m3 exhaust question - United Bimmer Community

**cabrit** · 06-02-2006, 01:53 PM

i finally install my m3 exhaust on my 1994 325i
to tell you the truth it feels kind of funny it seems that i have lost power on low rpm and feel a little gain on high rpm at time it almost feeels like something is holding it back from taking off. is this suppose to happen or something is wrong with the exhaust. or should i have also change to m3 catalytic converter. or is it something totally different
what do you guys think
thanks

**c1apton** · 06-02-2006, 03:32 PM

Have you done anything ti increase intake? (manifold,etc) All you did is increase it's breathing ability and I suspect the flow helped your upper end and took away from lower end. You need to increase the intake capacity. Whenever you "mod" performance, you're taking the factories' set 100% and "unbalancing" what they provided increasing one end but decreasing at another.

**cabrit** · 06-02-2006, 04:22 PM

somebody mentionned getting headers
what should do you think i should do

**c1apton** · 06-02-2006, 05:03 PM

Headers are a toss-up - depending on how they're made. The longer they are, the more top end you'll gain (but lose on lower end). The shorter they are the more torque you'll gain on bottom end but then the top end suffers. (I have adjustable headers on my bird and that's for tuning at the track for temp, surface and other variables)
Personally, for a street driven car, I'd avoid them - they don't wear well for year round driving, they generate ALOT of heat, they're noisy, and finding ones to fit your driving (in all conditions) can be tough & costly.

First decide where you want your power band and consider all conditions (year round weather, the types of driving your planning on doing not just those blasts down the highway, and the "big-gees" - what you're willing to spend on mods & maintenance.) I'm an advocate for mods as long as you know what the repercussions are before learning at your wallets' expense.

**ChrisWorrell** · 06-02-2006, 06:36 PM

The reason you feel a little less down low is because the m3 has less resistance to the travel of air so there is less backpressure which is a key aspect of Torque. The reason it feels stronger on the high end is because it is breathing stronger and as you speed up more air is able to pass through the exhaust since there is less resistance.

The perfect solution to a loss of low end torque. A twin screw superchager

**MrWonka** · 06-06-2006, 12:19 AM

You wont see much difference in sound from a stock exhaust to an M3 exhaust unless you gut it, which would make it pretty loud. Since your OBD1 another option is to get OBD2 cats which are more freeflowing and then gut the M3 exhaust, should get some more power/sound out of it.

Peace
-Mike

**Chris** · 06-06-2006, 12:22 AM

^^^

no. there's a difference... let me go start it up.... yeah, there's a difference.

**Dudesky** · 06-06-2006, 05:45 AM

Would a CAI help to balance it out somewhat?

**94bmw325i** · 06-06-2006, 11:00 PM

CAI would definetely help with an exhaust.

**B_w.** · 06-08-2006, 12:56 AM

exhausts on there own are not going to do much for performance. its more ofr the look and sound.

**MrWonka** · 06-08-2006, 09:48 PM

Like B.W. said, exhaust will give you like 5 hp max, an exhaust and CAI will give you a nice sound together and give about 10 hp or so, some companies claim around 15 hp or so alone for CAI's.

Mike

**B_w.** · 06-09-2006, 10:21 PM

and dont waste your money on headers. if you want some good power go ith the m3 cam kit from eurosport

**LWRNCE** · 07-04-2006, 02:08 PM

You didnt gain anything... You lost low-end torque and gained weight. The E36 M3 exhaust is heavy. Very Heavy. You traded loss in performance for sound.