Extra power

[Stonedified]

What are some things I can to do squeeze a little extra power/performance out of my 3.1 mfi? I'm not looking to spend $300 per part, but what can I replace easily on a car with 243,700 miles that I might have overlooked that are long overdue for a change, or anything small I can upgrade?

oil is fresh, spark plugs were replaced about 10,000 miles ago, but they were the cheapies...would spark plugs and plug wires help?

[Superdave]

Intake, Exhaust, Underdrive pully.. maybe something more in depth like an exhaust manifold swap (3400 manifolds flow more than the Gen2 manifolds)..

[Azrael]

A new cat. convertor might be a good idea if you're still on the original. As for sparkplugs stick to the ACDelco ones listed for your car. Despite the hype and marketing, the expensive ones don't really give anything back. Avoid Bosch ones at all costs.

[Stonedified]

cool thanks. and btw what does the underdrive pulley do?

[19Cutlass94]

The underdrive pulley turns the accesories slower, basically reducing the drag and giving you more power.

[Stonedified]

hmm...my car has no AC compressor, so would it still be possible to use an underdrive pulley? and would I still notice the same gains?

[Superdave]

If i remember right they're supposed to be like a 10 HP gain, there is dyno charts from the FFP underdrive pully somewhere... In reality expect less than 10.. more like 5 but the feel of the engine will improve and it'll rev quicker.

the A/C compressor has no effect on the crank pully

[3.1cutlass]

a computer chip from this site.

[3100 MPFI]

Stick with delco plugs, and good wires. New air filter, and replace the cat back.

Have a custom downpipe made for the exhaust, replace the cat converter, then get some good mufflers. Best size pipe is 2.5 in. You can also get a chip from Ben (from the 60 degree V6 store). Those are a LOT of help.

There are no different exhaust manifolds for your car. Those are for the GEN 3 engine, and yours is the GEN 2.

I do NOT recommend the underdrive pulley for anything other racing only applications. The FFP underdrive pulley does NOT have a harmonic dampener. Without the harmonic dampener your engine can resonate (what the dampener cancels out) and this causes more stress than the crankshaft can withstand.

Basically: 3.1 MPFI - Harmonic Balancer = KA-BOOM or
3.1 MPFI + Underdrive Pulley = KA-BOOM.

Here is a good read for ya:

http://en.wikipedia.org/wiki/Harmonic_balancer

[3100 MPFI]

Forgot to add that the stock exhaust downpipe is as smaller than 2 inches. I think the one I measured in my 3100 was like 1 15/16, and the 3100 has a larger downpipe than the 3.1 MPFI.

If you remove the downpipe from the rear manifold, and cut it off in front of the cat, you can have a muffler shop make you a downpipe out of larger pipe.

Also, your stock pipe will have the crinkle bends. They can do smooth bends, or even mandrel bends (the best).

Doing the downpipe and complete exhaust has been the best things for all of my cars. If I don't sell my 1990 Grand Prix STE, it will be getting it all as well.

[Stonedified]

cool thanks guys