LS9 Clutch fitted vxr8 ls3

[neal1980]

What is the benefit compared to an ACT or Mcleod??

An ACT with the light flywheel from summit delivered to door with all taxes £983.00

Does this cost less??

Edited by neal1980 on Sunday 26th October 10:23

[ATM]

pah250 said:

For the uninitiated, does the LS9 clutch have a dual mass flywheel out of interest?

Looking at the pic above I'd guess No. It looks like a solid piece of metal to me. Another pic from Google below.

bimbleuk said:

Stock Flywheel for a 2006 GTO (24 lbs). Stock plate and disc for GTO (26 lbs). Total = 50

LS7 aluminium flywheel RAM 2552 (17 lbs). LS7 plate and disc (33 lbs). Total = 50

LS7 steel flywheel (27 lbs). LS7 plate and disc (33 lbs) Total 60

I believe my car has an LS7 fly and clutch but don't know if it's steel or alu. What I do know is it's not exactly free revving. I know the rotating parts probably add up to a fair bit of weight but surely lightening or swapping the fly is an easier proposition.

[bimbleuk]

Though it is a very effective way of reducing the rotational mass in an LS engine you probably don't want to go to far as a super light engine assembly in a relatively heavey car wouldn't be a great daily drive. Plus the crank is still ~65kg which is pretty hefty.

I went with a lighter crank pulley, flywheel and my RX7 is 1200kg so benefits greatly from the reduce rotational mass.

[ATM]

bimbleuk said:

Though it is a very effective way of reducing the rotational mass in an LS engine you probably don't want to go to far as a super light engine assembly in a relatively heavey car wouldn't be a great daily drive. Plus the crank is still ~65kg which is pretty hefty.

I went with a lighter crank pulley, flywheel and my RX7 is 1200kg so benefits greatly from the reduce rotational mass.

How much can you save with the pulley - can you change that without taking the engine out and rebalancing etc?

[stevieturbo]

neal1980 said:

What is the benefit compared to an ACT or Mcleod??

An ACT with the light flywheel from summit delivered to door with all taxes £983.00

Does this cost less??

Depends how you look at it.

Flywheel aside, it's an OEM clutch. That means OEM reliability, driveability, availability etc etc

Which really can be hard to beat if the product suits your needs.

Initial retro-fitments of the OEM twin required the bellhousing to be spaced back 1/2" ? Not sure if that has changed now ?
Not practical for all applications

ACT twin is well made, it's sturdy and it is a good price, and with more power holding and friction disc options than the OEM part.
So for the most part I'd say it would have to be comparable

bimbleuk said:

Though it is a very effective way of reducing the rotational mass in an LS engine you probably don't want to go to far as a super light engine assembly in a relatively heavey car wouldn't be a great daily drive. Plus the crank is still ~65kg which is pretty hefty.

I went with a lighter crank pulley, flywheel and my RX7 is 1200kg so benefits greatly from the reduce rotational mass.

Presumably there is an error there somewhere, crank is nowhere near 65kgs ? 20-25kgs maybe

In general given the diameter and size of the LS clutches and flywheels, almost none would ever be considered truly lightweight. They're all bloody heavy !

One thing to consider though. Larger diameter discs will clamp more, that's simply physics.
But larger diameter discs tend to be heavier due to size, they also carry more inertia with that weight too because of the diameter
That means more work for the baulk rings to do when you try and change gear.

So as far as driving goes, larger diameter is always better. However as far as changing gear goes, smaller and lighter friction discs are better.

It's up to the user which will work the best for them. The ACT's are definitely pretty large diameter, not sure what size the LS9 discs are ?

I see that Monster crowd who offer twin plates, just modify a flywheel for twins and use an OEM single disc cover, and turn it into a twin plate clutch

[bimbleuk]

stevieturbo said:

Presumably there is an error there somewhere, crank is nowhere near 65kgs ? 20-25kgs maybe

Yes I was mixing my lbs n kgs up as it was early.

As you say about the size of the friction discs. The multi plate clutches are usually also smaller to reduce the inertia so if the LS9 twin plate is also smaller that's definitely the clutch I'd consider to replace my current LS7 hybrid.

Edited by bimbleuk on Sunday 26th October 14:18

[anonymous-user]

neal1980 said:

What is the benefit compared to an ACT or Mcleod??

An ACT with the light flywheel from summit delivered to door with all taxes £983.00

Does this cost less??

Edited by neal1980 on Sunday 26th October 10:23

Cannot comment on the ACT but I had a Mcleod twin plate and hated it. It was heavy in traffic and after a while started to drag which made changing gear really difficult. The LS9 as Stevie says is OEM and therefore has OEM relaibility, it also has more travel on the slave cylinder which means the clutch plates actually disengage so you can change gear! I think this why you need the spacer on the Monaro, not sure about the VXR8. LS9 clutch holds 800hp/800lbs so you will be fine.

After market stuff is often expensive ste made by idiots, OEM is made by clever engineers.

Edited by anonymous-user on Sunday 26th October 14:31

[stevieturbo]

Hydraulic clutches by nature are self adjusting.

