98 Buick Century power upgrade from '99 to 2000 model.

[Bucent98]

Let me talk a little about performance here. And basically not much when you talk about the 3.1 L Buick engine used in the Century. These days every horse counts. I drive a '98 with the 160 horse 3.1 V6. Good in '97 when it first appeared, but in 2000 horsepower went up to 175. Not much, but noticeable when driving. Not bad for a 3.1 V6 two valve push rod engine, but it could still use more. A great highway car, but I drive mine in the city 98% of the time. Yes I got what I wanted in a nice quiet good looking cruising car. Too bad I couldn't have gotten the Regal with the 3.8 L, but sometimes you don't have much choice when you don't have extra cash at the time. Besides I paid cash money for mine in September 2002. Used, but only 24K miles. Affordable!

In an ad I found for the 2000 Century it states, "Under the hood, the 2000 Century has plenty of good news: a newly revised 3.1 L 3100 V6 engine that delivers more horsepower and more torque than before. Output is 175 horsepower at 5200 rpm, up 15 horsepower from 1999. Torque is 195 foot-pounds of torque at 4000 rpm, up 10 from the previous edition. The 3100 V6 is fed by sequential-port fuel injection."

When it talks about a newly revised 3.1 V6, I would suspect their talking about something internal? Not neccessarily? How about a less restrictive convertor/exhaust system and minor engine tweaks such as timing, larger airbox, etc.? I'm just guessing of course. What I'm really wanting to ask is about how much more power is possible from the 3.1 V6 160 horse if you could make the breathing a lot more efficient with larger tubing all the way back? No, I'm not into noise so the exhaust system would be using a stock muffler obviously. But if you could take that engine and mount it on a dyno with a freer flowing dual exhaust into two convertors and two mufflers, what could be possible from that engine? Just curious how much horsepower could be released? Can you also suggest an oil additive? Teflon? Other? Thanks for the help and info. Kevin

[Bucent98]

Maybe I could ask an easier question. Any engine techies that could possibly answer where the extra 15 hp came from? I could sit here and think of over a dozen areas myself, but some of that would be guessing. If the extra 15 hp was achieved from outside the engine, then anyone including myself could make it a real consideration assuming they have and want to spend extra bucks on the project. I'm not going to lose any sleep over it, but thanks for any response. Kevin

[NTX5467]

From what I recall, the basic specs on those engines did not change significantly, if at all, in those particular years. If you take that power increase and factor it by .85, that's the "real" extra power that's getting to the ground. You can play those numbers all you like, but unless you're an advertising junkie or a non-bracket drag racer, those few extra horses or lbs-ft of torque might not ever be noticed. What makes "street performance" is responsiveness more than power at 4000rpm.

Therefore, if there were any changes, they might well have come from more refined engine management electronics as things became a little more fine-tuned with time or a more effective catalytic converter.

The Chevy 3.1L V-6 is a good running motor, generally, but is limited in performance by the intake manifolding and exhaust manifolding on the engine. It's all tuned to be working together and changing any one thing will not be worth the expense for the benefits received, typically.

For any performance "mods" and such, check out the Pontiac Grand Prix (W-car) websites plus RegalGS.org. Maybe even GMHighTechPerformance magazine, a bi-monthly publication.

Just remember that if you free up the exhaust, for example, you'll find the bottlenecks upstream of that area and will then need to made compensatory changes there to fully realize the possible benefits of the exhaust. One thing leads to another, as they say.

If you really want a neat 60 degree Chevy V-6, the first major "freshening" of the engine is under the hood of the 2004 Malibus in the form of the Vortec 3.5L V-6. It makes 200 horsepower and better torque than before, but does it much more fuel efficiently. It'll run circles around even the current 3.4L V-6 and get at least 10% better fuel economy in the process. I rented one of those cars last week and saw 36+mpg at highway speeds with the cruise control used. Neat car! Burns rubber, turns corners, stops, and still gets better fuel economy than many imported 4 cylinders! Maybe it's time to trade up??? A 3.9L version will be in the new Pontiac G6 too.

Don't even think about swapping one of those engines into your Century either! Much too involved and complicated. Not to mention emissions rules too!!!

Just some thoughts,

NTX5467

[Bucent98]

NTX5467, thanks for the response. Thought there for a while no one would. Fine. But I was just curious how the Chevy v-6 picked up the extra 15 HP from '99-2000. Like you said if it's both an intake, exhaust, timing and possible airbox mods, then I would be crazy to spend those kind of bucks on that engine just for 15 HP. Too bad I couldn't have afforded the Regal with the 3.8 supercharged 240 HP engine.

But as from past experience with most of my cars, there is always power to be had by making the exhaust breathe easier, especially at higher rpm's where the pump (engine) really gets going. As far as I'm concerned ALL exhaust systems on cars are restricted some these days. Better yes, but still restricted.

Here's an example not to say you need one. You sound very knowledgable. But this was a case for me in a '78 Olds Cutlass. I put a Chevy 350 in it. That was a waste. The engine was said to rate at 230 HP, but with my 2.25" single (ahem) exhaust I would say it was closer to 170 HP maybe. So a dual would have help immensely. Oh, and I wouldn't mind having a new Cheverolet Malibu either. Thanks. Kevin