New guy, exhaust question

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Mar 22, 2012 | 03:29 PM

DPits4Me

Thread Starter

3rd Gear

Joined: Mar 2012

Posts: 3

Likes: 0

From: Lawrenceburg IN

New guy, exhaust question

Hey guys. I'm new to the forums so if the following question has been discussed ad nauseum in another thread then please direct me to it and I'll just read that.

I have a BONE STOCK, 1980 L82. I'm looking to do some easy bolt on's but I want to do it right. I'm not looking to drop a TON of money, I just want to un-restrict what's already there. So if you guys could point me in the best direction I would REALLY appreciate it.

K&N Airfilter. Is it worth it?

Any cheap carburetor mods?

And the real question. Exhaust.

I'm wanting headers, no catalytic converter (I'm in Indiana and we don't need them so maybe a test pipe?), and dual pipes running to duel mufflers out the back.

Like I said I'm not trying to spend a TON of money so I was thinking about starting with these.

http://www.jegs.com/i/JEGS-Performan...30054/10002/-1

From there I was going to take suggestions. I need a shop to do the work so suggestions for me to get under the car and weld some pipe in aren't going to help.

Thanks in advance. I really appreciate lending me your experience. If there is a thread that covers this in detail just point me in that direction!

- Dave

Mar 22, 2012 | 03:41 PM

Sully1882

Melting Slicks

Joined: Feb 2006

Posts: 2,092

Likes: 5

From: Fayetteville Arkansas

Ive got the summit version of those headers and they are perfect. take them and your car to an exhaust shop and have them build you a 2.5 inch exhaust. While you are at Jegs might as well get the X-pipe and two new mufflers. This is what I am planning for my 72 this summer. Welcome to the forum. Use the search option and you will see lots of threads discussing exhaust options.

hth,

Sully

Mar 22, 2012 | 04:04 PM

Easy Mike

Team Owner

Joined: Jun 2000

Posts: 38,923

Likes: 1,481

From: Southbound

Cruise-In II Veteran

You will need a dual exhaust crossmember. Check with muffler shops in your area to see whether they can legally remove a cat con. My guess is that they cannot, so that chore will be left to you.

Last edited by Easy Mike; Mar 22, 2012 at 04:06 PM.

Mar 22, 2012 | 04:37 PM

DPits4Me

Thread Starter

3rd Gear

Joined: Mar 2012

Posts: 3

Likes: 0

From: Lawrenceburg IN

Can I just do this? Does this give me everything I need AS WELL AS eliminating the CC?

http://www.corvettecentralexhaust.co...mance_dual.php

Mar 22, 2012 | 04:46 PM

LancePearson

Drifting

Joined: Oct 2010

Posts: 1,972

Likes: 6

From: Chester Virginia

exhaust

Your l82 is a pretty good block and even the factory cam isn't supposed to be bad at all but you need to let it breath better is what most of us found with l48 or l82. Without changing the intake manifold, heads or carb. you can set the timing to run at higher numbers...my 76 was spec'ed at something like 6 or 7 degrees tdc and I run it at 13 now with 2800 rpm all in centrifugal and vacuum advance. I also got rid of the 2-1-2 through a pellet cat converter exhaust system and replaced it with true duals through Flowmaster mufflerss and with a wire grid bullet cat converter inline in each exhaust(virtually no flow restriction on the bullets). On the dyno I got 33 more hp than factory from these changes alone on my l48 stock '76 5.7 liter. Next steps would be heads with bigger valves, different intake, slightly wilder cam and maybe roller rocker stuff and I believe it would then have a ton of punch. However, I don't plan to do that as the engine runs so well as is and I have another vehicle with a 2008 ls2 with a 4:10 rear end in it and I get my punch there and my road driving on the 76.

Lance P.

Mar 22, 2012 | 05:22 PM

sstopczy

Racer

Joined: Jul 2009

Posts: 338

Likes: 9

From: South Bend IN

NCM Sinkhole Donor

Unless you are planning to make a lot more power the original exhaust manifold aren't bad. I got the true dual exhaust setup from Corvette Central and bolted it to the original manifolds quite easily. I have an '79 and the crossmember was already setup for dual exhaust so yours might be too. The hardest part is getting the old system off with all the rusty bolts.

Mar 22, 2012 | 06:16 PM

LancePearson

Drifting

Joined: Oct 2010

Posts: 1,972

Likes: 6

From: Chester Virginia

yes...a p.s.

I forgot to mention that I kept the original designed exhaust manifolds, the cast iron ram's horn design. Unless you put new heads with much more valve capacity they work as well as most. I would double check them when you have your exhaust off as they are cast manifolds and brittle and it's not unusual after all these years to have cracks in them. One of mine had been replaced on the old 2-1-2 system before I bought it and I found (heard) a crack on the other one so when we redid the entire exhaust we replaced that cast iron rams horn with a new one of the same design. Mine sounds fine, runs great and unless you need vastly more power, for modest funds you can get modest increases this way. For real punch it takes more money but your block is well set up for that if you want to do it. You can jack that engine up to rather a lot of horsepower and anything over 300 hp will begin to give the car more serious punch.

Lance...

Mar 22, 2012 | 06:22 PM

LancePearson

Drifting

Joined: Oct 2010

Posts: 1,972

Likes: 6

From: Chester Virginia

dyno

If you are interested here is the 44 second film of one dyno run on mine with the changes above. At 22 seconds he runs it up to about 130 mph to max hp. He has the computer screen right next to the driver's window. Listen to it with earphones on your laptop or good speakers so you hear the exhaust. Not a single puff of smoke out of that engine doing six or seven of these runs just like this as he dialed his machine in and learned mine. I watched and filmed one of them. Man, even a stock l48 winding up like that is a humbling thing to watch.

36 years old and does not use a drop of oil...not a drop.

http://www.youtube.com/watch?v=56CMNpa7LkU

Lance P.