I have been searching and have not come up with anything I was looking for. Well I have 410 hp with my FC and was wondering how much can my diff support? I hear it wineing alot making noise every now and then. I figured that making this much power it would hold up but not sure. Im scared to take it to the track because I will probably **** a diff or axels, I have spares but I would like to know if Im at my limit and what do I do if I want more power what are my options I have seen people go to Ford 9" and the ford cobra IRS but I like the way the clutch diff feels any imput would be appreciated

Thanks
Tony

 

Somewhere around 300hp.

 

any proof of that or references?

 

We need references now?

 

There are many people that have run over 400 hp on the stock TII diff. I thought the generally accepted number needing an upgrade was 500 hp. If you put aftermarket internals in there you should be good for much higher numbers.

There is one guy on here pushing 769 hp on the TII diff with the mazdaspeed 4.30 gearset (which is probably just infini ring and pinion). He is snapping axles, but the diff is taking it. How long will it take it; who knows?

If you hear it whining a lot, your's needs rebuilt. Usually that noise is from a worn ring and pinion.

Josh

 

you dont need references but 300 sounds like bs to me. I have a feeling its more like 400-500. of course it matters what type, i see that you have the clutch type which makes your car a s4. S4 Diffs are known to eat **** @ 30-50k. just rebuild it or use it as an excuse to get a better diff.

 

I have 2 TII diff how do I tell when if its a clutch or viscus type also the whining noise, could that be the diff low on fluid?

also does the stock clutch diff hold more power or does the viscus? and if I blow the clutch diff will it just slip or explode like viscus?

 

The S5 viscous will have different length stub axles, whereas the S4 clutch type has equal length.

 

What?


To the OP, replace your diff with a used one. It will be fine.

 

wtf? 30k, my stock s4 diff had 130k when i got it, ive put another 10k on it though diff motors and setups, thing works still

 

You do realize that the T2 diff (s4 one) is considered an upgrade for FD's who are drag racing? Look in the drag racing and single turbo forums. The T2 diff can consistently run 10's, just upgrade the diff mount and maybe run a pinion snubber. Look at the drag racing forum. Search for J-rat's threads in the time slips section. He is running 10's with 490rwhp and torque in I think the high 300's/low 400's.

500+ I'd say, on a rotary anyway, because you don't have enough torque to rip it apart like on a v8.

 

On street tires, they will hold quite a lot of power. Even the NA diff will.

You start breaking things when you get into slicks. After about 400 to the wheels, launching on sticky tires starts to get into the realm of unreliability.

 

Aarons right i have a NA diff and i have 340 at the wheels. but ive been meaning to buy a new ring and pinon from the 4.10 to a 3.9 and a softer meatal to so it can handle more power.

 

We have numerous 500+ & 600+ RWHP customers running the S4 TII diff internals in their FD's. Many of them drag race regularly, no problems.