Board logo

Someone using RX8 gearbox on a 7 ?
maurof74 - 27/10/19 at 11:05 AM

Hi All,
I've read many threads about installing an RX8 gearbox, but I'd like to read some feedback from someone that has actually ran it in a seven (5/6 speed, type of engine, hp, shift feeling, problems ...) ....I'm thinking about replacing the type 9 (I know I probably need some work on the tunnel)
Thank you


big_wasa - 27/10/19 at 03:39 PM

Myke2463 has a 6spd in his. I bought a 5spd to try but couldn’t be bothered to rework the tunnel or the pedal box for hydro clutch.
This could have been heavily influenced by the Mt75 and all the other needed bits sat next to it. I will live with a crap first.

I may revisit the Rx8 box if I change the engine again next year.


CosKev3 - 27/10/19 at 04:05 PM

I'm running a 6 speed with my AJ30 V6.
Love the box.
First gear is low though,so I've had to go down to a 3.14 ratio diff to make it useable,running 195/50 15 tyres.
Does just over 70mph in second gear,93mph in third hitting the limiter at 7100rpm.
Hit the limiter on the rolling road in fifth gear at 141mph.
Over all a lovely box at a bargain price.


Ugg10 - 27/10/19 at 04:18 PM

There is a guy on facebook that does a new clutch arm for cable clutch or there are details on turbosport forum how to modify the existing arm/pivot to use a cable clutch, both place the arm in the type 9 position. You then have the choice of front cable attachment (part of adaptor plate) or add a lug to the back to use the outer of the cable.

Ratios - just use 2-6th, same ratios as a Quaife Clubman straight cut but the rx8 is helical (quieter) and has more capacity (used in Nissan 200sx s14 with 250hp/Ftlb plus 1.25ton car).


CosKev3 - 27/10/19 at 07:02 PM

quote:
Originally posted by Ugg10
There is a guy on facebook that does a new clutch arm for cable clutch or there are details on turbosport forum how to modify the existing arm/pivot to use a cable clutch, both place the arm in the type 9 position. You then have the choice of front cable attachment (part of adaptor plate) or add a lug to the back to use the outer of the cable.

Ratios - just use 2-6th, same ratios as a Quaife Clubman straight cut but the rx8 is helical (quieter) and has more capacity (used in Nissan 200sx s14 with 250hp/Ftlb plus 1.25ton car).


No chance of that cable conversion fitting a seven type cars tunnel!

The bell housing fully fills the chassis on a Type9 designed chassis.

No chance of getting a cable operated clutch in there


big_wasa - 27/10/19 at 07:05 PM

The cable clutch conversion only works on the 6 spd as well.

[Edited on 27/10/19 by big_wasa]


SPYDER - 27/10/19 at 08:38 PM

I have the Lexus IS200 variant of the Aisin AZ6 in my Toyota 3SGE engined car. I had to move the shift lever forwards five inches as my engine sits well back in the chassis. Despite it's size I managed to shoehorn it in with no tunnel mods. ( My car does have a wide tunnel.)
First gear is a little short but the remaining five are perfectly spaced for my engine, nice and close. The car has 220bhp, a 3.62 diff and 195/50-15 tyres. The top half of the standard gearlever is rubber mounted and can be removed to leave a nice short lever. I believe the RX8 lever can be similarly shortened.
In summary, I can't recommend it enough.
Do whatever needs to be done to fit one. You will never regret it.


maurof74 - 28/10/19 at 01:49 AM

Spyder, how large is the inside of the tunnel of your phoenix ?
I think I will go for the rx8 variant as the spline will match my ford engine, but I've still some dubt about 5 speed / 6sp 1st serie / 6sp 2nd serie.
In terms of ratios (with a proper diff that in any case I have to replace for other reasons) I will have 5 usable ratios (more close in the 6sp, but with a so torquey engine is not so important), so the main drivers are:
SIZE: from the pictures it seems the 5sp is smaller in some sections, but I was not able to find data, someone has some measurement or drawings ?
STRENGHT: I've read that the 5sp is more robust, then I've read that the 6sp is more robust.... I have 220 hp, maybe 280/300 in the future with probably 350+ Nm torque


fishywick - 28/10/19 at 08:22 AM

I own an RX8 and the general concensus is that the 5 speed from the 192 RX8 is the strongest followed by the 6 speed from the 231, the later 6 speed from the 231 R3 is the weakest. Although all of them are very good if the correct oil is used.

The primary killer of these boxes is oil. The first thing to go is 4th gear synchro. I have the early 6 speed and the oil should be GL4 grade, I use Motul MT90, never GL5. I'm not sure what the 5 speed boxes use or indeed the later 6 speeds.


SPYDER - 28/10/19 at 07:05 PM

quote:
Originally posted by maurof74
Spyder, how large is the inside of the tunnel of your phoenix ?


It's not in my Phoenix, it's in my Spyder Silverstone. I've got a template of the tunnel which I will measure tomorrow.
I use Castrol Syntrans GL4 oil.
Here is a pic of the RX8 box alongside a type 9. Even at the narrow end it is very wide although you can trim the widest bits down a bit.