Vortech supercharger pulley change

99xtrm · 05-14-2008, 08:26 AM

I am going from a 3.12" pulley to a 2.62" pulley does anyone know how much i need to shorten the belt? I contacted vortech and they never got back to me. I guess i have to go to a parts store and use trial and error till i get the correct one. Thanks for any help

rentedmule · 05-14-2008, 12:44 PM

based on the diameters of each you're going from a pulley circumference of 9.82" to 8.25" so you're dropping 1.57" - I'd guess if your belt wraps about 1/2 of the pulley you'll need to get one that's just over 3/4" shorter.

I think that make sense but it did take me about 5 belts before I found the right size for mine so take it for what it's worth!

98 SS · 05-14-2008, 02:27 PM

when i do a pulley change, i just go to the parts store and try belts, then write the number under the hood

99xtrm · 05-14-2008, 06:59 PM

Quote: Originally Posted by rentedmule

based on the diameters of each you're going from a pulley circumference of 9.82" to 8.25" so you're dropping 1.57" - I'd guess if your belt wraps about 1/2 of the pulley you'll need to get one that's just over 3/4" shorter.

I think that make sense but it did take me about 5 belts before I found the right size for mine so take it for what it's worth!

thanks

99xtrm · 05-14-2008, 07:00 PM

Quote: Originally Posted by 98 SS

when i do a pulley change, i just go to the parts store and try belts, then write the number under the hood

Yeah thats what will probably happen but i hate working on my stuff in the parking lot, it seems to attract alot of idiots

quad16 · 05-14-2008, 10:29 PM

how much boost will you gain going from the stock 3.12 to the 2.62 I am wanting to do the same thing

99xtrm · 05-15-2008, 12:36 AM

Quote: Originally Posted by quad16

how much boost will you gain going from the stock 3.12 to the 2.62 I am wanting to do the same thing

vortech says 1-2psi with every change in pulley size this is the 2nd step smaller so it should be between 2-4 psi

i found some where stating that a stock vortech unit is putting out about 3psi at 2500 rpm and about 8-9psi around 5500rpm, so it all depends on truck and rpms etc there is no answer set in stone on how much you will gain but since your overdriving the supercharger it will be a gain regardless.

98 SS · 05-15-2008, 09:31 AM

make sure you dont overspin it, vortech has a calculator on their site.

99xtrm · 05-16-2008, 12:49 AM

Quote: Originally Posted by 98 SS

make sure you dont overspin it, vortech has a calculator on their site.

found the calculator how fast is to fast

98 SS · 05-16-2008, 09:38 AM

it tells you how fast each trim can spin

99xtrm · 05-17-2008, 02:30 PM

i had to go with a 1" shorter belt i went from 6k1020 to a 6k1010

98 SS · 05-18-2008, 12:49 PM

get a gator back, it helps with smaller pulleys

99xtrm · 05-18-2008, 03:38 PM

Quote: Originally Posted by 98 SS

get a gator back, it helps with smaller pulleys

yeah they are less likely to slip and dont stretch as bad as other belts

98 SS · 05-18-2008, 03:54 PM

oh they stretch alright

99xtrm · 05-18-2008, 03:57 PM

yeah but not as bad as the cheap ones

quad16 · 05-18-2008, 06:15 PM

how much boost were you making with the stock pulley I just got my gauges all installed and I am hitting 11psi at 5500rpm far as I know all stock vortech kit little more than I was thinking it would have

***Jess*** · 05-18-2008, 11:28 PM

i don't like the gator back belts.

99xtrm · 05-18-2008, 11:30 PM

actually i never checked but it was supposed to be a 8-9psi kit when i get my gauge i'll check i kept the belt and pulley of corse.--but it may be awhile before i report anything

IntheBatCave · 05-19-2008, 04:15 PM

Quote: Originally Posted by quad16

how much boost were you making with the stock pulley I just got my gauges all installed and I am hitting 11psi at 5500rpm far as I know all stock vortech kit little more than I was thinking it would have

Mine stock as well and I'm getting 11psi if not 12psi as well from my kit.

