Spec E30 Exhaust on a street/track car

#1

Finally got my Spec E30 exhaust from Paul P - I ordered an extra mid pipe so that I can install a cheap E-bay cat to pass Texas emissions.

Exhaust was about $305 shipped to me, with the extra pipe. I found this 2.25 inch cat on ebay:

http://cgi.ebay.com/ebaymotors/410225-FLOWMONSTER-Catalytic-Cat-Converter-2-25_W0QQitemZ150356833027QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item2301f73303&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|72%3A1171

not exactly the same seller - I paid $40 + 11 shipping I think.

Now the hard part - making it fit. My plan is to put it into the midpipe - but I really need to put it after the bend - this may be too far back to light off the cat - and it will fail emissions. Or I can put it in the front pipe - but that defeats the purpose of having a midpipe that I can swap out for track days…

I really need to layout everything under the car and see where the cat would sit - I don’t want to melt the tranny or shifter (or gas tank!)

Take look at the pics and let me know what you think.

thx

Jim

#2

photo 1 [file name=CIMG0015.jpg size=357878]http://spece30.com/media/kunena/attachments/legacy/files/CIMG0015.jpg[/file]

#3

try this link for photos…

http://s630.photobucket.com/albums/uu24/tzbfwt/?action=view&current=CIMG0025.jpg

http://s630.photobucket.com/albums/uu24/tzbfwt/?action=view&current=CIMG0026.jpg

http://s630.photobucket.com/albums/uu24/tzbfwt/?action=view&current=CIMG0015.jpg

#4

I keep a full exhaust around to pass cali emissions. It’s simple, and it works.

#5

Laz - that would be an option if I had a nice rust-free stock exhaust around - but I don’t - my system was shot from the cats back - so a Spec exhaust with a cheap cat was a much better idea (in concept anyway).

No real visual inspection of the cats here - you just have to pass a CO and HC sniffer test at idle and 2500 RPM - hopefully easy with a cat.

Anybody got any Spec exhaust fit-up tips they want to share? I was just going to fit the front y-pipe, then mount the mid pipe and see where I can locate the cat.

thx

Jim

PS - I hope you boys are having some cool racing weather out in Cali - it is TOO DAMN HOT to do anything outside here…

#6

OK guys…

I am now to the point where I need some “tribal knowledge” about the SE30 spec exhaust.

I FINALLY got the Spec Y-pipe installed on my stock downpipes - what a PITA. Cleaning the downpipes and oiling them up was NOT enough - I had to buy a China Freight pipe expander to flare out the Spec Y pipes. Then of course there’s not enough room BETWEEN the pipes to allow both clamps to fit side-by-side. I installed each one individually and cinched it down to reduce the pipe OD as much as possible. Then I loosened them and slid them up the downpipe until I could get them side by side. Then I pounded them on together with a punch and hammer - and they just barely fit.

For now, I’ve just loosely installed the mid pipe and rear muffler pipe. My questions are as follows:

  1. Even with the midpipe slammed up against the subframe, it seems like the back pipe hangs down too low. The TOP of the muffler exit is still 3-4" below the cut-out in the bumper. The forward hanger on the muffler is pretty close to its body mount, but the rear hanger is still a good 6 inches below its mount. It looks like the mid pipe needs another bend in it - so that the rear pipe will angle up and tuck in tighter to the body underside.
  2. What’s the trick to get those muffler rubber donut hangers on? Screwdriver and lots of stretching?
  3. Any other tweaks that help?

After I get the stock midpipe to fit, I’ll be making a second midpipe with a cat for the street. The Fun never stops…

Jim

#7

My exhaust just clears the sub frame. I think I twisted the mid pipe a bit to get my clearances to work out. Twisting the mid pipe can really move the tail pipe around and affect sub frame clearance. It took some playing around to get to fit but it did but just clear.

To get my rubber doughnuts on I actually opened up the body mounts just a bit and used a screwdriver to pry them into place. It was tight but once installed seems nice.

When I flared mu Y pipe I left the brackets in place to keep the clearance for them after the flare. My y pipe was a bit of a battle also.

#8

IIRC we also had to ‘adjust’ the metal bracket for the rear hangers. It bends fairly easily. That will also help tuck the exit up a bit. The center piece around the subframe is fiddly but the right angle will get it to work.

#9

OK - thanks for the tips. The plan is to fiddle with the mid pipe and the muffler hanger brackets and see if I can get the rear section to tuck up tighter. I’ve heard of ground clearance issues with the Spec exhaust (on the street anyway).

Does anybody have parking lot speed bump experience with a spec exhaust?

thanks

Jim

#10

The center of the car will hit the occasional bump or hefty driveway curb if you’re not careful. I also had problems getting the car on/off the trailer until I got the angle of the ramps just right. You’ll need to be careful.

#11

Here’s a pic of the mid pipe with cat installed - and the rear pipe/muffler.

The cat sits about 2-3 inches forward of the gas tank - it’s already got a speed bump rash on the bottom. But that was with my front camber plates installed wrong - I have about 1 inch more front ride ht now.

The mid pipe/cat is probably only going to be on the car until I pass emissions - so hopefully I won’t blow up the tank with the cat.

#12

pic attached

#13

Hopefully your cat can get up to temp that far back. Definitely get things good & hot before you pull in for inspection.

#14

Yeah - I hear you, it is pretty far back - but the stock cat is also back there aways… I have to pass an idle and a 2500 RPM point (both no load tests).

As you can see in the pics, it is getting hot enough to turn the stainless a nice copper color, so I hope I’m lighting it off.

I going to try to buzz it up the highway and then pull in for the test. I also have considered putting in a 3-4 gallons of E85 to make it run lean - that’s an old trick that the RX7 rotary guys use… Just don’t want to go too lean and make it misfire.

A bit off topic, but what octane do you guys run on the street in a 325i? Is 87 OK or do I need to bump to 89? (And no - this isn’t a 13:1 cheater motor).

Jim

#15

L8Apex wrote:

[quote]A bit off topic, but what octane do you guys run on the street in a 325i? Is 87 OK or do I need to bump to 89? (And no - this isn’t a 13:1 cheater motor.
[/quote]

I think the owners manual says 89 so that’s what I use.

Related issue. Gasman is prob the most knowledgeable guy here re. gas and he says any name brand gas is about as good as any other.

#16

Yep, what he said. Merry Christmas boys!

#17

Yeah - Merry Christmas all you Spec E30 nerds.

Who’s a shorter tow from Austin, Texas - Road Atlanta or some SoCal event?

I’m going to need someone to race with in 2010…

Jim

PS. Did you know that if you pull the fuel line off at the filter without first relieving the fuel pressure, you get a nice eye wash with 89 octane? Just ask me how I know…

#18

And she passes the emissions test today !!!

Passed by a lot on the 2500 RPM point, and by a little on the idle speed (750 RPM) point.

I think the cat is too far from the engine for a good idle reading - it’s probably cooling down as the test progresses. At least he ran the 2500 RPM point first.

But - it works !!! Tempted to leave the cat on for street driving but I am still afraid of the gas tank going boom… Felt the floorboard as I was driving it around today - it wasn’t even warm near the cat. Maybe I am OK - if I don’t take it out on a speed bump…

Jim