What have the experiences been on lag with those that have swapped out their pulleys to overdrive the S/C? In theory, when the S/C clutch engages the larger pulley would put more initial load on the engine to get the S/C spinning up to speed, like starting out in a higher gear on a stick. I'm more familiar with Turbos -- have seen a number of large turbo swaps that added big hp numbers on the top end on the track of strip but have sacrificed quite of bit of throttle response on the street. Also, has anyone experienced any electronic gremlins or S/C durability issues from overdriving it? Do they run stock belts?

 

I just installed an ASP pulley on a co-workers SRT this weekend...and it definitely didn't seem to add any lag. If anything, it remedied some of the original lag.

I think your theory is a little off too - with that bigger pulley, at idle the supercharger will be spinning faster - and therefore when the supercharger finally engages, it will already be spinning faster than with the original pulley - hence less lag if anything.

The belt with the ASP pulley is stock because it also includes two smaller pulleys to offset the oversized crank pulley.

The only issues I have seen have been the IAT sensor and Intercooler pump failures. These are common without the pulley, so they should be magnified with it. They are easy fixes though. Upgrading the heat exchanger and intake air cooling system would be a good idea regardless of whether you stay stock or if you overdrive the S/C.

I too am used to large single turbo setups creating some lag - this is not the case with the SRT6.

SQ

 

I haven't noticed any additonal lag - it just goes like hell!

 

Thanks for the feedback. I see ASP, Needswings, Renntech and LET pulleys referenced on these boards? Probably a whole other thread, but any pluses one over the other or with specific sizes? I'm assuming a 10-12% increase in max S/C speed is probably within or close to the tolerances that these were built for -- beyond that who knows. I'm guessing that should equate to another 1 1/2 to 2 lbs of boost -- maybe +35 hp at the crank w/o heat soak issues. But I'm not really clear how that lines up with the different size pulleys that I see referenced.

 

Rentech, EVO, ASP & LET offer a 178mm Pulley (14% boost) - I believe the Needswings pulley is an ASP pulley he offers in a package but I am not sure. With the exception of LET they all use the stock dampener where LET uses a fluid dampener. (actually it's pretty trick).

LET also offers a 181mm Pulley (16% boost) and a 185mm Pulley (20% boost) - I'm installing the 185mm pulley as I write - just waiting on a idler pulley spacer that LET forgot to ship with the pulley kit. Keep an eye out - I will have a write-up on it soon. I does look trick - totally different engineering then the other pulleys.

I have a Saturday Appt with the Dyno/Tuner that I hope I can keep.

 

Indeed it is.

As for the ASP pulley, I just installed one this weekend. It uses a stock dampener with a larger ring welded to the outside.

The good thing to this is that the pulley looks stock - you'd have a hard time telling it was aftermarket unless you really knew what you were looking at, or if you measured it. The factory part #'s are still stamped on the pulley's center section.

The downfall to this (other than the fact that it looks stock and not 'trick')is that the M112 motor is known to have issues where the dampener wears out and begins to wobble causing engine and driveline vibration. So, eventually, the pulley could become useless - at that point you either buy another $900 pulley set, or you go back to stock.

Keep us posted BB.

SQ

 

Hello,

I think because ASP uses only NEW factory MB-Pullies, the dampener should last for a long time. Have not heard of problems from ASP-Users for a long time...

Kind Regards
Bruno

 

No throttle lag for me, my gas pedal is very touchy. When I took my car in for a four wheel alignment after installing the Eibach springs and camber bushings, the guy driving the car on to the rack told the guy guiding him to get the hell out of the way because he was afraid he would run him over. And the few times that my wife has ridden in the car she gets on to me for throwing her head back when touching the gas pedal, she's not driven the car so she thinks I'm gunning it.

 

Ok so need some advice here ppl, I just got back from iraq, excited as hell to get my car and now this crap happens. It feels like im losing boost on my S/C, At times it goes all out but more often now when i get on it, it seems to only feel like it has 2 lbs. of boost. It shifts fine and there is no transmission leaks, It just doesnt have its "*****" all the time and its really starting to aggrevate me! Any ideas people? The car is still under full factory warranty just trying to give the guys a headsup before i take it in.

 

If it goes like heck when you first get in it and then looses power after it is warmed up..... replace your IC pump... that should fix it.

MikeR