ERA FIA Cobras Exhaust Upgrade - Page 2

fastd · #21 (**permalink**) 12-15-2009, 09:47 AM

Rare Iron,

Thanks for your suggestions and advice.

tkb289 · #22 (**permalink**) 12-15-2009, 02:15 PM

Rare Iron and those that commented ...
Thanks from me as well ... I am probably about 6 to 9 months away from needing an exhaust system for my FIA, but will keep in mind what has been suggested.

fastd ... Thanks for starting this thread ... let us know what you wind up with and how you like it

tkb289

fastd · #23 (**permalink**) 12-15-2009, 05:19 PM

Will do; I should have new exhaust and carb installed by the end of this week.

strictlypersonl · #24 (**permalink**) 12-16-2009, 05:24 AM

Be aware that the space underneath the floor is limited. Our standard-use muffler is 8-3/4" W x 3-3/8" high and already hangs (very) slightly below the main chassis rails because of the insulation and air gap above. Unless you want to show off the shiny new muffler (much of it is exposed below the rocker), you might consider painting it flat black.

fastd · #25 (**permalink**) 12-16-2009, 09:34 AM

Bob,

How much an air gap is there? How much to you think I need to leave on the new install?

Regards.

tkb289 · #26 (**permalink**) 12-16-2009, 10:19 AM

Quote:

Originally Posted by fastd

Bob,

How much an air gap is there? How much to you think I need to leave on the new install?

Regards.

Bob,

To add to fastd question ... is there a heat shield that is used, or can be used, above the muffler area to protect the bottom of the car?

Thanks.

- Tim

strictlypersonl · #27 (**permalink**) 12-16-2009, 11:18 AM

We typically use foil-backed insulation that's about 1/4" thick glued to the bottom of the aluminum floor panel. The air gap is small (~1/2") to ensure that the muffler won't hit the floor or insulation under engine motion.

fastd · #28 (**permalink**) 12-18-2009, 05:51 PM

tkb289,

Just got back from the shop where they installed my exhaust - 2.5" pipes into Flo-Pro Exhaust and 3" tips; beautifully done by the guys at DG Performance in Franklinton, NC just north of Wake Forest. I believe it probably added 15-20 hp and 25-30 lbs torque. Low rumble at idle, not too loud, in fact I would say the same or a tab quieter than the ERA Dynomax's because it is a much lower growl. At higher RPMs, again still quieter than the Dyomax's, much deeper and more powerful sound. Very satisfied.

Jim Holden · #29 (**permalink**) 12-18-2009, 06:14 PM

Are you able to post some pictures of the new setup?

Jim

fastd · #30 (**permalink**) 12-18-2009, 06:23 PM

Jim,

I took a couple of quick pictures with my cell phone. I am slightly embarrassed to say that I haven't quite figured out how to upload pictures to these posts. When I click on attach image above, it doesn't allow me to browse my hard drive, it asks for a url...?

Got the Bug · #31 (**permalink**) 12-18-2009, 06:45 PM

You need to click on the Gallery tab on the top of screen then the Upload Photos tab. Basically, the photos need to be uploaded to CC before you use them in a post.

Not super intuitive, but it works.

Email them to me and I'll post them for you if you want.

fastd · #32 (**permalink**) 12-18-2009, 06:59 PM

Thanks Jim; let's see if this worked...

I made sure to have them not to protrude too much; my daughter made it clear to me she did not want to have to worry about burned legs. I also didn't want to get too close to the tires or spats...

tkb289 · #33 (**permalink**) 12-18-2009, 09:35 PM

fastd,

Looks like you came up with a great setup, a bit more aggressive than the under car setup, but not quite as aggressive at the racing setup.

So if I have this right, you have the ERA primary pipes, a 2.5" pipe into the Flo-Pro exhaust and 3" tips. Where is the hanger attached ... near the outlet end of the muffler?

The photos look good, next time you have your car on a lift and have your camera handy, would love to see some photos from underneath the car!

Thanks for all of the info ... can't wait to get my car and set it up!

tkb289

fastd · #34 (**permalink**) 12-19-2009, 04:52 AM

tkb289,

You are correct, sir. Actually needed to put a 2" piece of 2.5" pipe at the exit outlet to clear the frame; then welded the 3" tips on. the hanger is attached near the exit outlet. the exhaust is in there very snuggly, and the system is so short as compared to previously, that I know it will stay in there good.

Will try to snap some underneath pictures and post. Good luck with the rest of your build.

Based on my experience, I would say that it would be very difficult to get more than 2.5" diameter pipe and exhaust to fit under an ERA FIA. The Flo-Pro muffler I had installed was nearly 1" wider and taller (same length). My guy spent a lot of time and care (he had to cut nearly all of the outlet nipples); I am not qualified to say this, but I think he is an artist. I think a 2.25" would fit a lot easier but flows a lot less.
According to an article I found on the internet, 2", 2.25", & 2.5" straight pipes flow at 283, 365, and 521 cfm, respectively. If you go with some custom, "after" ERA market exhaust, I think you really need to check the cfm rating on anything that you install to make sure you find something that flows right. I have found that there is a huge disparity in flow rates across mufflers of the same size and similar construction. My 2.5" Flo-Pro exhausts flow 480-500 cfm; so together I am getting 960-1000 cfm through my exhaust; based on my engine size and horsepower, I have heard that this is a happy medium between the lower and upper rpm performance. Good luck and keep posting your pictures also.

fastd · #35 (**permalink**) 12-19-2009, 05:04 AM

If someone can tell me how to post video, I have a little sound clip of a dyno run; the low rpm exhaust sounds capture the low grumble of the exhaust. When it gets past say 2,500 rpm, the video does no justice to actually being there.

strictlypersonl · #36 (**permalink**) 12-19-2009, 06:09 AM

Fastd,

You could upload the video to YouTube, then embed the video here. Look at the sticky near the top of this section.
Or you could extract the audio (for a smaller file) and post it on Houndbite, or last desperation method: Send it to me to host on our site. Then create a link to it here.

fastd · #37 (**permalink**) 12-19-2009, 07:30 AM

Strictly,

Thanks for the tips; see if this worked. Regards.

fastd · #38 (**permalink**) 12-19-2009, 07:32 AM

http://www.youtube.com/watch?v=vnCReeLIxTM

maybe this worked now...

*13* · #39 (**permalink**) 12-19-2009, 07:36 AM

Sounds good. I like the Exhaust tip exit. Looks nice!

smallblockhead · #40 (**permalink**) 12-19-2009, 11:07 AM

I recently took a slightly different approach to 289 FIA undercar exhaust modifications. I stuck with the 2" exhaust, just got a local shop to make an exhaust exit in front of the rear wheels. Mine was longer, and extends further outside the body work (I figured it might reduce fumes in cockpit and not throw heat on brakes). I have attached a couple of underneath shots. Sorry for the car condition, didn't do a wash job before putting it away for the winter!

Gary