think we have it figured out, I just wasn’t going to be out at the shop to check mine until the morning.

edit: sticker in place, but ink lettering gone
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Very interested in experimenting with this idea. Vehicle runs s2 6 port, s2 trans, lwfw/oe clutch, 5.12 R&P on 255/35/18. I conclude that 1st and 6th gear are completely useless track or street and is not a very good combo imo.

Quick thought would be to source a jdm 5spd and pair it with the 5.3. I imagine 1st will probably still be useless except for stop signs and red lights on the street.

Constructive thoughts and comments are very welcome. If anyone has or knows where to source a used jdm 5 speed, feel free to contact me or forward the information.

 

if you're looking for max acceleration, the 6 speed is still faster since 5th is 1.0 ratio vs 0.806 on the 5 speed. if you not trying to be competitive with lap times, then it doesn't matter.

 

idk, with a 5.3 r&p it might be pretty good, let me look at that and get back to you. Motorsports told me many years ago a lot of the RX8 track racers were using it instead of the 6 spd for reliability

 

my friend is building his rx8 for endurance racing (9 hour race each day), and will be using the 5 speed with 5.1 diff. that setup will suit him well for reliability and less shifting throughout the race.

 

so it takes a hit on the 1-2 & 2-3 shift dropping below the APV actuation point, but likely overcome that accelerating hard

otherwise on a track not dropping below 70 mph it should be fine for 3rd, 4th and 5th, but could depend on corner speeds

you could argue going to a steeper r&p for track

this is based on 25” OD tire diameter

*******************************
Final Gear Ratio : 5.30
Tire Size : 25.0” OD
Max Power RPM : 8300
Limit RPM : 9000
*******************************

*********************
Gear Ratio Compound
*********************
1 3.483 18.460
2 2.015 10.680
3 1.391 7.372
4 1.000 5.300
5 0.806 4.272

***************************************
Gear MPH/1000 MPH @8300 MPH @9000
***************************************
1 4.03 33 36
2 6.97 58 63
3 10.09 84 91
4 14.04 117 126
5 17.42 145 157

**********************************



Gear Change RPM drop (change @8300) RPM drop (change @9000)
************************************************** ***********
1->2 -3498 (To 4802) -3793 (To 5207)
2->3 -2570 (To 5730) -2787 (To 6213)
3->4 -2333 (To 5967) -2530 (To 6470)
4->5 -1610 (To 6690) -1746 (To 7254)
************************************************** ***********

 

I've daily driven my 5 speed quite a bit now paired to the S1 4.44 diff. The rpm drops are not as drastic in the 5speed especially in the lower end 1st/2nd. However it does seem to not pull as hard with the longer gears across the board which may be due to still being paired with the 4.44 diff. 1st would still be only used from stop. My 5speed doesn't downshift to 1st until the car is under ~8mph, going to rebuild it at some point.

I imagine pairing with a S2 diff or 5.X would work wonders.

 

here it is with the 5.80 r&p, looks pretty good to me, the diff will be spinning though, better have a good cooler setup for it


*******************************
Final Gear Ratio : 5.8
Tire Size : --
Max Power RPM : 8300
Limit RPM : 9000
*******************************

*********************
Gear Ratio Compound
*********************
1 3.483 20.201
2 2.015 11.687
3 1.391 8.068
4 1.000 5.800
5 0.806 4.675

***************************************
Gear MPH/1000 MPH @8300 MPH @9000
***************************************
1 3.68 31 33
2 6.37 53 57
3 9.22 77 83
4 12.83 106 115
5 15.92 132 143

************************************************** *****
MPH RPM (in Gears)
************************************************** *****




************************************************** *****

Gear Change RPM drop (change @8300) RPM drop (change @9000)
************************************************** ***********
1->2 -3498 (To 4802) -3793 (To 5207)
2->3 -2570 (To 5730) -2787 (To 6213)
3->4 -2333 (To 5967) -2530 (To 6470)
4->5 -1610 (To 6690) -1746 (To 7254)
************************************************** ***********

 

the 2-3 shift and 5-6 shift on the S2 are pretty fubar, pretty sure you can get the MX5 1.65 3rd gear to fix that, but not sure about the 6th gear, might know a shop that can offer it though

.

 

Greatly appreciate all the input so far guys and special thanks to Team for compiling / sharing his charts.

The jdm 5spd paired with 5.8 r&p looks very promising imo and I'm also very interested in the Mx-5 3rd gear swap for s2 6spd. Sourced from the 10th AE correct?

I'm interested in the shop you mention as well for the service.

 

the clutch is smaller on the 5-spd, never noticed that before until reviewing this again

6-spd: 236mm OD x 165mm ID
5-spd: 225mm OD x 155mm ID

 

​​​​​This guy has a 5.8 final drive on 6spd. He's added a 5.5 clutch in his last videos. You can get an idea of the 5.8 final drive.

 

well don’t be like him and keep over-revving past 9k like that if you want the engine performance to last longer

 

I should have added that Team.
it should be clear by now, but ppl still doing the same ol revving 'till 10k rpm youtube.
Please don't do that to your motor.
Take care.