I thought I would take a moment to share by personal battle with KR.
Like most 95-99 rivi owners, I was intrigued with the idea of swapping pulleys to increase performance. My brother has a heavily modified GTP, and shared some of his knowledge with me. Also, I scoured this site, as well as the other relevant sites. I read up on the vendor sites as well.
First on my attack list was the gutting the airbox, and slapping in a K&N, followed by a 3 inch downpipe, and a gift of V Force mufflers, that were just too loud on the GTP. Next came the 104 plugs, the PRJ wires (just because) and the 180 Tstat. I felt ready to try a pulley, and bolted on the zzp system with a 3.5. I thought I was a well-prepared soldier, knowing the KR war could go on, but I was launching a good offensive.
I scanned, and realized I had completely underestimated the enemy. I saw as much as 5KR under heavy load.. Damn. I also realized I had committed a tactical error- in my haste, I had forgotten the advice of the many generals I had consulted - I forgot to scan before I started adding mods.
Perhaps i was trying to take too much territory at once,,,I backed off to a 3.6 pulley. Surely that would do the trick, right? Nope. I scanned again and still saw up to 4KR. So pissed.
I started looking at my options. Like I said, I have a bro with a heavily modded 3.8, and I know what trick heads and cam and headers can do. But that wasn't what I was looking for. I wanted something more subtle.
Despite the mixed reviews, I ordered a stainless powerlog from ZZP. Would this be the final artillery piece needed for my offensive?
I plugged in the scanner and went for a ride, and ...Victory! KR was finally defeated. I think the highest we saw was a split second of .6 KR. I might try removing the resonator and see if it helps at all.
So, if you are reading this, and considering your own war against the forces that plague our beloved rivieras, heed my advice. No two of these cars react in the same exact way to mods. There are so many variables to be considered - even the differences in the build of the engine at the factory can skew your projected results. You may lose a battle before you win the war.
Having owned two of these cars now, I can say the mods, even on the milder side of things like mine, really make a difference. And opening up the throttle on a nice sunny day is a great feeling. Good luck!