Glasspack on 1987 Grand Marquis

[jjguitar]

I have just purchased a Thrush Glasspack for my 2-door 1987 Grand Marquis. A friend of mine told me they are very easy to install. Is it true that all that's involved is loosening the clamps to remove the old muffler?

[newwave]

No idea.. but.. do let us know how it goes... I've got a 1987 Mercury Grand Marquis Colony Park GS I'd like to do the same to.

[jjguitar]

Well I took a look under the car yesterday, and putting a glasspack on the Grand Marquis won't work. Here's why:

The muffler is shaped in such a way that the pipe going in and the pipe going out are not in line, so one would have to use a blow torch to bend the pipe on an angle. That in itself is too risky. Plus, with a car that old, the place where the tailpipe meets the muffler is all corroded, so if I had tried to unclamp the muffler at that spot, the tail pipe could very well snap in two.

Unless you get some sort of custom muffler system for it, it doesn't look like there's a cheap do-it-yourself way to do it.

Also: The glasspack I tried was a Dynomax Thrush. Maybe another brand would fit?

[MercCougarXR7]

I do believe, that the 1981-current CV/GM's have the same shaped exhaust underneath. At least, where they run from the 'X' pipe to the back bumper anyways.

I found a used set of flowmasters (40 series?), and put them on. The pipes on my car were offset as well, but you'll find that on most cars. So any muffler you pick up, make sure it has the right offset for your car.

I really do like the sound that the flowmasters give off, you can actually HEAR my car now when I'm stomping on the gas !

[Samurai0]

Originally Posted by jjguitar

Well I took a look under the car yesterday, and putting a glasspack on the Grand Marquis won't work. Here's why:

The muffler is shaped in such a way that the pipe going in and the pipe going out are not in line, so one would have to use a blow torch to bend the pipe on an angle. That in itself is too risky. Plus, with a car that old, the place where the tailpipe meets the muffler is all corroded, so if I had tried to unclamp the muffler at that spot, the tail pipe could very well snap in two.

Unless you get some sort of custom muffler system for it, it doesn't look like there's a cheap do-it-yourself way to do it.

Also: The glasspack I tried was a Dynomax Thrush. Maybe another brand would fit?

Dude, I removed the Y-pipe, and installed an H-pipe for dual Cherry Bomb glasspacks.
Just goto a local Meineke muffler shop, and get two "mandrel" bent pipes, to the correct offset. It'll cost you like $50.
Just be sure to install the K&N air filter, and expect your gas mileage to drop to 12mpg.


Later

[FordInPossession]

Gas mileage doesn't drop due to a free-flow exhaust and the addition of a K&N Filter.... it improves. I put muffler-less duals and a K&N in my 88 Grand marquis and went from 18 MPG to 21 MPG. Maybe you need to take your foot off the gas every once in a while and actually drive the car, rather than beat the hell out of it. As far as Glasspacks go.... Thrush makes a few adapters that are required to use the Glasspacks they sell. I had an Exhaust Shop (Like Exhaust Pros or Auto-Max) bend up mock pipes to fit where the mufflers did with the stock mounts. Go that route is what I recommend, the 4 cats in the car keep it quiet enough to be tolerable too

[Samurai0]

Originally Posted by FordInPossession

Gas mileage doesn't drop due to a free-flow exhaust and the addition of a K&N Filter.... it improves. I put muffler-less duals and a K&N in my 88 Grand marquis and went from 18 MPG to 21 MPG. Maybe you need to take your foot off the gas every once in a while and actually drive the car, rather than beat the hell out of it. As far as Glasspacks go.... Thrush makes a few adapters that are required to use the Glasspacks they sell. I had an Exhaust Shop (Like Exhaust Pros or Auto-Max) bend up mock pipes to fit where the mufflers did with the stock mounts. Go that route is what I recommend, the 4 cats in the car keep it quiet enough to be tolerable too

Uhh.. No.
So, you're saying that if a car takes in more air, it'll burn more efficiently?
That's bogus. I don't even think you know what your talking about.

What EEC version are you running, for TPI?

Since when does someone put a highflow filter and exhaust for effeciency or quietness? It's for only one purpose, to add performance, and to make the car into a psuedo-hotrod. Too have the engine breath more and faster. The only downside being the engine wearing faster.

If you put too much air into the system, then it'll run too lean.
The ideal way is to have a proper balance between backpressure, and airflow. That's not my goal, nor anybody else who wants glasspacks on their car.

If you're using it as a daily driver, for highway driving only. I can see maybe the mileage getting better, but here in NY with stop-an-go traffic, the vehicle is DEF a gas guzzler.

I'm not sure here. As a mechanic, I know I can do anything the dealership can do, and this car is running at top performance, and at 122400 miles. It is a Canadian production 2-Door sedan. With only a 15 gallon tank, not 20.

Besides, I don't have 4 Cat's. Only 2, 3-ways. The other's were taken out. And I have P225-50-R16, 8" tires in the rear, and P235-50-R16, 7" in the front. So that's why my mileage is less. Vogue tyres. Centerline Rims.

Have you performed any other sort of customizations?

I'm still doubtful. I can safely say the max milage this car every had was about 18mpg, with stock exhaust and tires/rims at P205-60-R15's.

Later

[Fedexjetmx]

I Hate to disagree with part of what your saying Samurai0.
Putting on a freer flowing airfilter(doesn't matter which one) and a freer flowing exhaust(doesn't matter which one) Does increase effeciency, it will not increase capacity. Unless the air filter is plugged up the only way to put more air into the engine is to change something that dictates cylinder volume I.E piston dome shape, head chamber size and cam lobe lift and duration. And as far as making it run lean...then there is something wrong with the fuel managmentsystem.

[Samurai0]

Jet,

Of course adding performance items like airfilter and straightpipes don't offer more capacity.

The guy above also uses the synthetic Amsoil in his engine, tranny, and differential. So right off the bat, things are working more efficient.

We need more stats on this guy's car. Like mileage, tires, and if highway usage is about 80% of his driving.

Here's a question.
My vehicle does not have a PCV valve. It just doesn't exist, and never has were it should be.
What makes up for not having it?

[Fedexjetmx]

As for your question about your PCV valve, it should have one.Its probably in a really obscure place, I have to take care of my mothers 91 and its litterally hidden on the back of the engine on the lifter valley.

[big_d0199]

i have a 93 marquis and it has air filter and full exhaust and my gas milage went down also