I have an L69 equiped stock 84 TA. I need to change the muffler due to a broken baffling that's annoying the hell out of me. I like the pipe setup, which I believe is a single 3" in and two 2.75"s out, so I'm leaving them in. Is my guess right?

My other option is to go with a Flowmaster 80 series, but they only make 2.5 and 3" inlet/outlet options from what I've heard.

What is the difference between a stock L69 system and the stock LG4 system if any from the cat-back?

Should I just keep the stock system in? I don't want to lose any power from stop. I only want performance out of the system. It sounds pretty damn good as it is when the ram air box opens up with 4 barrels pumping, and it hauls ***!

Sorry for all the questions, I've only had the car a couple weeks and it's got more tricks in the engine bay than my Supercharged T-Bird. Don't want to waste money messing it up.

 

I doubt it's a 3'' cat-back. I would order an aftermarket one, those are 3'' and mandrel bent.

What part of MD are you from? I live in Bowie.
Check out the Nationals Regional board on here for Thirdgen Nationals '03 in June.

 

I live in Germantown. My brother tells me the GM show in Carlisle is Father's Day weekend instead of late August this year, so I plan on going up there to see what I can see and learn. I'm not ready to show the car yet because it needs a couple cosmetic fixes.

All I need for this car is a couple replacement decals and the left plastic latch cup for the rear hatch. The problem is it's a weird car. It never had have a Louvre Bid(or whatever the name is). It needs a new silver nose bird $40, one rear trans am decal $8, one sail panel bird $8, and two 5.0 Liter H.O.s $40. My brother's 77 -Trans bird cost me $500, so its not going to be too bad. The rear is a locking 3.73 and the hood has the electric relay Cowl Induction instead of the dual snorkel everyone on here talks about. I didn't know there was an option. Engine and Trans are original with 59,000 miles. The engine isn't all chromed out, but it looks like it just rolled out of the plant. I have all the original paperwork including the window sticker.

I'm replacing the muffler Thurs morning with the same type that's in there using the same pipes. I'll hold out and put in a performance model when I get this one off, have time to measure it, and think over my options some more. I just have to get rid of the rattle.

 

Forgot to say, I'll be at the Nationals to look around for sure.

 

This is different, Thirdgen Nationals '03, in Frederick MD June 20-22nd , it's a show/gathering so don't worry about being show worthy, many won't be. It's only for 3 rd Gens, looks to be around 100 are going to be there hopefully.

Let me know if you're interested and I'll shoot you an email with all the details.

 

I'm definitely interested. Please send an email.

 

i too have an 84 TA 305 HO (L69) and it IS a 3in pipe with the 4 bolt on to the cat and i got the 80 series flowmaster with the 3 in and 2.5 out and it was a perfect install but it wasn;t too loud and i didn't like it, i bet if u got some 3 in tail pipes made it would sound a little better. but u might as well go with a cat-back but don't listen to anything anyones says on this site, u need to go out and hear them and that's it. people say borla sucks hooker's better or hooker sucks and slp is better and so on and so on see what i mean...too many to pick from

 

Are you guys sure its 3"?

My Z28 ('83 HO) should have the same exhaust system that you have, and my I-pipe is only 2.75" and i know for a fact it is the original exhaust system from the manifolds to the tips.

 

I also have an 83 Z28, and it was set up like Air_Adam's car.

I say WAS, because now I'm running TES headers and a Hooker cat back. I found out that the stock monolyhic (sp) cat that was on there would have to be special ordered for 300 plus bucks.

So I just had the 4 bolt flanges welded onto a 3" high flow cat, and went from there.

BTW....chio987 has a point. Listen to the different exhaust setups before you drop the coin. Just make sure you listen to the Hooker cat backs too!!!

 

Oh, and there are a couple differences that I know of between the LG4 exhaust and the L69.

The L69's had larger diameter pipes, 4 bolt monolythic cat (same as Corvette).

LG4's had slip on cats, smaller diameter pipes. Not sure if the exhaust manifolds doffer or not.

Unless you're restoring this car to original specs for show, the price for OEM parts will double or more for a L69 exhaust compared to an LG4 exhaust.

Never heard of one like yours, with the electric relay cowl induction. I always thought they were exclusive to CFI ??

 

No, it definitely has the electric relay cowl on it. I have the factory papers to prove it. The air intake has one snorkel with the typical air flow sensor that I think works with the egr valve, and a rubber sealed hole in the lid with bi-leveling so that the air goes through the filter before the intake. It has arrows you have to line up so that the cowl hole lines up properly with the intake. From the info I can gather this was the only intake option in 84 for the L69. The factory claims it adds about 40 hp, but if that's the case, I don't understand why they added the electric cooing fan and the different cam and heads and only came up with 190 hp v. 150 in the LG4. It also has a carburator cooling fan in the front right corner of the engine bay which prevents the gasoline from boiling away after the car is turned off. Tubes run under the air intake. It keeps gas there so the car will start easier next time, but it makes a hell of a racket for a good 30 minutes! I think it was changed in 85. GM and Pontiac in particular have always been a little mysterious. They put a 3.73 in my car, but it's not Posi? It's a Pontiac, come on!

