[Walked U]

Well ive been tweaking my exhaust now for a while.

I use to have 2.5 inch from the mid pipe back.



After talking to my buddy at magna flow he helped me out and we started working on a dual downpipe / primary cat back exhaust.

(this will not be a production model)


I originally wanted to go straight pipe all the way back. But the drone in the cabin was way too much for me. So we decided to put a 4 inch dual piped straight through resonator. I kept the primary cat on the car for now. Still thinking of deleting the cat or putting high flow cats on it.

Anyways its pretty straight forward. with minor fabrication to get the piping to fit. I cant really lower the car too much because it will cause the black plate under the car to rub. We had to put a lot of washers so the piping wouldnt rub on the black plate too.

It has a good deep growl now. Idle is noticbly louder also. I wouldnt reccomend it for people drive the car everyday tho. The drone comes on at 2k-2.3k/2.5k, so driving on the street can be kinda annoying. The power gains tho are pretty nice. Just from bolting it on I got 13 rwhp and 21 wtq peak. Throughout the whole power band around 7-10 rwhp and 8-15 wtq was made. (from my baseline with procede)

We are still going to fix the rear piping this weekend. Because the tips seemed to twist inwards due to too the stainless steel expanding under heat.

The whole system is stainless steel all the way down to the hangers. I still have 1 more experiment I want to do with the exhaust, before I finally make up my mind. ( I know some of my friends on the board already know it )


I also got the ITG filter installed last week. It was a super tight fit. Ened up cutting myself putting on the clamps. Hahha

I cant really say i notice anything since im not a butt dyno kinda guy. Im going to ask my buddy if i can flow bench both stock and ITG air filters to see which has better flow.

As for noise I cant really say either.


Heres some pictures and videos :















heres some videos of idle / take off.

dyno:


Idle :



Soft launch :




some pictures of the ITG filter :


















Ok heres some stuff for you guys. Havent posted this in a while.

Vs my friends 7k rev, intake, exhaust, headers, tune 350z. 20-100 mph. I was in 2nd gear.



Friends 350z s/c stage 1 tuned at 340 rwhp 290 wtq. From a 2nd in 40 :



My friends 440 rwhp 410 wtq gto with 7.2k redline. He makes 110 rwhp more than me Lol





80-155 mph. He has 3.91 gears so 80 in 3rd is pretty shitty for him... Oh and thats his car thats loud not mine. :



60-140

[DLSJ5]

The King is back, good stuff Brotha.

[Walked U]

Originally Posted by DLSJ5

The King is back, good stuff Brotha.

Hahahahha.


Thanks drew.

Ill have to upload more stuff but just too busy right now. I still have to ask my friend to give me some more runs of his z4m. I didnt have my camera that day. So I ended up taking some crappy camera phone pictures.

[Johnny Lin]

WOW! Nice that is super sweet!

[judec]

It sounds kinda ricer... really not for a daily driver, but the performance effect is impressive.

[Walked U]

Oh guys i forgot to tell you. Make sure when you get your stock mufflers pulled out they plug up that vaccum lin with a screw or somthing. Or else youll have a vaccum leak.

[itsbrokeagain]

woot. I cant wait to hear what mine will sound like.

If I ever scrounge up the $ for it.

[SfValley335i]

Originally Posted by Walked U

Hahahahha.


Thanks drew.

Ill have to upload more stuff but just too busy right now. I still have to ask my friend to give me some more runs of his z4m. I didnt have my camera that day. So I ended up taking some crappy camera phone pictures.

Whats the outcome when you run against the z4m? btw the exhaust seems like its deeper/more noticeable than the Zoomers you had.

[NaViT]

that was nice.... btw what does ur friend have on the gto?

[Walked U]

Originally Posted by SfValley335i

Whats the outcome when you run against the z4m? btw the exhaust seems like its deeper/more noticeable than the Zoomers you had.

We did mostly 60 / 80 mph rolls from 3rd.I would take it by 2.5CL's all the way to 155 mph. Then he would pull past that. He has his gonvoner removed.

We did a 10 mph in first all the way to around 100 mph also. Same outcome. If we did it to 155 mph I would have probably pulled around 3-4 CL's? Im not sure

The zm4 has a really good off the bat jump. Very good throttle response on that car. But I also had 3 people in my car...

[Walked U]

Originally Posted by NaViT

that was nice.... btw what does ur friend have on the gto?

