I'm gonna be putting some hefty power through my s5 TII drivetrain soon and I have some questions. Which is stronger s4 or s5? IIRC the s5 transmission has more ribbing on the underside and I was told it was stronger because of this. Does either series have stronger axles, diff or driveshaft or are these parts about the same in terms of strength. Which parts should I expect to snap first? I'm thinking the axles will be the first to give.

The reason I ask is because I'm thinking about getting spares parts ahead of time.

Mods are in sig. Power level will be probably around 400Hp+.

 

diff mount and u joint............

 

No idea which series parts are stronger though? I'm gonna probably get a SRmotorsports drag launch kit which includes a nice diff mount so that shouldn't be a problem.

Oh I need to correct one of my previous statements. I think the s5 transmission has more ribbing in general not the underside.

 

they are the same
just because it is s5 doesnt mean it is automatically better....

 

The S4 TII clutch style diff is definitely better than the S5 TII viscous diff.

Andrew

 

How so? I don't know much about the differences not having used either but I read the viscous diff. lasts considerably longer. JuiceH, although this may or may not be correct, you'd hope that if one were to be stronger than the other it'd be the S5 drivetrain due to the power increase, but they may not have changed them at all.

 

Well I just looked up some info on the 2 types of diffs and it sounds like the viscous type are not too great for high hp applications. Heres a link. After reading this I think I may be lookin to buy a KAAZ LSD.
http://www.splparts.com/Parts/S14/Dr...ff/default.asp

MazterDizazter, yeah you would think that s5 would be better. However, mazda made some cost cutting changes to the s5s and not everything on them is better. Some parts are in fact inferior. I dunno about the drivetrain. Would a viscous lsd be cheaper than a clutch type? If so it would fit into the cost cutting mazda did.

 

Anyone else care to chime in? I'm sure there are a few other high HP FCs out there that have broken drivetrain parts...

 

viscous lasts longer but I seem to remember them performing worse than clutch pack style lsds.

 

For drag type applications, go with the s4 clutch type first, the s6 torsen second, and the s5 viscous last...

For autocross/road racing, go with the s6 first, s4 second, and s5 last.

Viscous diffs do wear out and are not serviceable. They are a sealed unit. They do not have the locking force of the clutch type and are inferior. Any viscous with more than 70~80K miles on it is probably done unless it was used to drive Miss Daisy.

*Edit: When I say "done", I mean outside of factory spec. Again, they cannot be serviced, so once they are out of spec, the only way to return them to spec is to replace them. It might still work... Just not at the degree it originally did. Hence the myth that they last longer.