S2 Toyota C64 Gearbox solution.........

The Oily Bits S2 Specific Topics
1

As those who know me will tell you, I have been looking into a gearbox solution for the S2 Toyota C64 gearbox.

My requirements where as follows
Closer ratio’s
Stronger gearbox parts
Usable on the road
Good gearing for circuit use
Fits inside the standard casing.

I today agreed the basic design parameters for two Proto-type gearbox kits that meet the above requirements.

The gear kit will use the standard final drive pinion shaft and final drive ring gear. The other parts will be much wider than the standard parts as well as being only semi- helical cut (Sort of like Jubu sizes).

Additionally the standard 6th gear can be retained if needed for Motorway/road use (But this is not advised as it spoils the close ratio nature of the kit)

The planned ratio’s are as follows
1st 2.5:1 = 52mph @ 8000rpm
2nd 1.8:1 = 72mph @ 8000rpm
3rd 1.4:1 = 92mph @ 8000rpm
4th 1.2:1 = 111mph @ 8000rpm
5th 1.0:1 = 130mph @ 8000rpm
6th 0.9:1 = 144mph @ 8000rpm

For those with more specific needs (Racing, Hillclimbing etc) then the commercially available final drives can be used (5.0:1 & 4.8:1)
Or if you need more top speed then the Toyota final drives can be used (4.333:1 and 3.9:1)

Material wise I have asked for the top spec material to be used, Quality before price was how I put my request, So a material called M121 which was created by a german company called Bohler, This was originally developed by then for Xtrac.

Bohler now sell it as an
alternative to S156.

It is a triple vacuum melted steel that has the same high surface hardness of S156 but has a much stronger core. This makes it perfect for highly loaded gears etc as the higher core strength makes it more resistant to the shocks and
stresses associated with a hard working gearbox as well as having a very hard wearing outer surface as per S156, which is also being considered.

Our target price is sub �3000.00 for the kit

I will keep you all updated as things progress but our target is to have two gearboxes running in cars this year. With Production kits available early next year.

This project is not going to be cheap so any comments good or not so good are welcome…

2

Sounds great Dave, I think this will be a sort after kit.
Well done.

3

[quote=gp_fisher]Sounds great Dave, I think this will be a sort after kit.
Well done. [/quote]

I really do hope so as the development costs and initial batch of kits is a scary amount of money…

4

�3k for the gear set or �3k for a built box?

There is definitely a need for more solutions to this problem.

5

I’d say 3k is more than fair, i’d even say there would still be appetite at that plus vat considering how many are going pop

couple that with when the V6s hit the track, people will be modding more and more to ensure sustained willy waving rights :smiley:

6

With Jubu’s availability and the cost of the gears and final drive coming in at about �1800 + vat, I didnt think under �3000 + vat for a kit was to bad.
I know that a kaaz kit is ‘only’ about �2000 but the ratio’s are only ok with a 2.9 1st gear and they are only marginally stronger than standard.( They are also widely open to price fluctuations due to exchange rates)
The ratio’s that we have finaly selected are very very close to the Sadev ratios used by Lotus , very very close to the Hewland dogbox that we are currently testing as well as very very close to the ratio’s of some special boxes that Lotus tested that where made by TRD specially for Lotus (read very very close as the same or almost the same!!!)

Yes this will not be a cheap solution,as there will be added fitting costs plus any additional pparts like bearing, synchro’s LSD etc. Then there is the gearbox removal and refitting. But most of these costs will be there at some point for most people with decent power or heavy track use.

I am well aware it wont be for everyone, hence the reason for staring this post, i need opinions to gauge interest, This will help me decide on the number of kits to order 10 or 20 or 50 etc etc. As with all project the bigger the volume the lower the price.

7

I think your deffo doing the right thing Dave. As has been mentioned there is tonnes of tuning potential in the engine, its just that people are scared to do it with the gearbox the way it is.

This kit, coupled with a properly rebuilt box using high quality steel caged bearings etc etc will surely see Exige engine tuning in the UK really take off.

