Poor man's method to better belt wrap on an fbody
The belt slip was non-existent with this setup. It did its job well. When you are spinning the tires on the dyno and not the s/c belt, thats a step in the right direction..
https://ls1tech.com/forums/forced-in...-f1-setup.html
https://ls1tech.com/forums/forced-in...-f1-setup.html
Just wanted to follow up this post - yesterday I swapped to a 3.2" blower pulley (yay for better belt fit and more boost) and can now fit a 415K6 belt on. I'm trying to keep the belt nice and tight and still keep at least 3/16" between the belts as they pass eachother. I haven't done it yet but I'm going to make a witness mark with a Sharpie on the front of the j-bracket where the tensioner washer is when the belts are touching so I can easily see how much adjustment I have left.
I'll need to do some driving and retune for the smaller blower pulley (went 3.6" --> 3.2") and hopefully won't run out of injector... I still have green-top 42#'s - should be making another couple of psi with the new pulley setup if it doesn't slip !
Rob (Bad30th)
I'll need to do some driving and retune for the smaller blower pulley (went 3.6" --> 3.2") and hopefully won't run out of injector... I still have green-top 42#'s - should be making another couple of psi with the new pulley setup if it doesn't slip !
Rob (Bad30th)
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Awesome man, let us know how that goes for sure. Thanks so much for the extra idler you sent me for mock up Rob! I got it at the end of last week. 
I may be upping the boost on mine here soon as well since I'm already running entirely way too rich now with my 4.25 pulley..
I may be upping the boost on mine here soon as well since I'm already running entirely way too rich now with my 4.25 pulley.. That looks good man, but I'd find a way to get that 5th bolt installed. Just think of the 200hp "lost" on that head unit. That's a lot of energy trying to twist it out of the bracket!!! That's one of the really nice bonuses of Aster's setup, you get the 6th bolt added in....
Awesome man, let us know how that goes for sure. Thanks so much for the extra idler you sent me for mock up Rob! I got it at the end of last week. I may be upping the boost on mine here soon as well since I'm already running entirely way too rich now with my 4.25 pulley..
I may be upping the boost on mine here soon as well since I'm already running entirely way too rich now with my 4.25 pulley..And I wanna go for a ride in that beast
Just wanted to follow up this post with progress...
This mod may not be for the faint of heart - I'm still playing with blower pulley sizes and belts trying to find the perfect setup that keeps tight enough tension on the belt to keep it from slipping while keeping the belts reasonably seperated between the pulleys. I'm sure that my having the larger MMS crank pulley isn't helping the equation any...
My latest setup is a MMS crank pulley, 3.2" blower pulley and a 410K6 belt. It goes on fine but I have to be careful to not tension the belt down too close to the "belts are touching" mark I made on the front of the bracket, and I'd like to get the belt a little tighter. Unfortunately belt sizes are limited and there aren't a lot of incremental belt sizes I've been able to find between 407K6/410K6/415K6.
I'm also having an issue with the belt walking forward one rib on the crank pulley - probably just need to take a closer look at the alignment. I did notice that putting things back together this time with the 3.2" blower pulley I somehow gained a small amount of clearance between the alt and blower pulley that wasn't there before, maybe reassembling will straighten it out.
As a last resort, the good news with this setup is that if I decide to go another route I can always take the pulley/washers off the standoff and put it the belt/bracket back the way it was...
Cheers,
Rob (Bad30th)
This mod may not be for the faint of heart - I'm still playing with blower pulley sizes and belts trying to find the perfect setup that keeps tight enough tension on the belt to keep it from slipping while keeping the belts reasonably seperated between the pulleys. I'm sure that my having the larger MMS crank pulley isn't helping the equation any...
My latest setup is a MMS crank pulley, 3.2" blower pulley and a 410K6 belt. It goes on fine but I have to be careful to not tension the belt down too close to the "belts are touching" mark I made on the front of the bracket, and I'd like to get the belt a little tighter. Unfortunately belt sizes are limited and there aren't a lot of incremental belt sizes I've been able to find between 407K6/410K6/415K6.
I'm also having an issue with the belt walking forward one rib on the crank pulley - probably just need to take a closer look at the alignment. I did notice that putting things back together this time with the 3.2" blower pulley I somehow gained a small amount of clearance between the alt and blower pulley that wasn't there before, maybe reassembling will straighten it out.
As a last resort, the good news with this setup is that if I decide to go another route I can always take the pulley/washers off the standoff and put it the belt/bracket back the way it was...
Cheers,
Rob (Bad30th)
Last edited by Bad30th; Nov 28, 2009 at 09:19 AM.
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
Hmm.. sorry to hear you are having difficulties.. Just out of curiosity, why did you go with the smaller crank pulley as opposed to the standard procharger 7.65 8 rib pulley? 
**edit** nevermind, I just remembered you are still running a 6 rib setup..
I think that you may have better luck with the belt and pulley sizes by swapping over to an 8 rib setup.
**edit** nevermind, I just remembered you are still running a 6 rib setup..
I think that you may have better luck with the belt and pulley sizes by swapping over to an 8 rib setup.
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Verdad Gallardo Yep, still 6-rib, but the MMS crank pulley is actually larger (7.85").
I haven't given up yet, but wanted to post up some feedback... ...and yeah an 8-rib setup would be optimal, might just bite the bullet and switch...
