Buying advice for a Roadsport/Supersport

[SamCat7]

Hello Everyone,

I am finally in a position to purchase my very first Caterham ! and am very excited
By studying different models and reading and researching about different models, engines, options, etc. etc. and most importantly my budget, I am looking for a 1.6 Sigma engined S3. I don't want to get into the details of different options. My question is mainly this :

What are the main differences, advantages or disadvantages between these two models :
1- Roadsport 150 - 150bhp - 5 speed
2- Supersport 140 - Which has 140bhp but comes with LSD

Lets' say if both cars are within the same price range, same year and same milage/condition/options, which one would you pick and why ? Which one would be quicker ? Is there any differences in performance/ driving ? Am I missing any major differences ?

I will be using the Caterham mainly as a weekend toy on sunny days driving down the country roads as well as occasional track days ( 4-5 a year). I already have a 800bhp car so will not be looking for more power for the Caterham. I understand around 140-150bhp is the sweet spot for driving on the roads so I will stick with the same range power for this toy.

Please do not suggest/add a different model (K series, R300, etc.) as I would like to know and decide between these two specific models.

Many thanks for your help in advance and look forward to receiving your thoughts and suggestions.

Regards
Sam

Edited by SamCat7 on Thursday 7th November 16:54

[BertBert]

I don't know the answer, but I would look at all the differences between the supersport and the roadsport. I would expect there to be more differences than just the LSD.

And there I think will lie the answer.

For me the horsepower alone isn't a differentiator.

Bert

[SamCat7]

You are absolutely right Bert, there is more than just the LSD but to me the LSD is the big difference, I believe lighter flywheel, different ratio box, wide track front suspension, etc. are some of the differences but to me the main bit is LSD. I understand that I can always add LSD to let’s say a standard Roadsport 150. The good thing about Caterhams is that you can always change/add options and make them the way you want. But obviously it requires more money to spend so I ideally would like to get something that meets most of my needs. These two are the closest to what I’m looking for. The Roadsport 150 is the colour I want and has the right options and come from a reputable seller with warranty and piece of mind. However, the Supersport is a private sale and a few bits are not my favourites like the colour, higher mileage, etc. but on the other hand it has LSD.
So the question is should I go for the Roadsport because it’s closer to what I want or should I go for the Supersport because it is generally a better choice and then change the colour and other bits gradually !

[Dr Evil]

The supersport is track oriented; aeroscreen, tillet seats, harness, lightened flywheel, LSD. The roadsport is 'road' oriented with leather seats, inertia belts, windscreen, spare wheel carrier and weather equipment probably optioned. Out of the box, the roadsport will not be the fastest caterham on a track day, but still fun and a bit more practical on the road. The upgrade path if you feel you need it for the track and are handy with the spanners is there - seats ~1200gbp, flywheel ~500gbp, aeroscreen ~300gbp, LSD ~1000gbp, + wheel/tyre package etc. LSD, flywheel etc are options on roadsports so you could get lucky if the PO specc'd them. then you'll possibly want a track day rollbar, proper harnesses and maybe lowered floors if you are lanky.

[BertBert]

I'm sure it's personal choice, but the LSD is not the key difference for me. I've found that I much prefer the handling of the widetrack. So everything else being equal I'd go for the supersport.

ETA which does have the LSD
Bert

Edited by BertBert on Friday 8th November 08:01

[ghibbett]

Supersport has a shorter final drive ratio (but the same gearbox). However it makes a big difference to the way the car drives. I would pick a Supersport over a Roadsport all day long.

[BertBert]

I reckon you should buy the roadsport OP, but point me in the direction of the supersport so I can buy it

[Turn7]

I have the 150 Sigma SV Roadsport.

It came on 15" rims which I swiftly changed as I hated the handling.

It now sits on 13s with Toyo 888r's.

It has an open diff, but it also has more grip than power, therefore, I dont believe an LSD will be noticeable for road use.

[SwaffhamCountyFayre]

Hi Sam, the Supersport and Roadsport have the same transmission and final drive, the main Supersport changes were stiffer adjustable (track) suspension and 140bhp. The Roadsport 150 will have creature comforts as standard (leather seats, heater, windscreen and hood etc) but also the 150bhp Sigma has throttle bodies which make a fantastic induction roar which in my opinion really add to the experience.

