My E30 S50 exhaust plans and a few questions...

[smonkbmw]

I just ran a full e36 setup. S50 Mids and UUC catback.

+1, why restrict your exhuast options? use the e36 muffler hangers then you can use e36 catback systems.

[mazur]

^^ sorry for OT, but i can see you are also running hankook rs2's , how do you like em?
after two summers (3-4 track days and bunch autox'es) mine don't grip for $hit. (they are also 205s)

Yah...mine seem to have lost their bite. They can barely handle 2nd gear in a straight line. They still handle OK

[matt]

This is a thought I had aswell. I think I will just put a turn down on it, that should be ok.

What are your thoughts on the piping size for my single center section?

2.5" wherever you have a single pipe. Neatness counts in the merges and de-merges. You can buy Y-pipes from flowmaster and others that are pretty decent.

I would skip the cutout. I would also skip the IE catback and just use a single 2.5 all the way back. You can get a few different mufflers with tips integrated or you can add seperate tips.

[matt]

If I were you I would run a 3" center section. And to all those who think that a 24v is loud obv has never heard s14's...

The 24v motors are relatively quiet compared to other motors.


The cutout will prob be pretty dang loud though. When I first finished my swap and was on just headers it was loud as heck lol.

There are a lot of different things involved in how a motor sounds. More cylinders is quieter. More valves is louder. It has to do with how sharp the exhaust pulses are, which is a factor of how quickly the exhaust valves open... faster with 4V per cyl.

S14 louder than M50/S50 is louder than M20/M30

[1990m3]

S14 louder than M50/S50 is louder than M20/M30

he speaks the truth! My s14 is loud all the time...but in a good way. When I drive my swapped car it's so quiet I feel like I'm in a cadillac

[equate975]

YOU BASTARD, YOU STOLE MY SECRET IDEA!

I was gonna put a cut out on... just for fun. I know what was mentioned before about how it actually takes away from performance, but its cool!

Then I wouldn't tell anyone about it, until one day someone on r3v would figure it out and be like wtf mate you have a cut out? And we would lolz together at it and people would be like woah dude man thats funny cool shit I wish I thought of that, then we would lolz some more and maybe have a beer and do stuff.

[equate975]

2.5" wherever you have a single pipe. Neatness counts in the merges and de-merges. You can buy Y-pipes from flowmaster and others that are pretty decent.

I would skip the cutout. I would also skip the IE catback and just use a single 2.5 all the way back. You can get a few different mufflers with tips integrated or you can add seperate tips.

x2

I would just run one 2.5 inch and call her done. Just do that and toss on a magnaflow cat and muffler and your set. That more or less the setup I run, but I have stock headers merging with a Y pipe. Cost me $250 total.

[matt]

he speaks the truth! My s14 is loud all the time...but in a good way. When I drive my swapped car it's so quiet I feel like I'm in a cadillac

My swapped car is the loudest e30 I have ever heard... maybe second to another swapped e30 belonging to a friend who has almost no muffler at all.

When I drive my e46... that's the smooth ride, quiet car.

[1990m3]

My swapped car is the loudest e30 I have ever heard... maybe second to another swapped e30 belonging to a friend who has almost no muffler at all.

When I drive my e46... that's the smooth ride, quiet car.

Well mine will be loud shortly in light of my blown catalytic converter situation.

Back to the thread -- I just ordered a number of parts and will hopefully begin welding myself a nice new exhaust system within the next weekend or so. Unfortunately I don't think my parts will be here for this weekend. I've had an AA track pipe sitting around for a while which I will bolt onto my OBDII headers. It's only the first section of the AA track pipe. After that will go a 3" mandrel bend into a 3" --> 2.5" reducer cone. Then it will be 2.5" straight back with a high flow cat and muffler stuck in there somewhere. All stainless of course and it will be very nice. I've purchased a couple of mandrel bent sections I can cut apart and tack together underneath the car for the mock up. once it's all tacked up I'll remove it and tig weld all the joints.

It's going to be light, well flowing, and hopefully sound good.

[MR 325]

Well I am pretty commited to the IE catback since I already purchased it.

For the Y pipes, I plan to buy the pre-made Magnaflow ones.

As far as the single center section goes, would there be any real disadvantage to running 3" over the reccomended 2.5"?

[golde30]

matt, if yer running no CAT, why not just get 2 straigt pipes welded up with flanges @ the headers + catback. would be the simplest/cleanest setup. forget about that QTP cutout, it will just be horribly loud, and kill your low end torque. if i was running no-cat, i would have kept my IE exhaust and done it like that.

[1990m3]

As far as the single center section goes, would there be any real disadvantage to running 3" over the reccomended 2.5"?

based on my short research it seems that e36 guys with 3" single exhaust and dyno charts are losing some torque and showing minimal hp gains. dyno charts I saw with 2.5" single exhaust seems to show stronger torque curves and near identical hp curves with possibly higher peak numbers...if any of that makes sense. Point is, you will probably benefit from the additional backpressure a 2.5" setup will provide over a 3"

[matt]

based on my short research it seems that e36 guys with 3" single exhaust and dyno charts are losing some torque and showing minimal hp gains. dyno charts I saw with 2.5" single exhaust seems to show stronger torque curves and near identical hp curves with possibly higher peak numbers...if any of that makes sense. Point is, you will probably benefit from the additional backpressure a 2.5" setup will provide over a 3"

I was with you until you got to backpressure.

[static]

I was with you until you got to backpressure.

+1

read my posts here

http://www.r3vlimited.com/board/showthread.php?t=69373&page=9&highlight=scavenging

[MR 325]

matt, if yer running no CAT, why not just get 2 straigt pipes welded up with flanges @ the headers + catback. would be the simplest/cleanest setup. forget about that QTP cutout, it will just be horribly loud, and kill your low end torque. if i was running no-cat, i would have kept my IE exhaust and done it like that.

Well, I'm pretty set on the cutout setup [with a turndown on it]. The main reason for the single center section is the fact that the cutouts are $200 each.