COG back to 12-rib

Hey fellow forced induction enthusiasts, I have a few Q's.

1. I have a D1sc cog setup on my LT1 z28, and after 500 miles the crank key broke. I was going to put two full length keys in it but I'm starting to think twice because crank repairs and fluidamprs aren’t cheap. Does anyone out there have a cog setup that hasn’t failed in several thousand miles?

2. With a 12 rip setup using a SDCE bracket, can you make at least 15 psi and also not have the vibration that you get with the ati bracket?


Thanks in advance

sean
94z28 355cid, d1sc 21 psi, junk headers, M6

It appears the new thing to do is to get the ATI superdampr and get the Big Block style hub for it... It's twice as thick as the regular LT1 hub. I think TonyJ is running this, definitely seems the way to go. From what I've read, double keying shouldn't be necessary. Unless the machining is 100% accurate, all the stress will be on 1 key anyways. Do a search, this was discussed recently.

Originally posted by sean-k94z
Hey fellow forced induction enthusiasts, I have a few Q's.

1. I have a D1sc cog setup on my LT1 z28, and after 500 miles the crank key broke. I was going to put two full length keys in it but I'm starting to think twice because crank repairs and fluidamprs aren’t cheap. Does anyone out there have a cog setup that hasn’t failed in several thousand miles?

2. With a 12 rip setup using a SDCE bracket, can you make at least 15 psi and also not have the vibration that you get with the ati bracket?


Thanks in advance

sean
94z28 355cid, d1sc 21 psi, junk headers, M6


It seems to me that cog setups are pretty hard to get working properly. Alot of people spend alot of money and time and finally just give up. Is you car an everyday car or a street car? If it is a street car than get use to replacing the belt pretty often.

I honestly would go with an SD concepts spring loaded tensioner. The thing works flawless and you can make 15lbs off boost without a problem.

I like to drive it everyday, and drive it out of town, which I haven’t done since I put the cog drive on it. The first time I drove it down the street it sounded like the blower was going to explode, but it sure did make boost quick (5 PSI at 2200 rpm). I take it even a 50mm wide belt doesn’t last that long? Maybe I'll see if anyone here would be interested in my cog setup, that would help cover the cost of an sdce setup.


Thanks IDOXLR8


and Thanks TimbrSS I never had a problem with the hub breaking, but I'll check that out

Originally posted by sean-k94z
I like to drive it everyday, and drive it out of town, which I haven’t done since I put the cog drive on it. The first time I drove it down the street it sounded like the blower was going to explode, but it sure did make boost quick (5 PSI at 2200 rpm). I take it even a 50mm wide belt doesn’t last that long? Maybe I'll see if anyone here would be interested in my cog setup, that would help cover the cost of an sdce setup.


Thanks IDOXLR8


and Thanks TimbrSS I never had a problem with the hub breaking, but I'll check that out

I put made 14lbs of boost through my F1 with a 6 rib belt. This was with my SD concepts tensioner. There was no belt slippage what so ever. :)

hmmmmm.............maybe I'll take it off this weekend, and give the guys at sdce a call. I still need to send out my crank too.

Originally posted by sean-k94z
hmmmmm.............maybe I'll take it off this weekend, and give the guys at sdce a call. I still need to send out my crank too.

Why don't you install a new key yourself? :)

The snout is the problem, or else I would, I even put the balancer back on with a new key, hoping I could weld it on, but I started the engine and there was too much slop, it was wobbling :mad: So I have to take the crank out have it welded and turned, AND buy a new balancer. That why I'm looking for cog alternatives. I reallllllllllly don’t want to have to do this again soon. I'm not too bummed because I got 20K miles out of it so far, and I would like to see what condition the internal parts of the engine are in.

Mine is good so far. Definately go double keyed. If you go with the big hub from ATI, you'll never have to worry about breaking a keyway again. lol...

I'd also suggest the ATI with the underdrive dampner. It's a lot less mass hanging out there... The deal about only one key getting all the force may be true, but it should be a different key 50% of the time... Just a guess, though...