However the big thing to be aware of with Supersports is whether or not it was a race car in a previous life. Many Supersports were NOT originally the road car model but were a Supersport race car then converted back to a road car post racing life. These conversions are done to various levels from just removing the cage and giving it a quick tart up (still have fire extinguishers, holes in sideskin/interior panels from cage, original race seats and no heater etc) to full rebuild and restoration where no evidence of its racing life may be left. It’s not necessarily an issue but it could mean you potentially may not know exactly what you’re buying so just something to beware of, an original Supersport road car is actually a pretty rare thing.

Hope this helps.

Edited by SwaffhamCountyFayre on Saturday 9th November 09:25

[ghibbett]

Not sure they do have the same final drive.

IMO the Roadsport has an open diff and 3.62 final drive, whereas the Supersport has an LSD and 3.92 final drive. I've driven both and there's a very noticeable difference.

[SwaffhamCountyFayre]

I believe it's the transmission that dictates the diff ratio - 5-speed has 3.91 and 6-speed has 3.64 (BMW diff) or 3.62 (Sierra diff).

Edited by SwaffhamCountyFayre on Monday 11th November 08:30

[HustleRussell]

Is the 140 going to be Ford / Ford or Ford / BMW, is the 150 going to be Mazda?

What years are the cars OP?

[framerateuk]

SamCat7 said:

Hello Everyone,

I am finally in a position to purchase my very first Caterham ! and am very excited
By studying different models and reading and researching about different models, engines, options, etc. etc. and most importantly my budget, I am looking for a 1.6 Sigma engined S3. I don't want to get into the details of different options. My question is mainly this :

What are the main differences, advantages or disadvantages between these two models :
1- Roadsport 150 - 150bhp - 5 speed
2- Supersport 140 - Which has 140bhp but comes with LSD

Lets' say if both cars are within the same price range, same year and same milage/condition/options, which one would you pick and why ? Which one would be quicker ? Is there any differences in performance/ driving ? Am I missing any major differences ?

I will be using the Caterham mainly as a weekend toy on sunny days driving down the country roads as well as occasional track days ( 4-5 a year). I already have a 800bhp car so will not be looking for more power for the Caterham. I understand around 140-150bhp is the sweet spot for driving on the roads so I will stick with the same range power for this toy.

Please do not suggest/add a different model (K series, R300, etc.) as I would like to know and decide between these two specific models.

Many thanks for your help in advance and look forward to receiving your thoughts and suggestions.

Regards
Sam

Edited by SamCat7 on Thursday 7th November 16:54

I have a Roadsport 140 from 2009. It's a bit of an oddly specced car as it was originally owned by Caterham as a demo car, but given the spec it had (widetrack, LSD, 6 speed box, big brakes, fire extinguisher, fia roll bar, adjustable Bilsteins), I think it might have been originally planned as a Superlight 150, and then given the 140 engine instead - which was the newer revision. It does have leather seats and heater though.

The differences the between the 140 and 150 are pretty minor in terms of performance, but I believe the 150 had ITB's and was known to be a bit jumpy on low throttle, as well as not quite making the claimed 150bhp. (Happy to be corrected, just going on what owners told me and what I read many years ago when I bought mine!). The 140 is a great little engine and really goes well - I can't imagine there's much between them in the real world.

Anyway, so long as you have the mechanical spec you want, most things are very easy to change on a 7. My 'Roadsport' now has 13" wheels rather than 15 and an interchangeable windscreen/aero screen. The screen makes a huge difference to the car on trackdays.

Personally, I love the 6 speed box and LSD of my car, but the gearbox does make it a bit tiresome when touring, but for a day out it's brilliant. The Supersports had two different gearboxes. The original ones had a close ratio 5 speed, while later ones had the standard 5 speed. So it's worth asking about that if you try out any.

In terms of suspension, the 140 Supersport has a widetrack front, but doesn't have the full 'superlight' treatment in the rear with watts linkage. What difference this makes in the real world I'm not sure.

The options list is probably going to have more effect on these cars than the basic spec, I'd go and see at a few to see what you like the look of.

Edited by framerateuk on Tuesday 12th November 15:57

[framerateuk]

HustleRussell said:

Is the 140 going to be Ford / Ford or Ford / BMW, is the 150 going to be Mazda?

What years are the cars OP?

The 150's were up to 2009, so it would be Ford. I guess the 140 *could* be BMW, but my '09 car is a Ford.

[BertBert]

So it sounds like the normal set of 'updates'.

