Did a search, but couldn't find a direct answer to this question. What I've read is that:

S4 TII 5th gear is .762:1
S5 TII 5th gear is .711:1

JSpec S5 TII 5th gear isn't as tall as a USSpec 5th gear. So, what IS the gear ratio of JSpec S5 TII 5th gear? .762:1 again?

 

5th gear ratio for JSpec S4's is .806:1. So, not as tall as either US Spec 5th gears. Speculation is that .806 is the case for S5's, but still looking for confirmation. TurboTed, you out there??

 

I was always under the impression that all TII trannies (Aspec) had the same gear ratios. There was no difference between S4 and S5. I can't say the same for Jspec. But I do think the Aspec S4 and S5 TII trannies were the same.

 

0.806:1

From HyperRev magazine's list of FC specs.

 

No, s5 5th's were a bit taller then the s4's just like the NA trannies.

 

Nope, if I remember correctly, it's Zenki 0.762 and Kouki 0.719.
Side note, US-spec FD3S runs the same 0.719 5th gear as a Kouki FC3S turbo.


-Ted

 

ASpec S4 TII 5th gear is .762:1
ASpec S5 TII 5th gear is .711:1
JSpec S4 & S5 TII 5th gear is .806

Right?

 

From R&T Infini IV RX-7

5th 0.72:1
With a 4.30 ratio 5th is at 2675 cruising at 60.

 

Boy, if this ever gets on Jeopardy, I'm ready. :-)

Ok, with the exception of the limited production Infini IV RX-7 who has 5th gear at 0.72:1 complimented by a rear diff ratio of 4.30, the conclusion is:


ASpec S4 TII 5th gear is .762:1
ASpec S5 TII 5th gear is .711:1
JSpec S4 & S5 TII 5th gear is .806

Right?

 

So 5th gear will pull harder in a S4 than a S5 but run out sooner?

 

Based on the above said, this is true but for 5th gear only. Especially true if JSpec, but again 5th gear only.

 

Um, where did you get the 0.711 number?
I'm pretty sure it was 0.719, and my quick web search only turned up several references to an FD3S 5th gear of "0.72", which is probably rounded up from 0.719.


-Ted

 

by the TII master.

 

what rx7 pulls in, OR runs out of 5th gear???

well n/a's are like .66:1 bleh.

 

Nope... the .762 got dropped in 88 and replaced with the .711

Then changed again in 89 to a .719

So, it should be:

Aspec 86-87: .762:1
Aspec 88: .711:1
Aspec 89-91: .719:1

And I have only seen .806 for the Jspecs.

 

1987 ASpec S4 TII 5th gear is .762:1
1988 ASpec S4 TII 5ht dear is .711:1
All ASpec S5 TII 5th gear is .719:1
Except for Infini IV's, all JSpec (Infini 2 & 3) S4 & S5 TII 5th gear is .806
Infini IV's 5th gear is .72 (.719?):1 with a 4.30 third member ratio

Now, a simple search and the very valuable information is there for all.

Thanks to all for their help and input.

 

reviving an very old and dead tread

Based on my 1997 Competition Parts Catalog for transmission and 5th gear info.

the 0.711 was used on the 1986 non turbo in the (Smooth Case '79 to '91 RX7's gear box)

The 1987 to 1991 TII's share the same transmission as our TT's (2nd gen Rib case) but used
0.762 on 87-88 and
0.719 on 89-91

US 3rd TT's used 0.719's , JDM's used 0.762 and 0.806 depending on year and model