I'm staying in SMS( street mod steert tire, every region has some different abv. For this class for some reason?) so upgrading the clutch and fly aren't going tobeply an issue for me. The choice seems to be the exedy twin but I'm having a hard time on which one to choose, the SD or HD? And allthough this car isn't my DD I do like to go on Sunday cruz's so which out of the 2 is better suited for DD? Thanks for all the feed back guys, much appreciated!

 

the sd is more than enough for your power goals.

 

The main difference between the two clutches is the pressure plate torque rating. The HD clutch can hold another 100 FT/LBS of torque over the SD clutch.

Most vendors on here don't stock the SD anymore because there really is no pedal pressure difference and the HD holds that much more power.

Is the HD a little 'overkill' for your needs, maybe but, if it were my choice, I'd choose the Exedy Twin HD.


-Bink

 

The difference in price is only a hundred or 2, and if you're paying that much for a clutch anyways, is it safe to say that the HD is the better option for autox/DD? Can more people vouch for the SD and the HD feeling the same, pedal-wise? My power levels are around 350lbs of torque right now, but I have plans to push it to 400 in the future.

 

I can tell you one thing that should be key in deciding between clutches...will it solve high rpm lock out.
search this and you will see numerous cases of people upgrading from stock and other 6 puck or single disc upgraded clutches because none of them solve the flat-foot shifting at red line issue the way the twins do.

 

i don't think to many people flat foot shift in autocross though.... or road racing for that matter. i shifted at 8300rpm on my stock tranny with ACT HDSS and the only problem i had was the 5th and eventually 4th gear sycnros werent that great. it still went into gear though!

 

I flat foot shift sometimes in autocross, but I have Tephra's no-lift-to-shift mod. Sometimes it doesn't work if I shift too fast though. Milford, are you saying that either of these Exedy's should solve high rpm lockout?

 

After doing some research and pm'n a few of you the SD is the right choice for me. Thanks for the feed back guys

 

I too am deciding on a new clutch and would like to hear feedback on the high rpm lockout issue.

Is the Exedy twin really necessary, or can the ACT single disk units handle around 375 torque for a road racing car? Quick shifting is important, but I doubt we bang through the gears like the drag racers do.
A smooth engagement is key when on the road coarse to keep from upsetting the handling of the car at certain points on track.

Anyone else had good experience with ACT HDSS?

 

Theres a few threads around about success with the ACT XTSS and HDSS clutches. Hear plenty about lockout, but then those people dont report any. Front motormount replacement seems to be reported to help as well?

 

STU = stock clutch. It also means stock boost so no MBC.

 

^ I never said I was running in STU. I've always ran in SMS and will be also this season. So which exedy twin are you running and what do you think about it and what kind of power is your car making?

 

I LOVED my ACT sprung 6-puck, HD flywheel and streetlight flywheel. Held up great at the autoxs, no lockout issues at 7800rpm.