Rob (Bad30th)
I haven't given up yet, but wanted to post up some feedback... ...and yeah an 8-rib setup would be optimal, might just bite the bullet and switch...
Rob (Bad30th)
Hmm.. sorry to hear you are having difficulties.. Just out of curiosity, why did you go with the smaller crank pulley as opposed to the standard procharger 7.65 8 rib pulley?
**edit** nevermind, I just remembered you are still running a 6 rib setup..
I think that you may have better luck with the belt and pulley sizes by swapping over to an 8 rib setup.
**edit** nevermind, I just remembered you are still running a 6 rib setup..
I think that you may have better luck with the belt and pulley sizes by swapping over to an 8 rib setup.
Staging Lane
Joined: Sep 2009
Posts: 99
Likes: 0
From: Corpus Christi
Belt slip Thanks Chad for this idea. I am having some belt issues and now trying this setup. I have about a 2" idler pulley. I still have room with this setup to tighten belt if it gets looser on break in. Also I am going to use screen filter as other filter seems to limit boost. I'm thinking better flowing air will cause less belt slip. Here is some pics of my setup.
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I hope you're only talking about using that screen at the track. I would not drive that on the street. The supercharger is way to expensive to just let dust and dirt get in there. If you need a filter to flow the air get something bigger than what you've got.
Ok, you lost me. How is more boost gonna cause less belt slip? That doesnt make any sense. It should increase your belt slip cause the SC is making more boost with the same pullies.
Thread Starter
8 sec potential, 12 sec slip
iTrader: (50)
Joined: Apr 2002
Posts: 4,092
Likes: 2
From: Savannah, GA
What size head unit pulley are you running Z-28?
I know it seems that way Mike, but it is actually the opposite. The s/c doesnt have to work as hard to suck in air, which puts less strain on driving it. More boost and less slip is common actually when upgrading to the bigger K&N over the stock supplied one that comes with the fbody kits.
I know it seems that way Mike, but it is actually the opposite. The s/c doesnt have to work as hard to suck in air, which puts less strain on driving it. More boost and less slip is common actually when upgrading to the bigger K&N over the stock supplied one that comes with the fbody kits.
Staging Lane
Joined: Sep 2009
Posts: 99
Likes: 0
From: Corpus Christi
Answers The idler and the stand off are custom made from a performance shop here in my town.
3.1" S/C pulley, 7.625 crank pulley.
The filter is choking blower so by removing filter it gets more air and that gives it more boost. When filter is on and blower is choking for air, blower may not spin as fast as it should or as fast as crank is spinning so that will cause belt to slip. Crank is trying to spin belt faster than blower can spin. Blower can't keep up with crank spin.
Screen is only for racing. Filter is for street but limits boost. I have bigger filters but nowhere to put one. The cubby hole I have to put filter in is not very big and to get filter there I have to put much bend in tube from filter to turbo hat and the bend itself I think restricts good air flow. I am trying to get more than 12 lbs of boost with filter on it. Where do folks that have the twin coolers put thier filter?
When I had my twins (Both 3.5" and 4.5") I fit a 9" K&N over the intercooler on the driverside without a problem. I had some reinforced flexible tubing so the slight rise from the hat outlet to the filter position was easy.
I am now using a Spectre filter that it similar in size to the K&N with the reverse cone on the end, that They claim flows close to 1200 cfm. The part number is based on color, 9732 = Red, 9738 = no color, 9736 = blue.
Seriously what is your setup? Using a 3.1" head unit pulley on a D1SC with the normal crank size you should be more than capable of making better boost. Do you have the 4.5" or 3.5" twin intercoolers? Something doesn't sound right, unless that filter you have is really that small.
My 383 D1SC with a 3.85 makes 13 - 14+ psi depending on how cold it is. Warm day when tuned was 13psi, now that we've gone down to 40's at night I'm getting that 13 psi almost 1k rpms earlier.
I will tell you the screen is more restrictive than a good air filter. Its all about surface area and not just flow restriction which is why most including me think or used to think they flowed more with the screen etc... GL!
The filter is choking blower so by removing filter it gets more air and that gives it more boost. When filter is on and blower is choking for air, blower may not spin as fast as it should or as fast as crank is spinning so that will cause belt to slip. Crank is trying to spin belt faster than blower can spin. Blower can't keep up with crank spin.
Screen is only for racing. Filter is for street but limits boost. I have bigger filters but nowhere to put one. The cubby hole I have to put filter in is not very big and to get filter there I have to put much bend in tube from filter to turbo hat and the bend itself I think restricts good air flow. I am trying to get more than 12 lbs of boost with filter on it. Where do folks that have the twin coolers put thier filter?
The idler and the stand off are custom made from a performance shop here in my town.
3.1" S/C pulley, 7.625 crank pulley.
The filter is choking blower so by removing filter it gets more air and that gives it more boost. When filter is on and blower is choking for air, blower may not spin as fast as it should or as fast as crank is spinning so that will cause belt to slip. Crank is trying to spin belt faster than blower can spin. Blower can't keep up with crank spin.
The idler and the stand off are custom made from a performance shop here in my town.
3.1" S/C pulley, 7.625 crank pulley.
The filter is choking blower so by removing filter it gets more air and that gives it more boost. When filter is on and blower is choking for air, blower may not spin as fast as it should or as fast as crank is spinning so that will cause belt to slip. Crank is trying to spin belt faster than blower can spin. Blower can't keep up with crank spin.