yes or no on slp 25% underdrive pulley - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

hou30guy · 03-09-2016, 08:37 AM

Pros and or cons on slp 25% underdrive pulley on a 2011 l99. Should I or no and why

Badfinger · 03-09-2016, 02:44 PM

Tell us about your car is it stock?

christianchevell · 03-09-2016, 06:14 PM

under drive pulleys are best for a built car like my 950 rpm idling cammed car, and I do not under drive the A/C and with the idle higher it does not affect the car, I use a Fluidampr which has fluid inside to help harmful vibrations. Many moons ago I heard of some balancers falling apart and I think they might have been SLP ....its a bad sign if the thing has a rubber vibration ring to isolate vibrations like a old school harmonic balancer separating the two halves of the balancer, our engines are internally balanced and not so much as a good builder does not improve apon it as the crank is only balanced so well......And timing chains and bearings for cam and other things have been hurt by vibrations on cars when radically cammed. I know a fluidampr is $400 also compared to cheaper ones, you find a case of you get what you pay for. I had a TSP one once and my tuner did not want to install it because it looked cheap according to him and too much stock, I ended up selling it online, and know fluidampr or other high end brand are best.

62nalide · 03-09-2016, 07:33 PM

SLP underdrive for 3 years now zero issues what so ever best $200 ever spent

JCunningham · 03-09-2016, 10:44 PM

unless your cammed and idle at 800+rpm with a 7000+rpm redline it's no benefit to you. They do not free up power. There to keep the accessories running slower for high rpm applications. On mine when I put in a different cam that idled at 650 it made my dome lights flicker. old cam was 850rpm.

WHAMMO · 03-10-2016, 11:31 PM

Always had U/D pulleys and never had a problem. Mine is Powerbond. Yes do it.

TXM62SS · 03-11-2016, 07:09 AM

If you are cammed you should have no issue. Go for it.

Pro Stock John · 03-11-2016, 12:59 PM

Powerbond here. Every bit helps.

Rctreece · 03-11-2016, 01:11 PM

Would the affect the tune in anyway on a cammed car?

bhillakaiceberg · 03-11-2016, 02:34 PM

SLP 25% UDP here. No issues. Even run a Braille 21lb battery. All is well. Whatever gains it gives...Im fine with it. Def don't hurt.

45th rs/2ss · 12-29-2020, 01:50 PM

Currently running the SLP Pulley for 4 plus years on my L99. It will be removed next month for the stock unit when the Heartbeat tvs2300 gets installed, so it may be for sale on Camaro5 shortly.

It definitely makes your battery work harder. I kill a battery just about every year and a half to 2 years max. Before I added the pulley, I would get more battery life. I have no aftermarket Stereo equipment.

No other issues with any of the on board equipment. Only had the seat warmer on this morning (38 degrees), and my voltage was just under 12v or right at while in the Starbucks drive through.

I added the phastek race scoop to my CAI, and the UD Pulley at the same time, and shaved .2 off of my 1/4 mile ET for a bolt on car. I was full exhaust, CAI, and tune before that. No doubt it helps, but its give and take. Not enough for me to hate it either. Would do it again.

A little late, but wanted to get this info out there. Hope this helps anyone on the fence.

Bo White · 12-29-2020, 02:19 PM

Powerbond 25% for too long to remember. I will say that I've never had one with the stock cam. Mine has always been with a cam swap and raised idle rpm.

Silverado60 · 12-29-2020, 05:13 PM

I’m waiting on a fluid damper 25% under drive from jegs. It’s an easy 5 hp for the non electric power steering cars. Plus never hurts to add a damper

03-09-2016, 08:37 AM	#1
hou30guy Drives: 2011 convertible 2ss/rs Join Date: Sep 2015 Location: Houston Posts: 971	yes or no on slp 25% underdrive pulley Pros and or cons on slp 25% underdrive pulley on a 2011 l99. Should I or no and why

03-09-2016, 06:14 PM	#3
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	under drive pulleys are best for a built car like my 950 rpm idling cammed car, and I do not under drive the A/C and with the idle higher it does not affect the car, I use a Fluidampr which has fluid inside to help harmful vibrations. Many moons ago I heard of some balancers falling apart and I think they might have been SLP ....its a bad sign if the thing has a rubber vibration ring to isolate vibrations like a old school harmonic balancer separating the two halves of the balancer, our engines are internally balanced and not so much as a good builder does not improve apon it as the crank is only balanced so well......And timing chains and bearings for cam and other things have been hurt by vibrations on cars when radically cammed. I know a fluidampr is $400 also compared to cheaper ones, you find a case of you get what you pay for. I had a TSP one once and my tuner did not want to install it because it looked cheap according to him and too much stock, I ended up selling it online, and know fluidampr or other high end brand are best. __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop

03-09-2016, 07:33 PM	#4
62nalide Drives: 2013 SS Join Date: May 2013 Location: DFW Posts: 4,102	SLP underdrive for 3 years now zero issues what so ever best $200 ever spent __________________ https://frankensteined.net/ Martin@Frankensteined.net

03-09-2016, 10:44 PM	#5
JCunningham Drives: 2017 2SS M6 Join Date: Jun 2013 Location: WNY Posts: 7,070	unless your cammed and idle at 800+rpm with a 7000+rpm redline it's no benefit to you. They do not free up power. There to keep the accessories running slower for high rpm applications. On mine when I put in a different cam that idled at 650 it made my dome lights flicker. old cam was 850rpm. __________________ real ZL1 wheels and brakes, 285/305 Michelin Pilot Super Sports, Pray ported Intake manifold, Soler Throttle Body, Rotofab intake, EFI Tuning Flex fuel kit, full American Racing Headers Exhaust, 1 7/8" w/ cats H pipe and mufflers. Full 1LE suspension, with BMR adjustable sway bars and links, GM aluminum cradle bushings, Hurst shifter with lighter reverse spring, TWM shifter knob, Tick level 1 transmission. I should have bought a ZL1

