Good/Bad Idea?

I've read through the faqs and it says you can run a 3.6" on a pretty much stock riv. And a 3.5" with colder plugs, t-stat and intake as supporting mods. My riv has about 149k on it now, I monitored the KR with a powertuner and was getting about 3 to 5 degrees when it downshifts, I didnt really observe any from a dig WOT. Good or bad idea going with a 3.5"? Sorry for the newb post, I'm more or less asking for advice/ experience.

Dont even think about it. If your seeing 3-5* on a downshift...which is one of the funnest things to do... a 3.5/6 will not be good for you. I wouldnt run a smaller pulley without a 3" downpipe and those other supporting mods. with 150K miles, its going to be really hard to tell what kind of condition the motor is in. The current KR might be eliminated by different spark plugs or it could be from this hot ass weather we've been having.

Since your a newb......heres whatcha wanna get.

CAI-Cold air intake....open cone filter-K&N- insulated from the rest of your engine bay.

OR

FWI-Fenderwell intake....open cone filter-k&N installed inside the front passenger side fenderwell. It will insulate itself from the heat of the motor. it is generally alot cheaper than a CAI

3" downpipe- There are several availible on the market. My preference is Random Technology...you can find them on www.PFYC.COM or www.ZZPerformance.com. They are the most expensive availible but they are the best and they look great. You can get less expensive ones from www.wbodystore.com they will do the same thing, but they look like something you could make in your garage with a sawzall and a welder.

As for the 180* thermostat, plugs and pulley....I would reccomend purchasing an INTENSE PCM...www.intense-racing.com , and install that at the same time as a pulley, 180 t-stat, and plugs. Their PCM's are the best and they offer the best customer service. If you have a 97' I have one that im not using at my house. I can reprogram the VIN# to work with your car.

That should be a good start for you.....another thing I may suggest is getting a carfax report on your car if you dont know where its been those 150k miles. When i finally got one...after i ble wmy motor, i found out it had been rigorously maintained before i got it....and i got pulley happy
It will give you a pretty good idea about what kind of condition the car is really in.

97rivman wrote:

........................3" downpipe- There are several availible on the market. My preference is Random Technology...you can find them on www.PFYC.COM or www.ZZPerformance.com. They are the most expensive availible but they are the best and they look great. You can get less expensive ones from www.wbodystore.com they will do the same thing, but they look like something you could make in your garage with a sawzall and a welder........

A few of us have used Hogan Performance for 3" downpipes also. Mine isn't installed yet, but it looks like a very good quality piece of work, direct bolt-on also. Hogan is about $150 plus gaskets and shipping, and is listed as an H-body part, for the 97-03 Bonnevilles. You can buy direct instead of paying dealer markup prices:

www.hoganperformance.com/DP8S.htm

But as stated above, you do not want to drop pulley sizes when you're seeing any level of KR. I was KR free with stock setup, then did the mods I have listed, the 3.6 went on last, and suddenly I've got up to 5-6deg of KR on hard accel, not even WOT. I'm hoping my front PEM and 3" DP install will take care of that.

Let's get the engine running well enough for a 3.6" pulley before thinking about a 3.5". First do some routine maintenance to the car. Change fuel filter, do a top-end engine clean or at least a Techron fuel system cleaner, clean the MAF sensor, change or clean the air filter. Inspect belts and rubber hoses/vac lines for cracks.

Install a fresh set of Autolite 605 copper plugs, gap them to .058". Install a 180 deg T-stat, and flush/replace the coolant if it needs it. Check tranny fluid, change if dark in color, or hasn't been changed in 40k miles or more.

Now, before doing any pulley swap, wait for the outside temperature to get down to 75 deg or so (night is best). Fill up (an entire tank) of the highest octane fuel you can find. Do another WOT run and log a new scan. Try downshifting and see what happens. If KR is gone, you should be able to move down to a 3.6" without problems.

3-5 deg KR isn't good, but on really hot days I've seen it, too. This isn't the end of the world, but it's telling you that something must change before dropping SC pulley size. If you do all of the above, and the KR doesn't go away, it might be false KR. Any loose metal parts next to the engine could cause short spikes near shifts. Longer, sustained KR likely indicates real knock. If it seems to be false, check around under the hood for anything that could be making contact with the engine block or transmission.

If you are cheap (like me) and your primary concern is bang-for-the buck mods, I recommend you go for either a sewer pipe FWI or a swiss cheese airbox , which goes a step further than simply gutting the box.

Wow, thanks for the quick responses. I'll try doing what you guys suggested to get rid of the KR before thinking pulleys.