Joined
·
210 Posts
Hey I've seen mention of a relatively inexpensive pulley that supposedly adds 8-10 hp. Can someone link the part number or vendor package?
Looking for that Pully mod that adds 8-10 hp
1 - 20 of 23 Posts
Joined
·
7 Posts
Joined
·
277 Posts
AFAIK there is no pulley for the 09-10-11 5.7 Eagle.
Joined
·
1,051 Posts
Joined
·
210 Posts
Thanks guys. If a pulley says it's compatible with the '10 does that mean it also is compatible with the '11?
Joined
·
147 Posts
That's a good point...........although ADDING sounds better :browsmiley:
Joined
·
2,054 Posts
Just curious why you're looking at adding such a small amount. You'll never notice that increase while driving.
Joined
·
903 Posts
I wouldn't risk this mod. Small risk but still a risk... for well, really nothing.
Joined
·
120 Posts
There is NO risk to adding an under-drive pulley to the Challenger. I added one to my '10 SRT and have absolutely NO problems as a result. Charging is just fine and no overheating issues ever ( including getting stuck in rush hour traffic in 97 degree heat for over and hour!). Don't let anyone tell you there is risk with this mod if they themselves haven't personally experienced a problem with their car with the same mod. There are entirely too many people out there who are more than willing to give you "free" advice on something they themselves know nothing of. There is a slight difference in how the car responds to throttle, as it pertains to the engine's ability to "RPM" through the gears and this is measurable on a dyno. Will it make a dramatic difference?? NO....but it is of benefit and can help make the difference in a very close race. I'm using the SLP unit, but there are a few choices out there. Probably just a matter of preference. You will need to change to the correct length belt if you install the pulley.
Joined
·
210 Posts
er... what?
between the small amount of added performance ("to the rear wheels") of multiple mods - well the way I see it together the sum is well... noticable?
exhaust headers
high flow cats
cat back
custom tune
CAI
pully mod
what might be 5 hp gain between each well kind of adds up with all of them right? Or am I being stupid?
thanks bacdocmiller - the insight of someone with this mod is helpful.
Joined
·
8,332 Posts
Here are the two options.
For the 05-10 6.1 and 05-08 5.7 we have the SLP 25% Underdrive
SLP Harmonic Balancer Underdrive Pulley 05-08 300, Charger, Magnum 5.7L, 05-10 300, Charger, Magnum, Challenger 6.1L
For the 09-11 5.7 we have the ATI 15% Underdrive
ATI Super Damper 15% Underdrive Harmonic Balancer 09-10 300, Challenger, Charger R/T 5.7L
As noted these have ZERO negative affects on these cars, so don;t let anyoen scare you into your alternator running to slow or your lights not working etc...simply does not happen.
For the 05-10 6.1 and 05-08 5.7 we have the SLP 25% Underdrive
SLP Harmonic Balancer Underdrive Pulley 05-08 300, Charger, Magnum 5.7L, 05-10 300, Charger, Magnum, Challenger 6.1L
For the 09-11 5.7 we have the ATI 15% Underdrive
ATI Super Damper 15% Underdrive Harmonic Balancer 09-10 300, Challenger, Charger R/T 5.7L
As noted these have ZERO negative affects on these cars, so don;t let anyoen scare you into your alternator running to slow or your lights not working etc...simply does not happen.
Joined
·
210 Posts
Thanks Kris -
why is the second pulley twice as expensive as the first? What's the difference between 25% and 15% translate to?
why is the second pulley twice as expensive as the first? What's the difference between 25% and 15% translate to?
Those of you who state "no problems or it doesn't happen", I truly hope you consider every environmental operating condition that the platform will see before making that blanket statement.
There is a reason why Auburn Hills Powertrain and Electrical interface group chooses pulley sizing during the integrated platform development cycle. It is 110% true that you shed a percentage of parasitic FEAD belt loss by undersizing the pulley, you also wipe out your usual engineered in 1.25% safety factor.
For Southern States, chances are you won't notice anything as long as your potential cooling flow rates are at their nominal OEM capacity. You run the risk of cavitation and other fluid dynamic anomalies but, that depends on how the Reynolds Number formula was modeled and equated in the cooling passages since you have also slowed the impeller below its optimal idle speed.
However, take that same platform to Northern States and put a full demand high amperage load during an extended idle (ie, Plenum Defroster Max with max Fan speed, Elec Defrost on, Full Illumination and seat heaters) and let me know how you make out.
You might also want to put a thermocouple onto the alternator, so you can be horrified at the large temperature increase of the unit since you have also slowed its cooling efficiency across the windings by 25% during its highest demand cycle.
Don't forget to also factor in increased DC line loss and other parasitic voltage traps. Best case, the PCM starts load shedding by shutting down secondary systems, worse case, fire. And yes, fire has occurred many times by people running underdrive pullies. The older 5.0 Mustangs were particularly susceptible to this due to the closeness of the main Vbat cable to the IVR Vbat and Vref.
If you are really interested in shedding parasitic FEAD belt loss, petition Meziere or other companies to bring an electric water pump to market for the 5.7 and 6.1.
Look, not trying to come off like a D-Bag but, there is a reason why those of us who carry SAE memberships have spent careers developing, designing and testing. It's not some willy nilly thing on why ratios are picked, so please investigate deeply before you ditch your original set up.