If you need a spacer...which will not give you any extra travel, then the clutch has not been designed correctly for your vehicle in the first place.
That isnt to say it wont work and is wrong....well, it's not right either. But it would still work if the package is designed correctly.

No idea what the LS9 is actually rated to though ?

Do the kits fit inside the standard bellhousings now without spacers or modification ?

Actual design actually looks quite light compared to others.

http://lingenfelter.com/LPEforumfiles/showthread.p...

[ATM]

stevieturbo said:

If you need a spacer...which will not give you any extra travel, then the clutch has not been designed correctly for your vehicle in the first place.

I think the point of the spacer is to compensate for the difference in thickness of the clutch and fly being used. You dont want the shaft from the box going through the clutch too much or trying to. So if you're new assembly is an inch thicker [for example] then you'll need to either shorten the shaft by an inch [good luck with that] or add a 1 inch spacer. Make sense?

[stevieturbo]

ATM said:

I think the point of the spacer is to compensate for the difference in thickness of the clutch and fly being used. You dont want the shaft from the box going through the clutch too much or trying to. So if you're new assembly is an inch thicker [for example] then you'll need to either shorten the shaft by an inch [good luck with that] or add a 1 inch spacer. Make sense?

Spacer for a different application then.

Spec clutches used to require a shim/spacer behind the slave cylinder. Likely as the clutches they were selling were modified SBF units or something.

Again, depends where the spacer is being installed. When the first fitments of the LS9 were being sold for the aftermarket, they needed a 1/2" spacer so the clutch would fit inside the bellhousing. This would then move the trans 1/2"back too...not suitable for all.

[rich24v]

1/2" spacer is a lot!, the shaft spigot doesn't engage into the bearing much more than that, or was there a
mod for that too?

The only mod required to fit my 6 bolt LS9 was to swap the oe slave hydraulic feed pipework
to the new slave cylinder, plus a little tweak to the pipe bend.

[stevieturbo]

rich24v said:

1/2" spacer is a lot!, the shaft spigot doesn't engage into the bearing much more than that, or was there a
mod for that too?

The only mod required to fit my 6 bolt LS9 was to swap the oe slave hydraulic feed pipework
to the new slave cylinder, plus a little tweak to the pipe bend.

Not honestly sure, I guess moving the spigot bearing from the internal location to the full size bearing location might cover that aspect. So maybe later cars like VXR8 have plenty of room for the clutch anyway compared to older cars ?

[monkfish1]

rich24v said:

1/2" spacer is a lot!, the shaft spigot doesn't engage into the bearing much more than that, or was there a
mod for that too?

The only mod required to fit my 6 bolt LS9 was to swap the oe slave hydraulic feed pipework
to the new slave cylinder, plus a little tweak to the pipe bend.

This ^^^^. NO spacers required.

[EssexVXR8]

Replaced my ACT with LS9 for much better drive ability, lighter pedal, smoother engagement, better disengagement, no chattering, downside is doesn't rev so quickly .

[stevieturbo]

EssexVXR8 said:

Replaced my ACT with LS9 for much better drive ability, lighter pedal, smoother engagement, better disengagement, no chattering, downside is doesn't rev so quickly .

Which ACT did you have though ?

Their organic twin which would be the equivalent has totally smooth engagement same as OEM, no chattering etc.

Pedal effort as mentioned, ACT offer 3 covers with varying levels of grip and hence pedal effort required. SO unless you needed the heavier ones, not a lot of point really in them.

[ATM]

EssexVXR8 said:

Replaced my ACT with LS9 for much better drive ability, lighter pedal, smoother engagement, better disengagement, no chattering, downside is doesn't rev so quickly .

Interesting you can notice the difference in how quickly it revs. I wander what the difference is in weight.

[MyM8V8]

wormus said:

OEM is made by clever engineers.

Edited by wormus on Sunday 26th October 14:31

What, you mean like the stock Monaro clutch and slave cylinder set up?

Edited by MyM8V8 on Monday 27th October 08:29

[MyM8V8]

EssexVXR8 said:

Replaced my ACT with LS9 for much better drive ability, lighter pedal, smoother engagement, better disengagement, no chattering, downside is doesn't rev so quickly .

I have a 1085 ft lb rated ACT with semi race set up. No chattering but pedal is a bit heavier. The throttle response is awesome with good engine braking too.

Edited by MyM8V8 on Monday 27th October 08:31

[ATM]

This bad boy only weighs 20.4lb apparently. Would something like this with a standard ls9 clutch work?

http://www.ebay.co.uk/itm/161265681396

[monkfish1]

stevieturbo said:

Which ACT did you have though ?

Their organic twin which would be the equivalent has totally smooth engagement same as OEM, no chattering etc.

Pedal effort as mentioned, ACT offer 3 covers with varying levels of grip and hence pedal effort required. SO unless you needed the heavier ones, not a lot of point really in them.

By chatter, i think he means the gearbox chatter that is very prevalent on VXR8 under high load low RPM conditions once you put a lighter flywheel / clutch in. Not take up chatter.