Rotrex pulley change

R3drckt09 · 07-26-2014, 05:46 PM

Searched and found nothing, has anyone with a GTM SC changed the pulley on their rotrex supercharger? My stage 1.5 is running great but I found out they sent me a 92mm pulley when I had ordered an 88mm. They sent me the 88 and I'm ready to swap it, but after taking the 6 pulley bolts off it's still on there really tight.

lj909 · 07-26-2014, 06:43 PM

Don't you need some sort of press tool?

R3drckt09 · 07-26-2014, 06:55 PM

No idea. I did on my Cobalt ss sc, but this pulley looks alot different. And it says "Changing pulleys is a 20 minute job", I don't think I should have to remove the sc or anything

warpeacelove · 07-26-2014, 10:43 PM

88 pulley produces how much boost on the stage sc 1.5 ?

aszyd · 07-27-2014, 12:46 AM

Check out page 13 in the guide below.

http://www.rotrex.com/media/e859c20d...let%20V5_5_pdf

R3drckt09 · 07-27-2014, 07:55 AM

Thanks, the GTM one is different though like there's no center screw. Figured it out this morning though, I looked at the inside of the new pulley and there's a little intention for the shaft to fit in, so I just had to pry a little bit with a flat head and it popped off. Slapped the 88 on there and I'm hitting 11 pounds!

aszyd · 07-27-2014, 10:05 AM

Very nice!

ANMVQ · 07-28-2014, 08:30 AM

Quote:

Originally Posted by R3drckt09

Thanks, the GTM one is different though like there's no center screw. Figured it out this morning though, I looked at the inside of the new pulley and there's a little intention for the shaft to fit in, so I just had to pry a little bit with a flat head and it popped off. Slapped the 88 on there and I'm hitting 11 pounds!

Um retune! Or did you already?

kloudak47 · 07-31-2014, 06:55 PM

So changing the pulley is not a 20 minute deal unless the unit is not on the car.

I have a 1.5 kit for my HR and I had this same question when I swapped pullies. I asked Mike@GTM for the method of removal and what he said to do was take two screw drivers, wrap them with painters tape (so they dont scratch anything). Put one screw driver under the pulley from one side and then use the other screw driver in the same manner from the other side.

You then push down on the screw drivers and essentially pry up the pulley.

Of course the screws that keep the pulley mounted need to be out but if you work the screw drivers gently you'll pup the pulley off.

This assumes the SC itself is sitting in front of you and again not on the car. If you are clever enough this might be doable with the unit in the engine bay but it's probably a real PITA to do.

R3drckt09 · 08-01-2014, 06:32 PM

I was actually able to do it while it was on the car. I took the undertray off and moved the tensioner from below, took the screws out and I ended up just taking a screwdriver and prying it off. It probably only does take 20 minutes, I just waited to see if anyone knew cause I didnt wanna bend the shaft or anything crazy.

R3drckt09 · 08-01-2014, 06:35 PM

Quote:

Originally Posted by warpeacelove

88 pulley produces how much boost on the stage sc 1.5 ?

Not sure exactly what it's supposed to make, but my prosport gauge is reading 11 pounds. I think that's about right but it's not a super high end gauge or anything. Getting a dyno tune on Wednesday and then I should know the true psi.

1slow370 · 08-01-2014, 07:37 PM

and then some day go down to the 84mm pulley

R3drckt09 · 08-01-2014, 11:17 PM

Quote:

Originally Posted by 1slow370

and then some day go down to the 84mm pulley

Dude what's up with the 84 anyways, Sam refused to sell it to anyone??

1slow370 · 08-02-2014, 03:32 AM

I unno maybe it blows chargers up?

Sent from my HTCONE using Tapatalk

1slow370 · 08-03-2014, 12:19 AM

Supercharger kits are usually listed with different sizes of pulley and alot of times the really small sizes are for when you are running smaller crank pullies(especially on murican cars because there are many different options for crank pullies) some of the small sizes when run with a larger crank pulley can overspeed chargers. you would want to look at the redline on the charger and then figure crank pulley diameter/blower pulley diameter x crank rpm to figure out how fast the charger will be spun. sometimes this means you need to also calculate the step up n the chargers gearing when it's max rpm is listed at the impeller not input pulley

07-26-2014, 05:46 PM	#1 (permalink)
R3drckt09 Base Member Join Date: Jul 2013 Location: Texas Posts: 145 Drives: 09 Nissan 370Z Base Rep Power: 12	Rotrex pulley change Searched and found nothing, has anyone with a GTM SC changed the pulley on their rotrex supercharger? My stage 1.5 is running great but I found out they sent me a 92mm pulley when I had ordered an 88mm. They sent me the 88 and I'm ready to swap it, but after taking the 6 pulley bolts off it's still on there really tight.