03-10-2016, 11:31 PM	#6
WHAMMO Drives: 13' 1LE Join Date: Apr 2012 Location: Canada Posts: 2,642	Always had U/D pulleys and never had a problem. Mine is Powerbond. Yes do it. __________________ 13' 1LE Old setup: TSP 231-236/Tick 660/.105 PR, UDP, SW LT 2'' & HFC, stock NPP & H pipe, VR-DRX CAI, air scoop, Goertz1 manifold, 102mm BBK, 26" Toyo DRs, Forgestars R17x10 & F18x8, rear seat delete, remote Pat G tune Autocal, 7400 limiter, Spec Mini Twin. 91oct. 11.90@122.3, 0-60ft 2.0 / 11.99@123.6, 0-60ft 2.1 DA+819 ...519RWHP SAE Solid roller SBE LS3, FED, LLSR, 91oct, 605rwhp N/A. Tuned by Pat G. Build by me.

03-09-2016, 02:44 PM	#2
Badfinger Drives: 2010 2SS Join Date: Mar 2010 Location: Dayton, Ohio Posts: 387 View My Garage	Tell us about your car is it stock?

03-11-2016, 07:09 AM	#7
TXM62SS Drives: 2012 2SS/RS LS3 Join Date: May 2012 Location: Pearland, TX Posts: 388	If you are cammed you should have no issue. Go for it. __________________ Victory Red 2012 2SS/RS LS3 Camaro Pat G. Spec Cam from Cam Motion 228/236 .599/.599 112+2LSA Kooks 1-7/8" LTs w/ Cats Roto-Fab, Bo White TB, Borla Touring Catback 3.91 1LE Gears, MGW Tuned by Pat G

03-11-2016, 12:59 PM	#8
Pro Stock John Writer Drives: 2010 SS / 1967 Camaro Join Date: May 2009 Location: Chicago, IL Posts: 7,216	Powerbond here. Every bit helps. __________________ 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

03-11-2016, 01:11 PM	#9
Rctreece 2013 Victory Red LS3 Vert Drives: 2013 SS/RS Join Date: Jul 2013 Location: Caledonia, MS Posts: 323	Would the affect the tune in anyway on a cammed car? __________________

03-11-2016, 02:34 PM	#10
bhillakaiceberg Drives: 2011 2SS/RS & 2017 1SS Join Date: Apr 2011 Location: Maryland Posts: 1,960	SLP 25% UDP here. No issues. Even run a Braille 21lb battery. All is well. Whatever gains it gives...Im fine with it. Def don't hurt. __________________ *2011 Chevrolet Camaro 2SS/RS L99* (1 of 782) 10.78 @125mph ALL MOTOR SBE Built/Tuned by Me 2017 Chevrolet Camaro 1SS Auto 9.29 @144.57mph ALL MOTOR SBE #TEAMGPI Gwatney Performance Innovation

12-29-2020, 01:50 PM	#11
45th rs/2ss Drives: 45th Anniversary rs/2ss Join Date: Oct 2013 Location: Monterey Park CA Posts: 24	4-5 Years Currently running the SLP Pulley for 4 plus years on my L99. It will be removed next month for the stock unit when the Heartbeat tvs2300 gets installed, so it may be for sale on Camaro5 shortly. It definitely makes your battery work harder. I kill a battery just about every year and a half to 2 years max. Before I added the pulley, I would get more battery life. I have no aftermarket Stereo equipment. No other issues with any of the on board equipment. Only had the seat warmer on this morning (38 degrees), and my voltage was just under 12v or right at while in the Starbucks drive through. I added the phastek race scoop to my CAI, and the UD Pulley at the same time, and shaved .2 off of my 1/4 mile ET for a bolt on car. I was full exhaust, CAI, and tune before that. No doubt it helps, but its give and take. Not enough for me to hate it either. Would do it again. A little late, but wanted to get this info out there. Hope this helps anyone on the fence.

12-29-2020, 02:19 PM	#12
Bo White Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012 Location: Vance Alabama Posts: 8,019	Powerbond 25% for too long to remember. I will say that I've never had one with the stock cam. Mine has always been with a cam swap and raised idle rpm.

12-29-2020, 05:13 PM	#13
Silverado60 Drives: 2010 camaro 2SS/RS M6 Join Date: Sep 2014 Location: Pa Posts: 238	I’m waiting on a fluid damper 25% under drive from jegs. It’s an easy 5 hp for the non electric power steering cars. Plus never hurts to add a damper __________________ Texas speed F-35 cam, rollmaster timing set, melling hp pump, ls2 chain damper, fluid damper 25% under drive, Che rocker bushings, tsp .660 lift valve springs, BBK CAI Amzoil filter with Phastek ww relocation and scoop, Gmpp axle back, Speed engineering 1 7/8" LT's no cats, Peak speed shop ported tb, NGK tr6, MSD wires, Amsoil Zrod wix, heritage grill, 1.25" BMR springs, MRR 228, Nitto Nt05,dyno tuned by complete street performance, elite eng catch can, clean side separator, Hurst shifter, Zl1 addon wickerbill