well the other day i had a muffler rust right off my 76 heh, i thought it was weird that it sounded good all of a sudden. I dont have a clue where i should start on the exhaust, i was thinking about replacing it all. I saw that summit had some nice dynomax ceramic coated headers and possibly the whole exhaust setup. I want to go to true duals, i noticed that i had another hole in the crossmember for it last time i looked. any sugestions?

 

A good performance (and sound) increase can be had by running headers into 2.5" exhaust pipes with your choice of mufflers. To mellow the sound out and increase your horsepower even more add a cross-over pipe. The Dynomax Cerama-Coated headers seem to be the choice favorite around the forum.

 

The headers are nice, but not much better than the stock corvette manifold for your yr (or so I have been told by the local guru. The headers only really improve hi rpm flow, or some jumbo like that.).
I like the ravin 33 mufflers that midas carries. Sweet sounds and better flow than the flowmaster 40's.

I plan on getting them to re run 2.5 inch true dual from my exhaust manifolds w/2 cat. converters to 2 ravin 33's.


[Modified by 1976C3, 10:57 AM 10/2/2001]

 

the ceramicoats decrease engine bay heat BIGTIME

and i do mean BIGTIME.

that alone is worth it.

im running 2 chamber flowmasters.... has resonance around 1500-1800 rpm or somewhere around there...

u probably wanna go with some kinda crossover as it should eliminate the resonance,.

:flag

 

OK, I'll be the "stick in the mud" that says it: Don't forget about any local emissions restrictions in your area.

You can usually "get around them" in most places, but technically, if you don't have the stock configuration (2-1-2 with one catalytic converter), you're illegal. And if you can't get around the rules, it could get expensive.

 

If you go the legal route like I'm doing I went with the Hedman Part # 68301 header with the inlets for the smog pump. I'm sending them off to get Jet-Hot coated also. I also went with a Dynomax Hi-Flow catalytic converter. I will get a set of Flowmaster 40 or Monza tips for the exit. Just gotta wait to get my bumper repaired from my little accident last Wednesday and my exhaust will go on.

Matt

 

The emissions thing that says must be like factory irks me to no end! You can buy a new 6cyl mustang with true duals and dual cat's from the dealer, but you can not take a 2-1-2 system and make true duals with 2 cat's is just stoopid!

They should ammend the laws to account for modern improvements in exhaust systems!

www.goravin.com My next mufflers wil be Ravin 33's! My neighbor just got a set on his chevelle with mild mods and it sounds nicer than my flowmaster 40's.


[Modified by 1976C3, 12:16 PM 10/2/2001]

 

I'm keeping my exhaust manifolds on my '80 and swapping in the 75-79 true dual exhaust. Am going with that kit since I now have a modified x-member for the 700R4 that allows for passage of the two pipes on either side of the trans. 2.5" pipes all of the way back. Not bad for aluminized pipes: $229. You would still need to buy mufflers... but say less than $300 for the entire job if you get economy turbo mufflers from Mid-America.

 

As usual I'm typing slowly so I'll probably be repeating what people have posted while I've been typing :lol:
I didn't bother with headers as they only improve power at high revs. As I'm running stock L81 heads, cam, etc I don't think headers will improve things until I do something about the engine (apart from that my air con is dead & I'll cook with headers). If emission laws aren't a problem I'd very highly recommend dual 2 1/2" pipes - excellent improvement over the old 2-1-2 set up, I noticed a performance improvement even though running standard mufflers (got them from Mid America). For mufflers I fitted a set of the Monza style (single inlet, dual outlet). You can see right through them but they are fitted with absorbtion type baffles, which really do work. There is a bit of a drone at 20 - 25mph but nothing too bad (the interior rattles almost drown it out!!). At idle & cruising they sound mellow, nothing too loud, but at WOT they really come alive. Great fun, a grin factor of 10 :yesnod: When the throttle is blipped the exhausts "bark", but gently feather the throttle & they stay fairly quiet.
Sound levels are very subjective, but I think the Monzas are fine for the street (but I've spent 20 years riding an unsilenced bike & listening to loud music, so maybe my idea of OK might differ to that of the local constabulary ;) )
:cheers:
Paul

 

hmm weird didnt know that it was illegal to change to true duals from the 2-1-2 setup. I dont think indiana is too harsh on emissions. We dont even have any testing. I was wanting to change the manifolds for the headers because i want to eventually change to a more agressive cam. I guess i might as well do it now rather than messing with the exhaust later.

 

Where did you find the Hedman's with the smog inlets and how much were they? Also, are you getting them Jet-Hot coated for looks or does that help offset the extra heat headers put out?

 

wheres a good place to get teh dynomax coated headers at

 

http://www.jegs.com

 

Where is battle ground? I'm in Terre Haute, just east of Illinois on I-70. I'm planning the same setup for my 79. Still trying to determine whether I'll have to do the work myself or if someone will install the exhaust for me. I can install the headers, but I don't have any welding experience so I need to find a shop that will do the work. Even though we don't have any emissions testing, it is still illegal to switch to true dual.

 

Reading this thread makes me feel blessed...

When my 81 arrived from America it had all this smog crap and catalytic converters on it..... because it is what is known as a non compliance car one of the first things I did way spend an hour ripping out the smog pumps and welding up the headers... followed by taking it down to the local shop for a complete dual 2 1/2 .... couple of nice lukey mufflers and all legal.

My 71 has the same except custom 2 1/2 HPC extractors through to stainless 2 1/2 exhaust and stainles walker utlra-flow mufflers... all legal here in Aust.

 

Battle ground is a little north of West Lafayette, I go to school at Purdue.