Mid-America Dual Exhaust Conversion

[Last Ride]

Chambered Exhaust

Hey all--
Is that Chambered Exhuast that Mid America sells stainless or aluminum? I think that would make a great addition to my '78. It also says in the catalog that tubing is supplied for header-equipped cars. I don't have headers right now, but plan on going with some soon. I wonder if a similar exhuast could be fabricated locally otherwise?

 

[lg78VETTE]

DUAL EXHAUST

Maine Shark; I amlooking at the same MA system.I own a78 L82. I put in a comp cam 268h and an Edelbrock performer manifold.I wonder if anybody can tell me abut how much hp I may gain from the stock 220

 

[Dave L.]

20-30 hp gain compared to original system with cat conv.


Dave

 

[lg78VETTE]

Dave; I want to put true dual exhaust on what about headers I dont think its going to be much more of an improvement.Do you think ill be around 300hp with the manifold ;cam and dual exhaust.

 

[Glensgages]

lg78, I spoke w/ 'BURGLAR' last month regarding same question, I think. I'm going w/ headers & M-A kit, but BURGLAR says it'll need some 'modifications', as the M-A kit goes TO the OEM manifolds, not aft-market headers. If you complete your change-over before me, let me know how it works-out, OK?

 

[lg78VETTE]

Glensgages thanks for your reply.My 78 was just top flighted. Its time for me to add a little punch.We think with the additions ofintake manifold and cam we are about265;270hp.Think with dual exhaust maybe in 300s. Know anbody that might be able to figure the specs? Lou Lg78vette

 

[Dave L.]

Lg78vette - I would say with true dual exhaust conversion,cam and intake you spoke of,you would be in the 300 hp range. My plans are to upgrade to 300-350 hp via GM crate engine in the near future for my own car. BTW,welcome to CAC,always nice to have another C3 owner on board !

Dave

 

[lg78VETTE]

Dave I have a question? I want to keep the 78 looking as stock as possible:so I am looking at aluminized exhaust.Mainshark says heused Dynomax ultra flo mufflers any difference between those andDynomax super turbos I dont see ultra flos in aluminized.I WISH THE SYSTEM TO BE ADIRECT REPLACEMENT.aNY THOUGHTS?

 

[lg78VETTE]

Dave by the way Ilike your 81. A new crate engine your going all out I see you have dual exhaust on your baby what did you use? started mine today soundedgood God I CANT WAIT FOR WINTER GET OUT A HERE!

 

[Dave L.]

Lg78vette - I have the Mid-America system #603-862 (409 stainless steel). It is a direct replacement. It DOES eliminate the catalytic converter all together so check your local car inspection rules before proceding with this change. What do you mean when you say you want to" keep the the 78 looking as stock as possible"? Do you mean the mufflers? If so,I like the Walker Dynomax in stainless steel that Mid-Amnerica offers. I have Flowmaster mufflers on my car which don't look stock by any means. You have to fabricate (from a muffler shop) an inlet pipe on this type of muffler,but they sound great!! IMHO if you want the car to look stock from the back but have the added performance of duals,get exhaust system 603-840 (auto trans.) or 603-842 (manual trans) in stainless with the 603-572 Dynomax muffler kit and you will have a system you can put on your self and will give you great performnace and sound.

Dave

p.s. make sure to keep your old system ( I did) in case you ever want to return your 78 to 'stock' condition.

 

[lg78VETTE]

Thanks Dave I will certainly look atwhat you sugested.The original pipes and mufflers are alumin and since I do not drive the vette daily I thought alumin would look more stock.I keep every part you never know lgvette LOU

 

[Dave L.]

Lou - Ok,I follow you on the aluminum deal. But,I have heard second hand,on here I think, that those aluminized steel pipes will eventually show signs of rust. For the extra $$ I'd go 409 stainless. Mine look like the day I put them on.

Dave

 

[lg78VETTE]

Dave this is lg78.Thanks to you I have decided to get the MAduals in stainless .I se that you got flowmaster40s.Are they better than Dynomax Ulta Flos? COULD YOU TELL ME WHATFLOMASTERS i SHOULD GET FOR MY 78 i want adirect fit.

 

[Dave L.]

Lou - I would recommend calling the Flowmaster Tech Line (1-800-544-4761). Tell them what your thinking about doing and they can help you with muffler selection. To match the Mid-America pipes you'll need 2.5" inlet and 2.5" outlet. I have spoken to them several times and have found them very informative and helpfull. Just so you know,and they will tell you this,40 series Flowmasters are on the radical (loud) side. If you want to hear what 40's sound like,send me a private message sometime and I will arrange for you to listen to mine via telephone if you wish.
When you get on the throttle they make some noise. I love mine.
They aren't quite as loud as the glass packs I had on my old 64 Ford Falcon,but they are a close second at wide open throttle. Also,You have to get inlet pipes(the sharp bend that comes off the Mid-America pipes) made at a muffler shop. It is a tough angle to bend. Flowmaster does not make direct 'bolt on'mufflers for C3 Corvettes. The down spouts will also need to be made. Flowmaster makes quiter mufflers of course also. If you want bolt on mufflers without having to worry about getting pipes bent go with one of those muffler setups in the Mid-America catalog we spoke of before. Let me know if you have any more questions an what you decide to do.

Dave

 

[MaineShark]

The Dynomax Ultra-Flo mufflers are available in stainless (to match the pipes) and are direct bolt-on items. I have the Mid-America system with the Ultra-Flo mufflers, and I've been enjoying it. It's not so loud that you can't hear yourself think, when "just driving," but with a little push on the go-pedal, you get a very nice roar. I'd definitely recommend it, and I seem to recall that Mid-America has a sale going on, if you purchase an exhaust system and mufflers at the same time.

Joe

 

[Dave L.]

Thanks for the info,Joe !

Dave

 

[mvftw]

Did any of you guys look into Corvette Centrals Exhaust? I'm looking for pros or cons for their exhaust. I ask because a good vette source uses them. I was also told that the Federal law on the cats is 25 years plus 1 year. So a '77 this year would Not need cats. He said since I have a '78 and the inspection is not till the end of '03, he said have an early inspection in the spring then replace my exhaust minus cats...I would prefer true duals. Is this true?

 

[Dave L.]

As far as removing your converter,I would check with your local inspection shops before you do anything. I never heard of that 25 year exemption deal. I have a Corvette Central catalog here,I am going to take a look.

Dave

 

[MaineShark]

There is no Federal "25 year rule." Removing any emissions equipment (not just the cat - egr, smog pump, etc.) from a car which originally had that equipment is a Federal violation. Now, the fine is only $5000, which is far less than what it would cost to prosecute you, so you really don't have to actually worry about it, but you should be aware that it is a violation.

Some states also have their own laws, in addition to the Federal law. You need to be more careful of these, since it usually costs much less to prosecute you at the state level, so the fine may be enough in comparison to the cost, that they actually might go for it. Some states do have a "25 year rule" (or something similar), but I think this mostly applies to emissions sniffer testing, not the physical presence of the equipment.

Of course, I'm not a lawyer, so your best bet would be to ask the advice of a lawyer (or the Attorney General's office) in your state. Personally, I like the AG - in Maine, at least, if the AG gives you advice and it turns out to be wrong, you still can't be prosecuted for the violation (just make sure to get it in writing).

Joe

 

[mvftw]

I'm talking about emissions. If they don't check for emissions after 25 or 26 years that's fine with me. I'll only go to duals if there will be a gain, if there won't be I'll keep it stock. But the thought of true duals