Single serpentine setup?

[Cali]

I have some fitment issues, and I also like to have everything as "clean" as possible. So while I'm making some custom brackets, is there any real reason to run a seperate belt for the supercharger? I can understand having a stand-alone kit that doesn't need to vary for different applications, and possibly the increased belt tension on a blower may reduce the lifespan of other accessorys- but is there any other, serious reasons to not use a single belt?

[Michael]

I think the main reason why people run multiple belts is if they experience extreme belt slip with a serpentine system.

Generally, when people experience belt slip they step up to belts that have more ribs (ie. go from 6 rib to 8 rib) in order to get more contact area on the blower pulley. However, if the belt slip continues, it's not unheard of for some to run a separate cogged belt. That way, they can continue to run a serpentine belt for all the other systems on the engine, while running a dedicated cogged belt for the supercharger itself. Of course, this typically requires a lot of custom fabrication work.

[Cali]

At what point does slippage really become an issue? My build is far from a high-revving setup, I expect to peak around 5,000-ish. She's also no longer a DD, and will be registered as a classic next time the tags come up (yay!! no more smog) wich requires her to turn over less than 2,500 miles a year (let's not get into the ease of a cluster swap- I'm sure we're all legit here) so I'm just curious if the single belt setup would be kosher in my application.

[Michael]

Engine RPM will have very little to do with belt slip. The biggest culprits to belt slip are:

a) too little belt wrap around the blower pulley, and

b) very high boost output

Chances are, if you've installed the supercharger using brackets/hardware that were designed for your specific application, then there should be enough belt wrap to ensure no belt slippage. If however, you've designed the brackets/hardware yourself, then your personal experience/research with respect to superchargers will dictate whether you've provided enough belt wrap.

The issue of producing "very high boost" will probably not be a factor either. The most boost I've ever heard produced by an SN is about 8psi. As a comparison, modern centrifugal kits from other manufacturers (like Vortech or ProCharger) which produce upwards of 10psi-12psi use 6-rib and 8-rib single serpentine belt systems. So if their higher boost systems work fine with a single belt, your lower boost system should be fine too.

However, these two issues aren't mutually exclusive. Without enough belt wrap around the blower pulley, even at relatively low pressure (5psi-6psi) you could experience some belt slip at high RPM/boost.

As I said, engine RPM will have very little to do with belt slip. The supercharger's RPM, on the other hand, will play a significant roll. Much of what I've said above is based on the assumption that your pulleys are sized according to the maximum intended RPM of the blower (about 39,000 - 41,000 rpm for an SN), and that you're not planning to spin it beyond this.

[Cali]

I haven't even mocked up the install on this blower yet. Just got my block and crank back from the machine shop today. I'm running the FRPP tall valve covers (needed to clear my rocker girdle) and from what I understand, they're gonna hit the S/C- so I figure I'll fab a bracket and move it in-line with the crank- so I should be able to get some serious wrap into the design. I'm also trying to utilize my under-drive pulley on the crank- the head unit pulley I just bought should bring the revs to about max on the S/C for what I'm spinning the engine at. Since I haven't had my A/C charged for a decade, might as well stop lying to myself and admit that it's a non-A/C car. Gonna move the alternator over to above the P/S pump, should leave enough room to play with the S/C positioning.

Also going to run an intercooler (I know it's not really needed, but the summers in vegas get pretty hot and I like to be consistent)- this also looks to be a nightmare as far as routing.

[Michael]

Also going to run an intercooler (I know it's not really needed, but the summers in vegas get pretty hot and I like to be consistent)- this also looks to be a nightmare as far as routing.

How much boost are you planning to run? Running an intercooler on anything less than 8psi isn't going to help, and in fact it will cause a drop in boost (and overall performance).

[Cali]

I'm just going to spin this GSS to about 41k and go with whatever boost it gives.
I don't like doing things twice- if I do a custom stup now, I don't want to add to it later if I change out to an upgraded sn or novi2000 or vortech etc. (more than likely an upgraded sn- as much as I like to customize, I still like being as era correct as possible)

I'd honestly rather have a pointless intercooler, wich is alot easier to fab while the engine bay is empty and the front end is torn off- then have to go back and add after I install another charger.

[Michael]

The Novi-GSS is the 'ultimate' ball-drive supercharger. There is no other "upgrade" you can do to any SN series supercharger, apart from going to a VR-4 kit/conversion. Going to something like a Novi2000 or a Vortech unit will provide more power, but will negate a lot of the custom fabrication work you're doing in order to bolt up the GSS.

