Fan Belt Length

[doug_porsche]

Just an FYI for the future me

LS1 with stock FF fanbelt pullies

autozone 630k6 which has an OD of 63.55 inches works nicely.

[beeman]

Are you running the upper FFR bracket/pulley? I believe it's prone to noise?

[doug_porsche]

Are you running the upper FFR bracket/pulley? I believe it's prone to noise?

As they say. Its important to know what you dont know. And I dont know.
Do these picts answer your questions? And if so, is it the FFR bracket/pulley?
Sorry the second one is upside down.
20240303_095946.jpg
20240303_100012.jpg

[VRaptor SpeedWorks, LLC]

A couple things:

1. The idler pulley down between the alternator and crank pulley. You need to install something to support that pulley or the tension of the belt will bend that pulley down and the belt will come off. The later Gen II kits came with a steel link to support that pulley from below to one of the alternator bolts. If you don't have that, I have a support bracket available for that.

2. Looks like you have the stock donor belt tensioner installed....although that bracket looks a bit strange in the photo....not sure if that's the FFR bracket or not? Sometimes that tensioner works ok and sometimes it allows the belt to squeal or chirp every time you rev the engine. I also offer a manual belt tensioner bracket that is more rigid and doesn't allow the flex in the bracket that can also cause the belt to squeal.

You want to make sure all of the pulleys are in alignment by using a straight-edge across the crank pulley and measuring back to the edge of the belt and shim the alternator or tensioner as required to prevent the belt from squealing or grinding itself to destruction.

[doug_porsche]

I will check. It is a gen II car F5R1000412MS, but I bought the kit used, so I use President Regans thinking.
trust but verify!

[doug_porsche]

The later Gen II kits came with a steel link to support that pulley from below to one of the alternator bolts. If you don't have that, I have a support bracket available for that.
I just checked and yes my idler pulley does have a bracket on the bottom that does go down to the alternator.

Sometimes that tensioner works ok and sometimes it allows the belt to squeal or chirp every time you rev the engine.
I am going to use this setup until, at minimum, I get a VIN number and some millage on the car.


Thanks for the info!

[Shoeless]

I like spending other people's money. Go with the CTS-V Alternator and Bracket and Shane's tensioner and you will be rock solid here. Just make sure the get the proper year (actually its split the year it came out in two versions) CTS-V alternator that either uses a constant voltage to turn on or a 127hz 5V PWM signal to turn it on.

[doug_porsche]

I like spending other people's money. Go with the CTS-V Alternator and Bracket and Shane's tensioner and you will be rock solid here. Just make sure the get the proper year (actually its split the year it came out in two versions) CTS-V alternator that either uses a constant voltage to turn on or a 127hz 5V PWM signal to turn it on.

I think that is the direction I will end up going, but....
What I have now works, doesn't squeak, and the car would look so much better with a legal VIN number.
So I am going to prioritize and put the CTS-V alt in the "Future Enhancement" column.

Do you happen to recall what year and/or part number of the CTS-V stuff?

[Shoeless]

There are a number of post over on the other site, just search for CTS-V and they will come up. You'll need to hunt down the single wire 12V turn on version PN, I've got the other.

I chose to go with the PWM version as I'm running a MoTeC M170 that can send the proper PWM 5V signal to the alternator to continuously adjust the signal to keep me charging at 14.4V at all time regardless of RPM. The nice thing in the MoTeC is I can choose this target voltage, give it a range of frequencies to operate within and it does it all for me. I'm running a Braille ML30C battery and the Braille techs told me 14.0-14.8V is the ideal charge voltage so its nice to pick dead center of that and keep a very expensive battery happy.