quad16 · 05-27-2008, 11:03 PM

I just installed a 2.62 pulley on mine and its a big difference in power but it is to much I think for the stock fuel supply at about 11 to 12psi it falls on its face big time acts like no fuel so I put the stock pulley back on till I can up grade the fuel system

blacksharpie · 05-28-2008, 01:20 AM

Quote: Originally Posted by quad16

I just installed a 2.62 pulley on mine and its a big difference in power but it is to much I think for the stock fuel supply at about 11 to 12psi it falls on its face big time acts like no fuel so I put the stock pulley back on till I can up grade the fuel system

If you are out of fuel enough that you can feel it......its pretty bad. I know that with my mods and a stock fuel system when I command 12.8 AFR I go to 102% injector duty cycle @ 4800 RPM. I cant imagine 12 PSI stock, hopefully everything is ok.

rentedmule · 05-28-2008, 12:51 PM

blacksharpie, are you running an S/C or turbo yet? there's no way you can be maxing out your fuel system with just the mods in your sig - you're probably pushing less than 180 rwhp. Even without an FMU you can pull 220 rwhp from a S/C'd truck

blacksharpie · 05-29-2008, 01:54 AM

Quote: Originally Posted by rentedmule

blacksharpie, are you running an S/C or turbo yet? there's no way you can be maxing out your fuel system with just the mods in your sig - you're probably pushing less than 180 rwhp. Even without an FMU you can pull 220 rwhp from a S/C'd truck

Nope strait up just whats in the sig, I was shocked when I started tuning VE and could not richen up the top end no matter how drastic the changes made were. After some log sharing at the HPT forums its true im at 102% trying to get to 12.8 @ WOT. If you have HPT or even want to D/L the software just to look at the logs I would be happy to send them to ya.

Also even my W4M tune didnt command 12.8 more like 13.2 so I am asking for more than any stock tune, also AFR was meashured via WB. And yea im aware that you cant really go over 100% as they go static but one log even has a few frames @ 103%...so yea.....like i said I was SHOCKED.

blacksharpie · 05-29-2008, 02:15 AM

Link to a pic of the log showing a WOT run:
http://s198.photobucket.com/albums/a...ent=102inj.jpg

Tune type = Open Loop Speed Densety
AFR commanded = 12.72
AFR Actual = 13.39
INJ Duty cycle = 102%

If you look at all the parameters im logging you can see that the injectors go static and still cant attain the commanded afr.

Hope im not coming off like a jack ass but I couldn't really believe it myself.

rentedmule · 05-29-2008, 12:37 PM

Sorry, I didn't mean to come off like an ass either, I just found it hard to believe given the power that can be pushed out of the stock injectors. It makes it hard to believe that some guys can put down 250+ rwhp on just an FMU and a fuel pump!

blacksharpie · 05-29-2008, 01:33 PM

Quote: Originally Posted by rentedmule

Sorry, I didn't mean to come off like an ass either, I just found it hard to believe given the power that can be pushed out of the stock injectors. It makes it hard to believe that some guys can put down 250+ rwhp on just an FMU and a fuel pump!

Yep exactly what my thoughts were also, it prolly has allot to do with the FMU.....but who knows

05-14-2008, 08:26 AM	#1
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Vortech supercharger pulley change I am going from a 3.12" pulley to a 2.62" pulley does anyone know how much i need to shorten the belt? I contacted vortech and they never got back to me. I guess i have to go to a parts store and use trial and error till i get the correct one. Thanks for any help
	[Reply w/Quote]

05-14-2008, 12:44 PM	#2
rentedmule blown snowplow Age: 31 Join Date: May 2006 Posts: 857 Location: Edmonton, AB User is: OffLine	Re: Vortech supercharger pulley change based on the diameters of each you're going from a pulley circumference of 9.82" to 8.25" so you're dropping 1.57" - I'd guess if your belt wraps about 1/2 of the pulley you'll need to get one that's just over 3/4" shorter. I think that make sense but it did take me about 5 belts before I found the right size for mine so take it for what it's worth!
	[Reply w/Quote]

05-14-2008, 02:27 PM	#3
98 SS I call her: NIGHTMARE Join Date: Apr 2004 Posts: 1,774 Location: The TPK User is: OffLine	Re: Vortech supercharger pulley change when i do a pulley change, i just go to the parts store and try belts, then write the number under the hood
	[Reply w/Quote]

