400 plus hp c5
Pro
Joined: Apr 2005
Posts: 749
Likes: 2
From: West Yarmouth MA.
Not sure whether its worth it for what they cost but the underdriven pulley is like changing gears on your bike for easier peddling so to speak. It frees up a little horsepower by slowing down your accessories. 8-10 hp I believe. Every little bit counts.
Le Mans Master
Joined: May 2008
Posts: 5,892
Likes: 47
From: Helotes TEXAS
Uhhh..... nope, not gonna do it !
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
Any time I could find horsepower for only $22 per, along with longer accessory life and zero driveability issues, I would jump all over it.
The only cheaper horsepower out there is the air intake, after that it gets closer to $50 per for cam, heads, headers, tuning, etc, etc.
DG
The only cheaper horsepower out there is the air intake, after that it gets closer to $50 per for cam, heads, headers, tuning, etc, etc.
DG
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
IF it does really give your 8 HP, well worth the cost. I'd bet closer to 4-5. However, the stock pulley has been known to be unreliable, so that's another reason to upgrade when you're already doing a cam. I got a Powerbond on a group buy for $140, so shop around.
Le Mans Master
Joined: May 2008
Posts: 5,892
Likes: 47
From: Helotes TEXAS
Le Mans Master
Joined: May 2008
Posts: 5,892
Likes: 47
From: Helotes TEXAS
That's a little risky for my taste. I'd prefer to be safe than sorry. Wouldn't want to end up stranded somewhere. I can find a better use for that money. 
But hey, to each his own, right.
But hey, to each his own, right.
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Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
Safety Car
Joined: Oct 2000
Posts: 4,949
Likes: 10
From: Monticello MN
Melting Slicks
Joined: May 2006
Posts: 2,303
Likes: 40
From: Edmonton Alberta
Comp Cams LS1-GT2-3 is a good choice for streetable power.
Duration @ .050 207/220
Valve Lift .571/.578
Rocker Arm 1.7 ratio
Centerline 118.5
As for the underdrive pulley debate:
If your going to rip down the entire engine for cam, heads, intake, it is definitely worthwhile. GM's own crankshaft pulley isn't that great anyway.
There is enough extra capacity built in to the C5 Corvette for charging. Most issues are battery related for the 1997 to 1994 models. You can also get a smaller pulley for your altenator if your worried about not keeping up - it's never been a problem with my setup.
Duration @ .050 207/220
Valve Lift .571/.578
Rocker Arm 1.7 ratio
Centerline 118.5
As for the underdrive pulley debate:
If your going to rip down the entire engine for cam, heads, intake, it is definitely worthwhile. GM's own crankshaft pulley isn't that great anyway.
There is enough extra capacity built in to the C5 Corvette for charging. Most issues are battery related for the 1997 to 1994 models. You can also get a smaller pulley for your altenator if your worried about not keeping up - it's never been a problem with my setup.
Race Director
Joined: Sep 2005
Posts: 11,060
Likes: 291
From: Pasco WA
Drifting
Joined: Apr 2004
Posts: 1,530
Likes: 250
From: CT
Replacing the pulley with a 15-20 precent underdrive is pretty much standard procedure for a head/cam install, since you're in there anyway . Full alternator output with a 20% underdrive is at about 850 rpm idle speed. With even a medium size cam, idle will be 850-950 with a good tune. So battery charging is not an issue for most cases.
Burning Brakes
Joined: Jun 2007
Posts: 1,047
Likes: 69
From: Hanover MA.
need a proven recipe to make 400 hp to the wheels, without going to radical,without a stall, i have 01 c5 auto ,tpis long tubes, corsa catback, mti cold air, mti computer upgrade ,01 ls6 cam,springs, dyno 340 hp to wheels,12.5 in the quarter, pitifull 60 ft time in the 2,s , just purchase stock ls2 243 heads, I don"t want to spend much money on port work,whats a good cam thats streetable? thanks jim.
