New article - Portugal track day

[Croc]

 

 

Just finished writing up a new article on a Portugal track day

 

 

Linking here as not all of you explore in that section.

 

 

[fastg]

I went to the WSBK event in 2023, and stayed in Lisbon. Loved the track, would love to do a track day there. Lisbon is a cool town, great scenery and amazing food. I will return. I swapped from a Miata 5 speed to a 6 speed, huge difference.  You have to pull your box so just slide in a 6 speed, everything should fit including the drive shaft. 

 

Graham 

[Croc]

Which H pattern 6 speed Graham?  None I know of other than the old Caterham 6 speed will fit and I do not want to install one of those as they are no longer supported plus I would have to change the input shaft.  My only other options are:

1) change final drive from 3.9 to 3.6 - need to run gear calc but I am sure that will not change things other than bring second gear into play a little more at some circuits

2) install a Sadev 6 speed sequential (still have to change input shaft)

3) Could drop in a Quaife 5 or 6 speed sequential but not a fan of their boxes as I have had quality issues in the past and the sadev is the better product

4) drop in a BGH custom T9 box with ratios of my choice - would not be that much different to the existing Miata 5 speed in there so no. 

[JohnCh]

Another option I researched a couple of years ago is a Quaife close ratio gear set.  They make two for the Miata, both of which are on the tall side, although if needed that can be offset with a shorter ring & pinion from Turner Motorsports.  Unfortunately, real world feedback on the gear set was sparse when I looked into it, and I have yet to hear of anyone running it in a Caterham.  You can be the first  

[Croc]

31 minutes ago, JohnCh said:

 You can be the first  

 

No thanks.  I do enough "first" things with Caterhams and have the scars to prove it. 

[fastg]

Croc your right. I was thinking of the 1.6-1.8 NA/NB Miata trans, you can swap from the 5 to the 6 speed very easily. Sorry for the confusion. 

 

Graham

[MV8]

I would consider swapping to the miata six speed, change the final drive ratio to 4.30, with a tighter spread 2nd through 6th than the cat six speed 1st through 5th but the same top end. Food for thought .

Edited April 25 by MV8

[Croc]

12 hours ago, MV8 said:

I would consider swapping to the miata six speed, change the final drive ratio to 4.30, with a tighter spread 2nd through 6th than the cat six speed 1st through 5th but the same top end. Food for thought .

 

 

I agree completely - that would be ideal and I did investigate.  Sadly it does not fit the tunnel as the casing is differently shaped to the older 5 speed. 

 

I think the only practical outcome for now is considering gear calc  to go taller on final drive to see if that makes 3 gears (2-3-4) come into play more than the current mostly 2 gears (3-4).  I doubt it but its the only idea I have not run to ground.  Of course I could always go out and buy a new 420 Cup car....but no....

 

I am a little surprised that Caterham have not done something with this already by modifying the tunnel to take the 6 speed.    

[fastg]

Swapping to a 6 speed made a huge difference, went from a 2 speed car 3/4 to a three steed car 3/4/5. Well worth the effort if you can work it out. 

 

Graham 

[JohnCh]

19 hours ago, Croc said:

 

No thanks.  I do enough "first" things with Caterhams and have the scars to prove it. 

 

In that case, treat the following as a form of mild torment.  It's something I put together when investigating regearing options.

 

	Stock MX5	Quaife  1	Quaife  2
1st	3.136	2.564	2.345
2nd	1.888	1.67	1.544
3rd	1.33	1.277	1.222
4th		1	1
5th	0.814	0.794	0.868

[MV8]

I guess it is the 2016 and newer six speed that is too big? It looks bigger than the older six speed.

[Croc]

On 4/26/2024 at 12:18 PM, MV8 said:

I guess it is the 2016 and newer six speed that is too big? It looks bigger than the older six speed.

 

Yes that is right.  The newer one is too big but so is the older pre-2016 version.  The only thing that fits the tunnel is the old Miata 5 speed.  Lots have tried as it would be a brilliant solution otherwise.  Easy to mate to the Duratec which is a Mazda engine anyway. 

[Kitcat]

The ‘16 and on MX-5’s six speed is pretty fragile, unlike the earlier transmissions. Many have failed. My ‘19 has the 5th Mazda upgrade to the original ND transmission, which debuted in 2016. Any upgrade in power (turbo, supercharger) seems to aggravate the problem, as does track use and auto crossing.

 

Mazda built the ND version of the Miata using a “gram management” approach. So every single part was weighed (including lug nuts) and put on a diet. The result was a car that was 200+ pounds lighter and infinitely more fragile.