05-14-2008, 06:59 PM	#4
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by rentedmule based on the diameters of each you're going from a pulley circumference of 9.82" to 8.25" so you're dropping 1.57" - I'd guess if your belt wraps about 1/2 of the pulley you'll need to get one that's just over 3/4" shorter. I think that make sense but it did take me about 5 belts before I found the right size for mine so take it for what it's worth! thanks
	[Reply w/Quote]

05-14-2008, 07:00 PM	#5
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by 98 SS when i do a pulley change, i just go to the parts store and try belts, then write the number under the hood Yeah thats what will probably happen but i hate working on my stuff in the parking lot, it seems to attract alot of idiots
	[Reply w/Quote]


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05-14-2008, 10:29 PM	#6
quad16 Registered User Join Date: Jan 2007 Posts: 10 Location: User is: OffLine	Re: Vortech supercharger pulley change how much boost will you gain going from the stock 3.12 to the 2.62 I am wanting to do the same thing
	[Reply w/Quote]

05-15-2008, 12:36 AM	#7
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by quad16 how much boost will you gain going from the stock 3.12 to the 2.62 I am wanting to do the same thing vortech says 1-2psi with every change in pulley size this is the 2nd step smaller so it should be between 2-4 psi i found some where stating that a stock vortech unit is putting out about 3psi at 2500 rpm and about 8-9psi around 5500rpm, so it all depends on truck and rpms etc there is no answer set in stone on how much you will gain but since your overdriving the supercharger it will be a gain regardless.
	[Reply w/Quote]

05-15-2008, 09:31 AM	#8
98 SS I call her: NIGHTMARE Join Date: Apr 2004 Posts: 1,774 Location: The TPK User is: OffLine	Re: Vortech supercharger pulley change make sure you dont overspin it, vortech has a calculator on their site.
	[Reply w/Quote]

05-16-2008, 12:49 AM	#9
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by 98 SS make sure you dont overspin it, vortech has a calculator on their site. found the calculator how fast is to fast
	[Reply w/Quote]

05-16-2008, 09:38 AM	#10
98 SS I call her: NIGHTMARE Join Date: Apr 2004 Posts: 1,774 Location: The TPK User is: OffLine	Re: Vortech supercharger pulley change it tells you how fast each trim can spin
	[Reply w/Quote]

05-17-2008, 02:30 PM	#11
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change i had to go with a 1" shorter belt i went from 6k1020 to a 6k1010
	[Reply w/Quote]

05-18-2008, 12:49 PM	#12
98 SS I call her: NIGHTMARE Join Date: Apr 2004 Posts: 1,774 Location: The TPK User is: OffLine	Re: Vortech supercharger pulley change get a gator back, it helps with smaller pulleys
	[Reply w/Quote]

05-18-2008, 03:38 PM	#13
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by 98 SS get a gator back, it helps with smaller pulleys yeah they are less likely to slip and dont stretch as bad as other belts
	[Reply w/Quote]

05-18-2008, 03:54 PM	#14
98 SS I call her: NIGHTMARE Join Date: Apr 2004 Posts: 1,774 Location: The TPK User is: OffLine	Re: Vortech supercharger pulley change oh they stretch alright
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05-18-2008, 03:57 PM	#15
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change yeah but not as bad as the cheap ones
	[Reply w/Quote]

05-18-2008, 06:15 PM	#16
quad16 Registered User Join Date: Jan 2007 Posts: 10 Location: User is: OffLine	Re: Vortech supercharger pulley change how much boost were you making with the stock pulley I just got my gauges all installed and I am hitting 11psi at 5500rpm far as I know all stock vortech kit little more than I was thinking it would have
	[Reply w/Quote]

05-18-2008, 11:30 PM	#18
99xtrm I finally got blown Age: 30 Join Date: Dec 2003 Posts: 315 Location: northern kentucky User is: OffLine	Re: Vortech supercharger pulley change actually i never checked but it was supposed to be a 8-9psi kit when i get my gauge i'll check i kept the belt and pulley of corse.--but it may be awhile before i report anything
	[Reply w/Quote]

05-19-2008, 04:15 PM	#19
IntheBatCave Registered User Age: 28 Join Date: Jul 2001 Posts: 583 Location: User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by quad16 how much boost were you making with the stock pulley I just got my gauges all installed and I am hitting 11psi at 5500rpm far as I know all stock vortech kit little more than I was thinking it would have Mine stock as well and I'm getting 11psi if not 12psi as well from my kit.
	[Reply w/Quote]

