You'll need a shorter belt...dont know which one, mine is for a 3.4.
Yes absolutely that supercharger belt needs to be tight. Mine barely slips on when the tensioner is fully retracted and there is no play and no slippage. You will probably have to go 1" shorter. Also make sure that your supercharger spins freely when the pulley is spun by hand (without the belt on it) You should feel complete smoothness in rotation and no binding. IIRC, your setup is also using a one belt to drive everything configuration. If so that may have some influence. The supercharger pulley needs a full wrap around of the belt.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I've tried the next lower belt size by half and inch and could not get it over the pulley. Seriously. Did I not try hard enough?
This is a Dayco belt by the way. Any good? I hear Gatess is the best.
I remember these always were a pain to get on. Is there a trick I'm missing -- warm up the belt in a toaster oven?
The tensioner is flexing some, but I thought that was normal. I cant get much more of a wrap around the SC. Is almost impossible to go beyond 50%, so I guess it's a matter of creating higher tension.
This guide works for 96-03 Bonneville, 96-?? Riviera, 97.5-04 Regal, 97-07 Grand Prix, bascially any year with the Series II or Series III motor. Part Number Examples Napa/Gates: 060XXX Goodyear: 4060XXX Dayco: 5060XXX Duralast: XXXK6 Regal/Grand Prix/Monte Carlo/Impala No IC 3.8 (Stock): 665 3.2-3.5: 660 2.85-3.1: 650 2.7-2.85: 642 With 2.25” tall IC Core 6 Rib 3.3-3.8: 685 2.7-3.2: 680 (Note that the NAPA 680 may be too long for 2.8" and smaller. Try a NAPA 672) 2.5-2.6: 672 8 Rib NOTE: For these belts the part numbers are 080 rather than 060...or K8 with the Duralast rather than K6. 3.0-3.2: 685 2.6-2.9: 680 Gen 5 Blower 2.9-3.1: 685 2.7-3.0: 680 2.4-2.6: 675
With ZZP Stage 3 IC (??? tall Core) 6 Rib: 3.1-3.8: 685 2.6-3.0: 680 Gen 5 Blower 3.0-3.8: 685 2.6-2.9: 680 2.3-2.55: 675 Gen 5 Blower with ATI 10% overdrive balancer 2.8: 695 With ZZP SSIC (1” tall Core) 3.2-3.8: 670 3.0-3.1: 667 (Stock belt) 2.8: 660 With MAP IC (2.0” tall Core) 3.1-3.4: 680 2.8-3.0: 672 With WBS IC (1.91” tall Core) No information currently. MAP IC belt reference would be close but the belts listed there will be a bit long for some applications with the WBS IC. With Thrasher IC (2.5” tall Core) 2.8: 672 3.0: 680 ZZP SS M90 Conversion k060970 - SS M90 for 97/98 K060950 - SS M90 for 99+ Bonneville/Riviera Stock: 725 3.4: 715 With WBS Stage 3 2" Core 2.9: 725 Other Belts W body 060915 - Stock accessory belt for 99-03 -also works with either UD WP pulley or OD alt pulley but not both. 060905 - Stock Accessory belt for 04+ 060923 - Accessory belt for 99+ with UD WP pulley and alt UD pulley. 4060935 - Stock accessory belt for 97/98 (94"). 4060938 - Accessory belt for 97/98 with underdrive pulleys.
I've tried the next lower belt size by half and inch and could not get it over the pulley. Seriously. Did I not try hard enough?
This is a Dayco belt by the way. Any good? I hear Gatess is the best.
I remember these always were a pain to get on. Is there a trick I'm missing -- warm up the belt in a toaster oven?
The tensioner is flexing some, but I thought that was normal. I cant get much more of a wrap around the SC. Is almost impossible to go beyond 50%, so I guess it's a matter of creating higher tension.
Back up a bit to the question that you may have missed: IIRC the one belt belt routing on your install was very different that what 3800SC swaps usually use. If it is that could be the issue. Notice that GM designed the routing with a dedicated supercharger drive belt ------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
[This message has been edited by Dennis LaGrua (edited 08-14-2017).]
You are right Dennis (as always) I do have a custom route, with the only deviation being the added ALT (where the AC unit was installed).
Otherwise I still have the same or similar tensioner and SC wrapping.
It may just be a matter of fighting the smaller belt on.
GM must of been fearful of going to the 8 rib, but it seems only logical. As mentioned when the cooler weather hits, compressing that air will be a lot more work.
Oh yes and BTW my SC is running great. Smooth as butter she turns! Can't say that for the one I removed, and boy did it have some play in it.
Again, is there a trick for installing these belts? When I tried I cranked that tensioner all the way back and that belt just wont give.
