can someone explain the ati damper underdrive pully to me

[jon0m0berry]

I was on moes and keep seeing this ati underdrive pully and have heard a little about it on this site. I understand the underdrive pully part and know what it does. im curious though if there are any negative affects from everything spinning slower for just everyday use. but im completely in the dark about it being a damper. can you guys help me understand that part. also is this something someone could do in there drive way with basic tools and general mechanical knowledge? I don't consider myself a full blown mechanic but I think im ok in terms of working on vehicles

 

[Hemi450hp]

If you have a huge stereo or other accessories that would pull a lot of electrical draw, then the underdrive pulley could make it touch on your charging system because the alternator is not spinning as fast. I had a 10" sub with a 250 watt amp in my last truck with this pulley and never had a problem with that though.

As for the damper, that is what helps keep your crankshaft spinning true at higher rpms. For the guys going to the track or manually shifting over about 6200rpms, this is just good added insurance to make sure you dont have any vibration in the crank.

 

[GP4L]

I was on moes and keep seeing this ati underdrive pully and have heard a little about it on this site. I understand the underdrive pully part and know what it does. im curious though if there are any negative affects from everything spinning slower for just everyday use. but im completely in the dark about it being a damper. can you guys help me understand that part. also is this something someone could do in there drive way with basic tools and general mechanical knowledge? I don't consider myself a full blown mechanic but I think im ok in terms of working on vehicles

Well, you'll need a torque wrench to properly install the new crank pulley. So if that's not included in your basic tool set, you'll need one - preferably a high quality one (not the autozone rental that hasn't been calibrated in years). Removing the crank pulley bolt can be quite difficult as well, without the right tools.

One negative that can be experienced from an underdrive pulley is; all the driven accessories being less efficient at idle, like the alternator. I have no experience with the Hemi, but have seen it countless times with other makes/models.

ATI is regarded as a pretty damn good aftermarket harmonic balancer. But I prefer Fluidampr crank pulleys for a variety of experience related reasons.

However, I'm not sure if Fluidampr makes a pulley for these trucks. They might. I do know that Fluidampr is significantly more popular with imports.

I guess an appropriate question to ask is: what are you looking to gain out of purchasing an underdrive crank pulley? Myself, and others in the industry usually regard a quality aftermarket harmonic balancer as extra insurance on engines that are getting the snot beat out of them via big power, or track abuse. Not really the underdrive aspect - which often has nominal power at the wheels improvement. 15% underdrive doesn't = 15% more power. The normal everyday driver might not really gain anything significant enough to quantify the price.. So, what are you looking to gain?

 

[GP4L]

If you have a huge stereo or other accessories that would pull a lot of electrical draw, then the underdrive pulley could make it touch on your charging system because the alternator is not spinning as fast. I had a 10" sub with a 250 watt amp in my last truck with this pulley and never had a problem with that though.

As for the damper, that is what helps keep your crankshaft spinning true at higher rpms. For the guys going to the track or manually shifting over about 6200rpms, this is just good added insurance to make sure you dont have any vibration in the crank.

I know you guys sell ATI, but does Fluidampr make a harmonic balancer for our engines?

 

[Hemi450hp]

I know you guys sell ATI, but does Fluidampr make a harmonic balancer for our engines?

They dont. ATI is the only company making an underdrive pulley for the 4th gen Rams.