Underdrive Pulley - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

charles71 · 10-09-2015, 05:28 PM

Need some help. I had a SLP 25% under drive crank pulley installed and know my power steering at idle speed is nonexistent. The steering is fine once I get going but at parking lot speeds it is a "B" to turn the wheel. It worked fine before the swap. Has this happened to anyone before and how did you fix it besides removing the pulley? If the shop did not in stall the new smaller belts would this make a difference? The new belts are not much smaller and the old belts are pretty snug.

christianchevell · 10-09-2015, 05:58 PM

Cause and effect would sound like you may now need to purchase a smaller pulley for the power steering if it can fit to increase the distance traveled for the spinning pulley of the power steering pump. You may want to contact SLP and ask them. Even though having raised your cars idle with a cam to 900+ which can counter the effects of the under drive % in the electrical charging system the under driving is not good for the performance of the A/C system along with the power steering. Even though I have electric power steering I am using a Fluidampr which only under drives the electrical not the A/C and it is made with a detachable pulley. Good Luck to you. And of course if had to purchase a smaller pulley you may need a smaller belt....

Pro Stock John · 10-09-2015, 06:35 PM

I've been running an UDP for 15K miles, no issues like you described.

As for the performance gains, every bit counts.

Eric Baker · 10-10-2015, 07:11 AM

I too have an UDP pulley, SLP in my case too, nearly 20K on it with no issues whatsoever. I have a feeling there's a problem with your pump. They've been known to burn up doing donuts and such,, high revs while the steering is cranked to one side or the other. Not saying that's your case, but they have gone out on multiple other Camaros before.

christianchevell · 10-10-2015, 08:23 AM

See the guys with that pulley are chiming in: I have heard rarely of separation happening with a SLP underdrive and the thing falling apart... I also wonder if your driving the car way too low lugging it as cammed I have go to at least 1200 rpm. And 1500 is more optimal and less chance of surge/bucking. Anyone doing it should have had to install new belts as the old ones would not fit. the idler ok? is the belt routed right? is the power steering pump low on fluid now? is the belt the new one? many things to consider, and of course you should be able to easily turn the steering wheel with one finger at a stop..

10-09-2015, 05:28 PM	#1
charles71 Drives: 2011 Camaro SS Join Date: Aug 2015 Location: Southern Maryland Posts: 110 View My Garage	Underdrive Pulley Need some help. I had a SLP 25% under drive crank pulley installed and know my power steering at idle speed is nonexistent. The steering is fine once I get going but at parking lot speeds it is a "B" to turn the wheel. It worked fine before the swap. Has this happened to anyone before and how did you fix it besides removing the pulley? If the shop did not in stall the new smaller belts would this make a difference? The new belts are not much smaller and the old belts are pretty snug. __________________ Livernois Stage II Heads & Cam, LS7 Lifters, Ported Intake & Throttle Body, Rotofab CAI, BBK High Flow Fuel Rail @ Guage, Eaton Tru Trac Posi with 3.91 gears, 1000 HP Axels, Kooks Long tubes & full Corsa Exhaust, GM Hurst Short Throw Shifter, Mcleod RXT Twin Disc, Vitesse Throttle Controller, 1.5" Lowering Springs, Strut Tower Brace, SLP 25% Underdrive Pulley, Apex reservoir relocation kit and air scoop.

10-09-2015, 05:58 PM	#2
christianchevell old school chevy rodder Drives: 2013 2SS/RS Manual,DM exhaust,CRT Join Date: Jul 2012 Location: Oregon Posts: 5,587 View My Garage	Cause and effect would sound like you may now need to purchase a smaller pulley for the power steering if it can fit to increase the distance traveled for the spinning pulley of the power steering pump. You may want to contact SLP and ask them. Even though having raised your cars idle with a cam to 900+ which can counter the effects of the under drive % in the electrical charging system the under driving is not good for the performance of the A/C system along with the power steering. Even though I have electric power steering I am using a Fluidampr which only under drives the electrical not the A/C and it is made with a detachable pulley. Good Luck to you. And of course if had to purchase a smaller pulley you may need a smaller belt.... __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop Last edited by christianchevell; 10-10-2015 at 08:14 AM.

10-09-2015, 06:35 PM	#3
Pro Stock John Writer Drives: 2010 SS / 1967 Camaro Join Date: May 2009 Location: Chicago, IL Posts: 7,216	I've been running an UDP for 15K miles, no issues like you described. As for the performance gains, every bit counts. __________________ PROJECT HEAVY CHEVY Camaro Now: Mods for the Masses Part I \| Part II 13.15@106 1.95 \| 100% Stock 12.37@112 1.85 \| + Kooks Headers/Cats + 20" 555R + CAI + BW TB + UDP + Tune 12.06@113 1.70 \| + CD 3200 + 18" NT05R + RCR Intake + NE OTR + GPI Tune 11.84@115 1.59 \| + 3.91s + Race Star 17x7 Fronts 10.90@125 1.47 \| + GPI VVT Cam + BW Ported Heads + CD 3800

10-10-2015, 08:23 AM	#5
christianchevell old school chevy rodder Drives: 2013 2SS/RS Manual,DM exhaust,CRT Join Date: Jul 2012 Location: Oregon Posts: 5,587 View My Garage	See the guys with that pulley are chiming in: I have heard rarely of separation happening with a SLP underdrive and the thing falling apart... I also wonder if your driving the car way too low lugging it as cammed I have go to at least 1200 rpm. And 1500 is more optimal and less chance of surge/bucking. Anyone doing it should have had to install new belts as the old ones would not fit. the idler ok? is the belt routed right? is the power steering pump low on fluid now? is the belt the new one? many things to consider, and of course you should be able to easily turn the steering wheel with one finger at a stop.. __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop

10-10-2015, 07:11 AM	#4
Eric Baker Drives: Black/Black 2SS/RS 6M Join Date: Mar 2010 Location: Boston MA Posts: 987 View My Garage	I too have an UDP pulley, SLP in my case too, nearly 20K on it with no issues whatsoever. I have a feeling there's a problem with your pump. They've been known to burn up doing donuts and such,, high revs while the steering is cranked to one side or the other. Not saying that's your case, but they have gone out on multiple other Camaros before.