Another option, that has been on the forum once in a blue moon, is a bolt on bracket "belt wrap kit" that adds a pulley right at the supercharger. A quick eBay search of "L67 belt" made it the very first item shown. $150 option.
Interesting piece of engineering above. That would certainly get you more than the 50% wrap.
I could actually make one of those.
My solution now is to go back and try the smaller belt.
I had a Pontiac Grand Prix GTP many years ago. I remember how it was hard on belts, and changing them was crazy. There was an actually tool that aided in holding the tensioner back while you forced the belt on.
You are right Dennis (as always) I do have a custom route, with the only deviation being the added ALT (where the AC unit was installed).
Otherwise I still have the same or similar tensioner and SC wrapping.
It may just be a matter of fighting the smaller belt on.
GM must of been fearful of going to the 8 rib, but it seems only logical. As mentioned when the cooler weather hits, compressing that air will be a lot more work.
Oh yes and BTW my SC is running great. Smooth as butter she turns! Can't say that for the one I removed, and boy did it have some play in it.
Again, is there a trick for installing these belts? When I tried I cranked that tensioner all the way back and that belt just wont give.
Not always right, just sometimes!!! Tip: Always try to slip the belt over the smooth pulley not the grooved pulley. Is the belt being tensioned in the right spot?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
My configuration for the SC is simple. Sorry I cant post pictures.
Starting from the Crank and going clockwise. I have a smooth three inch idler (located about one o'clock above the crank) and then it moves directly to the SC pulley. From there down to the smooth three inch tensioner (adjacent to the other smooth idler), which provides an outward pressure to the belt. From there to the ALT (low mounted where the AC compressor was mounted stock) then back to the Crank.
I have excellent wrap around the Crank, and SC. I had no slip with the stock pulley.
Interestingly, when I went to check on the belt it is very loose. Understand, I could barely muscle it on initially. I thought the tensioner spring broke. Tensioner is fine. THESE BELTS STRETCH.
I'm going to try the smaller belt again. Another option is to move to a 3.5 pulley to take up the slack. I am sure this is a matter finding the right combination.
Just a reminder to some. SCs are hard on belts and also these little pulleys. When my GTP burst a pulley, I was left on the side of the road. They need checked, both belts and pulleys, cause these SCs are hard on them.
And to Dennis, Yes you are typically spot-on when it comes to these Fieros and there many engine configurations. When I ever have a issue I turn to you, one of the old sages on this forum, for your technical knowledge and your honest no nonsense assessment of the situation. I'm still waiting for you to pioneer the next engine swap, and can only hope it is not some wimpy electric-hybrid thing.
Giving long hard thought about your belt slippage. Are you using the same OEM tensioner that was used on the supercharger belt? You say that you have one belt driving both the supercharger and the alternator. At high demand alternators can require a decent amount of horsepower to drive, likewise the supercharger.. The one drive belt now has to function with two significant loads on it that are variable and unequal. You also decreased to a supercharger pulley size that requires more twisting force. IMO this would make the tension and the belt wrap more critical. Can this all be done with one belt? possibly but then again why did GM design the 3800SC with two belts?
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Thanks Dennis, and I may have time to look it all over this weekend.
I will first try again with the smaller belt.
I pieced this whole thing together a while back (6-7 years), and so I can not remember exactly my reasoning. I know I was set on keeping the ALT low mounted for aesthetic reasons. The thing is it worked well before the 3.5 upgrade.
As for modifications, these Fiero 3800s run with no steering pump, no AC (at least mine doesn't), and with a simpler belt configuration. My point is th engine revs up quicker. I know this because I drove a stock GTP for years, and so with the modified Fiero 3800SC there is consequently more torque being delivered to the belt at a faster rate. I noticed when I reved the engine the belt was orbiting at first. It really pulls down hard and relies heavily on that tensioner to take up the slack.
Also, those GM engineers (or Eaton Engineers) are smart guys, but they designed that SC belt to run with a stock 3.8 pulley. Did they anticipate hot rodders would attempt to under drive it? I think ideally this is a 8 rib (wider belt) setup and they were asking a lot from such a slim belt. Your thoughts?
You made sure that there is no bind in the supercharger, right? We may be over analyzing this but the tensioner that is on the supercharger belt and the tensioner that is on the other belt may be different. Perhaps they provide different tensions , a swing angle that provides a different mechanical advantage or the location of it is critical. IIRC, your setup uses only one tensioner for the belt that drives the supercharger, the alternator and water pump. Not sure if you have a full belt wrap on the supercharger pulley and/or the tension in the right place. If this were my setup I would revert back to the two belt method but I guess that goes against what you wish to do. . We have touched on all the possibilities but meanwhile a coat of anti-belt slip on the belt will provide a temporary fix. If there is a guy who might know the answer it would be Ryan from Sinister performance. He's a full time auto tech and performance guy.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Well, I went back to the half inch shorter belt. And, with some real effort and with a belt technique I believed I pioneered, I got it mounted and working.
