Pulley 101 .......info for dummies like me

[Turbo99]

Jamie,

I am sure that Ted has checked to rpm of the blower, but I am think you have just reached Tue max of the blower and more rototiller speed IE smaller pulley, will just result in more heat.

[PQ]

Originally Posted by Supercharged SS

Like these guys have said. The cogs isn't that loud. Mine is noticeable but I'm spinning the balls of my blower. I'm gonna try and get near 18-20 psi so ill let you know how loud it gets. I'm going to have Ted get me the 10 rib LPE setup tomorrow.

I'll live vicariously through you.

Originally Posted by maxdmax

OK, I had to drive down the road so I took my IPad and did a few in car videos. They are all with the Windows up (you can't really hear it if the window is cracked) They are not the best quality but they should give you a worst case condition unless you are going over 12 PSI. You actually can hear my differential more than the Cog drive most of the time due to the BMR bushings. YES it surprised me a little in 2nd I did not think it would spin that bad in 2nd rolling on a good road. LOL Go back and listen to the Dyno video after that and you will see what I mean. In the car it is not bad at all. This is what it sounds like..... Let me know what you think?

Wow. Thank you for the vids. That doesn't sound bad at all.

[Kronix]

Originally Posted by Supercharged SS

Smaller pulleys aren't always better. I spent yesterday testing this on my car. With the RIP 3.2 my car ran 10.07 and 10.08. That was first thing in the am when the weather was the best. After lunch, I threw on a standard 3.4 and ran 10.00 and 10.02. This also improved my 60's from 1.49's to 1.45's. The belt will slip even with the slightest change in size. I logged all these passes so I can see the boost rise and fall. The 3.4 on my set up slips too but not as much as the 3.2.

Jamie, I thought that when you change pulleys you have to retune it, am I incorrect? I'm running the stock 3.8 @ 6psi, but was thinking about dropping down to a 3.3 or 3.4. I've seen a few posts about people swapping out the pulley in an afternoon, but never mention of retuning.

[2010SSRSM6]

Originally Posted by Kronix

Jamie, I thought that when you change pulleys you have to retune it, am I incorrect? I'm running the stock 3.8 @ 6psi, but was thinking about dropping down to a 3.3 or 3.4. I've seen a few posts about people swapping out the pulley in an afternoon, but never mention of retuning.

You will want to get it retuned when ever you change your boost level.

What boost level are you wanting to get to? With the 3.8" and the OD cogs, I'm at 9.5#'s with ZERO chance of belt slip.

[PQ]

Originally Posted by 2010SSRSM6

You will want to get it retuned when ever you change your boost level.

What boost level are you wanting to get to? With the 3.8" and the OD cogs, I'm at 9.5#'s with ZERO chance of belt slip.

Mine was tuned with a 2.8 creating 8.5 -9 pound of boost and with a 3.2 creating 7.5 pounds. Vengeance told me that if I wanted to drive around with the 3.2 and put the 2.8 on for track days that the tune would adjust automatically.

[2010SSRSM6]

Originally Posted by PQ

Mine was tuned with a 2.8 creating 8.5 -9 pound of boost and with a 3.2 creating 7.5 pounds. Vengeance told me that if I wanted to drive around with the 3.2 and put the 2.8 on for track days that the tune would adjust automatically.

That sounds odd to me, but I'm sure he knows a lot more about this stuff then I do. I assumed that anytime you force that much more air into the motor you would need to adjust the fuel to keep the AFR where it needs to be to keep it from going lean.

Maybe the computer can make the adjustments off the MAF? I'm a big chicken and would rather tune it than break something.

[PQ]

Originally Posted by 2010SSRSM6

That sounds odd to me, but I'm sure he knows a lot more about this stuff then I do. I assumed that anytime you force that much more air into the motor you would need to adjust the fuel to keep the AFR where it needs to be to keep it from going lean.

Maybe the computer can make the adjustments off the MAF? I'm a big chicken and would rather tune it than break something.

I'm not exactly sure. They got to 560 at the wheels and it was apperently 104 degrees in the shop and he told me he could easily get 580 in the morning but wanted to keep it safe.

But he had dynoed it with the bigger pulley the first time and I told him I think I want to go with the bigger pulley to be safe. Eventhough I'd leave power on the table and he said why don't I just get both belts and pulleys.

I asked him specifically about having to have it tuned for that and he said no.

[2010SSRSM6]

Originally Posted by PQ

I'm not exactly sure. They got to 560 at the wheels and it was apperently 104 degrees in the shop and he told me he could easily get 580 in the morning but wanted to keep it safe.

But he had dynoed it with the bigger pulley the first time and I told him I think I want to go with the bigger pulley to be safe. Eventhough I'd leave power on the table and he said why don't I just get both belts and pulleys.

I asked him specifically about having to have it tuned for that and he said no.

Good to know. If I ever get the testicular fortitude to go with a smaller pulley it will save me the money on a tune.

