2nd Gen Firebird exhaust advice

[tonykim]

I'm getting my '78 Firebird road worthy and near the top of the list is to ditch the 25 year old 2.25" exhaust with glasspacks.
Below are the myriad of options I have come up with. I'm still trying to figure out how the hedman universal x-pipe head pipes
work. And I know that on the Pypes system I have to buy separate stainless head pipes.

Anyone out there have experience with the Cherry Bomb system? The muffler design looks really innovative. However, I don't
want the neighbors to call the cops on me.

The engine is a garden variety 355 SBC with forged internals, 270H comp cam, stock 1.94/1.50 heads with mild cleanup and milled
down to 72 ccs, edelbrock intake/1405 carb, Hedman hedders, built TH-350 and 3.73 posi 8.5 axle.

The options I have come up with are:

1. Hedman 18813 universal X-pipe, flowmaster 15801 tail pipes, and either VMS racing magnaflow knock offs or Borla Pro-XS
mufflers from Wicked Nicky's

2. Magnaflow 15896

3. Pypes SGF11R (the dual mufflers, not transverse muffler)

4. Cherry Bomb 300713

5. Summit Racing $190 exhaust just to get it on the road and then add a Dr. Gas or Hedman X-pipe later. I can also swap out
the mufflers later for a straight through design like the VMS racing or Borlas.

Advice and experience appreciated. I really don't want Flowmasters. I've had that as a daily driver before and I'm not interested
in that sound or drone.

[tflyboy77]

Pro-touringf-body.com
I love my spintech 3" oval x pipe system I got from these guys. The sound is incredible.

[tonykim]

I don't see exhaust on their website. I'll send them an email. thanks.

[tflyboy77]

Sorry, try ramairrestoration.com. I bought through PTFB but ram air is the place to go.

[avewhtboy]

I installed the Pypes stainless system on my Trans am, it sounded great and was an easy install. I had long tube headers so it wasn't necessary to get any extra tube. I would almost say go for the transverse system to gain ground clearance though, I doubt there is much difference in performance.

[tonykim]

tflyboy77 thanks very much for the tip on ramairresoration. their UCH-25 system is exactly what I am looking for. I might consider doing a 3" exhaust downstream but am not sure which way I will go with the engine. currently it probably makes only about 300 hp / 350 ft-lb so I will probably stay away from the 3" exhaust. I plan on either doing AFR heads and EFI or a pro-charger and EFI later.
what mufflers are you using with your setup? do you have any videos. I don't have any experience with the mufflers they offer. I sent them an email asking what price they would sell the kit for sans mufflers. i would like to keep the car pretty quiet.

[tflyboy77]

The mufflers are pretty loud, just to be honest. I had 3" all the way out the back and have since went to turndowns because of clearance issues. I will have some videos for you this weekend I hope.

[avewhtboy]

Here is a video of my car, stock 305, headers and Pypes exhaust

https://static1.pt-content.com/images/pt/2013/04/th_124-1.jpg (http://i304.photobucket.com/albums/nn164/avewhtboy/1981%20Trans%20Am%20Restoration%20pictures/124.mp4)

[Orange71]

Short video of mine. Hooker Super Comps, Pypes 2.5" exhaust with x-pipe and SpinTech low profile Sportsman 3000 street mufflers.

https://static1.pt-content.com/images/pt/2013/04/th_MOV04747-1.jpg (http://i21.photobucket.com/albums/b290/Orange71/2012%20Projects/MOV04747.mp4)

[tonykim]

tflyboy77 what mufflers did you use that were really loud. I'm considering the Goerlich long case. I sent them an email to find out if they sell the system minus mufflers but haven't heard back from them. I am thinking about trying the VMS racing magnaflow knock offs or Borla xs mufflers.

[tonykim]

orange 71 I like the sound of your car. how loud is the interior sound level? I am curious about what cam you have in the engine.

[Orange71]

orange 71 I like the sound of your car. how loud is the interior sound level? I am curious about what cam you have in the engine.

You can hear it! However, I can have a conversation with my wife and hear her just fine even with my old ears. I wanted my exhaust to be on the loud side and be the dominate sound over the gear drive.
The SpinTech mufflers replaced original 40 series Flowmasters and they are a bit quieter and sound much better!

[Flying Bandit]

I have polished stainless pypes 3 in with race pros. Spent a bunch of time fitting the tail pipes and TA splitters to make some extra ground clearance. I really like the sound and the whole systems is quite light too. The mufflers are smaller the my old flow masters and fit really nice. The lowest point on the exh is the long tube headers.

[tonykim]

yes i like the race pro sound. my hedders are quite low. the car is lowered about 2.5 inches in front so the collector flanges are only about 3-4 inches off the ground. you can't get an oil drain pan underneath them.

[Chadman27]

Avewhtboy, nice video however I do not like the fact that there is a for sale sign in your rear window... don't do it! :smashcomp

[tonykim]

Well I've had the car running now for 2 weeks and this last week i put 120 miles on it. I hadn't driven the car since October 2001 and since then have driven cars with several varieties of chambered and straight through mufflers (flowmaster, dynomax, magnaflow, etc.). I almost hate to admit this but I kinda like the mellow retro sound of the glasspacks. Kinda choppy at idle with absolutely zero drone in the operating range. I do think it would sound better with an x cross over. I think for now I will leave the 25 year old exhaust in place. I also realized while under the car replacing the fuel line that the front half is actually 2.5" not 2.25" as I had remembered.

Here is a video of warm idle after the first start up.

http://youtu.be/H14fyr7S_E4