 

Forgot to say, I think I am going to go with a Hooker muffler. I want the pipes to be stock size though and I want it to look similar to stock. Single in, dual out crosssectional muffler. They have a bunch of options for me.

I think the 3", 2.75" were options. If you got the 25 anniversary TA, or a Limited Edition L69 TA, that's what you got. I will check on that though.

 

FYI

The carb cooling fan wasn't installed at the factory. This was a band-aid fix to GM's problems with vaperlock w/ carbed cars.

This dealer installed under a tech service bulletin.


The factory pipe from the converter back is 2.75"........close to 3" but not quite...compared to most stock type replacement pipes installed by muffler shops, it does look huge.


And Catco makes a BOLT IN cat converter for your car ....same as the cat that is on my IROC......originally a LB9 305 TPI Car......

It's like $100.......



HTH

 

Now hold on ILikeFtLbs - I'm not sayin you're lyin at all. Sounds like a pretty unique model you have there. As I recall, all the L69's were rated at 190 Hp.

They added an electric cooling fan, different cam, heads (at least mine) are 416 castings. You also have an aluminum flywheel, and most likely drums too if you have the same one-legger rear I have in mine.

Got a pic of your air intake?? I thought mine was weird.

And ctandc - When I said OEM, I meant an original GM convertor. I believe I was quoted 345 bucks for the monolythic type it came with. That's why the shop just got a high flow cat and welded my old flanges on. Now I wish I woulda known they had bolt-in cats.

Is the carb cooling fan only needed on his type of intake? I know I don't have one...

 

Had nothing to do with the intake. Depending on where you lived, how hot it got etc, it was done by dealers on a case by case basis.

This happened on the Monte Carlo SS as well w/ the L69.

HTH

 

The electric carb cooling fan very well may have been installed at the dealer instead of the factory. All I know is it is there now.

Confused1- I don't mean that the car has more than 190 hp. I'm saying I don't think the cowl actually adds 40 hp. If it did, they wouldn't have bothered with the other engine changes. My car has 4 disc breaks and a 3.73 rearend. The window sticker has that listed. I'm pretty sure I don't have Posi, but I haven't checked the axl-code yet. I have the WS6 suspension package (listed as WY6 on the window sticker?) which I thought was supposed to come with Posi, so I'm confused.

I got under and actually measured the pipes. The exhaust was replaced by Midas in 1990 with 3 inch pipes necked down to 2.75 at the cat and 2.5 at the muffler intake. Muffler outlet is 2.5. They did a crappy job!

I will get pics of the electric cowl up tomorrow if possible.

 

Ok- I know what you mean. I agree. No way a cowl will give you 40 HP. If it did, I'd be all over it and have one by now!!

With disc brakes on all four corners, along with the WS6 package, you may well have a posi in it already. I'll be getting rid of my one-legger soon. I like the 3.73's out back, but I spin everytime I launch remotely hard.

Although that may look impressive to the kids, it doesn't mean squat when the other guy doesn't even chirp and gets the jump on you.

Have you checked the archives to see how many they made of your model?? Sounds kinda rare to me. And yes - If you happen to have pics of your cowl setup, I'd like to see it. I've never heard of it before.

Have you decided what to do with the exhaust yet?? IMO, if you want the performance, go with the 3" aftermarket catback system. I like the look and performance of mine. Oh, and the headers don't hurt either.

 

http://hometown.aol.com/paulkeats/myhomepage/index.html

Hope this works.

 

Sorry. Here it is correctly. I'm horrible with computers.

Fixed Link

 

Thanks for the pics!!

Till this day, I never new those small cowls on the 'birds were functional!

Looks clean BTW...

 

the cowl did not add 40 hp, no, all L69 were 190 hp eben in 84 when the functioning L69 hood were not used, is the ame 190hp L69 as in 82 and 83 with the functioning hoods

all L69 82-84 at least had the large exhaust and monolith converter

 

First of all, there was NO L69 in 82....plain and simple. The L69 was introdeced in LATE 1983 in the TA and Z28 and was run until 1986 being the last year for it. The "power bulge" hood was in fact functional. The 82-83 LU5 Crossfire cars, the mid-82 to 84 LG4 cars, and the 83-84 L69 cars. 85-86 used the flat hood with the dual snorkel air cleaner, no functioning hood. 87 brought the bulge hood back till 92 on the Formulas, but was non-functional with a block off plate in place of the screen used in 82-84. BTW, the early 82 LG4 cars used a flat Firebird style hood. Hope this clears some things up.

BTW, I also have the supposed "carb cooler" on my 15th. It dosent turn on. When is it supposed to come on and how is it wired?

 

The way mine works, it only comes on when the ignition is off and coolant temp is above 190 or so. There is a switch in the heater supply fitting that is wired to the motor. I have no idea if it was factory or added on later (it was in the '86 donor car, not the '82).