I looked around and found nothing about this. So I jumped on the job myself.

I went in to change the SC couplet. While I have it apart, I'm going to change the upper pulley as well. Reading over a bunch of old post, I find many that say you have to unbolt the SC to get the snout off. And to unbolt the SC, you have to remove the lid. Most were saying that you had to unbolt the SC to raise it up, so you can get to one of the bolts. When looking over my car (14' ZL1), I could get to all of the bolts, and I got them removed. However, it was not that easy. You do have to unbolt the SC because there is a nipple sticking out under the snout, that the snout can not clear. The SC has to be raised to clear it. I can tell you for a fact the struggle is real getting the back four bolts out of the lid. Other than those four bolts, removal is fairly easy and straight forward.

In the attached pic, the lid and the SC are just sitting there. Not bolted down.

 

please update us on how pulley change went- machine shop to press off and on? and coupler?

 

My car has 21K on the clock and the shaft was well beat up. But's kinda what I was expecting. Not knowing whats going on, that was the first thing the guy at the machine shop noticed.

Seeing as how there is a machine shop at my job, I could have did the work myself. All that's needed is a pulley puller to remove the pulley and a hydraulic press to install the hub. However, $30 is well worth it to let somebody else foot the bill should something go wrong.

The machine shop guy said it took allot of pressure to get the old one off. I can tell it was allot because of the indention in the front of the shaft. There are marks on the old pulley, but it's not destroyed. It can be used, if "in a pinch". I'll never use it again. He said it was like .008 of interference (don't quote me on that) on the between the hub and shaft. The hub is pressed on and ready to go. I went with Lingenfelter (Summit pulley: $102, Hub: $65). I'm going with the 2.55 pulley. The snout did not have to be machined. The coupling comes in tomorrow. I'll be putting it back together then.

 

I kind of figured it'd be tightly fit what if it were to slip, I mean its what drives and really spin that blower gotta be running 3-4-5? times crank speed, thanks for info

 

The install took about 3 hours and 4 beers. I lost a 10mm socket and a 10mm combo wrench that I'm hoping to find during the oil change. As expected, the back six bolts on the lid took the longest. Other than that, it was all pretty much straight forward. Attached is a pic of the removed parts. With the 2.55 pulley, the snout did not have to be machined. Using a 100mm idler pulley, I did not have to change the belt.

Off to the tuner we go!

 

Update: I found the wrench. The socket is still MIA.

I'll report back with dyno numbers after tuning next week.

 

The car made 568hp after being tuned by SS LSX in NC. Dynoed at 500hp beforehand The injectors are maxed out, so I had them turn the rev-limiter back to 5.5K until I get a new set of injectors, then we'll turn it up again.



The last pull after some cool down time.