Hi I'm new to the group and have some questions about my 1989 Pontiac Bonneville. First the thing is nearing 200,000 miles and i was wondering what kinds of mods would this car benefit from. It already has a K&N filter and set of Bosch Platinum +4 spark plugs. My other question is how can i tell what the axle ratio is in the car. Is there a tag or something. Also what transaxle would bolt into this car that has a lower ratio. My car is fast but it takes it awhile to get it'* speed up. No burning the tires with this car. thanks for the help and i'm looking forward to being part of the group

Welcome to the club. You'll find more info here than you ever wanted to know.

The first mods you want to do are a CAI (cold air intake) and exhaust. A K&N filter is a good start though.

I know there has been some discussion on Bosch plugs in this forum. Most people claim they work horribly in the the Bonnevilles but there are one or two that have had good luck with them.

As far as the axle ration, not really sure what yours would be. I'm sure some of the older Bonneville owners in here could help you out with that.

Again, Welcome!

I'll back up SSEi95 completely. Definitely get that thing breathing better. A CAI is great, but at least punch some holes in the box and duct it out with hose to cooler air behind the headlight or grille. Ditch the plugs. My personal experience is NGK V-Max. Just as good as Splitfire, but cheaper and more reliable. If your Bosch'* did what mine did (electrode erosion) you'll benefit immediately from the change.

I've got a 93, so I can't help you with the ratio, but some others here can. If you post your VIN number, I'd bet Deathrat can give you your axle ratio. He works for a Pontiac Dealer....in parts. Handy guy to have around.

The Bonneville gets off the line ok for a heavy car (the SC really do!) but remember, your car was built with long legs. You'll take most of the competition at 1/2 or a full mile. They might leave you at the line, but you'll show 'em taillights while they're gasping for breath!

Welcome to the club.
As for your "Final Drive" Ratio, find the RPO Label in the trunk (Deck Lid or Spare Tire Cover). Look for the "F" codes. Let me know what it is & I'll let you know what it is. Give me your "M" codes too & I'll see if there is a replacement lower ratio gear set for that Trans.

egladman, welcome to the club! 200,000 miles is getting up there, u must treat her good. I'm sure you'll find all the ideas u can handle here I also agree that a good CAI is the first place to start. I'm in the process of putting one on my car right now, just waiting on a filter.
Deathrat: I was also wondering what my final drive ratio was. I looked on the tire cover and the only " F " code I got was FE2. What other ratio'* are avilible and how hard are they to swap? Oh and the " M " codes I found were ME9 and MXO. Thanks...Andru.

Look for the "FW_" code! That other code is for suspension. ME9 is the 4T60 (THM440-T4) Trans; MX0 is a merchandising option for Overdrive.

There doesn't seem to be any FW? code. The ONLY code that starts with F is FE2. Is there another place I can look?

There is a way to estimate the axel ratio of your bonne.

Put the tranny in neutral and jack up the front of the car. Make a mark on the tire and another mark on a CV boot. Turn the axel with your hands and count how many times the axel has to turn to turn the wheel one revolution.

That can give you a rough idea of what the gear ratio is.

The Codes I found are FE1 and F17 and ME9 and MX0.

Thanks for all your help

"F17" is a final Drive Ratio RPO Code.
Transaxle, Final Drive, 2.84 Ratio.
"FE1" is a Suspension RPO Code.
Suspension System, Soft Ride.
"ME9" is a Transaxle RPO Code.
Transmission, Automatic 4-Speed, (THM440-T4/4T60)
"MX0" is a Merchandising Option RPO Code.
Transmission, Automatic, Overdrive.