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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
I have spent half a day with the Search function to avoid cluttering this forum with redundant threads - but couldn’t quite find the answer to my question, which is:
Would it be necessary to lift the supercharger to replace the isolator / coupler for an LS9 crate engine on an engine stand, not in the engine bay of a C6 car?
I have stepped into a 1973 Trans Am with a GMPP Crate LS9. My understanding is that the shop installed the engine right out of the crate with no modifications. I’d really like to address the isolator before I put too many miles on the car. Needless to say, the engine bay of the 2nd Gen F-body is considerably roomier than the C6. If working on the engine sitting on an engine stand would allow for the coupler swap without lifting the supercharger, that would tell me that it is the structural architecture of the C6 Engine Bay that makes lifting the SC necessary for coupler swap in the car - and it ‘might’ be possible to do without lifting the SC in a different engine bay. However, if the need to lift the supercharger to get to the coupler is due the the structural architecture of the block / intake / and SC, then it really doesn’t matter if the engine is on a stand, in a C6 or in a 2nd Gen F-body. Just trying to figure out what my options will (or will not) be with this project.
Also, how many street miles could one reasonably put on a brand new box-stock LS9 before significant damage to the SC shaft from the stock spring loaded isolator occurs? (Wondering if I can enjoy the car for the first year of ownership - maybe 3-5k miles - before committing to swapping the isolator.)
I replaced mine at 19K with a ZZ performance solid isolator coupler. It had a small groove on the shaft due to the OEM one.
I believe you don't need to remove the supercharger.
I removed mine because I wanted to change the fluid.
The drain plug is at the back top of the supercharger (crazy).
I would recommend changing the isolator coupler sooner than later.
I have spent half a day with the Search function to avoid cluttering this forum with redundant threads - but couldn’t quite find the answer to my question, which is:
Would it be necessary to lift the supercharger to replace the isolator / coupler for an LS9 crate engine on an engine stand, not in the engine bay of a C6 car?
I have stepped into a 1973 Trans Am with a GMPP Crate LS9. My understanding is that the shop installed the engine right out of the crate with no modifications. I’d really like to address the isolator before I put too many miles on the car. Needless to say, the engine bay of the 2nd Gen F-body is considerably roomier than the C6. If working on the engine sitting on an engine stand would allow for the coupler swap without lifting the supercharger, that would tell me that it is the structural architecture of the C6 Engine Bay that makes lifting the SC necessary for coupler swap in the car - and it ‘might’ be possible to do without lifting the SC in a different engine bay. However, if the lifting if the supercharger to get to the coupler is due the the structural architecture of the block / intake / and SC, then it really doesn’t matter if the engine is on a stand, in a C6 or in a 2nd Gen F-body. Just trying to figure out what my options will (or will not) be with this project.
Also, how many street miles could one reasonably put on a brand new box-stock LS9 before significant damage to the SC shaft from the stock spring loaded isolator occurs? (Wondering if I can enjoy the car for the first year of ownership - maybe 3-5k miles - before committing to swapping the isolator.)
Thank you all.
When I did mine in the car I had a good look at what would have been in the way if I tried to replace it without removing the supercharger. I believe you can do this but you will have to remove the water pump to get at the bottom bolts and the belt tensioner and maybe the supercharger lid because the manifold might be in the way.
This is what mine looked like after 24000 miles. It started getting noticeably noisey at about 18,000 miles.
That explanation helps quite a bit - this is my first LS equipped vehicle, so I am not familiar with the physical architecture of the front of the block and accessories. With the water pump and tensioner blocking the lower snout bolts, it makes complete sense that lifting the supercharger becomes the path of lesser resistance to get to those bolts.
As a weekender, I see myself putting under 5k fair weather miles a year on this car. It is scheduled for completion in June, so I’m betting I can enjoy it this summer and fall and look at scheduling the coupler swap either late this fall or early next spring.
Thank you very much for your post, explanation and pics!
That explanation helps quite a bit - this is my first KS equipped vehicle, so I am not familiar with the physical architecture of the front of the block and accessories. With the water pump and tensioner blocking the lower snout bolts, it makes complete sense that lifting the supercharger becomes the path of lesser resistance to get to those bolts.
As a weekender, I see myself putting under 5k fair weather miles a year on this car. It is scheduled for completion in June, so I’m betting I can enjoy it this summer and fall and look at scheduling the coupler swap either late this fall or early next spring.
Thank you very much for your post, explanation and pics!
You're welcome. There are many threads on this. According to a GM source (don't have the link on this site) this GM coupler will not cause an issue if left alone and will not allow debris into the air flow. They can get pretty noisy, sounds like marbles swirling in a tin can. I installed the Eaton (Manufacturer of the blower) replacement coupler from Lingenfelter engineering and she's quiet now. Didn't realize how noisy it was until I replaced it.
When you pull the cover watch for the little rubber retainer washers on the bolts. They're there to hold the bolts up for production. You don't really need them but they're easy to drop into the engine. Pulling the blower off isn't a big deal but to make sure you get the proper torque when re-installing the bolts. You need to clean the bolts and clean the threads in the cylinder heads. The factory uses a blue thread locker. The gasket is reusable but get some help to lift the blower off if you're doing it on the car, it's heavy.
04-09-2021, 09:31 AM
Coupler Replacement