Wide track front
Big brakes
LSD
Watt or radius arm rear
Short or long rack (is that still a thing)
Race m/c

For me...
Widetrack is a must, really feel the difference
Big brakes, medium good but not necessarily the be all and end all
LSD not all it's cracked up to be. Great for donuts though.
Watt linkage. Not worth worrying about.
Short rack is good.
Race m/c just makes the brakes hard to press.

What else do people value?

Bert

[ben5575]

I've owned several se7ens.

To me the LSD is one of the defining characteristics of the car. Whilst you can certainly tour in a Caterham, almost any other car in the world is better at it. That's not to say it's not great fun, but that fun you're buying is the character of the car and the LSD is instrumental in that. What's the point of buying an uncomfortable lightweight car if it doesn't drive and slide like you think a rwd car should/want it to drive like?

So Supersport for me all day long for me. You'll also find that the sweet spot is 180bhp for the road. 140/150 is rapid/fun, but 180bhp puts a proper smile on your face. 220bhp+ is just hilarious.

Watts linkage is nice to have, but adjustable roll bars are a better investment. Big brakes are good (I recommend Hi Spec as a cheaper, gucci alternative), but brake balance adjuster is more important, particularly for track use in the first instance. Then the suspension, carbon fibre, etc etc, welcome to Caterham ownership

[upsidedownmark]

I've only owned one, but I've been upgrading, so covered a few spec iterations

I highly rate the LSD.. BUT I think it's over harsh to say that the car doesn't slide / drive like a rwd. Pre-LSD it was a bit prone to spinning one wheel off roundabouts and the like, but I still managed to spin it on track.

When considering power, consider where you get it, and particularly where the torque is. Nobody mentions it, but how often do you drive around above 5000rpm - rarely on the road, no matter how much of a hero you think you are
Specifically my 'vanilla' 1.6k went to supersport cams, then to a big valve high flow head. The first raised everything all the way across the range. The effect was immediately obvious from the second I turned out of the driveway. The second didn't make any noticeable difference - rolling road and subsequent trackday showed a big improvement from 5k->7k. Car is undoubtedly faster, but you'd not know in general driving.

Lastly, @Bert in particular, can you comment on what the widetrack changes? Every time I ask I'm told 'better handling', but nobody can say specifically how/what - if it's that noticeable, I'd expect folks to say 'this, this and this'. So far I'm thinking it looks better, but otherwise unconvinced!

[HustleRussell]

framerateuk said:

HustleRussell said:

Is the 140 going to be Ford / Ford or Ford / BMW, is the 150 going to be Mazda?

What years are the cars OP?

The 150's were up to 2009, so it would be Ford. I guess the 140 *could* be BMW, but my '09 car is a Ford.

Aah, I’m getting mixed up with the current 150bhp ‘310R’ spec car.

Jury is out on LSD at this power level in my opinion- Depends what you are using the car for. The diff makes quite a drastic difference to how the car is best set up and driven. With an open diff on a track you have an added challenge of adapting your lines for traction and modulating the throttle to avoid spinning up the inside rear. An LSD certainly makes the car easier to lap quickly. You rotate the car and you pin it. On the road it noticeably changes the sensation of the drive- you can feel through the seat of your pants that there is a mechanical device working under there to tie the rear together. It can be felt and heard when negotiating tight corners off throttle. There is less mechanical ‘noise’ in the feedback from an open diff car as this extra mechanical device is missing.

Wide track looks better in my opinion. It supports the front of the car better on turn-in and makes the front of the car feel flatter and more immediate. It is somehow noticeable at all speeds. I wouldn’t be able to tell you how much of this difference is due to the wide track and how much of it is due to the uprated springs and presumably better dampers which come with the wide track though. Bit of both I suspect. There’s barely anything in it in terms of lap times.

For me the racing master cylinder is a must, I found it basically impossible to heel & toe consistently without it as with the standard MC the pedal is too soft and too long. It does mean that a lot of braking effort is required. The standard brakes are absolutely up to the job but the big brakes require less effort.

The ‘quick’ rack is very quick! On the whole I’d probably choose the ‘standard’ one which is already a quick rack in itself. You aren’t going to be cornering hand-over-hand with either of them.

[ben5575]

HustleRussell said:

On the road it noticeably changes the sensation of the drive- you can feel through the seat of your pants that there is a mechanical device working under there to tie the rear together.

100%

[carphotographer]

I really unsure about the benefit of wide track...... people who drive their cars on the road say better turn in, less under steer, but the real experts, the racers say it doesn't actually do anything. I've also quizzed a few people at Caterham and the came to the conclusion as the racers.