Supersport Gearbox

[nbc]

A newbie signing in, good morning.

 

I've been informed that my new Supersport will likely not have the close ratio gearbox and that, in reality, it doesn't make much difference to overall acceleration. Apparently, it's the 3.91 diff that makes it the 'sprint ratio gearing' listed in the spec but i've read the spec again and it also lists a '5-speed sprint ratio Caterham gearbox' too, so my questions are:

 

.1. Is it true that its the diff that makes the difference and not the gearbox?

.2. Why would they fit some with the 36G003A box close ratio box if it didn't make a difference?

.3. What would you do about excepting the car without it?

 

Incidently, the demo SS is fitted with the std box apparently.

 

I've been so excited for so long about picking this car up but this has tarnished things slightly; I feel very angry about it, especially that I wasn't informed by CC themselves about the spec change, afterall, the close ratio gearing was a big reason why I went the SS route and i feel I'm being short changed.

 

What should I do, what can I do? Any help/opinions hugely appreciated.

 

[Roadsport06]

1st gear is not good, you are in to 2nd straight away. Many people change the ratios when the engine ever comes out. This is what I'll be doing.

You ordered it with close ratio so that is what you should get.

Steve at SPC is a gears expert and does change ratios, I would speak to him to get a price. Let CC know the price and get them to knock this off your order. Steve will not charge the Earth for this.

[Roadsport06]

SPC here

[Graham King]

nbc, the description of the SuperSport on the Caterham website refers to "five-speed 'sprint' ratio gearing" being standard fitment. Acceleration is not the issue here, either box will accelerate quickly and is down to a mixture of box and diff ratio. I'm not sure of the revised ratios of the sprint box but as Roadsport06 implies the ratios in the standard box are not ideal, particularly 1st, as it is too high. So the statement about acceleration not being particulary affected may well be true but driveability will be.

 

I guess there is a problem with supply of sprint boxes hence the change back to standard, 3 courses of action as far as I can see.

 

1) Insist you want the Sprint ratio box

2) Ask Caterham to send the box to SPC (or similar) prior to supplying your car

3) Ask for a discount for an amount that you feel comfortable with

 

If it were me, I would want 1) preferably or if the wait would be too long then 2) as a backup.

 

I can understand why you are feeling disappointed.

 

Graham.

[Mankee]

The Caterham showroom page lists two sightly different gearsets for the Ford Type 9 5-speeder:

 

1st: 3.65:1

2nd: 1.97:1

3rd: 1.371

4th: 1.00:1

5th: 0.82:1

 

1st: 3.36:1

2nd: 1.81:1

3rd: 1.26:1

4th: 1.00:1

5th: 0.82:1

 

The second set has slightly leggier and closer packed first three gears, so maybe this is the spec classed as "sprint ratio", along with the shorter 3.92 diff? The first set is from a standard Sierra Type 9 and the second set is from a 2.8/2.9 V6.

 

If you can get the right gearbox spec the first time, then it might be a lot easier and cheaper to swap the diff later than to pull the engine/box out to swap the box. Gearboxes are always a bit of a mystery as you have to take the lid off and start counting teeth to find out what you actually have. Unless you go for the Caterham 6-speed option of course and then you know exactly what you are getting.

[Grubbster]

If the sprint box is one of the key selling points of the Supersport (it seems to be) then I wouldn't be happy to take one with a std 5 speeder Download gearcalc and put in the ratios to see what difference it actually makes.

[Mankee]

Quoting Grubbster: 

If the sprint box is one of the key selling points of the Supersport (it seems to be) then I wouldn't be happy to take one with a std 5 speeder Download gearcalc and put in the ratios to see what difference it actually makes.

I would agree with the above about the box being an important part of the Supersport spec.

 

I've already done a comparison of the two sets of ratios, as I've always been under the impression that I've got the standard set of ratios but have just found out that I have the slightly closer set. 1st is still too short for me though. You might find it different as my car doesn't do any road miles.

 

You can download the prepopulated Excel spreadsheet below and number-crunch to your heart's content:

 

here

 

Good luck.

[Z3MCJez]

The Academy used to use the close ratios until 2008. From 2009 it was standard ratios and from 2011 all of the series have used the standard ratios (including the Supersport series, which is the same engine configuration and LSD). General consensus is that for track the close ratios are better (1st is too short in standard. 2nd is used very very infrequently - Mallory hairpin and you can think about it at the Loop at Silverstone, or Montreal at Snetterton (note, this list is not exhaustive - I've not been everywhere!). Shell Oils at Oulton is 3rd for sure.)

 

I would think that for road the close box would be more appropriate, not less. But there aren't many of them left, as set out above.

 

Jez

[stevemersey]

I have just paid to have my first gear changed during a gearbox overhaul, and would say it was money well spent. I felt the original 3.65 I had was better suited to hill starting a ton of car than getting my 7 away from the lights.

 

I have ended up with a 2.75 first gear, which is quite low enough to get me away quickly on the road, but now when I change to second I do not drop off the power like I used to but get straight into a real chunk of beef in second gear.

 

Is my 0-60 time any quicker? Not sure - but it is a lot easier to drive smoothly and quickly in traffic.

 

I have no idea what you should be getting with your car, but if you can get it, a longer first gear is well worth having in my somewhat limited experience.

[Boss Hogg]

I received the 36G003A close ratio box and find that it works great. As others say, request the correct box or worst case get SPC to modify at Caterhams cost.

 

From another thread, the supersport ratios appear to be: 3.6, 1.97, 1.37, 1, 0.87

 

Good luck!

 

 

[irrotational]

I must be getting old - I don't know what these new-fangled supersport things are! 😳

 

Is it a sporty sigma 150?

[zetec]

Dig your heels in for the supersport box otherwise you"ll regret it!

[Graham King]

Those ratios from Boss Hogg are the standard ones, the supersport ratios I suspect are the 2nd set in Mankees post.

 

Graham.

[oldbuffer]

Quoting irrotational: 

I must be getting old - I don't know what these new-fangled supersport things are! 😳

 

Is it a sporty sigma 150?

 

140bhp Sigma.............Link to Supersport here

 

http://www.caterham.co.uk/assets/html/showroom/supersport.html

 

Edited by - oldbuffer on 30 Mar 2012 08:41:01

 

Edited by - oldbuffer on 30 Mar 2012 08:42:03

[nbc]

Many. many thanks for all your responses, really, very much appreciated.

 

I'm going to fight this one all the way as the orginal spec sheet from the time I placed my order clearly stated '5 speed cloe ratio Caterham gearbox', so that is what I'll get. It's now been revised incidentally with it omitted.

 

oh, whats this.... email form Tim... i'll keep you posted.

 

Thanks again

[Stationary M25 Traveller]

By the way - since no one else has said it - welcome to BlatChat