Too much crap to list.

Fully built rear end. c6 z06 tranny, CAI, long tube headers, catless full back exhaust, cam. Port and polish, ported throttle body. 3.91 gears. Under driver pullies. 7k raised redline. He has more just too long of a list.

[elmaki]

Walked u, i think a dyno would be a worthwhile invest for you, and you alone.

I agree with the previous poster, it does sound a lot deeper now.

GJ, GL, GB

[Walked U]

Originally Posted by elmaki

Walked u, i think a dyno would be a worthwhile invest for you, and you alone.

I agree with the previous poster, it does sound a lot deeper now.

GJ, GL, GB

Hahhah ya me and my friend we thinking about getting one but they are retarded expensive.

Its ok tho our friend hooks us up on that end.

Ya i like the sound a lot more deeper. Sound like my v8 s4 in real life. The camera doesnt really does it much justice.

[SfValley335i]

Originally Posted by Walked U

We did mostly 60 / 80 mph rolls from 3rd.I would take it by 2.5CL's all the way to 155 mph. Then he would pull past that. He has his gonvoner removed.

We did a 10 mph in first all the way to around 100 mph also. Same outcome. If we did it to 155 mph I would have probably pulled around 3-4 CL's? Im not sure

The zm4 has a really good off the bat jump. Very good throttle response on that car. But I also had 3 people in my car...

wow i wasnt expecting that outcome based on this video I saw on youtube. A stock 335 got spanked by a z4m... good to know we can take z4m's...

btw whats your whp/wtq with the new exhaust?

[Walked U]

Originally Posted by SfValley335i

wow i wasnt expecting that outcome based on this video I saw on youtube. A stock 335 got spanked by a z4m... good to know we can take z4m's...

btw whats your whp/wtq with the new exhaust?

Ya the z4m coupes are a lot faster than the m3's I can tell you that much stock for stock.

My buddy that drives it is no push over either.

344 rwhp 387 wtq on 91 STD corrected. 1.45 map. Without ITG filter.

You can probably except 5-10 rwhp with a primary cat delete.... Maybe, dont know until someone tries.

He gets the jump everytime we go tho by around 75% of a car then i pull it back. I believe its just the turbo lag. I dont brake boost so im not building boost until that moment when i hit the throttle.

Ill get more footage this weekend or somtime once i get the time to go out. I still need to head down to magna flow to fix the alighment on the tips.

[You Love It]

Nice sound clips, I really like the sound. Keep the footage coming

[all8up]

Walked U,
When you mentioned drone....do you still have it after you installed the Magnaflow muffler in the mid pipe? I am planning to do the same thing in an effort to get rid of the drone (2k rpms @ 60mph) with my exhaust.

[Walked U]

Originally Posted by all8up

Walked U,
When you mentioned drone....do you still have it after you installed the Magnaflow muffler in the mid pipe? I am planning to do the same thing in an effort to get rid of the drone (2k rpms @ 60mph) with my exhaust.

Ya its still there. My friend said bmw's are the hardest cars to get rid of drone in. Even with their e46 m3 production model exhaust it has a little bit of drone.


I think if you go 2.5 all the way back the drone shouldnt be too bad tho. I think the bigger pipping I went with makes it drone louder.

[imsambeen]

I have that exact drone. What about putting resonators back in?
And Sharewin nice picks and racing results.

cheers
Sam

[Walked U]

Originally Posted by imsambeen

I have that exact drone. What about putting resonators back in?
And Sharewin nice picks and racing results.

cheers
Sam

Thanks sam.

Even with my old exhaust 2.5 inch mid pipe back with a X pipe i had drone also. Not as bad as I do now. But i think its just the car.

I have tried a lot of stuff to get rid of the drone when on the street. Tired putting larger mufflers with a bigger resonator and it doesnt seem to work. It gets quieter but still drones. 2k-2.5k is the worst spot for drone. After that or below that theres no cabin drone at all.

My buddy at magna flow said that bmw will do anything to reduce sound noise in the cabin even if that means lossing a couple hp. Esp on the non M models, since they arent really " sporty."

Thats why on the stock exhaust there are a lot of unessesary crushes and crimps.

[renasis]

you are the man

[chbrules]

Maybe I missed it, but what is your car putting out in terms of HP? Is this tuned with one of the piggy-back units like procede/xede/TT? Awesome stuff, and I love the sound of that exhaust; sounds a bit ricer though