05-27-2008, 11:03 PM	#20
quad16 Registered User Join Date: Jan 2007 Posts: 10 Location: User is: OffLine	Re: Vortech supercharger pulley change I just installed a 2.62 pulley on mine and its a big difference in power but it is to much I think for the stock fuel supply at about 11 to 12psi it falls on its face big time acts like no fuel so I put the stock pulley back on till I can up grade the fuel system
	[Reply w/Quote]

05-28-2008, 01:20 AM	#21
blacksharpie Registered User Join Date: Jun 2007 Posts: 150 Location: User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by quad16 I just installed a 2.62 pulley on mine and its a big difference in power but it is to much I think for the stock fuel supply at about 11 to 12psi it falls on its face big time acts like no fuel so I put the stock pulley back on till I can up grade the fuel system If you are out of fuel enough that you can feel it......its pretty bad. I know that with my mods and a stock fuel system when I command 12.8 AFR I go to 102% injector duty cycle @ 4800 RPM. I cant imagine 12 PSI stock, hopefully everything is ok.
	[Reply w/Quote]

05-28-2008, 12:51 PM	#22
rentedmule blown snowplow Age: 31 Join Date: May 2006 Posts: 857 Location: Edmonton, AB User is: OffLine	Re: Vortech supercharger pulley change blacksharpie, are you running an S/C or turbo yet? there's no way you can be maxing out your fuel system with just the mods in your sig - you're probably pushing less than 180 rwhp. Even without an FMU you can pull 220 rwhp from a S/C'd truck
	[Reply w/Quote]

05-29-2008, 01:54 AM	#23
blacksharpie Registered User Join Date: Jun 2007 Posts: 150 Location: User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by rentedmule blacksharpie, are you running an S/C or turbo yet? there's no way you can be maxing out your fuel system with just the mods in your sig - you're probably pushing less than 180 rwhp. Even without an FMU you can pull 220 rwhp from a S/C'd truck Nope strait up just whats in the sig, I was shocked when I started tuning VE and could not richen up the top end no matter how drastic the changes made were. After some log sharing at the HPT forums its true im at 102% trying to get to 12.8 @ WOT. If you have HPT or even want to D/L the software just to look at the logs I would be happy to send them to ya. Also even my W4M tune didnt command 12.8 more like 13.2 so I am asking for more than any stock tune, also AFR was meashured via WB. And yea im aware that you cant really go over 100% as they go static but one log even has a few frames @ 103%...so yea.....like i said I was SHOCKED.
	[Reply w/Quote]

05-29-2008, 02:15 AM	#24
blacksharpie Registered User Join Date: Jun 2007 Posts: 150 Location: User is: OffLine	Re: Vortech supercharger pulley change Link to a pic of the log showing a WOT run: http://s198.photobucket.com/albums/a...ent=102inj.jpg Tune type = Open Loop Speed Densety AFR commanded = 12.72 AFR Actual = 13.39 INJ Duty cycle = 102% If you look at all the parameters im logging you can see that the injectors go static and still cant attain the commanded afr. Hope im not coming off like a jack ass but I couldn't really believe it myself.
	[Reply w/Quote]

05-29-2008, 12:37 PM	#25
rentedmule blown snowplow Age: 31 Join Date: May 2006 Posts: 857 Location: Edmonton, AB User is: OffLine	Re: Vortech supercharger pulley change Sorry, I didn't mean to come off like an ass either, I just found it hard to believe given the power that can be pushed out of the stock injectors. It makes it hard to believe that some guys can put down 250+ rwhp on just an FMU and a fuel pump!
	[Reply w/Quote]

05-29-2008, 01:33 PM	#26
blacksharpie Registered User Join Date: Jun 2007 Posts: 150 Location: User is: OffLine	Re: Vortech supercharger pulley change Quote: Originally Posted by rentedmule Sorry, I didn't mean to come off like an ass either, I just found it hard to believe given the power that can be pushed out of the stock injectors. It makes it hard to believe that some guys can put down 250+ rwhp on just an FMU and a fuel pump! Yep exactly what my thoughts were also, it prolly has allot to do with the FMU.....but who knows
	[Reply w/Quote]