07-26-2014, 06:43 PM	#2 (permalink)
lj909 Track Member Join Date: May 2014 Location: Riverside Posts: 584 Drives: 40th 370Z Rep Power: 12	Don't you need some sort of press tool? aszyd likes this. __________________ PW 07 HR350Z R.I.P. Totaled by 82yr old woman 2010 40th Anniversary 370Z

07-27-2014, 12:46 AM	#5 (permalink)
aszyd Track Member Join Date: May 2014 Location: Florida Posts: 877 Drives: Magma Red 370z T+S Rep Power: 21	Check out page 13 in the guide below. http://www.rotrex.com/media/e859c20d...let%20V5_5_pdf __________________ Competition Clutch\|Fast Intentions\|Maxbore\|NST\|Setrab\|Stillen\|Tomei\|Uprev\| Z1 Avant Garde\|SPC\|Stance\|Whiteline Aerojacket\|Seibon\|Tanabe\|TRS\|TWM Last edited by aszyd; 07-27-2014 at 12:48 AM.

07-27-2014, 07:55 AM	#6 (permalink)
R3drckt09 Base Member Join Date: Jul 2013 Location: Texas Posts: 145 Drives: 09 Nissan 370Z Base Rep Power: 12	Thanks, the GTM one is different though like there's no center screw. Figured it out this morning though, I looked at the inside of the new pulley and there's a little intention for the shaft to fit in, so I just had to pry a little bit with a flat head and it popped off. Slapped the 88 on there and I'm hitting 11 pounds! aszyd likes this.

07-27-2014, 10:05 AM	#7 (permalink)
aszyd Track Member Join Date: May 2014 Location: Florida Posts: 877 Drives: Magma Red 370z T+S Rep Power: 21	Very nice! R3drckt09 likes this. __________________ Competition Clutch\|Fast Intentions\|Maxbore\|NST\|Setrab\|Stillen\|Tomei\|Uprev\| Z1 Avant Garde\|SPC\|Stance\|Whiteline Aerojacket\|Seibon\|Tanabe\|TRS\|TWM

07-26-2014, 06:55 PM	#3 (permalink)
R3drckt09 Base Member Join Date: Jul 2013 Location: Texas Posts: 145 Drives: 09 Nissan 370Z Base Rep Power: 12	No idea. I did on my Cobalt ss sc, but this pulley looks alot different. And it says "Changing pulleys is a 20 minute job", I don't think I should have to remove the sc or anything

07-26-2014, 10:43 PM	#4 (permalink)
warpeacelove Enthusiast Member Join Date: Nov 2011 Location: NY Posts: 281 Drives: G37x GTM TT Rep Power: 14	88 pulley produces how much boost on the stage sc 1.5 ?

07-31-2014, 06:55 PM	#9 (permalink)
kloudak47 Base Member Join Date: Jun 2012 Location: WA Posts: 2 Drives: 08 350Z Rep Power: 13	So changing the pulley is not a 20 minute deal unless the unit is not on the car. I have a 1.5 kit for my HR and I had this same question when I swapped pullies. I asked Mike@GTM for the method of removal and what he said to do was take two screw drivers, wrap them with painters tape (so they dont scratch anything). Put one screw driver under the pulley from one side and then use the other screw driver in the same manner from the other side. You then push down on the screw drivers and essentially pry up the pulley. Of course the screws that keep the pulley mounted need to be out but if you work the screw drivers gently you'll pup the pulley off. This assumes the SC itself is sitting in front of you and again not on the car. If you are clever enough this might be doable with the unit in the engine bay but it's probably a real PITA to do.

08-01-2014, 06:32 PM	#10 (permalink)
R3drckt09 Base Member Join Date: Jul 2013 Location: Texas Posts: 145 Drives: 09 Nissan 370Z Base Rep Power: 12	I was actually able to do it while it was on the car. I took the undertray off and moved the tensioner from below, took the screws out and I ended up just taking a screwdriver and prying it off. It probably only does take 20 minutes, I just waited to see if anyone knew cause I didnt wanna bend the shaft or anything crazy.

08-01-2014, 07:37 PM	#12 (permalink)
1slow370 A True Z Fanatic Join Date: Aug 2009 Location: In the D Posts: 3,732 Drives: v8 74 260z ;) Rep Power: 7251	and then some day go down to the 84mm pulley R3drckt09 likes this. __________________ ANSWER PRICE LIST Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50

08-02-2014, 03:32 AM	#14 (permalink)
1slow370 A True Z Fanatic Join Date: Aug 2009 Location: In the D Posts: 3,732 Drives: v8 74 260z ;) Rep Power: 7251	I unno maybe it blows chargers up? Sent from my HTCONE using Tapatalk __________________ ANSWER PRICE LIST Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50

08-03-2014, 12:19 AM	#15 (permalink)
1slow370 A True Z Fanatic Join Date: Aug 2009 Location: In the D Posts: 3,732 Drives: v8 74 260z ;) Rep Power: 7251	Supercharger kits are usually listed with different sizes of pulley and alot of times the really small sizes are for when you are running smaller crank pullies(especially on murican cars because there are many different options for crank pullies) some of the small sizes when run with a larger crank pulley can overspeed chargers. you would want to look at the redline on the charger and then figure crank pulley diameter/blower pulley diameter x crank rpm to figure out how fast the charger will be spun. sometimes this means you need to also calculate the step up n the chargers gearing when it's max rpm is listed at the impeller not input pulley R3drckt09 likes this. __________________ ANSWER PRICE LIST Answers - - - - - - - - - - - - - - - - $0.75 Answers (requiring thought) - - - - $1.25 Answers (correct) - - - - - - - - - - $12.50

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