension design cures many of the handling ills that I find dissatisfactory in my regular roadsport model Seven - rear bump steering and over-reaction to poor road surfaces. Some of this is because I live in an area with crap roads which is a downside to my owning a car like this.

[11Budlite]

Here's a photo I found a while back showing the difference in size between a standard car and an SV:

[Taber10]

Croc,

 

....Only one SV at LOG30--yours.... Is that another jab because I wasn't at the picture? Autocross? Track Day?

 

Mike,

 

At least you didn't say anything like, "I could spot the SV owners/drivers because of their weight and girth...."

 

Taber

[scannon]

Here's a photo I found a while back showing the difference in size between a standard car and an SV:

Do you by chance have a front view of these same two cars?

[Croc]

Croc, ....Only one SV at LOG30--yours.... Is that another jab because I wasn't at the picture? Autocross? Track Day?

 

 

Hi Taber :seeya:

 

It was not a jab as I had no idea you had an SV. In fact I assumed you had an S3 given you are far more svelte than tubby old me!

 

Cheers

[Kitcat]

Bruce:

 

I have seen the pic you posted above before and, based on it, thot that it wld be easy to tell the 2 models apart. But from ground level (as opposed to overhead), and with different colors and options (spare tire/no spare tire), the difference is much more subtle than the photo above suggests.

 

Croc-I have not noticed any evil handling w/my car, even on rough roads. I have a Dedion with the softer all-around suspension, as opposed to the track oriented suspension. But I am running race rubber on the street and still the ride is acceptable smooth, firm but probably softer than my stock M3 rides or my prior vehicle, a stock R package Miata.

 

Mike

[11Budlite]

Do you by chance have a front view of these same two cars?

 

Sorry Skip. I think I found that picture on Blatchat and I don't think there were any other views with it.

 

Mike - I agree with you. That photo does seem to emphasize/enhance the size difference.

[scannon]

I've found that when my SV is parked near an S3 sized 7 the difference is immediately obvious regardless of color, It's when I see a Se7en parked by itself that I have to look at the mouth to determine which size it is.

[Boxologist]

the key to making an S3 and an SV look the same is perspective.

ta da!

http://inlinethumb21.webshots.com/3092/2171786510099946657S600x600Q85.jpg[/urlhttp://inlinethumb51.webshots.com/13554/2725543560099946657S600x600Q85.jpg

but from the right angle its very appearent

http://inlinethumb50.webshots.com/40433/2162232130099946657S600x600Q85.jpg

Edited October 29, 2010 by Boxologist
visible pcitures

[Hank]

Boxologist,

 

All 3 links above coming up "Forbidden" on my computer.

[S1Steve]

Boxologist,

 

All 3 links above coming up "Forbidden" on my computer.

 

Jon, x2

[supersportsp]

My wife got me this book for xmas. It has great details on the development of the CSR chassis. http://www.amazon.com/Caterham-Sevens-Official-Sportscar-Conception/dp/189987061X/ref=sr_1_2?s=books&ie=UTF8&qid=1288319965&sr=1-2

 

several other factors weighed in on the development as well:

 

- Rising rate vs. falling rate

- Aero improvement (drag/lift) of getting the shocks out of the airflow