I.E. Stage two headers

[bmwstudent]

Just purchased the stage two headers from I.E. I'm torn on how to finish the exhaust. I have to run a cat here in De so a high flow cat is in the plan. I'm just not sure if I want to go with dual pipes back to a Remus muffler or go with something quieter. I've been looking at the flowmaster Hushpower series and was wondering if anyone has any opinions on them.
My current setup is 2.5 with a Bimmerheads head and 272 cam, I.E. rockers. Turner chip. My intake manifold has been port matched to the head, the runners have been opened up very slightly and the throttle body is about four or five mm larger with throttle plate to match. I've just purchased a Miller PSIK and WAR chip but I want to do the exhaust first as it's currently a bone stock setup. See my build thread "my delphin" for pics of everything.
So does anyone have a Hushpower muffler and do they like it?

[MR 325]

On the BimmerHeads E30 truck we have a Hushpower muffler in the center and a 40 series Flowmaster at the rear. Running IE shorty headers and no cat. It's loud but it sounds amazing.

If I were you I'd merge the exhaust to a single 2.5" after the headers.

[bmwstudent]

I was going to pm you directly and ask for your advise on the exhaust setup but I figured that's what the forum is for. I'll be running a cat but it will be a high flow unit most likely from magna flow or dynomax. Do you think a single muffler would be too loud? I want a high flow exhaust, but I appreciate being able to leave an intersection quickly without drawing attention.

[MR 325]

I think you'll want to run a cat and some sort of center muffler along with a rear muffler.

[bmwstudent]

So in the meantime while I wait for more money to magically appear in my e30 account, I'll be installing an exhaust setup I've had laying around for a while. I got this setup from another member here and have been hesitant to install it due to a very loud looking muffler (OBX unit). Here is a pic of the stock system next to the setup i'm putting on for now.

I'm putting the stock system on my brothers car because his current system has a big hole in the pipes before the muffler and the muffler is rather beat up as well. We are removing his headers and putting them away for another project (joint venture autocross car). He is putting together a 90 e30 w/s50 swap and he doesn't want to dump any more money into his old setup.



Anyway, I managed to get the front header fit in my car. All it required was a quick shortening of a couple exhaust studs. More to come, including the long tubes from I.E. but that won't be for a while. I'm going to do that system up really nice.

[bmwstudent]

Headers received, time to fit them and and x-pipe, get some bell flange collectors or maybe some v-bands. Then I'll get them coated. Will post pics of them at some point.

[bmwstudent]

I figured since I want to get the I.E's coated and fitted. Why wait for a high flow exhaust system when I have a set of Stahls and a mid pipe w/dynomax cat sitting here doing nothing. So i combined the stahls and the midpipe that was on my brothers car with the rear section I had from the pic above. I turned out ok, I had to cut the rear section into two pieces to get everything lined up under the car and fitted properly at the rear. Welded on a couple of hooks for the existing hangars and that was it.





I haven't actually driven it yet but it sounds loud. I was lucky enough to already have two sensor bungs already welded into the Stahls so I was able to install the wide band sensor. Once I ran the wiring and tapped into a key on power circuit I was able to start and run the car. When I first ran it I hadn't put the band clamps on the collector to midpipe connections and they were leaking a little bit. When I brought the car up off of idle just a little I noticed that the AFR would lean out to the point where the gauge wouldn't even register, it would show three dashes indicating zero fuel(AFM wideband setup). It does the same thing when you goto zero throttle and the motor is decelerating. Obviously once the dme takes over and it's idling it's reading around 14.7 or so, but just off idle it would go dead lean. So I put the band clamps on and not only did the small leaks at the collector seal up but the lean condition off idle stopped immediately. I'm guessing that the leaks were causing the sensor to put off some odd readings, because the sensor is rather close to the end of the collector. I would imagine that if I had run it that way it might have allowed the vehicles o2 sensor to really send the dme into vicious rich/lean battle. Any way moral of the story is don't run your car with exhaust leaks near the sensor.

[bmwstudent]

I drove it, it's a little loud. I do feel like throttle response is better and low end power seems stronger. Perhaps a better muffler will help, but I think i'll keep it like this for a while and work on the I.E. system. I'll try to get a sound clip.