Running an intercooler is (obviously) your choice, and you're correct in saying that it's much easier to fabricate, locate, and install while the engine bay is empty. And if it truly was 'pointless' (meaning there were neither positive or adverse effects), then I'd say go for it. Unfortunately, the added volume of the intercooler itself and it's associated plumbing causes a pressure drop in systems producing less than 8psi of boost. So given the typical boost levels seen from SN series superchargers, the fact of the matter is you'll never get the "full" benefit of the supercharger if you run an intercooler.

If charge cooling is what you're after, then I'd suggest investigating a water/methanol injection system. For low boost systems (8psi and under) a water/meth injection system is more efficient with respect to cooling, and you won't have to deal with all the complex intake tubes/plumbing and fabrication work.

There's a very informative two-part write up regarding water/meth injection by our very own 'SN guru' Speedytang. Definitely worth a read-through before making a final decision on which form of charge cooling to go with.

Water/Meth Injection Part 1: http://www.superchargerhelp.com/showthread.php?t=9623

Water/Meth Injection Part 2: http://www.superchargerhelp.com/showthread.php?t=9633

Now, if you're hell-bent on getting a VR-4, then plumbing-in an intercooler would be a good idea. The added boost and airflow from the VR-4 would make having an intercooler very worth-while. Just so long as you keep in mind the intercooler will limit the performance of the GSS.

[pavement pounde]

The beutyfull thing about the SN type supercharger and even the VR4 is that it is a drawtrue design supercharger is, meaning that when the supercharger is not spinning you can still drive your car with all hoses atached.
I had mine SN93 and later VR4 on a seperate 6 rib belt and later on a 10 rib belt, and when it died far away from home I could just simply take of the extra belt and drive home.

[Oldfox]

Slippage? Take a look at how a Kenne Bell is set up. Look how much belt surface touches the supercharger pulley I think that might be the trick. And one belt looks a lot cleaner.
If you can make your own brackets and stuff then I would think it would be worth it.



Ok Just saw that this is not a good picture. But the lower part of this belt goes back to to bottom of the supercharger pulley.

[Cali]

Odd you replied today, just started on my "remount". Sheared an 1 7/8" off of my factory paxton bracket, to bring the head unit closer into the engine. I wound up ditching my A/C (finally stop lying to myself that I was going to get it charged 7 years after I drained the system originally), smog pumps been gone for awhile. Flipped the alternator over to the factory A/C's position- wich left nothing but room to mount the blower on the passenger side. Intercooler mounted perfectly, with the generic piping kit fitting better than planned around & under the core support. Mock-up went extremely well, damn near 300 degrees of pulley wrap should be easy to acheive. Hopefully I'll be done this week with pictures if anyone's interested.

On a side note- talked to the fab guy about the experimental SN impeller- he's been short on spare time, but hopefully soon....

[Cali]

[Oldfox]

Darn that looks nice. And yes pictures as go please

[Cali]

Please excuse the crudeness on the mounting- this is only a "mark I", I ran through alot of fitment changes in order to get everything to finally snuggle together.

Motor is being ran N/A just to make sure everything assembled alright.


Th intercooler and head-unit fluid cooler take up ALL the space available behind the bumper cover.Yes- the fluid cooler and fan fit, it's very tight, about a quarter inch on the side with a cervinis "stalker" bumper. Fan pokes out underneath the bumper maybe half an inch.

I had toyed with the notion of putting the fluid cooler and fan "sideways" inside the fender area in front of the tire. I may move it there still, now that I discovered how tight and vulnerable it is up front.




Trimmed 1 7/8" off of the factory bracket to put the GSS in alignment with the original serpentine setup. Also re-drilled the mounting plate to lower the head unit and move it toward the passenger inner fender to gain clearance with the cyliner head/valve cover and "factory" radiator hose placement.

[Cali]

Finalized bracket.
Since this bracket was originally use to mount the supercharger, alternator and smog pump, and was now only being used for the S/C, there was plenty of boss's available for re-mounting. I used steel tubing to make stand-offs (2 1/8") to use the other boss's that were offset for other accesories.

I had to REALLY think before i did this since CUNDN wants $250 for this piece of aluminum.


Fan- free with fluidyne radiator (been sitting on a shelf for 2 years)
Mr. gasket fuel pump- found on the frame of a bronco I bought for suspension
Inverted flare fittings and stainless braided lines- free from a friend with a hydraulics shop
Cooler- $50 on ebay