New gearbox for Academy cars - from MX5

[Grubbster]

Apparently the MX5 box will be fitted to next years cars so I assume it will become the standard fit?

 

Edited by - grubbster on 8 Dec 2013 14:21:29

[Roger Ford]

Thanks, Caterham, another headache for us and the Sigma-Graduates class.

 

Don't suppose you know the ratios in them, do you? If the ratios are similar, it shouldn't be a problem, but if they're significantly different from the current box it could be an issue.

[Jason Plato]

6 speed

[Grubbster]

I don't have the details Roger, just found out this was a change for next year. Someone has also suggested they will have variable valve timing and a cold air intake but I'm not sure how they'd do this?

 

CC's Academy web page still says 5 speed, but they are not know for their speediness to update such details so who knows!

[Jason Plato]

confirmed by mic as 5 speed 😶‍🌫️

[Z3MCJez]

The Late Sigma crate engines have VVT but I expect Caterham to run them as if they didn't have it.

 

Roger - there are lots of current spec cars that will be forced out of the official series in years to come, but it makes it harder, I agree. Ford diff for instance will be banned for 2015.

 

Jez

 

Edited by - Z3MCJez on 8 Dec 2013 18:44:56

[CharlesElliott]

At least we have a year to review the impact....

[Wrightpayne]

a year of free R&D before they hit the road cars per chance 😬

[CharlesElliott]

The Academy sees Caterham building 50 cars at an otherwise quiet time, I'm sure they would prefer to use 'new stock' than their remaining supply of Type-9s....

[Rob Walker]

Ratios 1st 3.136 2nd 1.888 3rd 1.330 4th 1.000 5th 0.814 I recon that the mx5 box will be both stronger and nicer to use than the type 9, Its just a shame that the mx5 6 speed box will not fit the Caterham S3 transmission tunnel or I would be fitting one in my car.

 

Rob

[Jaseb]

It's a nice box, believe it's the same as fitted the Frontlines LE50 MGBs.

 

LE50

 

 

Edited by - JaseB on 10 Dec 2013 09:15:22

[Mark Durrant]

Comparison of ratio's

 

.............. Type 9.....................MX5

1st..............3.36.......................3.136

2nd.............1.81.......................1.888

3rd..............1.26.......................1.33

4th..............1.00.......................1.00

5th..............0.82.......................0.814

 

[Roger Ford]

Useful, thanks. If I'm reading that right, the slightly higher first might be a marginal advantage on starts, but first is irrelevant during races. The lower second gear is a disadvantage, but that might be made up by third being slightly lower as well. The higher fifth would be a definite disadvantage, if the difference wasn't so marginal.

 

All in all, I don't think we need worry about either box having a big advantage over the other. Each will probably be slightly better for particular circuits. I suppose if we allow either there's a slight risk that very well-healed racers will swap boxes to get the best one for the circuit, but I think we'll just deal with that by laughing at them and making them buy the beers.

[Z3MCJez]

Slightly longer first is better off the start. But it's marginal. The Megas have a worse "off the line" with their long first (and the K is peakier too) but by saving more than a whole gearchange it would be better to be longer than the MX5 box. Something in the low 2s would work for me!

 

A shorter second and third is a definite disadvantage. Second is really still too short in the Ford box, useful only at Mallory, Cadwell and Snetterton, and that's with AO48s (even less use with CR500s). The gap is similar, which will still leave the "2 and a half" gear corners. However, the gap from 3rd to 4th in the MX5 box looks a worry (a 25% rev drop, from a max of 7,200 to 5,400, where my engine only comes alive at that point).

 

Fourth and fifth are effectively the same. As the car is flat out at about 120 with no assistance (which would require gearing of about 0.95 in 5th on AO48s) then a 0.90 fifth (or so) would be ideal. If I had to spec the perfect box, it would be something like (with useable speed in brackets in mph on AO48s, based on a rev range of 5,400-7,200):

 

1st - 2.20 (52)

2nd - 1.68 (52-69)

3rd - 1.33 (65-87)

4th - 1.11 (79-105)

5th - 0.90 (97-129 theoretical)

 

On balance, I prefer the Ford ratios!

 

Jez

 

Edited by - Z3MCJez on 11 Dec 2013 16:15:15

[7 wonders of the world]

Nice box but lets hope some of the aftermarket guys start making gear kits for them as for upgrade use those ratios are way out.

 

I know Quaife do some MX-5 kit but they wouldn't be my first port of call, so all things considered an ally cased type 9 will still offer better more choice and are likely to do so for some time yet.

[ants21uk]

Thanks for the responses.

 

Think I will speak to CC tomorrow. Likely to opt for the Mazda box I think.