[PQ]

Originally Posted by 2010SSRSM6

Good to know. If I ever get the testicular fortitude to go with a smaller pulley it will save me the money on a tune.

I'm running a 3.4 inch pulley now with JREs tensioner and making 7.5 pounds according to my OBD logger. BUT dropping to 48 pounds in fuel pressure. So Not sure what to think about that. Obviously I need a fuel pump upgrade.

[maxdmax]

Originally Posted by PQ

Mine was tuned with a 2.8 creating 8.5 -9 pound of boost and with a 3.2 creating 7.5 pounds. Vengeance told me that if I wanted to drive around with the 3.2 and put the 2.8 on for track days that the tune would adjust automatically.

I have been through all of this starting out with a stock 3.8 then a 3.6, then slipping with a 3.4, adding the Jannetty super tensioner then the 3.2 and more slipping and added the 1:1 cog drive. Now I am running the OD Cog drive and a 3.4. The consern is that you are making a very low amount of boot with the 3.2 and the 2.8 already, you almost got to have slippage or something else going on. My car made 9.5 psi on a 3.2 and my car seems to make less boost than most. I was at 9.5 PSI and added the OD Cog drive and went up from a 3.2 to a 3.4 front pulley and now I am at 12 PSI. Most people guessed I would have made 14 PSI. This is a little more substancial than just changing front pulleys. If you go to the super tensioner, rear OD cog and then a 3.8, 3.6 or a 3.4 it should not slip ever. If I were you I would at least take it back to them to check it. All they would need to do is connect the O2 sensor and laptop up and take drive with you just to be sure. I would hate to see you make 11 or 12 PSI without a new tune. What ever you do I wish you the best of luck and you can put this slipping issue behind you.

[Kronix]

Originally Posted by 2010SSRSM6

You will want to get it retuned when ever you change your boost level.

What boost level are you wanting to get to? With the 3.8" and the OD cogs, I'm at 9.5#'s with ZERO chance of belt slip.

That's what I thought, but I could've sworn I saw PQ mention he swapped out pulleys himself, and didn't mention retune.

Right now I'm running the 3.8 that came with the SLP Maggie and I also have the Jannetty Super Tensioner. Just added Kooks LTs with no cats and ALKY Control Meth kit running 100% Meth. I was thinking of dropping to the 3.3 or 3.4 pulley, adding the ZR1 MAP & ZR1 plugs also. Most of this is fairly new to me, when I had my 83 Z28, 87 5.7 IROC & 89 Vette, doing stuff like this was pretty unheard of. I'm still a little confused as to what this OD Cog drive stuff is too. So any explanation on that and it's benefits would be great. As far as how much boost I'm looking for, I just want to keep it fairly safe, but get the best bang out of it.

[PQ]

Originally Posted by maxdmax

I have been through all of this starting out with a stock 3.8 then a 3.6, then slipping with a 3.4, adding the Jannetty super tensioner then the 3.2 and more slipping and added the 1:1 cog drive. Now I am running the OD Cog drive and a 3.4. The consern is that you are making a very low amount of boot with the 3.2 and the 2.8 already, you almost got to have slippage or something else going on. My car made 9.5 psi on a 3.2 and my car seems to make less boost than most. I was at 9.5 PSI and added the OD Cog drive and went up from a 3.2 to a 3.4 front pulley and now I am at 12 PSI. Most people guessed I would have made 14 PSI. This is a little more substancial than just changing front pulleys. If you go to the super tensioner, rear OD cog and then a 3.8, 3.6 or a 3.4 it should not slip ever. If I were you I would at least take it back to them to check it. All they would need to do is connect the O2 sensor and laptop up and take drive with you just to be sure. I would hate to see you make 11 or 12 PSI without a new tune. What ever you do I wish you the best of luck and you can put this slipping issue behind you.

I don't have a clue why the low boost. Even with Janetty super tensioner it's only 7.5 with a 3.4 pulley. And it's as tight as it can be.

[2010SSRSM6]

Originally Posted by Kronix

That's what I thought, but I could've sworn I saw PQ mention he swapped out pulleys himself, and didn't mention retune.

Right now I'm running the 3.8 that came with the SLP Maggie and I also have the Jannetty Super Tensioner. Just added Kooks LTs with no cats and ALKY Control Meth kit running 100% Meth. I was thinking of dropping to the 3.3 or 3.4 pulley, adding the ZR1 MAP & ZR1 plugs also. Most of this is fairly new to me, when I had my 83 Z28, 87 5.7 IROC & 89 Vette, doing stuff like this was pretty unheard of. I'm still a little confused as to what this OD Cog drive stuff is too. So any explanation on that and it's benefits would be great. As far as how much boost I'm looking for, I just want to keep it fairly safe, but get the best bang out of it.

OD cogs replace the 1:1 drive system on the rear of the blower and cause the blower to spin faster without having to make the front pulley smaller and produces a nice tone that lets you know your blower is there.

I want to say it increases the speed 16%, but don't quote me on that.


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[Jessika]

OD cogs add 3 to 3.5psi over 1:1


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