Exaust Pipe Diameter

[BigRandCarFan_5]

Hey everyone.
With the plans I have for my car, one of them is of course, is a higher flow exaust system.
I'm unsure of what diamtere of pipe would be best for my applications however.
I've decided to go with a Flowmaster Delta 50 for my project. It has a 2.25" inlet, with dual 2.00" outlets.
My manager at work, who is also a Grand Am Owners Club member, adviced me that a 2.25" exaust system might be to big for a naturally aspirated engine like mine will be, and said that 2.25" and larger are usually better for force inducted engines.
Is this true? Or will I be fine going with the 2.25" exaust system for my car desptie it being naturally aspirated?

If you all can let me know what you think, that'd be awesome.

Thanxs for your time.

Chris.

[Zero]

I am having trouble in finding an dual exhaust system for my 98. What other cat-backs do they for the 3.1

[bballr4567]

Ive got 2.5" cat back as do many other people with no problems at all.

[Jchiasson]

The SEs' came with 2.25, GTs' come with 2.5 so going that extra .25 is a no brainer if your going to do up your exhaust. Of course the biggest compliment to that , with out spending big $$$ is a CAI.

[dmbprep69]

I have 2.5 on my 3100 so dont worry about it, but if ur muffler is 2.25 just go with that, theres no point in goin bigger than what the muffler inlet is. Anyway good luck.
Peace,
Andrew

[Matt95GT]

2.25" cat-back is ideal for your 3100.

Not so sure about your muffler selection though... single 2.25" in / single 2.25" out would be easier to work with.

Originally posted by Zero
I am having trouble in finding an dual exhaust system for my 98. What other cat-backs do they for the 3.1

None are made... must be custom fabricated.

Originally posted by Jchiasson
The SEs' came with 2.25, GTs' come with 2.5 so going that extra .25 is a no brainer if your going to do up your exhaust. Of course the biggest compliment to that , with out spending big $$$ is a CAI.

Only if you have a 99+. Pre-99 is 2.0" stock.

[Vampyrate]

Originally posted by BigRandCarFan_5

My manager at work, who is also a Grand Am Owners Club member, adviced me that a 2.25" exaust system might be to big for a naturally aspirated engine like mine will be, and said that 2.25" and larger are usually better for force inducted engines.
Is this true? Or will I be fine going with the 2.25" exaust system for my car desptie it being naturally aspirated?

If you all can let me know what you think, that'd be awesome.

Thanxs for your time.

Chris.
i have the flowmaster 40 series with a 2.5" in and outlet. I did a full 2.5" mandrel bend all the way back from the stock cat. i don't think it is too big and i have a CAI with other mods in the future and just with the CAI for now, it is not too big at all. Just the right size for my baby to growl and breath a lot better.

[Houndawg]

Originally posted by Jchiasson
The SEs' came with 2.25, GTs' come with 2.5 so going that extra .25 is a no brainer if your going to do up your exhaust. Of course the biggest compliment to that , with out spending big $$$ is a CAI.

Negative. I just pulled the exhaust off of my SE and the pipe is 1 7/8" ID and 2" OD. Pipe is measured by inner diameter.

[Jchiasson]

Originally posted by Matt95GT
Only if you have a 99+. Pre-99 is 2.0" stock.
I stand corrected, good catch thanks.