I have looked on the forums and did not find any solid information. My buddy wants to use S4 Tii low compression rotors in his build and wants to know what needs to be done to use these rotors if anything.

Thanks,

 

Really just needs to use the whole rotating assembly - rotors along with the front and rear counterweights. You would probably want to get a rear counterweight that works with an '87-88 TII and use a light flywheel.

I'd get some more opinions and do some more research as well, this is not something I've personally done.

Dale

 

The s4 T2 stock flywheel has the rear counterweight built in.

 

It does, but it's WAY heavy, heavier than the FD flywheel if memory serves. I'd go for a light flywheel if I was doing this build.

Dale

 

The stock flywheel is 28lbs for the s4 T2, according to RacingBeat. If you need a separate counterweight you can use the counterweight from the automatic models (all USDM automatic FC models were non turbo). I'm not sure what flywheels the auto counterweight works with.

 

ask Banzai Racing i believe they built a few fd motors with t2 rotors to run higher boost

 

As usual Dale has the right info. You can use the stock S4 TII flywheel but it is a heavy one.

 

Just get an S4 N/A auto counterweight and bolt on any aftermarket TII/FD flywheel. To install the OEM S4 TII flywheel, you need to grind down the inspection plate area on the rear iron to allow the built-in CW to rotate without interference.

Bigger problem is the front CW. The thrust bearings and spacers are smaller on the FC. To use the FC CW all these parts need replacement as well. There are a couple of ways to do this. Change the entire stationary gear with all the associated bearings, spacers and plates or take your chances installing the smaller parts in the FD stationary gear, that is setup for the larger diameter thrust bearings/washer/spacer.

Hope that helps to clear up the confusion in this thread.

 

Just to add some info to this thread...

Here are some pictures of what needs to be done to run the stock S4 flywheel with an S6 rear iron.

Another tidbit is that with my particular S4 front counterweight, the center bore measured out to 1.178", whereas the center bore of the S6/FD counterweight measures to 1.182". Therefore, my S4 counterweight did not fit on my S6 E-shaft. So...I had to enlarge the bore. I don't know if all S4 E-shafts have a different nose diameter or if they changed to 1.182 part-way through the run or what...but that's what I encountered.

-James

 

all e-shaft bore sizes are the same, yours had just shrunk somehow. possibly from someone bead blasting it or corrosion buildup on the face. wouldn't be the first time i've seen a front CW that was very tight on the shaft which could just be a minor fault in the machining process of the CW.