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Sport 250 clutch & gearbox options....


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Its that time of year where i'm thinking (possibly dreamingūüėĄ) of winter jobs.¬†

 

With the power/set up i'm running i'm probably pretty close to the limit of the MX5 speed gearbox and clutch, so i'm thinking of possibilities of upgrading, or sourcing parts to keep as spares.

 

 I have an MX5 MK3 gearbox, I dont know what exact clutch I have but have to assume its whatever Westfield supplied CIRCA 3/4 years ago

 

Im not really sure where to start with this as i have never really looked into upgrade clutches and gearboxes.

 

Do I simply look for an mk3 MX5 uprated clutch kit or is the MX5-Ecoboost/Duratec  some kind of hybrid/custom clutch setup?

Similar with the gearbox, does anyone know of an uprated box or internals?

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Steve (sdh2903)

I never came across any uprated versions of the gearbox. 

 

Clutch wise. Are you running the upgraded Westfield clutch? If so I believe its a bespoke item made for Westfield. 

 

If Westfield use the mk3 mazda flywheel then yes you can just buy an uprated mx5 clutch off the shelf. However as Westfield went to the trouble of getting a bespoke clutch plate made it makes me think the flywheel isn't a standard mx5 item. 

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thanks Steve, see thats what I need to find out, i dont know whats actually been fitted, it wasn't a factory built car either. 

 

The engine and box are coming out anyway so I  should be able to see what i've got currently.

 

The clutch listed on the parts store certainly seems to be a bespoke made item https://parts.westfield-sportscars.co.uk/model-specific/sport-250?product_id=1040

 

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Steve (sdh2903)

At best guess I'd say so unless it's bespoke. I used the mx5 starter, flywheel and clutch. 

 

If shopping for a clutch just make sure its for a 5 speed as its different to the 6

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Carl Warren

I’m pretty sure I ordered my fly wheel from vittese. You need a mk3 mx5 one. 
marries up with the helix racing clutch from westfield. 

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Thanks lads. 
yeah I noticed the 6 speed is different splines. 
I’ll get in touch with Vitesse as they seem to deal with the 5 speed NC box a lot. 

If it’s an Mx5 fly I have then there lots of bolt on clutch options out there. 
hopefully  there are identifying part numbers once it’s opened up. 
 

I might try and get a peek In with a bore scope 
 

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Carl Warren

That’s the flywheel fitted by westfield for

the racing clutch. 
vitesse invoice. image.thumb.jpg.8c1959be2a55427ab8c0c8f1492e56b3.jpg

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Adge Cutler- Dorset AO
1 hour ago, Carl Warren said:

That’s the flywheel fitted by westfield for

the racing clutch. 
vitesse invoice. 


Hopefully won’t need it, but noted just in case. Thanks

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Is there someone about the NC 6 speed that stops us using them? 
physical size? 

the only people who I’ve found who can uprate the 5 speed NC internals are in America 

 

what about running a Type 9 variant? Theres lots of them around. 
 


 

 

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Steve (sdh2903)

Gear ratios mainly. They're dreadful something like a 3.8 first gear. They are bigger but I don't know if they are too big. 

 

It would have to be a pretty special type 9 to cope with 300ftlb. 

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Ah good point about ratios.

 

This is what ive manged to find, not many options out there...

 

Quaife have an option of the¬†The QBE60G & Duratec bell housing & input shaft¬† which is a 6 speed sequential box (Same as caterham i think) conservatively rated to 300 lb-ft, but you nee DEEP pockets, be somewhere like ¬£8K¬†ūü§Į

sequential though....yes please

 

 I've spoken to a company called Roadcraft.  they have 3 gearboxes which ive never heard mentioned before...American maybe?

 

Tremec T-5            - Ratios  -  1st 2.95,  2nd 1.94,  3rd 1.34,  4th 1.00,  5th 0.63 Torque Capacity 300 lb-ft

Tremec TKO 500 -  Ratios -   1st 3.27, 2nd 1.97, 3rd 1.34, 4th 1.00, 5th 0.68 Torque Capacity 500 lb-ft

Tremec TKO 600 - Ratios -    1st 2.87, 2nd 1.89, 3rd 1.28, 4th 1.00, 5th 0.82 Torque Capacity 600 lb-ft

The TKO also comes in 6 speed 

these would be circa £3K

https://roadcraftuk.co.uk/index.php?route=product/product&path=45_141&product_id=620

 

They dont currently have a Duratec bell housing, but the chap said that they have been asked about them several times now so may look into producing one if the demand is there. 

 

bit of an eye opener when you see the prices and also the extra work fitting a different box.  maybe just stick with the MX5, they're cheap as chips (£200!) and loads available if you break one, or brand new they can be bought from Vitesse for £1300

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Tim (TimDave25) - Joint Thames Valley AO
On 16/09/2020 at 08:54, DMc said:

I've spoken to a company called Roadcraft.  they have 3 gearboxes which ive never heard mentioned before...American maybe?

 

...

 

bit of an eye opener when you see the prices and also the extra work fitting a different box.  maybe just stick with the MX5, they're cheap as chips (£200!) and loads available if you break one, or brand new they can be bought from Vitesse for £1300

Yes I believe they are American.

 

I went down the same path with my 1.6 ecoboost built as I had one eye on future power upgrades. 

 

£6-8k on gearbox was too much for me.

£3k type 9 might be ok but would be on the limit and such old engineering base.

 

I ended up with the £250 MX-5 box and if I turns out to be a chocolate box I've not lost much.

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My thoughts exactly.

 

I feel like im at the engineering limit of the box torque wise,  so I cant increase the power. Plus, It nice to know you have some 'head room' with the capabilities of the drive train

 

there's chat about the RX8 box but from searching on here it would seem that it doesn't fit in the tunnel

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