Installed ACT SB7-HDSS
 

I recently installed the ACT SB7-HDSS due to my OEM clutch slipping at higher gears. The issue with the new clutch is, I'm getting a stutter/issue when taking off from a dead stop. I have to rev it up from 850RPM to about 1200 for the clutch to engage/grab. But when it does, it feels like the car wants to stutter/buck/feel like it's dragging. It's making take off a bit challenging to be smooth

Is it that the idle RPM is low? Once I get going, it shifts perfectly fine. But taking off from dead stop is the issue.

I'm running JRSC and e85.

I have put 600 miles (city driving) on it and figured the issue would go away after breaking it in.

Usually takes 2-3k miles to break in clutch. I have the same model and it has similar behavior, more so when warmed up and only noticeable when moving from stop. Add gas and don't ride the clutch. My car is rarely driven on street, primarily tracked, so it doesn't bother me.

Yep, it's happens mostly when warmed up. Its not my DD but I'm looking to get it corrected haha.

After I'm in 2nd, it shifts smoothly. But the hesitation/strange feeling I'm getting is only when accelerating from a dead stop. Hopefully it's nothing major. I don't want to drop the trans trans then REPUMP oil in both the diff and trans lol

Lighter weight flywheel plus drive by wire.

Is this a normal thing? How can I finx/adjust the issue?

Was the flywheel re-surfaced? This could cause the "stutter/buck/feel".

The flywheel was brand new. Everything was replaced with the SCT parts. Came as a kit rather than just the disk.

The combination of boost, lighter flywheel, and drive by wire always has a small lag at first startup generally from stop in 1st gear. Sometimes a similar feeling is experienced during downshift rev-matching. The FA20 is not the most responsive system as well. Try slowing down all your actions and make them a bit more exaggerated in the beginning so you can feel out your car. Our CSG BRZ has the SB8-XTSS Prolite XTSS clutch kit on a high boost C30 setup. We can drive it in heavy traffic with minimal slip and chugging when most have issues even engaging that clutch without stalling. It's all in your actions and practice. :)

I have this clutch - it's easier to manage once broken in, but definitely doesnt feel like stock. Like the poster above said, practice and make your movements very deliberate. You'll get used to it.

I am about install this exact clutch along with an EBSC. Is this just normal adjustments that come with a new clutch, or is the stutter quite exaggerated.

CSGMike didnt mention much to me on this when we discussed this clutch, and i imagine he would have made note of it to me if it was going to be, a more than reasonable change. Just asking for my own expectations.

I have ran a clutchmaster 400X on a boosted BRZ. I have ran a exedy Twin disc setup on a highly modified Evo X and driven a few other similar setups. Since the SB7-HDSS is not a drastic(track) clutch, I assume the issues the OP is having would come across as normal to someone with previous clutch upgrades.

But let me know your thoughts.

I've had a few different aftermarket clutches on other cars and haven't had an issue. This one seems to be a little different. There isn't much "chatter" like others have mentioned, it seems to be the grabbing point along with the take off.

Nonetheless, once I'm in 2nd, it's smooth as can be. I guess changing the position or engagement of the clutch threw me off. I have a long drive this weekend coming up. So maybe after a few hundred miles more, it will be better!

Break it in properly. I drove several BRZ/FR-S at 86CUP with the SB7-HDSS & SB8-HDSS. It may seem rougher, but the reality is, you are essentially decreasing flywheel mass and increasing clamping force. It will definitely feel more responsive in that sense and adjustments need to be made on the driver's part. It'll feel great @brzaapi. :)

OP - understand for sure. Its hard to gauge someones point of reference.

CSGdavid - I have complete faith in you all. Everytime i go against Mike's advice i realized i made a mistake. But with no car yet to install my parts, i have nothing better to do than ask hypothetical questions.

Thanks.

Your BRZ will be excellent. :thumbup:

Nice S2000 pic. Makes me want to drive mine again too, but with RC1s and 3" of standing water in heavy rain, I'll hold off a bit.