There is a reason why Auburn Hills Powertrain and Electrical interface group chooses pulley sizing during the integrated platform development cycle. It is 110% true that you shed a percentage of parasitic FEAD belt loss by undersizing the pulley, you also wipe out your usual engineered in 1.25% safety factor.
For Southern States, chances are you won't notice anything as long as your potential cooling flow rates are at their nominal OEM capacity. You run the risk of cavitation and other fluid dynamic anomalies but, that depends on how the Reynolds Number formula was modeled and equated in the cooling passages since you have also slowed the impeller below its optimal idle speed.
However, take that same platform to Northern States and put a full demand high amperage load during an extended idle (ie, Plenum Defroster Max with max Fan speed, Elec Defrost on, Full Illumination and seat heaters) and let me know how you make out.
You might also want to put a thermocouple onto the alternator, so you can be horrified at the large temperature increase of the unit since you have also slowed its cooling efficiency across the windings by 25% during its highest demand cycle.
Don't forget to also factor in increased DC line loss and other parasitic voltage traps. Best case, the PCM starts load shedding by shutting down secondary systems, worse case, fire. And yes, fire has occurred many times by people running underdrive pullies. The older 5.0 Mustangs were particularly susceptible to this due to the closeness of the main Vbat cable to the IVR Vbat and Vref.
If you are really interested in shedding parasitic FEAD belt loss, petition Meziere or other companies to bring an electric water pump to market for the 5.7 and 6.1.
Look, not trying to come off like a D-Bag but, there is a reason why those of us who carry SAE memberships have spent careers developing, designing and testing. It's not some willy nilly thing on why ratios are picked, so please investigate deeply before you ditch your original set up.
Joined
·
120 Posts
While it's true that factory engineers have to plan for worst case senarios when designing systems such as has been brought up, it is just that....a worst case senario that rarely happens. Today's hemi has a very well engineered cooling system with a lot of excess capacity, so slowing down the water pump by 25% is not going to create any type of over-heating problem, even with the A/C going, in anything but the very most extreme temps. Alternator temps. will also quickly return to normal once engine rpm is brought up even a little bit with resumed vehicular operation.
The senario used as an an example for extreme electrical load is valid, but not at all common when you consider that the rear electrical defroster is on an automatic timer and therefore will not be used constantly, in all likelihood. Also the front defroster will also not be used constantly on Max. setting for any great length of time, as once the windshield is cleared it is no longer necessary to run it at Max setting to keep it clear...also the noise will usually force the driver to set it to a lower setting, thus also reducing the electrical loading.
With these factors in mind, and also noting how good the factory hemi charging system is to begin with, it would indeed be a rare exception that the under-drive pulley would create a problem. Also, as far as Hemi Challenger owners are concerned, the vast majority of them put there cars away for the winters in northern states where winters are often cold and snowy.
Again, while it's true that worst case senarios must be anticipated/designed for from the factory, these senarios are certainly the exception, and very rarely encountered by the typical Hemi Challenger owner. Could a problem occur with the use of an under-drive pulley?....yes.....in rare circumstances......but is it likely to occur in typical usage?.....no. As long as the owner understands how the pulley works and what exactly it does, the likelhood of there being a problem with utilizing and under-drive pulley on the Hemi Challenger is fairly remote overall. I do agree that an electric water pump and also an electric power steering pump across the entire hemi line-up would negate the need for/use of an under-drive pulley setup to begin with. That would certainly be my preference.
Joined
·
8,332 Posts
Sigh....
Here is the deal..these have been running on late model 5.7 and 6.1 cars for the last 6+ years...hot climates... Cold climates...stock cars...modded cars...thousands and thousands have been sold...cars with low miles cars with high miles...cars in the us, Canada, south America, austrailia, Europe...I have yet to hear of someone that had any serious issues because of an under drive on these cars...if you are worried about it don't do ... The oem engineers also didn't plan on heads cam nitrous or superchargers, tuners etc etc etc...if you...if you base all decisions on that factor you should just keep your car stock. I have heard the 5.0 mustang argument for the last 6 years...yes there were issues on the mustangs...but that was a car completely different in every way possible from what we are talking about here..Not to mention the fact it was 20+ years ago
Anyway...those are the facts...unless someone has something to the contrary..that I have somehow never heard since the late model hemi was introduced about the vast problems that are occurring on lx and lc platform cars running under drive pullies
Here is the deal..these have been running on late model 5.7 and 6.1 cars for the last 6+ years...hot climates... Cold climates...stock cars...modded cars...thousands and thousands have been sold...cars with low miles cars with high miles...cars in the us, Canada, south America, austrailia, Europe...I have yet to hear of someone that had any serious issues because of an under drive on these cars...if you are worried about it don't do ... The oem engineers also didn't plan on heads cam nitrous or superchargers, tuners etc etc etc...if you...if you base all decisions on that factor you should just keep your car stock. I have heard the 5.0 mustang argument for the last 6 years...yes there were issues on the mustangs...but that was a car completely different in every way possible from what we are talking about here..Not to mention the fact it was 20+ years ago
Anyway...those are the facts...unless someone has something to the contrary..that I have somehow never heard since the late model hemi was introduced about the vast problems that are occurring on lx and lc platform cars running under drive pullies
Joined
·
120 Posts
AMEN!!! My feelings/experience exactly!
1 - 20 of 23 Posts
