vette4mud

So, I'm swapping out my balancer to a 6 rib on the AC side, with a ZR1 compressor and pulley, and currently getting my jackshaft pulley machined to add the extra 2 ribs, bc I'll be running Dallas performance direct drive.

My question is, what is everyone's running as a AC tensioner for 6 rib? I've heard the C5 bracket is an upgrade, more wrap but will it support a 6 rib?

5 Liter Eater

C5 bracket is definitely an upgrade due to the extra tensioner/idler but still only 4 rib. I suppose you could put six rib pulleys on it if the extra ribs on the crank pulley go towards the front. But I'm not sure if either C5 or C6 bracket will work with the ZR1 compressor or not.

vette4mud

What kind of bracket system does a ZR1 have?

DOUG @ ECS

It has the std C6 system, just swap out the idlers on the C5 bracket system. That's what we have done in the past.

vette4mud

Thanks Doug, any particular idlers y'all use?

DOUG @ ECS

We made our own for the couple we did here, sorry they are not a production item, but being flat side idlers any will do really.

speedz06

Hey just in case the situation arises, why a ZR1 compressor and pulley? Any lit I could find wld be great. Thnx

irok

because ZR1 comes with 6 rib pulley and belt versus 4 rib pulley and belt on other C6's

tuboy19

You don't need to buy the whole compressor... You can buy just the clutch assembly, it's about $120.

schpenxel

Whole compressor is ~$250 on Amazon. Might as well just replace it all while you're at it IMO

gotjuice?

I just replace the a/c pulley assy. not the complete compressor. I replaced both the idler and tensioner pulley on the C5 bracket with some smooth ones that I had laying around. I also replaced the other idler, by the jackshaft with a better pulley. I used the largest pulleys that would fit to give more belt wrap.

vette4mud

you wouldn't happen to know which pulleys you used, do you? i know the ac idler pulleys are 2.5 diameter, 6 rib is around 1" but I dont know where to get them.

barum

Apologies for digging up an old thread, but is this the correct part number for the ZR1 6-rib clutch assembly: #89019075?

Compressors seem to be out of stock everywhere.

schpenxel

Summit shows that as a 4 rib version, no idea if it's accurate or not.

barum

Yeah, they do, but then again all major GM part stores list it as a part for ZR1.

tuboy19

That is the correct part number.

barum

I suppose everyone (at least all I've seen on the forums) has been using IW 8..10 rib damper by machining two extra grooves in the accessory drive/pulley?

I'd be more inclined to ATI 10 rib due to more simple structure and ability to rebuild it w/o having to ship it to the manufacturer, but it comes with only 4 rib accessory drive. It has been anodized black, so it may require grinding the hard layer off before machining additional grooves.

Just wondering why IW and ATI don't make them 6 rib compatible in the first place.

Edit: IW does make 10% OD 10 rib + 6 rib accessory combination, part number 856.

barum

Regarding the aftermarket dampers made for LS9, would they fit to LS7?

- Both are dry sump engines => long snout cranks
- Same aftermarket cranks (like Dragonslayer) fit in both
- LS9 oil pump fits to LS7
- LS9 a/c compressor is a direct fit to LS7
=> accessory drive is in the same location in both, but is there a difference in the location of that 11 rib drive?