Ok, so heres the scenario. I love loud anything. I love loud cars, bikes, music, clothes, movies. You name it, I love it. I was raised around race cars and sport bikes so it is just in my blood. I am one of the few guys who stands behind our 1300HP 917-10 when it cold starts.

For that reason, about 3 months ago I cut the back boxes, or large mufflers in the rear, off of my M5 and replaced them with straight pipes. While it is quite loud, throaty, and would suffice for most people, I want it to be louder. It is LOUD upon 80-100% throttle, but very civilized at idle or a tad higher. When I put these pipes on, all the people on the M5 board were saying, "don't do it, you are going to mess up the engine, its going to sound like shXX, etc. etc." It is the exact opposite!

So, I have come to a point where I want to take it a step further. If I were to remove my Cats and front resonators, what affect would that have on the following:

1. Sound
2. Performance
3. Engine Reliability/ability to run correctly
4. Would it shoot flames upon deceleration

 

Do you have any sound clips of your exhaust?

 

nothing worthwile, I will try and take some tomorrow!

 

Thanks!

 

have you thought about powerloss or powergain with what you want to go for?

 

test pipes! Catless is the way to go... flames and loudness...

 

+2 on sound clips! Very interested to see how it sounds

 

Talk to BLKM3

 

I am an engineering major. I will answer your questions the best i can.

1) It will be loud, think Formula 1 car loud.

2) Since you wll have no back pressure you will lose low end torque but will gain it back in the top end.

3) You engine might run a little odd due to the lack of back pressure. However, the ECU might be able to adapt.

4) Yes it will shoot flames. Flames are unburned fuel hitting the hot exhaust.

I has straight pipes on my E46 M3 and it was too loud but it did shoot flames which was cool. It kept people from tailgating at night for sure.

 

Wanna sell them?

 

i had stright pipes on my m3 also and i ddidnt think it was loud at all.. my set up sounded SICK>

 

I already sold the car with the exhaust.

 

I had straight pipes from the block back with headers and 2.25" mandrel bent true duals with an X-pipe. There no wasy you can think this system is not too loud. I had a headache after more than 3 minutesin the car.

 

ur just like me man. i love loud cars. If you put a straight pipe all the way from the headers it wil sure as hell be loud. similar to f1. Shooting flames is sweet. although i think you might have trouble at SMOG test it would totally be worth it. doooooooo it and get us a sound clip

 

I had the priviledge of listening to a Murci with straight pipes, not that is loud.
I'm thinking doing the same to the M5