These belts are just so tight and they do stretch. From my first impression and driving a little around town it is working great with no slip.
Boy, is the power increase noticeable! The torque is immediate, even more so than before. Just to remind you I had a 3.8 (stock) pulley and this 3.5 created a very noticeable difference. It was well worth the effort though I have no idea what all this additional HP is needed for.
Question: I have a ZZ Performance pulley. Is the belt to be centered exactly on the pulley? Anyone know. The pulley is made for a 8 rib, and our belts are 6.
My belt technique involved routing the belt around all pulley and idlers, and then routing it around the crank only partially. I then ratcheted back the tensioner as far as it would go with one hand, while I with another wrench rotated the crank pulley (the engine). This worked great and is similar to those days as a child when you put the chain back on your bicycle. I actually rotated the engine backward and it pulled the belt onto the crank. IT was rather simple, but a little tricky.
To Dennis: Yeah, I believe you are right. My configuration was a solution in the moment and I may have problems in the future. My ALT bracket cracked two years ago. But, I cant say it was engineered well. I used some scrap steel. I wonder if the ALT and those bearing are able to take all the power being inline with the SC. Perhaps that is why it carries it own belt. I noticed when I rev the engine that creates the most stress on the whole belt system.
BTW, I do run two belts. I have a short belt to drive the water pump. I have no AC.
Well, I went back to the half inch shorter belt. And, with some real effort and with a belt technique I believed I pioneered, I got it mounted and working.
These belts are just so tight and they do stretch. From my first impression and driving a little around town it is working great with no slip.
Boy, is the power increase noticeable! The torque is immediate, even more so than before. Just to remind you I had a 3.8 (stock) pulley and this 3.5 created a very noticeable difference. It was well worth the effort though I have no idea what all this additional HP is needed for.
Question: I have a ZZ Performance pulley. Is the belt to be centered exactly on the pulley? Anyone know. The pulley is made for a 8 rib, and our belts are 6.
My belt technique involved routing the belt around all pulley and idlers, and then routing it around the crank only partially. I then ratcheted back the tensioner as far as it would go with one hand, while I with another wrench rotated the crank pulley (the engine). This worked great and is similar to those days as a child when you put the chain back on your bicycle. I actually rotated the engine backward and it pulled the belt onto the crank. IT was rather simple, but a little tricky.
To Dennis: Yeah, I believe you are right. My configuration was a solution in the moment and I may have problems in the future. My ALT bracket cracked two years ago. But, I cant say it was engineered well. I used some scrap steel. I wonder if the ALT and those bearing are able to take all the power being inline with the SC. Perhaps that is why it carries it own belt. I noticed when I rev the engine that creates the most stress on the whole belt system.
BTW, I do run two belts. I have a short belt to drive the water pump. I have no AC.
After some additional thought, I believe the places that you apply stresses to a belt at different points may increase the chance of slippage and wear. I usually change my supercharger belt every two years and I don't drive the car that much. With more drive members on it, the belt will flex more and you might have to change the belt yearly. Glad that you got the smaller belt on and that the slip went away. As for the smaller ZZ pulley, they must have been made in six and eight rib types as I have the 3.4" six rib. As to using the 8 rib with a six rib belt, that's a good question. I would just eye it up and try to align the belt edge to a straight edge reference point on the other 6 rib pulleys, perhaps the inner or outer rib. If you have a laser ruler that would be the easiest way.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Dennis, I agree with the monitoring and maintenance of the belts, but also the pulleys. A couple of years ago I had a strange squeaking noise coming from the engine compartment. It wasn't until I removed the idler pulley and spun the pulley on my finger did I realize the bearing was binding. When I had my GTP I had a pulley exploded, threw the small bearings all over the engine compartment and of course tossed the belt. These little guys actually have long life, but are under a lot of duress. They are self-contained with little lubrication and yet have to spin constantly under quite a load. I immediately changed all mine. My old daily driver had an "interference engine" and it is also relied on a idler pulley to maintain tension on the belt. The pulley when and took the engine with it. (I believe water got to it.)
As far as the belt, my old belt (the 3.8 pulley one), looked great but only had about 5k on it.
Now, I only have to figure out what to do with the old SC? Needs a new coupler, but other than that should I keep it as a spare? Rebuild and sell it? Are they worth anything?