8

I would be interested on the uprated box Dave. Do you have an official figure of the power the box can handle?

9

Very good question…
I could b–ls–t and say 500 bhp and 450nm of torque but the true figures are limited by the standard casing, scyncros, bearings etc.
I have asked for the top spec materials within the size limits of the remaining standard parts, as i said earlier the materials used are a development of the materials used by Xtrac,
When speaking to the designers i did say over 350bhp and 250 nm which the new gears should be eassily capable of taking. I really cant comment on the other toyota parts, but once we have the test boxes in cars things will become much clearer.

Without producing a completely new gearbox at �10,000 or more (sadev, hewland, drexler etc etc) An upgrade will always sadly have some compomises, what im trying to achieve is a gearbox that ticks as many boxes as possible and is a better solution than the current elastoplast repairs/upgrades, Lets hope i acheive my goal.
I have a Hewland dogbox which is currently being run by sector111 with some great initial results, however it is NO GOOD for road use at all, This is why this project was born

10

[quote=SeanB]I think your deffo doing the right thing Dave. As has been mentioned there is tonnes of tuning potential in the engine, its just that people are scared to do it with the gearbox the way it is.

This kit, coupled with a properly rebuilt box using high quality steel caged bearings etc etc will surely see Exige engine tuning in the UK really take off. [/quote]

Lets hope so Sean.
My thoughts where the Jubu route seems to hold up, so whay not make a full gearkit in Jubu size with proper close ratio’s. I also need a decent road car box as my car is getting close now and with a JSR/Syvecs ecu, 2Bular gt system, bigger injectors and smaller pulley will break a standard box.
I also eventually want to install proper rods and pistons to allow the use of a Harrop 1320 SC. So for me this box is a an absolute must

11

not using the 153 box and a 1320 SC… franks going to love you :smiley:

__

12

This sounds ambitious, but do-able.
I think it will work and will sell. Regrettably a couple of months too late for me, but�3k is very reasonable for a bespoke project.
Congratulations for going ahead, as this area needed the injection of resources that only you wealthy retailers can afford


PPS Did you get your wheels back??

13

[quote=Muu]not using the 153 box and a 1320 SC… franks going to love you :smiley:

[/quote]
Oh well never mind ‘Mad dogs and Englishmen’ and all that :smiley:
Yes its all been done before etc etc but I would like to tread my own path…

14

[quote=661]This sounds ambitious, but do-able.
I think it will work and will sell. Regrettably a couple of months too late for me, but�3k is very reasonable for a bespoke project.
Congratulations for going ahead, as this area needed the injection of resources that only you wealthy retailers can afford


PPS Did you get your wheels back?? [/quote]
No mate nothing on the wheels unfortunately :frowning:

Who are the wealthy retailers you refer to??? 1/2penny and bum scratch spring to mind!!! :sunglasses:

15

:sunglasses:

16

:sunglasses: [/quote]
Hear hear
Good luck with it Dave :smiley:

17

Hurry up and get this done, I want to see it work for you guys…but

The E153 will take all the power you can make at half the price…Shifting is so last year… :whistle:

18

[quote=frank]Hurry up and get this done, I want to see it work for you guys…but

The E153 will take all the power you can make at half the price…Shifting is so last year… :whistle: [/quote]

Thanks Frank
A very nice and unexpected response from you…
I know it wont take what your E153 solution will, bit some here want the close ratio’s in the standard casing.
(Well i do anyway)Im only looling to get towards about 350-400bhp so this should be achievable with this kit (I hope!!!)

19

[quote=seriouslylotus]
Im only looling to get towards about 350-400bhp [/quote]

Yeah, right. You know power corrupts. If you are doing the internals , you’ll be drawn in by the new ported head and cams and then by the better S/C. 450 there for the taking.

20

[quote=661][quote=seriouslylotus]
Im only looling to get towards about 350-400bhp [/quote]

Yeah, right. You know power corrupts. If you are doing the internals , you’ll be drawn in by the new ported head and cams and then by the better S/C. 450 there for the taking. [/quote]

NOOOO 350 Ish I promise…fingers crossed!!