What is the torque capacity of the stock clutch assy

[babydriver]

What is the torque capacity of the stock FR-S clutch assembly? I have looked in the online FR-S repair manual but can't find the specification anywhere.

Does the BRZ manual have this listed?

Thanks!

[CSG Mike]

It's not specified, but we generally see it start to slip around the 230wtq mark, with a driver that has clean technique. If you're technique isn't perfect, it may be much lower.

As a rule of thumb, If you're FI + E85, you will eventually need a clutch.

[babydriver]

Originally Posted by CSG Mike

It's not specified, but we generally see it start to slip around the 230wtq mark, with a driver that has clean technique. If you're technique isn't perfect, it may be much lower.

As a rule of thumb, If you're FI + E85, you will eventually need a clutch.

Actually, I'm just NA E85 with CAI and a tune, but I'm noticing some moderate slip when shifting from 2-3 and 3-4 at 7500, dropping to about 5000. That has just showed up and it doesn't slip under any other circumstances. My technique is pretty good, so I am reading this as an early warning.

Thanks for the reply!

[CSG Mike]

Originally Posted by babydriver

Actually, I'm just NA E85 with CAI and a tune, but I'm noticing some moderate slip when shifting from 2-3 and 3-4 at 7500, dropping to about 5000. That has just showed up and it doesn't slip under any other circumstances. My technique is pretty good, so I am reading this as an early warning.

Thanks for the reply!

Get me a datalog and I can confirm both slippage and technique.

[babydriver]

Two things:

For whatever reason, the clutch has stopped slipping immediately after the shift under WOT. Now it works perfectly... so I can't complain about a clutch that is doing what it is supposed to do.

Second, I took your suggestion and did some datalogs using the OFT. They reflected the situation I described, no clutch slippage for now. I don't believe that I imagined the slipping but maybe it was due to something like light glazing of the friction disc, which wore off after a day or two? If the problem reappears at least now I know how to evaluate it. So thank you for that.

[babydriver]

Update: I drove to work this morning with the air temperature at 40 F. Going on to the freeway, I was able to do a WOT through 2nd and 3rd gears, peaking at redline (7500 rpm) from a rolling start in 1st gear. I did not notice any slip between 1st and 2nd but then it did slip briefly between 2nd and 3rd. So far, I have been unsuccessful in getting it to slip while the datalogging was going on.


I neglected to mention that I have an HKS snorkel AND a TRD CAI, so according to the OFT device the air comes into the intake is just barely above (or at) the ambient air temp. Also I have added a Cusco rear differential brace, which improves the transfer of torque from the drivetrain to the wheels by greatly reducing the twist in the differential when power is applied suddenly. I also noticed that both times the slip has occurred, it was in the early morning on a day that was cool (less than 45 degrees). This suggests to me that the bump in power and torque is just enough to cause the disc to slip a little. Still, it doesn't seem that it should be slipping at all, given that the motor is NA.



Given the torque spec you mentioned, it doesn't seem to me that the friction plate should be slipping in any gear, even with some extra power from the air intake, the E-85 and the tune. I am also confused by the fact that it seems to be slipping between 2nd and 3rd and has slipped between 3rd and 4th. It has never slipped between 1st and 2nd, nor between 4th and 5th. I would think that the slip would be most severe between 1st and 2nd? Or is it related to the difference in the gear ratios from gear to gear, with those later gear changes being "taller" than the 1st to 2nd change?


Any thoughts or insights are appreciated!

[CSG Mike]

Originally Posted by babydriver

Update: I drove to work this morning with the air temperature at 40 F. Going on to the freeway, I was able to do a WOT through 2nd and 3rd gears, peaking at redline (7500 rpm) from a rolling start in 1st gear. I did not notice any slip between 1st and 2nd but then it did slip briefly between 2nd and 3rd. So far, I have been unsuccessful in getting it to slip while the datalogging was going on.


I neglected to mention that I have an HKS snorkel AND a TRD CAI, so according to the OFT device the air comes into the intake is just barely above (or at) the ambient air temp. Also I have added a Cusco rear differential brace, which improves the transfer of torque from the drivetrain to the wheels by greatly reducing the twist in the differential when power is applied suddenly. I also noticed that both times the slip has occurred, it was in the early morning on a day that was cool (less than 45 degrees). This suggests to me that the bump in power and torque is just enough to cause the disc to slip a little. Still, it doesn't seem that it should be slipping at all, given that the motor is NA.



Given the torque spec you mentioned, it doesn't seem to me that the friction plate should be slipping in any gear, even with some extra power from the air intake, the E-85 and the tune. I am also confused by the fact that it seems to be slipping between 2nd and 3rd and has slipped between 3rd and 4th. It has never slipped between 1st and 2nd, nor between 4th and 5th. I would think that the slip would be most severe between 1st and 2nd? Or is it related to the difference in the gear ratios from gear to gear, with those later gear changes being "taller" than the 1st to 2nd change?


Any thoughts or insights are appreciated!

Your clutch may be nearing the end of its life, and that brief slippage is enough to get the disk warmer. The extra heat gives it a little more friction, which is enough to hold the power.

Just speculation, but viable.

It's also possible there may be moisture/water inside the assembly, and when it slips, it drys off enough to make it not slip. If it eventually goes away, it could be moisture.

I've seen this scenario happen when an engine bay get water dumped onto it during a wash/detail and/or pressure washed.